# This is how we control whether or not the additional warnings are applied.
.-warn = $(STRICT_WARN)
build-warn = $(STRICT_WARN)
+rtl-ssa-warn = $(STRICT_WARN)
GCC_WARN_CFLAGS = $(LOOSE_WARN) $(C_LOOSE_WARN) $($(@D)-warn) $(if $(filter-out $(STRICT_WARN),$($(@D)-warn)),,$(C_STRICT_WARN)) $(NOCOMMON_FLAG) $($@-warn)
GCC_WARN_CXXFLAGS = $(LOOSE_WARN) $($(@D)-warn) $(NOCOMMON_FLAG) $($@-warn)
reorg.o \
resource.o \
rtl-error.o \
+ rtl-ssa/accesses.o \
+ rtl-ssa/blocks.o \
+ rtl-ssa/changes.o \
+ rtl-ssa/functions.o \
+ rtl-ssa/insns.o \
rtl-tests.o \
rtl.o \
rtlhash.o \
"depdir":C) $SHELL $ac_aux_dir/mkinstalldirs $DEPDIR ;;
"gccdepdir":C)
${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs build/$DEPDIR
- for lang in $subdirs c-family common analyzer
+ for lang in $subdirs c-family common analyzer rtl-ssa
do
${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs $lang/$DEPDIR
done ;;
ZW_CREATE_DEPDIR
AC_CONFIG_COMMANDS([gccdepdir],[
${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs build/$DEPDIR
- for lang in $subdirs c-family common analyzer
+ for lang in $subdirs c-family common analyzer rtl-ssa
do
${CONFIG_SHELL-/bin/sh} $ac_aux_dir/mkinstalldirs $lang/$DEPDIR
done], [subdirs="$subdirs" ac_aux_dir=$ac_aux_dir DEPDIR=$DEPDIR])
class temp_slot;
typedef class temp_slot *temp_slot_p;
class predefined_function_abi;
+namespace rtl_ssa { class function_info; }
/* Information mainlined about RTL representation of incoming arguments. */
struct GTY(()) incoming_args {
different ABIs. */
const predefined_function_abi *GTY((skip)) abi;
+ rtl_ssa::function_info *GTY((skip)) ssa;
+
/* For function.c */
/* # of bytes of outgoing arguments. If ACCUMULATE_OUTGOING_ARGS is
--- /dev/null
+// On-the-side RTL SSA representation -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef GCC_RTL_SSA_H
+#define GCC_RTL_SSA_H 1
+
+// This is an aggregation header file. This means it should contain only
+// other include files.
+
+#if 0
+// Files that use this one should first have:
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#endif
+
+// Needed by splay-tree-utils.h and directly by rtl-ssa.
+#include "pretty-print.h"
+
+// Needed directly by recog.h.
+#include "insn-config.h"
+
+// Needed directly by rtl-ssa.
+#include "splay-tree-utils.h"
+#include "recog.h"
+#include "regs.h"
+#include "function-abi.h"
+#include "obstack-utils.h"
+#include "mux-utils.h"
+#include "rtlanal.h"
+
+// Provides the global crtl->ssa.
+#include "tm_p.h"
+#include "memmodel.h"
+#include "emit-rtl.h"
+
+// The rtl-ssa files themselves.
+#include "rtl-ssa/accesses.h"
+#include "rtl-ssa/insns.h"
+#include "rtl-ssa/blocks.h"
+#include "rtl-ssa/changes.h"
+#include "rtl-ssa/functions.h"
+#include "rtl-ssa/is-a.inl"
+#include "rtl-ssa/access-utils.h"
+#include "rtl-ssa/insn-utils.h"
+#include "rtl-ssa/movement.h"
+#include "rtl-ssa/change-utils.h"
+#include "rtl-ssa/member-fns.inl"
+
+#endif
--- /dev/null
+// Access-related utilities for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// Return a referene to the whole of register REGNO.
+inline resource_info
+full_register (unsigned int regno)
+{
+ return { reg_raw_mode[regno], regno };
+}
+
+// Return true if sorted array ACCESSES includes an access to hard registers.
+inline bool
+accesses_include_hard_registers (const access_array &accesses)
+{
+ return accesses.size () && HARD_REGISTER_NUM_P (accesses.front ()->regno ());
+}
+
+// Return true if sorted array ACCESSES includes an access to memory.
+inline bool
+accesses_include_memory (const access_array &accesses)
+{
+ return accesses.size () && accesses.back ()->is_mem ();
+}
+
+// If sorted array ACCESSES includes an access to memory, return the access,
+// otherwise return null.
+template<typename T>
+inline auto
+memory_access (T accesses) -> decltype (accesses[0])
+{
+ if (accesses.size () && accesses.back ()->is_mem ())
+ return accesses.back ();
+ return nullptr;
+}
+
+// If sorted array ACCESSES includes a reference to REGNO, return the
+// access, otherwise return null.
+template<typename T>
+inline auto
+find_access (T accesses, unsigned int regno) -> decltype (accesses[0])
+{
+ unsigned int start = 0;
+ unsigned int end = accesses.size ();
+ while (start < end)
+ {
+ unsigned int mid = (start + end) / 2;
+ unsigned int found = accesses[mid]->regno ();
+ if (found == regno)
+ return accesses[mid];
+ if (found < regno)
+ start = mid + 1;
+ else
+ end = mid;
+ }
+ return nullptr;
+}
+
+// If sorted array ACCESSES includes a reference to REGNO, return the
+// index of the access, otherwise return -1.
+inline int
+find_access_index (access_array accesses, unsigned int regno)
+{
+ unsigned int start = 0;
+ unsigned int end = accesses.size ();
+ while (start < end)
+ {
+ unsigned int mid = (start + end) / 2;
+ unsigned int found = accesses[mid]->regno ();
+ if (found == regno)
+ return mid;
+ if (found < regno)
+ start = mid + 1;
+ else
+ end = mid;
+ }
+ return -1;
+}
+
+// If ACCESS is a set whose result is used by at least one instruction,
+// return the access as a set_info, otherwise return null.
+inline const set_info *
+set_with_nondebug_insn_uses (const access_info *access)
+{
+ if (access->is_set_with_nondebug_insn_uses ())
+ // No need for as_a; this test is just as definitive.
+ return static_cast<const set_info *> (access);
+ return nullptr;
+}
+
+// A non-const version of the above.
+inline set_info *
+set_with_nondebug_insn_uses (access_info *access)
+{
+ if (access->is_set_with_nondebug_insn_uses ())
+ return static_cast<set_info *> (access);
+ return nullptr;
+}
+
+// Return true if SET is the only set of SET->resource () and if it
+// dominates all uses (excluding uses of SET->resource () at points
+// where SET->resource () is always undefined).
+inline bool
+is_single_dominating_def (const set_info *set)
+{
+ return set->is_first_def () && set->is_last_def ();
+}
+
+// SET is known to be available on entry to BB. Return true if it is
+// also available on exit from BB. (The value might or might not be live.)
+inline bool
+remains_available_on_exit (const set_info *set, bb_info *bb)
+{
+ return (set->is_last_def ()
+ || *set->next_def ()->insn () > *bb->end_insn ());
+}
+
+// ACCESS is known to be associated with an instruction rather than
+// a phi node. Return which instruction that is.
+inline insn_info *
+access_insn (const access_info *access)
+{
+ // In release builds this function reduces to a single pointer reference.
+ if (auto *def = dyn_cast<const def_info *> (access))
+ return def->insn ();
+ return as_a<const use_info *> (access)->insn ();
+}
+
+// If ACCESS records a use, return the value that it uses. If ACCESS records
+// a set, return that set. If ACCESS records a clobber, return null.
+inline const set_info *
+access_value (const access_info *access)
+{
+ if (!access)
+ return nullptr;
+
+ if (auto *use = dyn_cast<const use_info *> (access))
+ return use->def ();
+
+ return dyn_cast<const set_info *> (access);
+}
+
+// A non-const version of the above.
+inline set_info *
+access_value (access_info *access)
+{
+ auto *const_access = const_cast<const access_info *> (access);
+ return const_cast<set_info *> (access_value (const_access));
+}
+
+// If ACCESS is a degenerate phi, return the set_info that defines its input,
+// otherwise return ACCESS itself.
+template<typename T>
+inline const T *
+look_through_degenerate_phi (const T *access)
+{
+ if (auto *phi = dyn_cast<const phi_info *> (access))
+ if (phi->is_degenerate ())
+ return phi->input_value (0);
+ return access;
+}
+
+// A non-const version of the above.
+template<typename T>
+inline T *
+look_through_degenerate_phi (T *access)
+{
+ auto *const_access = const_cast<const T *> (access);
+ return const_cast<T *> (look_through_degenerate_phi (const_access));
+}
+
+// If CLOBBER is in a group, return the first clobber in the group,
+// otherwise return CLOBBER itself.
+inline clobber_info *
+first_clobber_in_group (clobber_info *clobber)
+{
+ if (clobber->is_in_group ())
+ return clobber->group ()->first_clobber ();
+ return clobber;
+}
+
+// If CLOBBER is in a group, return the last clobber in the group,
+// otherwise return CLOBBER itself.
+inline clobber_info *
+last_clobber_in_group (clobber_info *clobber)
+{
+ if (clobber->is_in_group ())
+ return clobber->group ()->last_clobber ();
+ return clobber;
+}
+
+// If DEF is a clobber in a group, return the containing group,
+// otherwise return DEF.
+inline def_mux
+clobber_group_or_single_def (def_info *def)
+{
+ if (auto *clobber = dyn_cast<clobber_info *> (def))
+ if (clobber->is_in_group ())
+ return clobber->group ();
+ return def;
+}
+
+// Return the first definition associated with NODE. If NODE holds
+// a single set, the result is that set. If NODE holds a clobber_group,
+// the result is the first clobber in the group.
+inline def_info *
+first_def (def_node *node)
+{
+ return node->first_def ();
+}
+
+// Likewise for something that is either a node or a single definition.
+inline def_info *
+first_def (def_mux mux)
+{
+ return mux.first_def ();
+}
+
+// Return the last definition associated with NODE. If NODE holds
+// a single set, the result is that set. If NODE holds a clobber_group,
+// the result is the last clobber in the group.
+inline def_info *
+last_def (def_node *node)
+{
+ if (auto *group = dyn_cast<clobber_group *> (node))
+ return group->last_clobber ();
+ return node->first_def ();
+}
+
+// Likewise for something that is either a node or a single definition.
+inline def_info *
+last_def (def_mux mux)
+{
+ return mux.last_def ();
+}
+
+int lookup_use (splay_tree<use_info *> &, insn_info *);
+int lookup_def (def_splay_tree &, insn_info *);
+int lookup_clobber (clobber_tree &, insn_info *);
+int lookup_call_clobbers (insn_call_clobbers_tree &, insn_info *);
+
+// Search backwards from immediately before INSN for the first instruction
+// recorded in TREE, ignoring any instruction I for which IGNORE (I) is true.
+// Return null if no such instruction exists.
+template<typename IgnorePredicate>
+insn_info *
+prev_call_clobbers_ignoring (insn_call_clobbers_tree &tree, insn_info *insn,
+ IgnorePredicate ignore)
+{
+ if (!tree)
+ return nullptr;
+
+ int comparison = lookup_call_clobbers (tree, insn);
+ while (comparison <= 0 || ignore (tree->insn ()))
+ {
+ if (!tree.splay_prev_node ())
+ return nullptr;
+
+ comparison = 1;
+ }
+ return tree->insn ();
+}
+
+// Search forwards from immediately after INSN for the first instruction
+// recorded in TREE, ignoring any instruction I for which IGNORE (I) is true.
+// Return null if no such instruction exists.
+template<typename IgnorePredicate>
+insn_info *
+next_call_clobbers_ignoring (insn_call_clobbers_tree &tree, insn_info *insn,
+ IgnorePredicate ignore)
+{
+ if (!tree)
+ return nullptr;
+
+ int comparison = lookup_call_clobbers (tree, insn);
+ while (comparison >= 0 || ignore (tree->insn ()))
+ {
+ if (!tree.splay_next_node ())
+ return nullptr;
+
+ comparison = -1;
+ }
+ return tree->insn ();
+}
+
+// If ACCESS is a set, return the first use of ACCESS by a nondebug insn I
+// for which IGNORE (I) is false. Return null if ACCESS is not a set or if
+// no such use exists.
+template<typename IgnorePredicate>
+inline use_info *
+first_nondebug_insn_use_ignoring (const access_info *access,
+ IgnorePredicate ignore)
+{
+ if (const set_info *set = set_with_nondebug_insn_uses (access))
+ {
+ // Written this way to emphasize to the compiler that first_use
+ // must be nonnull in this situation.
+ use_info *use = set->first_use ();
+ do
+ {
+ if (!ignore (use->insn ()))
+ return use;
+ use = use->next_nondebug_insn_use ();
+ }
+ while (use);
+ }
+ return nullptr;
+}
+
+// If ACCESS is a set, return the last use of ACCESS by a nondebug insn I for
+// which IGNORE (I) is false. Return null if ACCESS is not a set or if no
+// such use exists.
+template<typename IgnorePredicate>
+inline use_info *
+last_nondebug_insn_use_ignoring (const access_info *access,
+ IgnorePredicate ignore)
+{
+ if (const set_info *set = set_with_nondebug_insn_uses (access))
+ {
+ // Written this way to emphasize to the compiler that
+ // last_nondebug_insn_use must be nonnull in this situation.
+ use_info *use = set->last_nondebug_insn_use ();
+ do
+ {
+ if (!ignore (use->insn ()))
+ return use;
+ use = use->prev_use ();
+ }
+ while (use);
+ }
+ return nullptr;
+}
+
+// If DEF is null, return null.
+//
+// Otherwise, search backwards for an access to DEF->resource (), starting at
+// the end of DEF's live range. Ignore clobbers if IGNORE_CLOBBERS_SETTING
+// is YES, otherwise treat them like any other access. Also ignore any
+// access A for which IGNORE (access_insn (A)) is true.
+//
+// Thus if DEF is a set that is used by nondebug insns, the first access
+// that the function considers is the last such use of the set. Otherwise,
+// the first access that the function considers is DEF itself.
+//
+// Return the access found, or null if there is no access that meets
+// the criteria.
+//
+// Note that this function does not consider separately-recorded call clobbers,
+// although such clobbers are only relevant if IGNORE_CLOBBERS_SETTING is NO.
+template<typename IgnorePredicate>
+access_info *
+last_access_ignoring (def_info *def, ignore_clobbers ignore_clobbers_setting,
+ IgnorePredicate ignore)
+{
+ while (def)
+ {
+ auto *clobber = dyn_cast<clobber_info *> (def);
+ if (clobber && ignore_clobbers_setting == ignore_clobbers::YES)
+ def = first_clobber_in_group (clobber);
+ else
+ {
+ if (use_info *use = last_nondebug_insn_use_ignoring (def, ignore))
+ return use;
+
+ insn_info *insn = def->insn ();
+ if (!ignore (insn))
+ return def;
+ }
+ def = def->prev_def ();
+ }
+ return nullptr;
+}
+
+// Search backwards for an access to DEF->resource (), starting
+// immediately before the point at which DEF occurs. Ignore clobbers
+// if IGNORE_CLOBBERS_SETTING is YES, otherwise treat them like any other
+// access. Also ignore any access A for which IGNORE (access_insn (A))
+// is true.
+//
+// Thus if DEF->insn () uses DEF->resource (), that use is the first access
+// that the function considers, since an instruction's uses occur strictly
+// before its definitions.
+//
+// Note that this function does not consider separately-recorded call clobbers,
+// although such clobbers are only relevant if IGNORE_CLOBBERS_SETTING is NO.
+template<typename IgnorePredicate>
+inline access_info *
+prev_access_ignoring (def_info *def, ignore_clobbers ignore_clobbers_setting,
+ IgnorePredicate ignore)
+{
+ return last_access_ignoring (def->prev_def (), ignore_clobbers_setting,
+ ignore);
+}
+
+// If DEF is null, return null.
+//
+// Otherwise, search forwards for a definition of DEF->resource (),
+// starting at DEF itself. Ignore clobbers if IGNORE_CLOBBERS_SETTING
+// is YES, otherwise treat them like any other access. Also ignore any
+// definition D for which IGNORE (D->insn ()) is true.
+//
+// Return the definition found, or null if there is no access that meets
+// the criteria.
+//
+// Note that this function does not consider separately-recorded call clobbers,
+// although such clobbers are only relevant if IGNORE_CLOBBERS_SETTING is NO.
+template<typename IgnorePredicate>
+def_info *
+first_def_ignoring (def_info *def, ignore_clobbers ignore_clobbers_setting,
+ IgnorePredicate ignore)
+{
+ while (def)
+ {
+ auto *clobber = dyn_cast<clobber_info *> (def);
+ if (clobber && ignore_clobbers_setting == ignore_clobbers::YES)
+ def = last_clobber_in_group (clobber);
+ else if (!ignore (def->insn ()))
+ return def;
+
+ def = def->next_def ();
+ }
+ return nullptr;
+}
+
+// Search forwards for the next access to DEF->resource (),
+// starting immediately after DEF's instruction. Ignore clobbers if
+// IGNORE_CLOBBERS_SETTING is YES, otherwise treat them like any other access.
+// Also ignore any access A for which IGNORE (access_insn (A)) is true;
+// in this context, ignoring a set includes ignoring all uses of the set.
+//
+// Thus if DEF is a set with uses by nondebug insns, the first access that the
+// function considers is the first such use of the set.
+//
+// Return the access found, or null if there is no access that meets the
+// criteria.
+//
+// Note that this function does not consider separately-recorded call clobbers,
+// although such clobbers are only relevant if IGNORE_CLOBBERS_SETTING is NO.
+template<typename IgnorePredicate>
+access_info *
+next_access_ignoring (def_info *def, ignore_clobbers ignore_clobbers_setting,
+ IgnorePredicate ignore)
+{
+ if (use_info *use = first_nondebug_insn_use_ignoring (def, ignore))
+ return use;
+
+ return first_def_ignoring (def->next_def (), ignore_clobbers_setting,
+ ignore);
+}
+
+// Return true if ACCESS1 should before ACCESS2 in an access_array.
+inline bool
+compare_access_infos (const access_info *access1, const access_info *access2)
+{
+ gcc_checking_assert (access1 == access2
+ || access1->regno () != access2->regno ());
+ return access1->regno () < access2->regno ();
+}
+
+// Sort [BEGIN, END) into ascending regno order. The sequence must have
+// at most one access to a given a regno.
+inline void
+sort_accesses (access_info **begin, access_info **end)
+{
+ auto count = end - begin;
+ if (count <= 1)
+ return;
+
+ if (count == 2)
+ {
+ gcc_checking_assert (begin[0]->regno () != begin[1]->regno ());
+ if (begin[0]->regno () > begin[1]->regno ())
+ std::swap (begin[0], begin[1]);
+ return;
+ }
+
+ std::sort (begin, end, compare_access_infos);
+}
+
+// Sort the accesses in CONTAINER, which contains pointers to access_infos.
+template<typename T>
+inline void
+sort_accesses (T &container)
+{
+ return sort_accesses (container.begin (), container.end ());
+}
+
+// The underlying non-template implementation of merge_access_arrays.
+access_array merge_access_arrays_base (obstack_watermark &, access_array,
+ access_array);
+// Merge access arrays ACCESSES1 and ACCESSES2, including the allocation
+// in the area governed by WATERMARK. Return an invalid access_array if
+// ACCESSES1 and ACCESSES2 contain conflicting accesses to the same resource.
+//
+// T can be an access_array, a def_array or a use_array.
+template<typename T>
+inline T
+merge_access_arrays (obstack_watermark &watermark, T accesses1, T accesses2)
+{
+ return T (merge_access_arrays_base (watermark, accesses1, accesses2));
+}
+
+// The underlying non-template implementation of insert_access.
+access_array insert_access_base (obstack_watermark &, access_info *,
+ access_array);
+
+// Return a new access_array that contains the result of inserting ACCESS1
+// into sorted access array ACCESSES2. Allocate the returned array in the
+// area governed by WATERMARK. Return an invalid access_array if ACCESSES2
+// contains a conflicting access to the same resource as ACCESS1.
+//
+// T can be an access_array, a def_array or a use_array.
+template<typename T>
+inline T
+insert_access (obstack_watermark &watermark,
+ typename T::value_type access1, T accesses2)
+{
+ return T (insert_access_base (watermark, access1, accesses2));
+}
+
+// The underlying non-template implementation of remove_note_accesses.
+access_array remove_note_accesses_base (obstack_watermark &, access_array);
+
+// If ACCESSES contains accesses that only occur in notes, return a new
+// array without such accesses, allocating it in the area governed by
+// WATERMARK. Return ACCESSES itself otherwise.
+//
+// T can be an access_array, a def_array or a use_array.
+template<typename T>
+inline T
+remove_note_accesses (obstack_watermark &watermark, T accesses)
+{
+ return T (remove_note_accesses_base (watermark, accesses));
+}
+
+}
--- /dev/null
+// Implementation of access-related functions for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#include "rtl-ssa.h"
+#include "rtl-ssa/internals.inl"
+
+using namespace rtl_ssa;
+
+// This clobber belongs to a clobber_group but m_group appears to be
+// out of date. Update it and return the new (correct) value.
+clobber_group *
+clobber_info::recompute_group ()
+{
+ using splay_tree = clobber_info::splay_tree;
+
+ // Splay this clobber to the root of the tree while searching for a node
+ // that has the correct group. The root always has the correct group,
+ // so the search always breaks early and does not install this clobber
+ // as the root.
+ clobber_info *cursor = m_parent;
+ auto find_group = [](clobber_info *node, unsigned int)
+ {
+ return node->m_group->has_been_superceded () ? nullptr : node->m_group;
+ };
+ clobber_group *group = splay_tree::splay_and_search (this, nullptr,
+ find_group);
+ gcc_checking_assert (m_parent);
+
+ // If the previous splay operation did anything, this clobber is now an
+ // ancestor of CURSOR, and all the nodes inbetween have a stale group.
+ // Since we have visited the nodes, we might as well update them too.
+ //
+ // If the previous splay operation did nothing, start the update from
+ // this clobber instead. In that case we change at most two clobbers:
+ // this clobber and possibly its parent.
+ if (cursor == m_parent)
+ cursor = this;
+
+ // Walk up the tree from CURSOR updating clobbers that need it.
+ // This walk always includes this clobber.
+ while (cursor->m_group != group)
+ {
+ cursor->m_group = group;
+ cursor = cursor->m_parent;
+ }
+
+ gcc_checking_assert (m_group == group);
+ return group;
+}
+
+// See the comment above the declaration.
+void
+resource_info::print_identifier (pretty_printer *pp) const
+{
+ if (is_mem ())
+ pp_string (pp, "mem");
+ else
+ {
+ char tmp[3 * sizeof (regno) + 2];
+ snprintf (tmp, sizeof (tmp), "r%d", regno);
+ pp_string (pp, tmp);
+ }
+}
+
+// See the comment above the declaration.
+void
+resource_info::print_context (pretty_printer *pp) const
+{
+ if (HARD_REGISTER_NUM_P (regno))
+ {
+ if (const char *name = reg_names[regno])
+ {
+ pp_space (pp);
+ pp_left_paren (pp);
+ pp_string (pp, name);
+ if (mode != E_BLKmode)
+ {
+ pp_colon (pp);
+ pp_string (pp, GET_MODE_NAME (mode));
+ }
+ pp_right_paren (pp);
+ }
+ }
+ else if (is_reg ())
+ {
+ pp_space (pp);
+ pp_left_paren (pp);
+ if (mode != E_BLKmode)
+ {
+ pp_string (pp, GET_MODE_NAME (mode));
+ pp_space (pp);
+ }
+ pp_string (pp, "pseudo");
+ pp_right_paren (pp);
+ }
+}
+
+// See the comment above the declaration.
+void
+resource_info::print (pretty_printer *pp) const
+{
+ print_identifier (pp);
+ print_context (pp);
+}
+
+// Some properties can naturally be described using adjectives that attach
+// to nouns like "use" or "definition". Print such adjectives to PP.
+void
+access_info::print_prefix_flags (pretty_printer *pp) const
+{
+ if (m_is_temp)
+ pp_string (pp, "temporary ");
+ if (m_has_been_superceded)
+ pp_string (pp, "superceded ");
+}
+
+// Print properties not handled by print_prefix_flags to PP, putting
+// each property on a new line indented by two extra spaces.
+void
+access_info::print_properties_on_new_lines (pretty_printer *pp) const
+{
+ if (m_is_pre_post_modify)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "set by a pre/post-modify");
+ pp_indentation (pp) -= 2;
+ }
+ if (m_includes_address_uses)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "appears inside an address");
+ pp_indentation (pp) -= 2;
+ }
+ if (m_includes_read_writes)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "appears in a read/write context");
+ pp_indentation (pp) -= 2;
+ }
+ if (m_includes_subregs)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "appears inside a subreg");
+ pp_indentation (pp) -= 2;
+ }
+}
+
+// Return true if there are no known issues with the integrity of the
+// link information.
+inline bool
+use_info::check_integrity ()
+{
+ auto subsequence_id = [](use_info *use)
+ {
+ if (use->is_in_nondebug_insn ())
+ return 1;
+ if (use->is_in_debug_insn ())
+ return 2;
+ return 3;
+ };
+
+ use_info *prev = prev_use ();
+ use_info *next = next_use ();
+
+ if (prev && subsequence_id (prev) > subsequence_id (this))
+ return false;
+ if (next && subsequence_id (next) < subsequence_id (this))
+ return false;
+ if (m_is_last_nondebug_insn_use != calculate_is_last_nondebug_insn_use ())
+ return false;
+
+ if (!prev && last_use ()->next_use ())
+ return false;
+ if (!next)
+ if (use_info *use = last_nondebug_insn_use ())
+ if (!use->m_is_last_nondebug_insn_use)
+ return false;
+
+ return true;
+}
+
+// See the comment above the declaration.
+void
+use_info::print_location (pretty_printer *pp) const
+{
+ if (is_in_phi ())
+ pp_access (pp, phi (), PP_ACCESS_INCLUDE_LOCATION);
+ else
+ insn ()->print_identifier_and_location (pp);
+}
+
+// See the comment above the declaration.
+void
+use_info::print_def (pretty_printer *pp) const
+{
+ if (const set_info *set = def ())
+ pp_access (pp, set, 0);
+ else
+ {
+ pp_string (pp, "undefined ");
+ resource ().print (pp);
+ }
+}
+
+// See the comment above the declaration.
+void
+use_info::print (pretty_printer *pp, unsigned int flags) const
+{
+ print_prefix_flags (pp);
+
+ const set_info *set = def ();
+ if (set && set->mode () != mode ())
+ {
+ pp_string (pp, GET_MODE_NAME (mode ()));
+ pp_space (pp);
+ }
+
+ pp_string (pp, "use of ");
+ print_def (pp);
+ if (flags & PP_ACCESS_INCLUDE_LOCATION)
+ {
+ pp_string (pp, " by ");
+ print_location (pp);
+ }
+ if (set && (flags & PP_ACCESS_INCLUDE_LINKS))
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "defined in ");
+ set->insn ()->print_location (pp);
+ pp_indentation (pp) -= 2;
+ }
+ if (flags & PP_ACCESS_INCLUDE_PROPERTIES)
+ print_properties_on_new_lines (pp);
+}
+
+// See the comment above the declaration.
+void
+def_info::print_identifier (pretty_printer *pp) const
+{
+ resource ().print_identifier (pp);
+ pp_colon (pp);
+ insn ()->print_identifier (pp);
+ resource ().print_context (pp);
+}
+
+// See the comment above the declaration.
+void
+def_info::print_location (pretty_printer *pp) const
+{
+ insn ()->print_identifier_and_location (pp);
+}
+
+// See the comment above the declaration.
+void
+clobber_info::print (pretty_printer *pp, unsigned int flags) const
+{
+ print_prefix_flags (pp);
+ if (is_call_clobber ())
+ pp_string (pp, "call ");
+ pp_string (pp, "clobber ");
+ print_identifier (pp);
+ if (flags & PP_ACCESS_INCLUDE_LOCATION)
+ {
+ pp_string (pp, " in ");
+ insn ()->print_location (pp);
+ }
+ if (flags & PP_ACCESS_INCLUDE_PROPERTIES)
+ print_properties_on_new_lines (pp);
+}
+
+// See the comment above the declaration.
+void
+set_info::print_uses_on_new_lines (pretty_printer *pp) const
+{
+ for (const use_info *use : all_uses ())
+ {
+ pp_newline_and_indent (pp, 2);
+ if (use->is_live_out_use ())
+ {
+ pp_string (pp, "live out from ");
+ use->insn ()->print_location (pp);
+ }
+ else
+ {
+ pp_string (pp, "used by ");
+ use->print_location (pp);
+ }
+ pp_indentation (pp) -= 2;
+ }
+ if (m_use_tree)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "splay tree:");
+ pp_newline_and_indent (pp, 2);
+ auto print_use = [](pretty_printer *pp,
+ splay_tree_node<use_info *> *node)
+ {
+ pp_string (pp, "use by ");
+ node->value ()->print_location (pp);
+ };
+ m_use_tree.print (pp, m_use_tree.root (), print_use);
+ pp_indentation (pp) -= 4;
+ }
+}
+
+// See the comment above the declaration.
+void
+set_info::print (pretty_printer *pp, unsigned int flags) const
+{
+ print_prefix_flags (pp);
+ pp_string (pp, "set ");
+ print_identifier (pp);
+ if (flags & PP_ACCESS_INCLUDE_LOCATION)
+ {
+ pp_string (pp, " in ");
+ insn ()->print_location (pp);
+ }
+ if (flags & PP_ACCESS_INCLUDE_PROPERTIES)
+ print_properties_on_new_lines (pp);
+ if (flags & PP_ACCESS_INCLUDE_LINKS)
+ print_uses_on_new_lines (pp);
+}
+
+// See the comment above the declaration.
+void
+phi_info::print (pretty_printer *pp, unsigned int flags) const
+{
+ print_prefix_flags (pp);
+ pp_string (pp, "phi node ");
+ print_identifier (pp);
+ if (flags & PP_ACCESS_INCLUDE_LOCATION)
+ {
+ pp_string (pp, " in ");
+ insn ()->print_location (pp);
+ }
+
+ if (flags & PP_ACCESS_INCLUDE_PROPERTIES)
+ print_properties_on_new_lines (pp);
+
+ if (flags & PP_ACCESS_INCLUDE_LINKS)
+ {
+ basic_block cfg_bb = bb ()->cfg_bb ();
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "inputs:");
+ unsigned int i = 0;
+ for (const use_info *input : inputs ())
+ {
+ basic_block pred_cfg_bb = EDGE_PRED (cfg_bb, i)->src;
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "bb");
+ pp_decimal_int (pp, pred_cfg_bb->index);
+ pp_colon (pp);
+ pp_space (pp);
+ input->print_def (pp);
+ pp_indentation (pp) -= 2;
+ i += 1;
+ }
+ pp_indentation (pp) -= 2;
+
+ print_uses_on_new_lines (pp);
+ }
+}
+
+// See the comment above the declaration.
+void
+set_node::print (pretty_printer *pp) const
+{
+ pp_access (pp, first_def ());
+}
+
+// See the comment above the declaration.
+void
+clobber_group::print (pretty_printer *pp) const
+{
+ auto print_clobber = [](pretty_printer *pp, const def_info *clobber)
+ {
+ pp_access (pp, clobber);
+ };
+ pp_string (pp, "grouped clobber");
+ for (const def_info *clobber : clobbers ())
+ {
+ pp_newline_and_indent (pp, 2);
+ print_clobber (pp, clobber);
+ pp_indentation (pp) -= 2;
+ }
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "splay tree");
+ pp_newline_and_indent (pp, 2);
+ m_clobber_tree.print (pp, print_clobber);
+ pp_indentation (pp) -= 4;
+}
+
+// Return a clobber_group for CLOBBER, creating one if CLOBBER doesn't
+// already belong to a group.
+clobber_group *
+function_info::need_clobber_group (clobber_info *clobber)
+{
+ if (clobber->is_in_group ())
+ return clobber->group ();
+ return allocate<clobber_group> (clobber);
+}
+
+// Return a def_node for inserting DEF into the associated resource's
+// splay tree. Use a clobber_group if DEF is a clobber and a set_node
+// otherwise.
+def_node *
+function_info::need_def_node (def_info *def)
+{
+ if (auto *clobber = dyn_cast<clobber_info *> (def))
+ return need_clobber_group (clobber);
+ return allocate<set_node> (as_a<set_info *> (def));
+}
+
+// LAST is the last thing to define LAST->resource (), and is where any
+// splay tree root for LAST->resource () is stored. Require such a splay tree
+// to exist, creating a new one if necessary. Return the root of the tree.
+//
+// The caller must call LAST->set_splay_root after it has finished with
+// the splay tree.
+def_splay_tree
+function_info::need_def_splay_tree (def_info *last)
+{
+ if (def_node *root = last->splay_root ())
+ return root;
+
+ // Use a left-spine rooted at the last node.
+ def_node *root = need_def_node (last);
+ def_node *parent = root;
+ while (def_info *prev = first_def (parent)->prev_def ())
+ {
+ def_node *node = need_def_node (prev);
+ def_splay_tree::insert_child (parent, 0, node);
+ parent = node;
+ }
+ return root;
+}
+
+// Search TREE for either:
+//
+// - a set_info at INSN or
+// - a clobber_group whose range includes INSN
+//
+// If such a node exists, install it as the root of TREE and return 0.
+// Otherwise arbitrarily choose between:
+//
+// (1) Installing the closest preceding node as the root and returning 1.
+// (2) Installing the closest following node as the root and returning -1.
+//
+// Note that this routine should not be used to check whether INSN
+// itself defines a resource; that can be checked more cheaply using
+// find_access_index.
+int
+rtl_ssa::lookup_def (def_splay_tree &tree, insn_info *insn)
+{
+ auto go_left = [&](def_node *node)
+ {
+ return *insn < *first_def (node)->insn ();
+ };
+ auto go_right = [&](def_node *node)
+ {
+ return *insn > *last_def (node)->insn ();
+ };
+ return tree.lookup (go_left, go_right);
+}
+
+// Search TREE for a clobber in INSN. If such a clobber exists, install
+// it as the root of TREE and return 0. Otherwise arbitrarily choose between:
+//
+// (1) Installing the closest preceding clobber as the root and returning 1.
+// (2) Installing the closest following clobber as the root and returning -1.
+int
+rtl_ssa::lookup_clobber (clobber_tree &tree, insn_info *insn)
+{
+ auto compare = [&](clobber_info *clobber)
+ {
+ return insn->compare_with (clobber->insn ());
+ };
+ return tree.lookup (compare);
+}
+
+// Search for a definition of RESOURCE at INSN and return the result of
+// the search as a def_lookup. See the comment above the class for more
+// details.
+def_lookup
+function_info::find_def (resource_info resource, insn_info *insn)
+{
+ def_info *first = m_defs[resource.regno + 1];
+ if (!first)
+ // There are no nodes. The comparison result is pretty meaningless
+ // in this case.
+ return { nullptr, -1 };
+
+ // See whether the first node matches.
+ auto first_result = clobber_group_or_single_def (first);
+ if (*insn <= *last_def (first_result)->insn ())
+ {
+ int comparison = (*insn >= *first->insn () ? 0 : -1);
+ return { first_result, comparison };
+ }
+
+ // See whether the last node matches.
+ def_info *last = first->last_def ();
+ auto last_result = clobber_group_or_single_def (last);
+ if (*insn >= *first_def (last_result)->insn ())
+ {
+ int comparison = (*insn <= *last->insn () ? 0 : 1);
+ return { last_result, comparison };
+ }
+
+ // Resort to using a splay tree to search for the result.
+ def_splay_tree tree = need_def_splay_tree (last);
+ int comparison = lookup_def (tree, insn);
+ last->set_splay_root (tree.root ());
+ return { tree.root (), comparison };
+}
+
+// Add DEF to the function's list of definitions of DEF->resource (),
+// inserting DEF immediately before BEFORE. DEF is not currently in the list.
+void
+function_info::insert_def_before (def_info *def, def_info *before)
+{
+ gcc_checking_assert (!def->has_def_links ()
+ && *before->insn () > *def->insn ());
+
+ def->copy_prev_from (before);
+ if (def_info *prev = def->prev_def ())
+ {
+ gcc_checking_assert (*prev->insn () < *def->insn ());
+ prev->set_next_def (def);
+ }
+ else
+ m_defs[def->regno () + 1] = def;
+
+ def->set_next_def (before);
+ before->set_prev_def (def);
+}
+
+// Add DEF to the function's list of definitions of DEF->resource (),
+// inserting DEF immediately after AFTER. DEF is not currently in the list.
+void
+function_info::insert_def_after (def_info *def, def_info *after)
+{
+ gcc_checking_assert (!def->has_def_links ()
+ && *after->insn () < *def->insn ());
+
+ def->copy_next_from (after);
+ if (def_info *next = def->next_def ())
+ {
+ gcc_checking_assert (*next->insn () > *def->insn ());
+ next->set_prev_def (def);
+ }
+ else
+ m_defs[def->regno () + 1]->set_last_def (def);
+
+ def->set_prev_def (after);
+ after->set_next_def (def);
+}
+
+// Remove DEF from the function's list of definitions of DEF->resource ().
+void
+function_info::remove_def_from_list (def_info *def)
+{
+ def_info *prev = def->prev_def ();
+ def_info *next = def->next_def ();
+
+ if (next)
+ next->copy_prev_from (def);
+ else
+ m_defs[def->regno () + 1]->set_last_def (prev);
+
+ if (prev)
+ prev->copy_next_from (def);
+ else
+ m_defs[def->regno () + 1] = next;
+
+ def->clear_def_links ();
+}
+
+// Add CLOBBER to GROUP and insert it into the function's list of
+// accesses to CLOBBER->resource (). CLOBBER is not currently part
+// of an active group and is not currently in the list.
+void
+function_info::add_clobber (clobber_info *clobber, clobber_group *group)
+{
+ // Search for either the previous or next clobber in the group.
+ // The result is less than zero if CLOBBER should come before NEIGHBOR
+ // or greater than zero if CLOBBER should come after NEIGHBOR.
+ int comparison = lookup_clobber (group->m_clobber_tree, clobber->insn ());
+ gcc_checking_assert (comparison != 0);
+ clobber_info *neighbor = group->m_clobber_tree.root ();
+
+ // Since HEIGHBOR is now the root of the splay tree, its group needs
+ // to be up-to-date.
+ neighbor->update_group (group);
+
+ // If CLOBBER comes before NEIGHBOR, insert CLOBBER to NEIGHBOR's left,
+ // otherwise insert CLOBBER to NEIGHBOR's right.
+ clobber_info::splay_tree::insert_child (neighbor, comparison > 0, clobber);
+ clobber->set_group (group);
+
+ // Insert the clobber into the function-wide list and update the
+ // bounds of the group.
+ if (comparison > 0)
+ {
+ insert_def_after (clobber, neighbor);
+ if (neighbor == group->last_clobber ())
+ group->set_last_clobber (clobber);
+ }
+ else
+ {
+ insert_def_before (clobber, neighbor);
+ if (neighbor == group->first_clobber ())
+ group->set_first_clobber (clobber);
+ }
+}
+
+// Remove CLOBBER from GROUP, given that GROUP contains other clobbers too.
+// Also remove CLOBBER from the function's list of accesses to
+// CLOBBER->resource ().
+void
+function_info::remove_clobber (clobber_info *clobber, clobber_group *group)
+{
+ if (clobber == group->first_clobber ())
+ {
+ auto *new_first = as_a<clobber_info *> (clobber->next_def ());
+ group->set_first_clobber (new_first);
+ new_first->update_group (group);
+ }
+ else if (clobber == group->last_clobber ())
+ {
+ auto *new_last = as_a<clobber_info *> (clobber->prev_def ());
+ group->set_last_clobber (new_last);
+ new_last->update_group (group);
+ }
+
+ clobber_info *replacement = clobber_info::splay_tree::remove_node (clobber);
+ if (clobber == group->m_clobber_tree.root ())
+ {
+ group->m_clobber_tree = replacement;
+ replacement->update_group (group);
+ }
+ clobber->set_group (nullptr);
+
+ remove_def_from_list (clobber);
+}
+
+// Add CLOBBER immediately before the first clobber in GROUP, given that
+// CLOBBER is not currently part of any group.
+void
+function_info::prepend_clobber_to_group (clobber_info *clobber,
+ clobber_group *group)
+{
+ clobber_info *next = group->first_clobber ();
+ clobber_info::splay_tree::insert_child (next, 0, clobber);
+ group->set_first_clobber (clobber);
+ clobber->set_group (group);
+}
+
+// Add CLOBBER immediately after the last clobber in GROUP, given that
+// CLOBBER is not currently part of any group.
+void
+function_info::append_clobber_to_group (clobber_info *clobber,
+ clobber_group *group)
+{
+ clobber_info *prev = group->last_clobber ();
+ clobber_info::splay_tree::insert_child (prev, 1, clobber);
+ group->set_last_clobber (clobber);
+ clobber->set_group (group);
+}
+
+// Put CLOBBER1 and CLOBBER2 into the same clobber_group, given that
+// CLOBBER1 occurs immediately before CLOBBER2 and that the two clobbers
+// are not currently in the same group. LAST is the last definition of
+// the associated resource, and is where any splay tree is stored.
+void
+function_info::merge_clobber_groups (clobber_info *clobber1,
+ clobber_info *clobber2,
+ def_info *last)
+{
+ if (clobber1->is_in_group () && clobber2->is_in_group ())
+ {
+ clobber_group *group1 = clobber1->group ();
+ clobber_group *group2 = clobber2->group ();
+ gcc_checking_assert (clobber1 == group1->last_clobber ()
+ && clobber2 == group2->first_clobber ());
+
+ if (def_splay_tree tree = last->splay_root ())
+ {
+ // Remove GROUP2 from the splay tree.
+ int comparison = lookup_def (tree, clobber2->insn ());
+ gcc_checking_assert (comparison == 0);
+ tree.remove_root ();
+ last->set_splay_root (tree.root ());
+ }
+
+ // Splice the trees together.
+ group1->m_clobber_tree.splice_next_tree (group2->m_clobber_tree);
+
+ // Bring the two extremes of GROUP2 under GROUP1. Any other
+ // clobbers in the group are updated lazily on demand.
+ clobber2->set_group (group1);
+ group2->last_clobber ()->set_group (group1);
+ group1->set_last_clobber (group2->last_clobber ());
+
+ // Record that GROUP2 is no more.
+ group2->set_first_clobber (nullptr);
+ group2->set_last_clobber (nullptr);
+ group2->m_clobber_tree = nullptr;
+ }
+ else
+ {
+ // In this case there can be no active splay tree.
+ gcc_assert (!last->splay_root ());
+ if (clobber2->is_in_group ())
+ prepend_clobber_to_group (clobber1, clobber2->group ());
+ else
+ append_clobber_to_group (clobber2, need_clobber_group (clobber1));
+ }
+}
+
+// GROUP spans INSN, and INSN now sets the resource that GROUP clobbers.
+// Split GROUP around INSN and return the clobber that comes immediately
+// before INSN.
+clobber_info *
+function_info::split_clobber_group (clobber_group *group, insn_info *insn)
+{
+ // Search for either the previous or next clobber in the group.
+ // The result is less than zero if CLOBBER should come before NEIGHBOR
+ // or greater than zero if CLOBBER should come after NEIGHBOR.
+ int comparison = lookup_clobber (group->m_clobber_tree, insn);
+ gcc_checking_assert (comparison != 0);
+ clobber_info *neighbor = group->m_clobber_tree.root ();
+
+ clobber_tree tree1, tree2;
+ clobber_info *prev;
+ clobber_info *next;
+ if (comparison > 0)
+ {
+ // NEIGHBOR is the last clobber in what will become the first group.
+ tree1 = neighbor;
+ tree2 = tree1.split_after_root ();
+ prev = neighbor;
+ next = as_a<clobber_info *> (prev->next_def ());
+ }
+ else
+ {
+ // NEIGHBOR is the first clobber in what will become the second group.
+ tree2 = neighbor;
+ tree1 = tree2.split_before_root ();
+ next = neighbor;
+ prev = as_a<clobber_info *> (next->prev_def ());
+ }
+
+ // Use GROUP to hold PREV and earlier clobbers. Create a new group for
+ // NEXT onwards.
+ clobber_info *last_clobber = group->last_clobber ();
+ clobber_group *group1 = group;
+ clobber_group *group2 = allocate<clobber_group> (next);
+
+ // Finish setting up GROUP1, making sure that the roots and extremities
+ // have a correct group pointer. Leave the rest to be updated lazily.
+ group1->set_last_clobber (prev);
+ tree1->set_group (group1);
+ prev->set_group (group1);
+
+ // Finish setting up GROUP2, with the same approach as for GROUP1.
+ group2->set_first_clobber (next);
+ group2->set_last_clobber (last_clobber);
+ next->set_group (group2);
+ tree2->set_group (group2);
+ last_clobber->set_group (group2);
+
+ return prev;
+}
+
+// Add DEF to the end of the function's list of definitions of
+// DEF->resource (). There is known to be no associated splay tree yet.
+void
+function_info::append_def (def_info *def)
+{
+ gcc_checking_assert (!def->has_def_links ());
+ def_info **head = &m_defs[def->regno () + 1];
+ def_info *first = *head;
+ if (!first)
+ {
+ // This is the only definition of the resource.
+ def->set_last_def (def);
+ *head = def;
+ return;
+ }
+
+ def_info *prev = first->last_def ();
+ gcc_checking_assert (!prev->splay_root ());
+
+ // Maintain the invariant that two clobbers must not appear in
+ // neighboring nodes of the splay tree.
+ auto *clobber = dyn_cast<clobber_info *> (def);
+ auto *prev_clobber = dyn_cast<clobber_info *> (prev);
+ if (clobber && prev_clobber)
+ append_clobber_to_group (clobber, need_clobber_group (prev_clobber));
+
+ prev->set_next_def (def);
+ def->set_prev_def (prev);
+ first->set_last_def (def);
+}
+
+// Add DEF to the function's list of definitions of DEF->resource ().
+// Also insert it into the associated splay tree, if there is one.
+// DEF is not currently part of the list and is not in the splay tree.
+void
+function_info::add_def (def_info *def)
+{
+ gcc_checking_assert (!def->has_def_links ()
+ && !def->m_is_temp
+ && !def->m_has_been_superceded);
+ def_info **head = &m_defs[def->regno () + 1];
+ def_info *first = *head;
+ if (!first)
+ {
+ // This is the only definition of the resource.
+ def->set_last_def (def);
+ *head = def;
+ return;
+ }
+
+ def_info *last = first->last_def ();
+ insn_info *insn = def->insn ();
+
+ int comparison;
+ def_node *root = nullptr;
+ def_info *prev = nullptr;
+ def_info *next = nullptr;
+ if (*insn > *last->insn ())
+ {
+ // This definition comes after all other definitions.
+ comparison = 1;
+ if (def_splay_tree tree = last->splay_root ())
+ {
+ tree.splay_max_node ();
+ root = tree.root ();
+ last->set_splay_root (root);
+ }
+ prev = last;
+ }
+ else if (*insn < *first->insn ())
+ {
+ // This definition comes before all other definitions.
+ comparison = -1;
+ if (def_splay_tree tree = last->splay_root ())
+ {
+ tree.splay_min_node ();
+ root = tree.root ();
+ last->set_splay_root (root);
+ }
+ next = first;
+ }
+ else
+ {
+ // Search the splay tree for an insertion point.
+ def_splay_tree tree = need_def_splay_tree (last);
+ comparison = lookup_def (tree, insn);
+ root = tree.root ();
+ last->set_splay_root (root);
+
+ // Deal with cases in which we found an overlapping live range.
+ if (comparison == 0)
+ {
+ auto *group = as_a<clobber_group *> (tree.root ());
+ if (auto *clobber = dyn_cast<clobber_info *> (def))
+ {
+ add_clobber (clobber, group);
+ return;
+ }
+ prev = split_clobber_group (group, insn);
+ next = prev->next_def ();
+ }
+ // COMPARISON is < 0 if DEF comes before ROOT or > 0 if DEF comes
+ // after ROOT.
+ else if (comparison < 0)
+ {
+ next = first_def (root);
+ prev = next->prev_def ();
+ }
+ else
+ {
+ prev = last_def (root);
+ next = prev->next_def ();
+ }
+ }
+
+ // See if we should merge CLOBBER with a neighboring clobber.
+ auto *clobber = dyn_cast<clobber_info *> (def);
+ auto *prev_clobber = safe_dyn_cast<clobber_info *> (prev);
+ auto *next_clobber = safe_dyn_cast<clobber_info *> (next);
+ // We shouldn't have consecutive clobber_groups.
+ gcc_checking_assert (!(clobber && prev_clobber && next_clobber));
+ if (clobber && prev_clobber)
+ append_clobber_to_group (clobber, need_clobber_group (prev_clobber));
+ else if (clobber && next_clobber)
+ prepend_clobber_to_group (clobber, need_clobber_group (next_clobber));
+ else if (root)
+ {
+ // If DEF comes before ROOT, insert DEF to ROOT's left,
+ // otherwise insert DEF to ROOT's right.
+ def_node *node = need_def_node (def);
+ def_splay_tree::insert_child (root, comparison >= 0, node);
+ }
+ if (prev)
+ insert_def_after (def, prev);
+ else
+ insert_def_before (def, next);
+}
+
+// Remove DEF from the function's list of definitions of DEF->resource ().
+// Also remove DEF from the associated splay tree, if there is one.
+void
+function_info::remove_def (def_info *def)
+{
+ def_info **head = &m_defs[def->regno () + 1];
+ def_info *first = *head;
+ gcc_checking_assert (first);
+ if (first->is_last_def ())
+ {
+ // DEF is the only definition of the resource.
+ gcc_checking_assert (first == def);
+ *head = nullptr;
+ def->clear_def_links ();
+ return;
+ }
+
+ // If CLOBBER belongs to a clobber_group that contains other clobbers
+ // too, then we need to update the clobber_group and the list, but any
+ // splay tree that contains the clobber_group is unaffected.
+ if (auto *clobber = dyn_cast<clobber_info *> (def))
+ if (clobber->is_in_group ())
+ {
+ clobber_group *group = clobber->group ();
+ if (group->first_clobber () != group->last_clobber ())
+ {
+ remove_clobber (clobber, group);
+ return;
+ }
+ }
+
+ // If we've created a splay tree for this resource, remove the entry
+ // for DEF.
+ def_info *last = first->last_def ();
+ if (def_splay_tree tree = last->splay_root ())
+ {
+ int comparison = lookup_def (tree, def->insn ());
+ gcc_checking_assert (comparison == 0);
+ tree.remove_root ();
+ last->set_splay_root (tree.root ());
+ }
+
+ // If the definition came between two clobbers, merge them into a single
+ // group.
+ auto *prev_clobber = safe_dyn_cast<clobber_info *> (def->prev_def ());
+ auto *next_clobber = safe_dyn_cast<clobber_info *> (def->next_def ());
+ if (prev_clobber && next_clobber)
+ merge_clobber_groups (prev_clobber, next_clobber, last);
+
+ remove_def_from_list (def);
+}
+
+// Require DEF to have a splay tree that contains all non-phi uses.
+void
+function_info::need_use_splay_tree (set_info *def)
+{
+ if (!def->m_use_tree)
+ for (use_info *use : def->all_insn_uses ())
+ {
+ auto *use_node = allocate<splay_tree_node<use_info *>> (use);
+ def->m_use_tree.insert_max_node (use_node);
+ }
+}
+
+// Compare two instructions by their position in a use splay tree. Return >0
+// if INSN1 comes after INSN2, <0 if INSN1 comes before INSN2, or 0 if they are
+// the same instruction.
+static inline int
+compare_use_insns (insn_info *insn1, insn_info *insn2)
+{
+ // Debug instructions go after nondebug instructions.
+ int diff = insn1->is_debug_insn () - insn2->is_debug_insn ();
+ if (diff != 0)
+ return diff;
+ return insn1->compare_with (insn2);
+}
+
+// Search TREE for a use in INSN. If such a use exists, install it as
+// the root of TREE and return 0. Otherwise arbitrarily choose between:
+//
+// (1) Installing the closest preceding use as the root and returning 1.
+// (2) Installing the closest following use as the root and returning -1.
+int
+rtl_ssa::lookup_use (splay_tree<use_info *> &tree, insn_info *insn)
+{
+ auto compare = [&](splay_tree_node<use_info *> *node)
+ {
+ return compare_use_insns (insn, node->value ()->insn ());
+ };
+ return tree.lookup (compare);
+}
+
+// Add USE to USE->def ()'s list of uses. inserting USE immediately before
+// BEFORE. USE is not currently in the list.
+//
+// This routine should not be used for inserting phi uses.
+void
+function_info::insert_use_before (use_info *use, use_info *before)
+{
+ gcc_checking_assert (!use->has_use_links () && use->is_in_any_insn ());
+
+ set_info *def = use->def ();
+
+ use->copy_prev_from (before);
+ use->set_next_use (before);
+
+ if (use_info *prev = use->prev_use ())
+ prev->set_next_use (use);
+ else
+ use->def ()->set_first_use (use);
+
+ before->set_prev_use (use);
+ if (use->is_in_nondebug_insn () && before->is_in_debug_insn_or_phi ())
+ def->last_use ()->set_last_nondebug_insn_use (use);
+
+ gcc_checking_assert (use->check_integrity () && before->check_integrity ());
+}
+
+// Add USE to USE->def ()'s list of uses. inserting USE immediately after
+// AFTER. USE is not currently in the list.
+//
+// This routine should not be used for inserting phi uses.
+void
+function_info::insert_use_after (use_info *use, use_info *after)
+{
+ set_info *def = use->def ();
+ gcc_checking_assert (after->is_in_any_insn ()
+ && !use->has_use_links ()
+ && use->is_in_any_insn ());
+
+ use->set_prev_use (after);
+ use->copy_next_from (after);
+
+ after->set_next_use (use);
+
+ if (use_info *next = use->next_use ())
+ {
+ // The last node doesn't change, but we might need to update its
+ // last_nondebug_insn_use record.
+ if (use->is_in_nondebug_insn () && next->is_in_debug_insn_or_phi ())
+ def->last_use ()->set_last_nondebug_insn_use (use);
+ next->set_prev_use (use);
+ }
+ else
+ {
+ // USE is now the last node.
+ if (use->is_in_nondebug_insn ())
+ use->set_last_nondebug_insn_use (use);
+ def->first_use ()->set_last_use (use);
+ }
+
+ gcc_checking_assert (use->check_integrity () && after->check_integrity ());
+}
+
+// If USE has a known definition, add USE to that definition's list of uses.
+// Also update the associated splay tree, if any.
+void
+function_info::add_use (use_info *use)
+{
+ gcc_checking_assert (!use->has_use_links ()
+ && !use->m_is_temp
+ && !use->m_has_been_superceded);
+
+ set_info *def = use->def ();
+ if (!def)
+ return;
+
+ use_info *first = def->first_use ();
+ if (!first)
+ {
+ // This is the only use of the definition.
+ use->set_last_use (use);
+ if (use->is_in_nondebug_insn ())
+ use->set_last_nondebug_insn_use (use);
+
+ def->set_first_use (use);
+
+ gcc_checking_assert (use->check_integrity ());
+ return;
+ }
+
+ if (use->is_in_phi ())
+ {
+ // Add USE at the end of the list, as the new first phi.
+ use_info *last = first->last_use ();
+
+ use->set_prev_use (last);
+ use->copy_next_from (last);
+
+ last->set_next_use (use);
+ first->set_last_use (use);
+
+ gcc_checking_assert (use->check_integrity ());
+ return;
+ }
+
+ // If there is currently no splay tree for this definition, see if can
+ // get away with a pure list-based update.
+ insn_info *insn = use->insn ();
+ auto quick_path = [&]()
+ {
+ // Check if USE should come before all current uses.
+ if (first->is_in_phi () || compare_use_insns (insn, first->insn ()) < 0)
+ {
+ insert_use_before (use, first);
+ return true;
+ }
+
+ // Check if USE should come after all current uses in the same
+ // subsequence (i.e. the list of nondebug insn uses or the list
+ // of debug insn uses).
+ use_info *last = first->last_use ();
+ if (use->is_in_debug_insn ())
+ {
+ if (last->is_in_phi ())
+ return false;
+ }
+ else
+ last = last->last_nondebug_insn_use ();
+
+ if (compare_use_insns (insn, last->insn ()) > 0)
+ {
+ insert_use_after (use, last);
+ return true;
+ }
+
+ return false;
+ };
+ if (!def->m_use_tree && quick_path ())
+ return;
+
+ // Search the splay tree for an insertion point. COMPARISON is less
+ // than zero if USE should come before NEIGHBOR, or greater than zero
+ // if USE should come after NEIGHBOR.
+ need_use_splay_tree (def);
+ int comparison = lookup_use (def->m_use_tree, insn);
+ gcc_checking_assert (comparison != 0);
+ splay_tree_node<use_info *> *neighbor = def->m_use_tree.root ();
+
+ // If USE comes before NEIGHBOR, insert USE to NEIGHBOR's left,
+ // otherwise insert USE to NEIGHBOR's right.
+ auto *use_node = allocate<splay_tree_node<use_info *>> (use);
+ def->m_use_tree.insert_child (neighbor, comparison > 0, use_node);
+ if (comparison > 0)
+ insert_use_after (use, neighbor->value ());
+ else
+ insert_use_before (use, neighbor->value ());
+}
+
+// If USE has a known definition, remove USE from that definition's list
+// of uses. Also remove if it from the associated splay tree, if any.
+void
+function_info::remove_use (use_info *use)
+{
+ set_info *def = use->def ();
+ if (!def)
+ return;
+
+ // Remove USE from the splay tree.
+ if (def->m_use_tree && use->is_in_any_insn ())
+ {
+ int comparison = lookup_use (def->m_use_tree, use->insn ());
+ gcc_checking_assert (comparison == 0);
+ def->m_use_tree.remove_root ();
+ }
+
+ use_info *prev = use->prev_use ();
+ use_info *next = use->next_use ();
+
+ use_info *first = def->first_use ();
+ use_info *last = first->last_use ();
+ if (last->last_nondebug_insn_use () == use)
+ last->set_last_nondebug_insn_use (prev);
+
+ if (next)
+ next->copy_prev_from (use);
+ else
+ first->set_last_use (prev);
+
+ if (prev)
+ prev->copy_next_from (use);
+ else
+ def->set_first_use (next);
+
+ use->clear_use_links ();
+ gcc_checking_assert ((!prev || prev->check_integrity ())
+ && (!next || next->check_integrity ()));
+}
+
+// Allocate a temporary clobber_info for register REGNO in insn INSN,
+// including it in the region of the obstack governed by WATERMARK.
+// Return a new def_array that contains OLD_DEFS and the new clobber.
+//
+// OLD_DEFS is known not to define REGNO.
+def_array
+function_info::insert_temp_clobber (obstack_watermark &watermark,
+ insn_info *insn, unsigned int regno,
+ def_array old_defs)
+{
+ gcc_checking_assert (watermark == &m_temp_obstack);
+ auto *clobber = allocate_temp<clobber_info> (insn, regno);
+ clobber->m_is_temp = true;
+ return insert_access (watermark, clobber, old_defs);
+}
+
+// A subroutine of make_uses_available. Try to make USE's definition
+// available at the head of BB. On success:
+//
+// - If the use would have the same def () as USE, return USE.
+//
+// - If BB already has a degenerate phi for the same definition,
+// return a temporary use of that phi.
+//
+// - Otherwise, the use would need a new degenerate phi. Allocate a
+// temporary phi and return a temporary use of it.
+//
+// Return null on failure.
+use_info *
+function_info::make_use_available (use_info *use, bb_info *bb)
+{
+ set_info *def = use->def ();
+ if (!def)
+ return use;
+
+ if (is_single_dominating_def (def))
+ return use;
+
+ // FIXME: Deliberately limited for fwprop compatibility testing.
+ basic_block cfg_bb = bb->cfg_bb ();
+ bb_info *use_bb = use->bb ();
+ if (single_pred_p (cfg_bb)
+ && single_pred (cfg_bb) == use_bb->cfg_bb ()
+ && remains_available_on_exit (def, use_bb))
+ {
+ if (def->ebb () == bb->ebb ())
+ return use;
+
+ resource_info resource = use->resource ();
+ set_info *ultimate_def = look_through_degenerate_phi (def);
+
+ // See if there is already a (degenerate) phi for DEF.
+ insn_info *phi_insn = bb->ebb ()->phi_insn ();
+ phi_info *phi;
+ def_lookup dl = find_def (resource, phi_insn);
+ if (set_info *set = dl.matching_set ())
+ {
+ // There is an existing phi.
+ phi = as_a<phi_info *> (set);
+ gcc_checking_assert (phi->input_value (0) == ultimate_def);
+ }
+ else
+ {
+ // Create a temporary placeholder phi. This will become
+ // permanent if the change is later committed.
+ phi = allocate_temp<phi_info> (phi_insn, resource, 0);
+ auto *input = allocate<use_info> (phi, resource, ultimate_def);
+ input->m_is_temp = true;
+ phi->m_is_temp = true;
+ phi->make_degenerate (input);
+ if (def_info *prev = dl.prev_def ())
+ phi->set_prev_def (prev);
+ if (def_info *next = dl.next_def ())
+ phi->set_next_def (next);
+ }
+
+ // Create a temporary use of the phi at the head of the first
+ // block, since we know for sure that it's available there.
+ insn_info *use_insn = bb->ebb ()->first_bb ()->head_insn ();
+ auto *new_use = allocate_temp<use_info> (use_insn, resource, phi);
+ new_use->m_is_temp = true;
+ return new_use;
+ }
+ return nullptr;
+}
+
+// See the comment above the declaration.
+use_array
+function_info::make_uses_available (obstack_watermark &watermark,
+ use_array uses, bb_info *bb)
+{
+ unsigned int num_uses = uses.size ();
+ if (num_uses == 0)
+ return uses;
+
+ auto **new_uses = XOBNEWVEC (watermark, access_info *, num_uses);
+ for (unsigned int i = 0; i < num_uses; ++i)
+ {
+ use_info *use = make_use_available (uses[i], bb);
+ if (!use)
+ return use_array (access_array::invalid ());
+ new_uses[i] = use;
+ }
+ return use_array (new_uses, num_uses);
+}
+
+// Return true if ACCESS1 can represent ACCESS2 and if ACCESS2 can
+// represent ACCESS1.
+static bool
+can_merge_accesses (access_info *access1, access_info *access2)
+{
+ if (access1 == access2)
+ return true;
+
+ auto *use1 = dyn_cast<use_info *> (access1);
+ auto *use2 = dyn_cast<use_info *> (access2);
+ return use1 && use2 && use1->def () == use2->def ();
+}
+
+// See the comment above the declaration.
+access_array
+rtl_ssa::merge_access_arrays_base (obstack_watermark &watermark,
+ access_array accesses1,
+ access_array accesses2)
+{
+ if (accesses1.empty ())
+ return accesses2;
+ if (accesses2.empty ())
+ return accesses1;
+
+ auto i1 = accesses1.begin ();
+ auto end1 = accesses1.end ();
+ auto i2 = accesses2.begin ();
+ auto end2 = accesses2.end ();
+
+ access_array_builder builder (watermark);
+ builder.reserve (accesses1.size () + accesses2.size ());
+
+ while (i1 != end1 && i2 != end2)
+ {
+ access_info *access1 = *i1;
+ access_info *access2 = *i2;
+
+ unsigned int regno1 = access1->regno ();
+ unsigned int regno2 = access2->regno ();
+ if (regno1 == regno2)
+ {
+ if (!can_merge_accesses (access1, access2))
+ return access_array::invalid ();
+
+ builder.quick_push (access1);
+ ++i1;
+ ++i2;
+ }
+ else if (regno1 < regno2)
+ {
+ builder.quick_push (access1);
+ ++i1;
+ }
+ else
+ {
+ builder.quick_push (access2);
+ ++i2;
+ }
+ }
+ for (; i1 != end1; ++i1)
+ builder.quick_push (*i1);
+ for (; i2 != end2; ++i2)
+ builder.quick_push (*i2);
+
+ return builder.finish ();
+}
+
+// See the comment above the declaration.
+access_array
+rtl_ssa::insert_access_base (obstack_watermark &watermark,
+ access_info *access1, access_array accesses2)
+{
+ access_array_builder builder (watermark);
+ builder.reserve (1 + accesses2.size ());
+
+ unsigned int regno1 = access1->regno ();
+ auto i2 = accesses2.begin ();
+ auto end2 = accesses2.end ();
+ while (i2 != end2)
+ {
+ access_info *access2 = *i2;
+
+ unsigned int regno2 = access2->regno ();
+ if (regno1 == regno2)
+ {
+ if (!can_merge_accesses (access1, access2))
+ return access_array::invalid ();
+
+ builder.quick_push (access1);
+ access1 = nullptr;
+ ++i2;
+ break;
+ }
+ else if (regno1 < regno2)
+ {
+ builder.quick_push (access1);
+ access1 = nullptr;
+ break;
+ }
+ else
+ {
+ builder.quick_push (access2);
+ ++i2;
+ }
+ }
+ if (access1)
+ builder.quick_push (access1);
+ for (; i2 != end2; ++i2)
+ builder.quick_push (*i2);
+
+ return builder.finish ();
+}
+
+// See the comment above the declaration.
+access_array
+rtl_ssa::remove_note_accesses_base (obstack_watermark &watermark,
+ access_array accesses)
+{
+ for (access_info *access : accesses)
+ if (access->only_occurs_in_notes ())
+ {
+ access_array_builder builder (watermark);
+ builder.reserve (accesses.size ());
+ for (access_info *access2 : accesses)
+ if (!access2->only_occurs_in_notes ())
+ builder.quick_push (access2);
+ return builder.finish ();
+ }
+ return accesses;
+}
+
+// Print RESOURCE to PP.
+void
+rtl_ssa::pp_resource (pretty_printer *pp, resource_info resource)
+{
+ resource.print (pp);
+}
+
+// Print ACCESS to PP. FLAGS is a bitmask of PP_ACCESS_* flags.
+void
+rtl_ssa::pp_access (pretty_printer *pp, const access_info *access,
+ unsigned int flags)
+{
+ if (!access)
+ pp_string (pp, "<null>");
+ else if (auto *phi = dyn_cast<const phi_info *> (access))
+ phi->print (pp, flags);
+ else if (auto *set = dyn_cast<const set_info *> (access))
+ set->print (pp, flags);
+ else if (auto *clobber = dyn_cast<const clobber_info *> (access))
+ clobber->print (pp, flags);
+ else if (auto *use = dyn_cast<const use_info *> (access))
+ use->print (pp, flags);
+ else
+ pp_string (pp, "??? Unknown access");
+}
+
+// Print ACCESSES to PP. FLAGS is a bitmask of PP_ACCESS_* flags.
+void
+rtl_ssa::pp_accesses (pretty_printer *pp, access_array accesses,
+ unsigned int flags)
+{
+ if (accesses.empty ())
+ pp_string (pp, "none");
+ else
+ {
+ bool is_first = true;
+ for (access_info *access : accesses)
+ {
+ if (is_first)
+ is_first = false;
+ else
+ pp_newline_and_indent (pp, 0);
+ pp_access (pp, access, flags);
+ }
+ }
+}
+
+// Print NODE to PP.
+void
+rtl_ssa::pp_def_node (pretty_printer *pp, const def_node *node)
+{
+ if (!node)
+ pp_string (pp, "<null>");
+ else if (auto *group = dyn_cast<const clobber_group *> (node))
+ group->print (pp);
+ else if (auto *set = dyn_cast<const set_node *> (node))
+ set->print (pp);
+ else
+ pp_string (pp, "??? Unknown def node");
+}
+
+// Print MUX to PP.
+void
+rtl_ssa::pp_def_mux (pretty_printer *pp, def_mux mux)
+{
+ if (auto *node = mux.dyn_cast<def_node *> ())
+ pp_def_node (pp, node);
+ else
+ pp_access (pp, mux.as_a<def_info *> ());
+}
+
+// Print DL to PP.
+void
+rtl_ssa::pp_def_lookup (pretty_printer *pp, def_lookup dl)
+{
+ pp_string (pp, "comparison result of ");
+ pp_decimal_int (pp, dl.comparison);
+ pp_string (pp, " for ");
+ pp_newline_and_indent (pp, 0);
+ pp_def_mux (pp, dl.mux);
+}
+
+// Dump RESOURCE to FILE.
+void
+dump (FILE *file, resource_info resource)
+{
+ dump_using (file, pp_resource, resource);
+}
+
+// Dump ACCESS to FILE. FLAGS is a bitmask of PP_ACCESS_* flags.
+void
+dump (FILE *file, const access_info *access, unsigned int flags)
+{
+ dump_using (file, pp_access, access, flags);
+}
+
+// Dump ACCESSES to FILE. FLAGS is a bitmask of PP_ACCESS_* flags.
+void
+dump (FILE *file, access_array accesses, unsigned int flags)
+{
+ dump_using (file, pp_accesses, accesses, flags);
+}
+
+// Print NODE to FILE.
+void
+dump (FILE *file, const def_node *node)
+{
+ dump_using (file, pp_def_node, node);
+}
+
+// Print MUX to FILE.
+void
+dump (FILE *file, def_mux mux)
+{
+ dump_using (file, pp_def_mux, mux);
+}
+
+// Print RESULT to FILE.
+void
+dump (FILE *file, def_lookup result)
+{
+ dump_using (file, pp_def_lookup, result);
+}
+
+// Debug interfaces to the dump routines above.
+void debug (const resource_info &x) { dump (stderr, x); }
+void debug (const access_info *x) { dump (stderr, x); }
+void debug (const access_array &x) { dump (stderr, x); }
+void debug (const def_node *x) { dump (stderr, x); }
+void debug (const def_mux &x) { dump (stderr, x); }
+void debug (const def_lookup &x) { dump (stderr, x); }
--- /dev/null
+// Access-related classes for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// Forward declarations.
+class bb_info;
+class clobber_group;
+class def_node;
+class ebb_info;
+class insn_info;
+class phi_info;
+class set_info;
+
+// Used as a boolean argunent to certain routines.
+enum class ignore_clobbers { NO, YES };
+
+// Represents something that the SSA form tracks: either a register
+// or memory.
+class resource_info
+{
+public:
+ // Return true if this resource represents memory.
+ bool is_mem () const { return regno == MEM_REGNO; }
+
+ // Return true if this resource represents a register.
+ bool is_reg () const { return regno != MEM_REGNO; }
+
+ // Print the name of the resource to PP.
+ void print_identifier (pretty_printer *pp) const;
+
+ // Possibly print additional information about the resource to PP.
+ void print_context (pretty_printer *pp) const;
+
+ // A combination of print_identifier and print_context.
+ void print (pretty_printer *pp) const;
+
+ // The mode with which the resource is being defined or used. This is
+ // always BLKmode for memory. It can also be BLKmode for registers if
+ // we don't yet know the real mode, or if the mode is not relevant for
+ // some reason.
+ machine_mode mode;
+
+ // The pseudo register or single hard register that the resource represents,
+ // or MEM_REGNO for memory.
+ unsigned int regno;
+};
+
+// For simplicity, we treat memory as a single unified entity.
+const resource_info memory = { E_BLKmode, MEM_REGNO };
+
+// Flags used when printing access_infos.
+//
+// Print the location at which the access occurs. This is redundant
+// when the access is being printed as part of the instruction or phi node
+// that contains the access.
+const unsigned int PP_ACCESS_INCLUDE_LOCATION = 1U << 0;
+//
+// Print links to other accesses: the definition that defines a use,
+// the uses of a definition, and the inputs of a phi node.
+const unsigned int PP_ACCESS_INCLUDE_LINKS = 1U << 1;
+//
+// Print additional properties about the access.
+const unsigned int PP_ACCESS_INCLUDE_PROPERTIES = 1U << 2;
+//
+// The usual flags when printing an access in isolation.
+const unsigned int PP_ACCESS_DEFAULT = (PP_ACCESS_INCLUDE_LOCATION
+ | PP_ACCESS_INCLUDE_LINKS
+ | PP_ACCESS_INCLUDE_PROPERTIES);
+//
+// The usual flags when printing a def_info from its defining instruction.
+const unsigned int PP_ACCESS_SETTER = (PP_ACCESS_INCLUDE_LINKS
+ | PP_ACCESS_INCLUDE_PROPERTIES);
+//
+// The usual flags when printing a use_info from its user.
+const unsigned int PP_ACCESS_USER = PP_ACCESS_INCLUDE_PROPERTIES;
+
+// The various ways of accessing a resource. The two range checks that
+// we need to perform are [SET, PHI] (for set_info) and [SET, CLOBBER]
+// (for def_info), so the ordering tries to make those tests as
+// efficient as possible.
+enum class access_kind : uint8_t
+{
+ // Set the resource to a useful value.
+ SET,
+
+ // A form of SET that collects the possible incoming values of the
+ // resource using a phi node; the resource does not actually change value.
+ PHI,
+
+ // Set the resource to a value that is both unknown and not useful.
+ CLOBBER,
+
+ // Use the current value of the resource.
+ USE
+};
+
+// A base class that represents an access to a resource.
+class access_info
+{
+ // Size: 1 LP64 word
+ friend class function_info;
+
+public:
+ // Return the resource that is being accessed.
+ resource_info resource () const { return { m_mode, m_regno }; }
+
+ // Return true if the access is to memory.
+ bool is_mem () const { return m_regno == MEM_REGNO; }
+
+ // Return true if the access is to a register.
+ bool is_reg () const { return m_regno != MEM_REGNO; }
+
+ // If the access is to a register, return the register number,
+ // otherwise return MEM_REGNO.
+ unsigned int regno () const { return m_regno; }
+
+ // For sets, return the mode of the value to which the resource is being set.
+ // For uses, return the mode in which the resource is being used (which for
+ // hard registers might be different from the mode in which the resource
+ // was set).
+ //
+ // When accessing memory, the mode is always BLKmode. When accessing
+ // pseudo registers, the mode is always the mode of the pseudo register
+ // (and so doesn't, for example, take subregs into account).
+ machine_mode mode () const { return m_mode; }
+
+ // Return the kind of access that this is.
+ access_kind kind () const { return m_kind; }
+
+ // Return true if the access occurs in a phi node or an "artificial"
+ // instruction (see insn_info), false if it occurs in a real instruction.
+ bool is_artificial () const { return m_is_artificial; }
+
+ // Return the opposite of is_artificial.
+ bool is_real () const { return !m_is_artificial; }
+
+ // Return true if this access is a set_info whose result is used by at least
+ // one nondebug instruction.
+ bool is_set_with_nondebug_insn_uses () const;
+
+ // Return true if the access describes a set_info and if the value
+ // is defined by an RTX_AUTOINC rtx.
+ bool is_pre_post_modify () const { return m_is_pre_post_modify; }
+
+ // Return true if the access is a clobber_info that describes the effect
+ // of a called function. This kind of clobber is added for -fipa-ra
+ // functions that clobber only a strict subset of the normal ABI set.
+ bool is_call_clobber () const { return m_is_call_clobber; }
+
+ // Return true if the access is a use_info that simply marks a point in
+ // the live range of a set_info at which the value is live out from
+ // the containing EBB.
+ bool is_live_out_use () const { return m_is_live_out_use; }
+
+ // Return true if the access is a use_info for an instruction and if
+ // at least some of the uses occur within a MEM address.
+ //
+ // There shouldn't be a need to check whether *all* uses occur within
+ // a MEM address, since in principle:
+ //
+ // A: (set (reg:SI R1) (mem:SI (post_inc:SI (reg:SI R2))))
+ //
+ // should be semantically equivalent to:
+ //
+ // B: (parallel [(set (reg:SI R1) (mem:SI (reg:SI R2)))
+ // (set (reg:SI R2) (plus:SI (reg:SI R2) (const_int 4)))])
+ //
+ // even though R2 occurs only in MEMs for A but occurs outside MEMs for B.
+ bool includes_address_uses () const { return m_includes_address_uses; }
+
+ // Return true if the access occurs in an instruction and if at least
+ // some accesses to resource () occur in a read-modify-write context.
+ // This is equivalent to the DF_REF_READ_WRITE flag.
+ bool includes_read_writes () const { return m_includes_read_writes; }
+
+ // Return true if the access occurs in an instruction and if at least
+ // some accesses to resource () occur in a subreg context.
+ bool includes_subregs () const { return m_includes_subregs; }
+
+ // Return true if the access occurs in an instruction and if at least
+ // some accesses to resource () occur in a multi-register REG.
+ // This implies that resource () is a hard register.
+ bool includes_multiregs () const { return m_includes_multiregs; }
+
+ // Return true if the access occurs in a real nondebug instruction
+ // and if all accesses to resource () occur in notes, rather than
+ // in the main instruction pattern.
+ bool only_occurs_in_notes () const { return m_only_occurs_in_notes; }
+
+protected:
+ access_info (resource_info, access_kind);
+
+ void print_prefix_flags (pretty_printer *) const;
+ void print_properties_on_new_lines (pretty_printer *) const;
+
+private:
+ void set_mode (machine_mode mode) { m_mode = mode; }
+
+ // The values returned by the accessors above.
+ unsigned int m_regno;
+ access_kind m_kind : 8;
+
+protected:
+ // The value returned by the accessors above.
+ unsigned int m_is_artificial : 1;
+ unsigned int m_is_set_with_nondebug_insn_uses : 1;
+ unsigned int m_is_pre_post_modify : 1;
+ unsigned int m_is_call_clobber : 1;
+ unsigned int m_is_live_out_use : 1;
+ unsigned int m_includes_address_uses : 1;
+ unsigned int m_includes_read_writes : 1;
+ unsigned int m_includes_subregs : 1;
+ unsigned int m_includes_multiregs : 1;
+ unsigned int m_only_occurs_in_notes : 1;
+
+ // True if this access is a use_insn that occurs in a nondebug instruction,
+ // and if there are no following uses by nondebug instructions. The next use
+ // is null, a use_info for a debug instruction, or a use_info for a phi node.
+ //
+ // Providing this helps to optimize use_info::next_nondebug_insn_use.
+ unsigned int m_is_last_nondebug_insn_use : 1;
+
+ // True if this access is a use_info for a debug instruction or
+ // a phi node.
+ unsigned int m_is_in_debug_insn_or_phi : 1;
+
+private:
+ // Used as a flag during various update routines; has no long-lasting
+ // meaning.
+ unsigned int m_has_been_superceded : 1;
+
+ // Indicates that this access has been allocated on the function_info's
+ // temporary obstack and so is not (yet) part of the proper SSA form.
+ unsigned int m_is_temp : 1;
+
+ // Bits for future expansion.
+ unsigned int m_spare : 2;
+
+ // The value returned by the accessor above.
+ machine_mode m_mode : 8;
+};
+
+// A contiguous array of access_info pointers. Used to represent a
+// (mostly small) number of definitions and/or uses.
+using access_array = array_slice<access_info *const>;
+
+// A class for building an access_array on an obstack. It automatically
+// frees any in-progress array if the build attempt fails before finish ()
+// has been called.
+class access_array_builder : public obstack_watermark
+{
+public:
+ using obstack_watermark::obstack_watermark;
+
+ // Make sure that the array has enough for NUM_ACCESSES accesses.
+ void reserve (unsigned int num_accesses);
+
+ // Add ACCESS to the end of the array that we're building, given that
+ // reserve () has already made room.
+ void quick_push (access_info *access);
+
+ // Finish and return the new array. The array survives the destruction
+ // of the builder.
+ array_slice<access_info *> finish ();
+};
+
+// An access_info that represents the use of a resource in either a phi node
+// or an instruction. It records which set_info (if any) provides the
+// resource's value.
+class use_info : public access_info
+{
+ // Overall size: 5 LP64 words.
+ friend class set_info;
+ friend class function_info;
+
+public:
+ // Return true if the access occurs in an instruction rather than a phi node.
+ // The instruction might be a debug instruction or a nondebug instruction.
+ bool is_in_any_insn () const { return m_insn_or_phi.is_first (); }
+
+ // Return true if the access occurs in a nondebug instruction,
+ // false if it occurs in a debug instruction or a phi node.
+ bool is_in_nondebug_insn () const { return !m_is_in_debug_insn_or_phi; }
+
+ // Return true if the instruction occurs in a debug instruction.
+ bool is_in_debug_insn () const;
+
+ // Return true if the access occurs in a phi node rather than in an
+ // instruction.
+ bool is_in_phi () const { return m_insn_or_phi.is_second (); }
+
+ // Return true if the access occurs in a debug instruction or a phi node,
+ // false if it occurs in a nondebug instruction.
+ bool is_in_debug_insn_or_phi () const { return m_is_in_debug_insn_or_phi; }
+
+ // Return the instruction that uses the resource. Only valid is
+ // is_in_any_insn ().
+ insn_info *insn () const { return m_insn_or_phi.known_first (); }
+
+ // Return the phi node that uses the resource. Only valid if is_in_phi ().
+ phi_info *phi () const { return m_insn_or_phi.known_second (); }
+
+ // Return the basic block that contains the access.
+ bb_info *bb () const;
+
+ // Return the extended basic block that contains the access.
+ ebb_info *ebb () const;
+
+ // Return the set_info whose result the access uses, or null if the
+ // value of the resource is completely undefined.
+ //
+ // The value is undefined if the use is completely upwards exposed
+ // (i.e. has no preceding definition) or if the preceding definition
+ // is a clobber rather than a set.
+ //
+ // The mode of the definition can be different from the mode of the use;
+ // for example, a hard register might be set in DImode and used in SImode.
+ set_info *def () const { return m_def; }
+
+ // Return the previous and next uses of the definition. See set_info
+ // for details about the ordering.
+ //
+ // These routines are only meaningful when def () is nonnull.
+ use_info *prev_use () const;
+ use_info *next_use () const;
+
+ // Return the next use by a nondebug instruction, or null if none.
+ //
+ // This is only valid if is_in_nondebug_insn (). It is equivalent to,
+ // but more efficient than:
+ //
+ // next_use () && next_use ()->is_in_nondebug_insn ()
+ // ? next_use () : nullptr
+ use_info *next_nondebug_insn_use () const;
+
+ // Return the next use by an instruction, or null if none. The use might
+ // be by a debug instruction or a nondebug instruction.
+ //
+ // This is only valid if is_in_any_insn (). It is equivalent to:
+ //
+ // next_use () && next_use ()->is_in_any_insn () ? next_use () : nullptr
+ use_info *next_any_insn_use () const;
+
+ // Return the previous use by a phi node in the list, or null if none.
+ //
+ // This is only valid if is_in_phi (). It is equivalent to:
+ //
+ // prev_use () && prev_use ()->is_in_phi () ? prev_use () : nullptr
+ use_info *prev_phi_use () const;
+
+ // Return true if this is the first use of the definition. See set_info
+ // for details about the ordering.
+ //
+ // This routine is only meaningful when def () is nonnull.
+ bool is_first_use () const;
+
+ // Return true if this is the last use of the definition. See set_info
+ // for details about the ordering.
+ //
+ // This routine is only meaningful when def () is nonnull.
+ bool is_last_use () const;
+
+ // Print a description of def () to PP.
+ void print_def (pretty_printer *pp) const;
+
+ // Print a description of the location of the use to PP.
+ void print_location (pretty_printer *pp) const;
+
+ // Print a description of the use to PP under the control of
+ // PP_ACCESS_* flags FLAGS.
+ void print (pretty_printer *pp,
+ unsigned int flags = PP_ACCESS_DEFAULT) const;
+
+private:
+ // If we only create a set_info splay tree for sets that are used by
+ // three instructions or more, then only about 16% of uses need to be in
+ // a splay tree. It is therefore more memory-efficient to use separate
+ // nodes for the splay tree, instead of storing the child nodes
+ // directly in the use_info.
+
+ // Make insn_info the first (and thus directly-encoded) choice since
+ // insn () is read much more often than phi ().
+ using insn_or_phi = pointer_mux<insn_info, phi_info>;
+
+ // The use belongs to a list that is partitioned into three sections:
+ //
+ // (1) all uses in nondebug instructions, in reverse postorder
+ //
+ // (2) all uses in debug instructions, in reverse postorder
+ //
+ // (3) all phi nodes, in no particular order.
+ //
+ // In order to preserve memory:
+ //
+ // - The set_info just has a pointer to the first use.
+ //
+ // - The first use's "prev" pointer points to the last use.
+ //
+ // - The last use's "next" pointer points to the last use in a nondebug
+ // instruction, or null if there are no such uses.
+ using last_use_or_prev_use = pointer_mux<use_info>;
+ using last_nondebug_insn_use_or_next_use = pointer_mux<use_info>;
+
+ use_info (insn_or_phi, resource_info, set_info *);
+
+ use_info *last_use () const;
+ use_info *last_nondebug_insn_use () const;
+ bool calculate_is_last_nondebug_insn_use () const;
+
+ void record_reference (rtx_obj_reference, bool);
+ void set_insn (insn_info *);
+ void set_def (set_info *set) { m_def = set; }
+ void set_is_live_out_use (bool value) { m_is_live_out_use = value; }
+ void copy_prev_from (use_info *);
+ void copy_next_from (use_info *);
+ void set_last_use (use_info *);
+ void set_prev_use (use_info *);
+ void set_last_nondebug_insn_use (use_info *);
+ void set_next_use (use_info *);
+ void clear_use_links ();
+ bool has_use_links ();
+ bool check_integrity ();
+
+ // The location of the use.
+ insn_or_phi m_insn_or_phi;
+
+ // The overloaded "prev" and "next" pointers, as described above.
+ last_use_or_prev_use m_last_use_or_prev_use;
+ last_nondebug_insn_use_or_next_use m_last_nondebug_insn_use_or_next_use;
+
+ // The value of def ().
+ set_info *m_def;
+};
+
+// Iterators for lists of uses.
+using use_iterator = list_iterator<use_info, &use_info::next_use>;
+using reverse_use_iterator = list_iterator<use_info, &use_info::prev_use>;
+
+// Like use_iterator, but specifically for uses by nondebug instructions,
+// uses by any kind of instruction, and uses by phi nodes respectively.
+// These iterators allow a nullptr end point even if there are other types
+// of use in the same definition.
+using nondebug_insn_use_iterator
+ = list_iterator<use_info, &use_info::next_nondebug_insn_use>;
+using any_insn_use_iterator
+ = list_iterator<use_info, &use_info::next_any_insn_use>;
+using phi_use_iterator = list_iterator<use_info, &use_info::prev_phi_use>;
+
+// A view of an access_array in which every entry is known to be a use_info.
+using use_array = const_derived_container<use_info *, access_array>;
+
+// An access_info that describes a definition of a resource. The definition
+// can be a set or a clobber; the difference is that a set provides a known
+// and potentially useful value, while a clobber provides an unknown and
+// unusable value.
+//
+// Every definition is associated with an insn_info. All definitions of
+// a given resource are stored in a linked list, maintained in reverse
+// postorder.
+class def_info : public access_info
+{
+ // Overall size: 4 LP64 words
+ friend class function_info;
+ friend class clobber_group;
+
+public:
+ // Return the instruction that contains the definition.
+ insn_info *insn () const { return m_insn; }
+
+ // Return the basic block that contains the definition.
+ bb_info *bb () const;
+
+ // Return the extended basic block that contains the access.
+ ebb_info *ebb () const;
+
+ // Return the previous and next definitions of the same resource,
+ // in reverse postorder, or null if no such definition exists.
+ def_info *prev_def () const;
+ def_info *next_def () const;
+
+ // Return true if this is the first definition in the list.
+ bool is_first_def () const;
+
+ // Return true if this is the last definition in the list.
+ bool is_last_def () const;
+
+ // Print the location of the definition to PP.
+ void print_location (pretty_printer *pp) const;
+
+ // Print a unique identifier for this definition to PP. The identifier has
+ // the form <resource>:<insn uid>.
+ void print_identifier (pretty_printer *pp) const;
+
+protected:
+ def_info (insn_info *insn, resource_info resource, access_kind kind);
+
+private:
+ // In order to preserve memory, the list head only points to the first
+ // definition in the list. The "prev" entry of the first definition
+ // then points to the last definition.
+ using last_def_or_prev_def = pointer_mux<def_info>;
+
+ // For similar memory-saving reasons, if we want to create a splay tree
+ // of accesses to a resource, we hang the root off the "next" entry of
+ // the last definition in the list.
+ using splay_root_or_next_def = pointer_mux<def_node, def_info>;
+
+ void set_insn (insn_info *insn) { m_insn = insn; }
+
+ def_info *last_def () const;
+ def_node *splay_root () const;
+
+ void record_reference (rtx_obj_reference, bool);
+ void copy_prev_from (def_info *);
+ void copy_next_from (def_info *);
+ void set_last_def (def_info *);
+ void set_prev_def (def_info *);
+ void set_splay_root (def_node *);
+ void set_next_def (def_info *);
+ void clear_def_links ();
+ bool has_def_links ();
+
+ // The location of the definition.
+ insn_info *m_insn;
+
+ // The overloaded "prev" and "next" pointers, as described above.
+ last_def_or_prev_def m_last_def_or_prev_def;
+ splay_root_or_next_def m_splay_root_or_next_def;
+};
+
+// Iterators for lists of definitions.
+using def_iterator = list_iterator<def_info, &def_info::next_def>;
+using reverse_def_iterator = list_iterator<def_info, &def_info::prev_def>;
+
+// A view of an access_array in which every entry is known to be a
+// def_info.
+using def_array = const_derived_container<def_info *, access_array>;
+
+// A def_info that sets the resource to a value that is both
+// unknown and not useful. This is only ever used for registers,
+// since memory always has some useful contents.
+//
+// Neighboring clobbers are grouped into clobber_groups, so that it's
+// possibly to skip over all neighboring clobbers in a single step.
+class clobber_info : public def_info
+{
+ // Overall size: 8 LP64 words
+ friend class default_splay_tree_accessors<clobber_info *>;
+ friend class default_splay_tree_accessors_with_parent<clobber_info *>;
+ friend class function_info;
+ friend class clobber_group;
+
+public:
+ using splay_tree = default_rootless_splay_tree<clobber_info *>;
+
+ // Return true if the clobber belongs to a clobber_group, false if it
+ // is standalone.
+ bool is_in_group () const { return m_group; }
+
+ // Return the group that the clobber is in, or null if none.
+ //
+ // Complexity: amortized O(1), worst case O(N), where N is the number
+ // of clobbers in the containing clobber_group.
+ clobber_group *group () const;
+
+ // Print a description of the clobber to PP under the control of
+ // PP_ACCESS_* flags FLAGS.
+ void print (pretty_printer *pp,
+ unsigned int flags = PP_ACCESS_DEFAULT) const;
+
+private:
+ // Once normal call clobbers are taken out of the equation by
+ // insn_call_clobbers_notes, clobber_infos account for roughly 6% of all
+ // def_infos, with the rest being set_infos. clobber_infos are
+ // therefore much less size-sensitive than set_infos are.
+ //
+ // As noted above, we want to group neighboring clobbers together so that
+ // we can quickly step over them to find the previous or next "real" set.
+ // We also want to be able to split the group in sublinear time,
+ // for example when inserting a set/use pair between two clobbers
+ // in a group.
+ //
+ // So:
+ //
+ // - Clobbers need to have ready access to their group, so that we
+ // can cheaply skip over the whole group. This means that they
+ // need a group pointer.
+ //
+ // - We need to be able to update the group pointer lazily, so that
+ // the cost of updating it is counted against accesses to the clobbers
+ // that need updating.
+ //
+ // We also want to be able to insert clobbers into a group in
+ // amortized logarithmic time.
+ //
+ // We therefore use a splay tree to represent the clobbers in a group,
+ // with the nodes storing their parent node. It is then possible to
+ // perform splay operations without first getting hold of the root.
+ // The root of the splay tree always has a valid, up-to-date group,
+ // so lazy group updates can get the new group from there.
+ //
+ // Roughly 90% of clobbers have a neighboring definition in the same
+ // block, which means that most need to be stored in a splay tree.
+ // We therefore store the splay tree fields directly in the clobber_info
+ // rather than using a separate node object.
+
+ clobber_info (insn_info *, unsigned int);
+
+ void set_group (clobber_group *group) { m_group = group; }
+ void update_group (clobber_group *);
+ clobber_group *recompute_group ();
+
+ // The child and parent nodes in the splay tree.
+ clobber_info *m_children[2];
+ clobber_info *m_parent;
+
+ // The last known value of group (), which might now be out of date.
+ clobber_group *m_group;
+};
+
+using clobber_tree = clobber_info::splay_tree::rooted;
+
+// A def_info that sets the resource to a useful value. It records
+// all uses of the value in a linked list. The list is partitioned
+// into three sections:
+//
+// (1) all uses by nondebug instructions, in reverse postorder, followed by
+// (2) all uses by debug instructions, in reverse postorder, followed by
+// (3) all uses by phi nodes, in no particular order.
+//
+// There are two cases:
+//
+// - If we know in advance that there is a single definition of a resource R
+// and therefore decide not to use phi nodes for R, (1) and (2) contain
+// all uses of R, regardless of which blocks contain the uses. (3) is
+// then empty.
+//
+// - Otherwise, (1) only contains uses in the same extended basic block
+// as the definition, and it is terminated by a use that marks the end
+// of the live range for the EBB. In other words, if the resource dies
+// in the EBB, the last use by a nondebug instruction marks the point at
+// which it dies, otherwise there is a fake live-out use at the end of
+// the EBB.
+//
+// Since debug instructions should not affect codegen, they opportunisticly
+// attach to the same set_info as nondebug instructions where possible.
+// If a nondebug instruction would attach to a degenerate phi and if no
+// such phi exists, debug instructions instead attach to whichever set_info
+// provides the value, regardless of where that set_info is.
+class set_info : public def_info
+{
+ // Overall size: 6 LP64 words.
+ friend class function_info;
+ using use_splay_tree = splay_tree<use_info *>;
+
+public:
+ // Return the first and last uses of the set, or null if the list is empty.
+ // See the comment above for details about the order.
+ use_info *first_use () const { return m_first_use; }
+ use_info *last_use () const;
+
+ // Return the first and last uses of the set by nondebug instructions,
+ // or null if there are no such uses. The uses are in reverse postorder.
+ use_info *first_nondebug_insn_use () const;
+ use_info *last_nondebug_insn_use () const;
+
+ // Return the first use of the set by any kind of instruction, or null
+ // if there are no such uses. The uses are in the order described above.
+ use_info *first_any_insn_use () const;
+
+ // Return the last use of the set by phi inputs, or null if there are no
+ // such uses. The phi input uses are in no particular order.
+ use_info *last_phi_use () const;
+
+ // Return true if at least one nondebug instruction or phi node uses
+ // the set's result. This is equivalent to testing whether the set is
+ // ever live.
+ bool has_nondebug_uses () const;
+
+ // Return true if anything uses the set's result. Note that this includes
+ // uses by debug instructions, so it should not be used for optimization
+ // decisions.
+ bool has_any_uses () const { return m_first_use; }
+
+ // Return true if at least one nondebug instruction uses the set's result.
+ bool has_nondebug_insn_uses () const;
+
+ // Return true if at least one phi node uses the set's result.
+ bool has_phi_uses () const;
+
+ // Return true if the set and its uses are contained within a single
+ // extended basic block, with the set coming first. This implies
+ // that all uses are by instructions rather than phi nodes.
+ bool is_local_to_ebb () const;
+
+ // List all the uses of the set, in the order described above.
+ iterator_range<use_iterator> all_uses () const;
+
+ // Return uses () in reverse order.
+ iterator_range<reverse_use_iterator> reverse_all_uses () const;
+
+ // List the uses of the set by nondebug instructions, in reverse postorder.
+ iterator_range<nondebug_insn_use_iterator> nondebug_insn_uses () const;
+
+ // Return nondebug_insn_uses () in reverse order.
+ iterator_range<reverse_use_iterator> reverse_nondebug_insn_uses () const;
+
+ // List the uses of the set by any kind of instruction. The list follows
+ // the order described above.
+ iterator_range<any_insn_use_iterator> all_insn_uses () const;
+
+ // List the uses of the set by phi nodes, in no particular order.
+ // There is therefore no reversed equivalent of this list.
+ iterator_range<phi_use_iterator> phi_uses () const;
+
+ // Print a description of the set to PP under the control of
+ // PP_ACCESS_* flags FLAGS.
+ void print (pretty_printer *pp,
+ unsigned int flags = PP_ACCESS_DEFAULT) const;
+
+protected:
+ set_info (insn_info *, resource_info, access_kind);
+
+ // Print information about uses () to PP, continuing information printed
+ // about the set itself.
+ void print_uses_on_new_lines (pretty_printer *pp) const;
+
+private:
+ // Sets (including phis) account for about 94% of all definitions
+
+ set_info (insn_info *, resource_info);
+
+ void set_first_use (use_info *);
+
+ // The first use in the list.
+ use_info *m_first_use;
+
+ // The root of a splay tree of all uses, built lazily when we first
+ // think it's needed.
+ use_splay_tree m_use_tree;
+};
+
+// A set_info for an on-the-side phi node. The phi node is attached
+// to an extended basic block EBB and has one input for each incoming edge.
+// The inputs are represented as an array of use_infos, with input I
+// corresponding to EDGE_PRED (EBB->first_bb ()->cfg_bb (), I).
+//
+// Each phi node has a densely-allocated unique identifier, which is intended
+// to be suitable for bitmaps or sbitmaps.
+//
+// All the phi nodes in an extended basic block are chained together
+// into a linked list. The list has no particular order.
+class phi_info : public set_info
+{
+ // Overall size: 8 LP64 words
+ friend class function_info;
+
+public:
+ // Return the previous and next phi nodes in the extended basic block's list,
+ // or null if none.
+ phi_info *prev_phi () const { return m_prev_phi; }
+ phi_info *next_phi () const { return m_next_phi; }
+
+ // Return the number of phi inputs. This is 1 for degenerate phis,
+ // otherwise it is equal to the number of incoming edges.
+ unsigned int num_inputs () const { return m_num_inputs; }
+
+ // Return true if the phi node is degenerate, i.e. if it has only a
+ // single input.
+ bool is_degenerate () const { return m_num_inputs == 1; }
+
+ // Return the phi node's unique identifier.
+ unsigned int uid () const { return m_uid; }
+
+ // Return the array of inputs. For degenerate phi nodes, this array contains
+ // a single element, otherwise it has one input per incoming edge,
+ // with element E corresponding to incoming edge E.
+ use_array inputs () const;
+
+ // Return the use_info that describes the phi input for incoming edge E.
+ use_info *input_use (unsigned int e) const;
+
+ // Return the value of resource () on incoming edge E, or null if the
+ // value is completely undefined for that edge.
+ set_info *input_value (unsigned int e) const;
+
+ // Print a description of the phi node to PP under the control of
+ // PP_ACCESS_* flags FLAGS.
+ void print (pretty_printer *pp,
+ unsigned int flags = PP_ACCESS_DEFAULT) const;
+
+private:
+ phi_info (insn_info *insn, resource_info resource, unsigned int uid);
+
+ void make_degenerate (use_info *);
+ void set_inputs (use_array inputs);
+ void set_prev_phi (phi_info *prev_phi) { m_prev_phi = prev_phi; }
+ void set_next_phi (phi_info *next_phi) { m_next_phi = next_phi; }
+ void clear_phi_links () { m_prev_phi = m_next_phi = nullptr; }
+ bool has_phi_links () { return m_prev_phi || m_next_phi; }
+
+ // The values returned by the accessors above.
+ unsigned int m_uid;
+ unsigned int m_num_inputs;
+ union
+ {
+ access_info *const *m_inputs;
+ access_info *m_single_input;
+ };
+ phi_info *m_prev_phi;
+ phi_info *m_next_phi;
+};
+
+// An iterator for lists of phi nodes.
+using phi_iterator = list_iterator<phi_info, &phi_info::next_phi>;
+
+// One node in a splay tree of definitions. This base class represents
+// a single def_info, but it is structured to allow derived classes
+// to add a range.
+class def_node
+{
+ // Size: 3 LP64 words.
+ friend class function_info;
+ friend class default_splay_tree_accessors<def_node *>;
+
+public:
+ // Return the first definition that the node represents.
+ def_info *first_def () const;
+
+ // Return which type of access first_def () is.
+ bool contains_clobber () const { return m_clobber_or_set.is_first (); }
+ bool contains_set () const { return m_clobber_or_set.is_second (); }
+
+protected:
+ // More nodes are clobbers rather than sets, so put clobbers first.
+ // Neither choice can be null.
+ using clobber_or_set = pointer_mux<clobber_info, set_info>;
+
+ // Construct a node that represents FIRST_DEF (and possibly later
+ // definitions too, if called from a derived class).
+ def_node (clobber_or_set first_def);
+
+ // The first definition in the node.
+ clobber_or_set m_clobber_or_set;
+
+private:
+ // The splay tree child nodes.
+ def_node *m_children[2];
+};
+
+// One node in a splay tree of def_infos, representing a single set_info.
+class set_node : public def_node
+{
+ // Overall size: 3 LP64 words.
+ friend class function_info;
+
+public:
+ // Return the set that the node contains.
+ set_info *set () const { return m_clobber_or_set.known_second (); }
+
+ // Print a description of the node to PP.
+ void print (pretty_printer *pp) const;
+
+private:
+ // Construct a node for SET.
+ set_node (set_info *set) : def_node (set) {}
+};
+
+// One node in a splay tree of def_infos. This class represents
+// a list of contiguous clobber_infos, in execution order.
+class clobber_group : public def_node
+{
+ // Overall size: 5 LP64 words.
+ friend class function_info;
+
+public:
+ // Return the first and last clobbers in the group. The results are
+ // always nonnull.
+ clobber_info *first_clobber () const;
+ clobber_info *last_clobber () const { return m_last_clobber; }
+
+ // Return true if this group has been replaced by new clobber_groups.
+ bool has_been_superceded () const { return !m_last_clobber; }
+
+ // Return a list of the clobbers in the group, in execution order.
+ iterator_range<def_iterator> clobbers () const;
+
+ // Print a description of the group to PP.
+ void print (pretty_printer *pp) const;
+
+private:
+ clobber_group (clobber_info *clobber);
+
+ // Set the values of first_clobber () and last_clobber ().
+ void set_first_clobber (clobber_info *c) { m_clobber_or_set = c; }
+ void set_last_clobber (clobber_info *c) { m_last_clobber = c; }
+
+ // The value returned by last_clobber ().
+ clobber_info *m_last_clobber;
+
+ // A splay tree that contains all the clobbers in the group.
+ // The root of the splay tree always has an up-to-date group
+ // pointer, but the other clobbers in the tree might not.
+ clobber_tree m_clobber_tree;
+};
+
+// A splay tree in which one node represents a standalone set_info or a
+// range of consecutive clobber_infos. The nodes follow execution order
+// and maintain the invariant that no two groups of clobber_infos appear
+// next to each other (instead, the groups are merged).
+using def_splay_tree = default_splay_tree<def_node *>;
+
+// This type represents a choice between:
+//
+// (1) a single definition of a resource
+// (2) a node in a def_splay_tree that represents either a single
+// set or a group of clobbers.
+class def_mux : public pointer_mux<def_info, def_node>
+{
+ using parent = pointer_mux<def_info, def_node>;
+
+ // Provide the same constructors as the pointer_mux.
+ using parent::parent;
+
+public:
+ // Return the first definition associated with this mux. If the mux holds
+ // a single definition, the result is that definition. If the mux holds
+ // a clobber_group, the result is the first clobber in the group.
+ def_info *first_def () const;
+
+ // Return the last definition associated with this mux. If the mux holds
+ // a single definition, the result is that definition. If the mux holds
+ // a clobber_group, the result is the last clobber in the group.
+ def_info *last_def () const;
+
+ // If the pointer represents a set_info, return that set_info,
+ // otherwise return null.
+ set_info *set () const;
+};
+
+// This class represents the result of looking up the definition of a
+// resource at a particular point, here referred to as point P.
+// There are four states:
+//
+// - MUX is null if there were no definitions to search.
+//
+// - Otherwise, COMPARISON is 0 if we found a definition at P or a
+// clobber_group that spans P. MUX then contains this definition
+// or clobber_group.
+//
+// - Otherwise, COMPARISON is less than 0 if we found the definition
+// that precedes P or the group of clobbers that precedes P. MUX then
+// contains this definition or clobber_group.
+//
+// - Otherwise, COMPARISON is greater than zero and we found the
+// definition that follows P, or the group of clobbers that follows P.
+// MUX then contains this definition or clobber_group.
+class def_lookup
+{
+public:
+ // If we found a clobber_group that spans P, return the definition
+ // that precedes the start of the group, or null if none.
+ //
+ // Otherwise, return the last definition that occurs before P,
+ // or null if none.
+ def_info *prev_def () const;
+
+ // If we found a clobber_group that spans P, return the definition
+ // that follows the end of the group, or null if none.
+ //
+ // Otherwise, return the first definition that occurs after P,
+ // or null if none.
+ def_info *next_def () const;
+
+ // If we found a set_info at P, return that set_info, otherwise return null.
+ set_info *matching_set () const;
+
+ // If we found a set_info at P, return that set_info, otherwise return
+ // prev_def ().
+ def_info *matching_or_prev_def () const;
+
+ // If we found a set_info at P, return that set_info, otherwise return
+ // next_def ().
+ def_info *matching_or_next_def () const;
+
+ def_mux mux;
+ int comparison;
+};
+
+void pp_resource (pretty_printer *, resource_info);
+void pp_access (pretty_printer *, const access_info *,
+ unsigned int flags = PP_ACCESS_DEFAULT);
+void pp_accesses (pretty_printer *, access_array,
+ unsigned int flags = PP_ACCESS_DEFAULT);
+void pp_def_node (pretty_printer *, const def_node *);
+void pp_def_mux (pretty_printer *, def_mux);
+void pp_def_lookup (pretty_printer *, def_lookup);
+
+}
+
+void dump (FILE *, rtl_ssa::resource_info);
+void dump (FILE *, const rtl_ssa::access_info *,
+ unsigned int flags = rtl_ssa::PP_ACCESS_DEFAULT);
+void dump (FILE *, rtl_ssa::access_array,
+ unsigned int flags = rtl_ssa::PP_ACCESS_DEFAULT);
+void dump (FILE *, const rtl_ssa::def_node *);
+void dump (FILE *, rtl_ssa::def_mux);
+void dump (FILE *, rtl_ssa::def_lookup);
+
+void DEBUG_FUNCTION debug (const rtl_ssa::resource_info *);
+void DEBUG_FUNCTION debug (const rtl_ssa::access_info *);
+void DEBUG_FUNCTION debug (const rtl_ssa::access_array);
+void DEBUG_FUNCTION debug (const rtl_ssa::def_node *);
+void DEBUG_FUNCTION debug (const rtl_ssa::def_mux &);
+void DEBUG_FUNCTION debug (const rtl_ssa::def_lookup &);
--- /dev/null
+// Implementation of basic-block-related functions for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#include "rtl-ssa.h"
+#include "rtl-ssa/internals.inl"
+#include "cfganal.h"
+#include "cfgrtl.h"
+#include "predict.h"
+
+using namespace rtl_ssa;
+
+// See the comment above the declaration.
+void
+bb_info::print_identifier (pretty_printer *pp) const
+{
+ char tmp[3 * sizeof (index ()) + 3];
+ snprintf (tmp, sizeof (tmp), "bb%d", index ());
+ pp_string (pp, tmp);
+ if (ebb_info *ebb = this->ebb ())
+ {
+ pp_space (pp);
+ pp_left_bracket (pp);
+ ebb->print_identifier (pp);
+ pp_right_bracket (pp);
+ }
+}
+
+// See the comment above the declaration.
+void
+bb_info::print_full (pretty_printer *pp) const
+{
+ pp_string (pp, "basic block ");
+ print_identifier (pp);
+ pp_colon (pp);
+
+ auto print_insn = [pp](const char *header, const insn_info *insn)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, header);
+ pp_newline_and_indent (pp, 2);
+ if (insn)
+ pp_insn (pp, insn);
+ else
+ pp_string (pp, "<uninitialized>");
+ pp_indentation (pp) -= 4;
+ };
+
+ print_insn ("head:", head_insn ());
+
+ pp_newline (pp);
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "contents:");
+ if (!head_insn ())
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "<uninitialized>");
+ pp_indentation (pp) -= 2;
+ }
+ else if (auto insns = real_insns ())
+ {
+ bool is_first = true;
+ for (const insn_info *insn : insns)
+ {
+ if (is_first)
+ is_first = false;
+ else
+ pp_newline (pp);
+ pp_newline_and_indent (pp, 2);
+ pp_insn (pp, insn);
+ pp_indentation (pp) -= 2;
+ }
+ }
+ else
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "none");
+ pp_indentation (pp) -= 2;
+ }
+ pp_indentation (pp) -= 2;
+
+ pp_newline (pp);
+ print_insn ("end:", end_insn ());
+}
+
+// See the comment above the declaration.
+void
+ebb_call_clobbers_info::print_summary (pretty_printer *pp) const
+{
+ pp_string (pp, "call clobbers for ABI ");
+ if (m_abi)
+ pp_decimal_int (pp, m_abi->id ());
+ else
+ pp_string (pp, "<null>");
+}
+
+// See the comment above the declaration.
+void
+ebb_call_clobbers_info::print_full (pretty_printer *pp) const
+{
+ print_summary (pp);
+ pp_colon (pp);
+ pp_newline_and_indent (pp, 2);
+ auto print_node = [](pretty_printer *pp,
+ const insn_call_clobbers_note *note)
+ {
+ if (insn_info *insn = note->insn ())
+ insn->print_identifier_and_location (pp);
+ else
+ pp_string (pp, "<null>");
+ };
+ print (pp, root (), print_node);
+ pp_indentation (pp) -= 2;
+}
+
+// See the comment above the declaration.
+void
+ebb_info::print_identifier (pretty_printer *pp) const
+{
+ // first_bb is populated by the constructor and so should always
+ // be nonnull.
+ auto index = first_bb ()->index ();
+ char tmp[3 * sizeof (index) + 4];
+ snprintf (tmp, sizeof (tmp), "ebb%d", index);
+ pp_string (pp, tmp);
+}
+
+// See the comment above the declaration.
+void
+ebb_info::print_full (pretty_printer *pp) const
+{
+ pp_string (pp, "extended basic block ");
+ print_identifier (pp);
+ pp_colon (pp);
+
+ pp_newline_and_indent (pp, 2);
+ if (insn_info *phi_insn = this->phi_insn ())
+ {
+ phi_insn->print_identifier_and_location (pp);
+ pp_colon (pp);
+ if (auto phis = this->phis ())
+ {
+ bool is_first = true;
+ for (const phi_info *phi : phis)
+ {
+ if (is_first)
+ is_first = false;
+ else
+ pp_newline (pp);
+ pp_newline_and_indent (pp, 2);
+ pp_access (pp, phi, PP_ACCESS_SETTER);
+ pp_indentation (pp) -= 2;
+ }
+ }
+ else
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "no phi nodes");
+ pp_indentation (pp) -= 2;
+ }
+ }
+ else
+ pp_string (pp, "no phi insn");
+ pp_indentation (pp) -= 2;
+
+ for (const bb_info *bb : bbs ())
+ {
+ pp_newline (pp);
+ pp_newline_and_indent (pp, 2);
+ pp_bb (pp, bb);
+ pp_indentation (pp) -= 2;
+ }
+
+ for (ebb_call_clobbers_info *ecc : call_clobbers ())
+ {
+ pp_newline (pp);
+ pp_newline_and_indent (pp, 2);
+ pp_ebb_call_clobbers (pp, ecc);
+ pp_indentation (pp) -= 2;
+ }
+}
+
+// Add a dummy use to mark that DEF is live out of BB's EBB at the end of BB.
+void
+function_info::add_live_out_use (bb_info *bb, set_info *def)
+{
+ // There is nothing to do if DEF is an artificial definition at the end
+ // of BB. In that case the definitino is rooted at the end of the block
+ // and we wouldn't gain anything by inserting a use immediately after it.
+ // If we did want to insert a use, we'd need to associate it with a new
+ // instruction that comes after bb->end_insn ().
+ if (def->insn () == bb->end_insn ())
+ return;
+
+ // If the end of the block already has an artificial use, that use
+ // acts to make DEF live at the appropriate point.
+ unsigned int regno = def->regno ();
+ if (find_access (bb->end_insn ()->uses (), regno))
+ return;
+
+ // Currently there is no need to maintain a backward link from the end
+ // instruction to the list of live-out uses. Such a list would be
+ // expensive to update if it was represented using the usual insn_info
+ // access arrays.
+ use_info *use = allocate<use_info> (bb->end_insn (), def->resource (), def);
+ use->set_is_live_out_use (true);
+ add_use (use);
+}
+
+// Return true if all nondebug uses of DEF are live-out uses.
+static bool
+all_uses_are_live_out_uses (set_info *def)
+{
+ for (use_info *use : def->all_uses ())
+ if (!use->is_in_debug_insn () && !use->is_live_out_use ())
+ return false;
+ return true;
+}
+
+// SET, if nonnull, is a definition of something that is live out from BB.
+// Return the live-out value itself.
+set_info *
+function_info::live_out_value (bb_info *bb, set_info *set)
+{
+ // Degenerate phis only exist to provide a definition for uses in the
+ // same EBB. The live-out value is the same as the live-in value.
+ if (auto *phi = safe_dyn_cast<phi_info *> (set))
+ if (phi->is_degenerate ())
+ {
+ set = phi->input_value (0);
+
+ // Remove the phi if it turned out to be useless. This is
+ // mainly useful for memory, because we don't know ahead of time
+ // whether a block will use memory or not.
+ if (bb == bb->ebb ()->last_bb () && all_uses_are_live_out_uses (phi))
+ replace_phi (phi, set);
+ }
+
+ return set;
+}
+
+// Add PHI to EBB and enter it into the function's hash table.
+void
+function_info::append_phi (ebb_info *ebb, phi_info *phi)
+{
+ phi_info *first_phi = ebb->first_phi ();
+ if (first_phi)
+ first_phi->set_prev_phi (phi);
+ phi->set_next_phi (first_phi);
+ ebb->set_first_phi (phi);
+ add_def (phi);
+}
+
+// Remove PHI from its current position in the SSA graph.
+void
+function_info::remove_phi (phi_info *phi)
+{
+ phi_info *next = phi->next_phi ();
+ phi_info *prev = phi->prev_phi ();
+
+ if (next)
+ next->set_prev_phi (prev);
+
+ if (prev)
+ prev->set_next_phi (next);
+ else
+ phi->ebb ()->set_first_phi (next);
+
+ remove_def (phi);
+ phi->clear_phi_links ();
+}
+
+// Remove PHI from the SSA graph and free its memory.
+void
+function_info::delete_phi (phi_info *phi)
+{
+ gcc_assert (!phi->has_any_uses ());
+
+ // Remove the inputs to the phi.
+ for (use_info *input : phi->inputs ())
+ remove_use (input);
+
+ remove_phi (phi);
+
+ phi->set_next_phi (m_free_phis);
+ m_free_phis = phi;
+}
+
+// If possible, remove PHI and replace all uses with NEW_VALUE.
+void
+function_info::replace_phi (phi_info *phi, set_info *new_value)
+{
+ auto update_use = [&](use_info *use)
+ {
+ remove_use (use);
+ use->set_def (new_value);
+ add_use (use);
+ };
+
+ if (new_value)
+ for (use_info *use : phi->nondebug_insn_uses ())
+ if (!use->is_live_out_use ())
+ {
+ // We need to keep the phi around for its local uses.
+ // Turn it into a degenerate phi, if it isn't already.
+ use_info *use = phi->input_use (0);
+ if (use->def () != new_value)
+ update_use (use);
+
+ if (phi->is_degenerate ())
+ return;
+
+ phi->make_degenerate (use);
+
+ // Redirect all phi users to NEW_VALUE.
+ while (use_info *phi_use = phi->last_phi_use ())
+ update_use (phi_use);
+
+ return;
+ }
+
+ // Replace the uses. We can discard uses that only existed for the
+ // sake of marking live-out values, since the resource is now transparent
+ // in the phi's EBB.
+ while (use_info *use = phi->last_use ())
+ if (use->is_live_out_use ())
+ remove_use (use);
+ else
+ update_use (use);
+
+ delete_phi (phi);
+}
+
+// Create and return a phi node for EBB. RESOURCE is the resource that
+// the phi node sets (and thus that all the inputs set too). NUM_INPUTS
+// is the number of inputs, which is 1 for a degenerate phi. INPUTS[I]
+// is a set_info that gives the value of input I, or null if the value
+// is either unknown or uninitialized. If NUM_INPUTS > 1, this array
+// is allocated on the main obstack and can be reused for the use array.
+//
+// Add the created phi node to its basic block and enter it into the
+// function's hash table.
+phi_info *
+function_info::create_phi (ebb_info *ebb, resource_info resource,
+ access_info **inputs, unsigned int num_inputs)
+{
+ phi_info *phi = m_free_phis;
+ if (phi)
+ {
+ m_free_phis = phi->next_phi ();
+ *phi = phi_info (ebb->phi_insn (), resource, phi->uid ());
+ }
+ else
+ {
+ phi = allocate<phi_info> (ebb->phi_insn (), resource, m_next_phi_uid);
+ m_next_phi_uid += 1;
+ }
+
+ // Convert the array of set_infos into an array of use_infos. Also work
+ // out what mode the phi should have.
+ machine_mode new_mode = resource.mode;
+ for (unsigned int i = 0; i < num_inputs; ++i)
+ {
+ auto *input = safe_as_a<set_info *> (inputs[i]);
+ auto *use = allocate<use_info> (phi, resource, input);
+ add_use (use);
+ inputs[i] = use;
+ if (input)
+ new_mode = combine_modes (new_mode, input->mode ());
+ }
+
+ phi->set_inputs (use_array (inputs, num_inputs));
+ phi->set_mode (new_mode);
+
+ append_phi (ebb, phi);
+
+ return phi;
+}
+
+// Create and return a degenerate phi for EBB whose input comes from DEF.
+// This is used in cases where DEF is known to be available on entry to
+// EBB but was not previously used within it. If DEF is for a register,
+// there are two cases:
+//
+// (1) DEF was already live on entry to EBB but was previously transparent
+// within it.
+//
+// (2) DEF was not previously live on entry to EBB and is being made live
+// by this update.
+//
+// At the moment, this function only handles the case in which EBB has a
+// single predecessor block and DEF is defined in that block's EBB.
+phi_info *
+function_info::create_degenerate_phi (ebb_info *ebb, set_info *def)
+{
+ access_info *input = def;
+ phi_info *phi = create_phi (ebb, def->resource (), &input, 1);
+ if (def->is_reg ())
+ {
+ unsigned int regno = def->regno ();
+
+ // Find the single predecessor mentioned above.
+ basic_block pred_cfg_bb = single_pred (ebb->first_bb ()->cfg_bb ());
+ bb_info *pred_bb = this->bb (pred_cfg_bb);
+
+ if (!bitmap_set_bit (DF_LR_IN (ebb->first_bb ()->cfg_bb ()), regno))
+ {
+ // The register was not previously live on entry to EBB and
+ // might not have been live on exit from PRED_BB either.
+ if (bitmap_set_bit (DF_LR_OUT (pred_cfg_bb), regno))
+ add_live_out_use (pred_bb, def);
+ }
+ else
+ {
+ // The register was previously live in to EBB. Add live-out uses
+ // at the appropriate points.
+ insn_info *next_insn = nullptr;
+ if (def_info *next_def = phi->next_def ())
+ next_insn = next_def->insn ();
+ for (bb_info *bb : ebb->bbs ())
+ {
+ if ((next_insn && *next_insn <= *bb->end_insn ())
+ || !bitmap_bit_p (DF_LR_OUT (bb->cfg_bb ()), regno))
+ break;
+ add_live_out_use (bb, def);
+ }
+ }
+ }
+ return phi;
+}
+
+// Create a bb_info for CFG_BB, given that no such structure currently exists.
+bb_info *
+function_info::create_bb_info (basic_block cfg_bb)
+{
+ bb_info *bb = allocate<bb_info> (cfg_bb);
+ gcc_checking_assert (!m_bbs[cfg_bb->index]);
+ m_bbs[cfg_bb->index] = bb;
+ return bb;
+}
+
+// Add BB to the end of the list of blocks.
+void
+function_info::append_bb (bb_info *bb)
+{
+ if (m_last_bb)
+ m_last_bb->set_next_bb (bb);
+ else
+ m_first_bb = bb;
+ bb->set_prev_bb (m_last_bb);
+ m_last_bb = bb;
+}
+
+// Called while building SSA form using BI, with BI.current_bb being
+// the entry block.
+//
+// Create the entry block instructions and their definitions. The only
+// useful instruction is the end instruction, which carries definitions
+// for the values that are live on entry to the function. However, it
+// seems simpler to create a head instruction too, rather than force all
+// users of the block information to treat the entry block as a special case.
+void
+function_info::add_entry_block_defs (build_info &bi)
+{
+ bb_info *bb = bi.current_bb;
+ basic_block cfg_bb = bi.current_bb->cfg_bb ();
+ auto *lr_info = DF_LR_BB_INFO (cfg_bb);
+
+ bb->set_head_insn (append_artificial_insn (bb));
+ insn_info *insn = append_artificial_insn (bb);
+ bb->set_end_insn (insn);
+
+ start_insn_accesses ();
+
+ // Using LR to derive the liveness information means that we create an
+ // entry block definition for upwards exposed registers. These registers
+ // are sometimes genuinely uninitialized. However, some targets also
+ // create a pseudo PIC base register and only initialize it later.
+ // Handling that case correctly seems more important than optimizing
+ // uninitialized uses.
+ unsigned int regno;
+ bitmap_iterator in_bi;
+ EXECUTE_IF_SET_IN_BITMAP (&lr_info->out, 0, regno, in_bi)
+ {
+ auto *set = allocate<set_info> (insn, full_register (regno));
+ append_def (set);
+ m_temp_defs.safe_push (set);
+ bi.record_reg_def (regno, set);
+ }
+
+ // Create a definition that reflects the state of memory on entry to
+ // the function.
+ auto *set = allocate<set_info> (insn, memory);
+ append_def (set);
+ m_temp_defs.safe_push (set);
+ bi.record_mem_def (set);
+
+ finish_insn_accesses (insn);
+}
+
+// Called while building SSA form using BI. Create phi nodes for the
+// current EBB, leaving backedge inputs to be filled in later. Set
+// bi.last_access to the values that are live on entry to the EBB,
+// regardless of whether or not they are phi nodes.
+void
+function_info::add_phi_nodes (build_info &bi)
+{
+ ebb_info *ebb = bi.current_ebb;
+ basic_block cfg_bb = ebb->first_bb ()->cfg_bb ();
+ auto *lr_info = DF_LR_BB_INFO (cfg_bb);
+
+ // Get a local cache of the predecessor blocks' live out values.
+ unsigned int num_preds = EDGE_COUNT (cfg_bb->preds);
+ auto_vec<const bb_live_out_info *, 16> pred_live_outs (num_preds);
+ bool has_backedge = false;
+ bool has_eh_edge = false;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, cfg_bb->preds)
+ {
+ bb_info *pred_bb = this->bb (e->src);
+ const bb_live_out_info *live_out = &bi.bb_live_out[e->src->index];
+
+ // In LR (but not LIVE), the registers live on entry to a block must
+ // normally be a subset of the registers live on exit from any
+ // given predecessor block. The exceptions are EH edges, which
+ // implicitly clobber all registers in eh_edge_abi.full_reg_clobbers ().
+ // Thus if a register is upwards exposed in an EH handler, it won't
+ // be propagated across the EH edge.
+ //
+ // Excluding that special case, all registers live on entry to
+ // EBB are also live on exit from PRED_BB and were (or will be)
+ // considered when creating LIVE_OUT.
+ gcc_checking_assert ((e->flags & EDGE_EH)
+ || !bitmap_intersect_compl_p (&lr_info->in,
+ DF_LR_OUT (e->src)));
+ if (!pred_bb || !pred_bb->head_insn ())
+ {
+ has_backedge = true;
+ live_out = nullptr;
+ }
+ has_eh_edge |= (e->flags & EDGE_EH);
+ pred_live_outs.quick_push (live_out);
+ }
+
+ // PRED_REG_INDICES[I] tracks the index into PRED_LIVE_OUTS[I]->reg_values
+ // of the first unused entry.
+ auto_vec<unsigned int, 16> pred_reg_indices (num_preds);
+ pred_reg_indices.quick_grow_cleared (num_preds);
+
+ // Use this array to build up the list of inputs to each phi.
+ m_temp_defs.safe_grow (num_preds);
+
+ // Return true if the current phi is degenerate, i.e. if all its inputs
+ // are the same.
+ auto is_degenerate_phi = [&]()
+ {
+ if (has_backedge)
+ return false;
+
+ for (unsigned int i = 1; i < num_preds; ++i)
+ if (m_temp_defs[i] != m_temp_defs[0])
+ return false;
+
+ return true;
+ };
+
+ // Finish calculating the live-in value for RESOURCE. Decide how to
+ // represent the value of RESOURCE on entry to EBB and return its definition.
+ auto finish_phi = [&](resource_info resource) -> set_info *
+ {
+ access_info **inputs;
+ unsigned int num_inputs;
+ if (is_degenerate_phi ())
+ {
+ auto *input = safe_as_a<set_info *> (m_temp_defs[0]);
+ if (!input)
+ // The live-in value is completely uninitialized.
+ return nullptr;
+
+ unsigned int regno = input->regno ();
+ if (input->is_reg () && !bitmap_bit_p (bi.ebb_use, regno))
+ // The live-in value comes from a single source and there
+ // are no uses of it within the EBB itself. We therefore
+ // don't need a phi node.
+ return input;
+
+ // The live-in value comes from a single source and might be
+ // used by the EBB itself. Create a degenerate phi for it.
+ inputs = m_temp_defs.begin ();
+ num_inputs = 1;
+ }
+ else
+ {
+ obstack_grow (&m_obstack, m_temp_defs.address (),
+ num_preds * sizeof (access_info *));
+ inputs = static_cast<access_info **> (obstack_finish (&m_obstack));
+ num_inputs = num_preds;
+ }
+ return create_phi (ebb, resource, inputs, num_inputs);
+ };
+
+ if (bi.ebb_live_in_for_debug)
+ bitmap_clear (bi.ebb_live_in_for_debug);
+
+ // Get the definition of each live input register, excluding registers
+ // that are known to have a single definition that dominates all uses.
+ unsigned int regno;
+ bitmap_iterator in_bi;
+ EXECUTE_IF_AND_IN_BITMAP (&lr_info->in, m_potential_phi_regs,
+ 0, regno, in_bi)
+ {
+ for (unsigned int pred_i = 0; pred_i < num_preds; ++pred_i)
+ {
+ set_info *input = nullptr;
+ if (const bb_live_out_info *pred_live_out = pred_live_outs[pred_i])
+ {
+ // Skip over registers that aren't live on entry to this block.
+ unsigned int reg_i = pred_reg_indices[pred_i];
+ while (reg_i < pred_live_out->num_reg_values
+ && pred_live_out->reg_values[reg_i]->regno () < regno)
+ reg_i += 1;
+
+ // As we asserted above, REGNO is live out from the predecessor
+ // block, at least by the LR reckoning. But there are three
+ // cases:
+ //
+ // (1) The live-out value is well-defined (the normal case),
+ // with the definition coming either from the block itself
+ // or from a predecessor block. In this case reg_values
+ // has a set_info entry for the register.
+ //
+ // (2) The live-out value was not modified by the predecessor
+ // EBB and did not have a defined value on input to that
+ // EBB either. In this case reg_values has no entry for
+ // the register.
+ //
+ // (3) The live-out value was modified by the predecessor EBB,
+ // but the final modification was a clobber rather than
+ // a set. In this case reg_values again has no entry for
+ // the register.
+ //
+ // The phi input for (2) and (3) is undefined, which we
+ // represent as a null set_info.
+ if (reg_i < pred_live_out->num_reg_values)
+ {
+ set_info *set = pred_live_out->reg_values[reg_i];
+ if (set->regno () == regno)
+ {
+ input = set;
+ reg_i += 1;
+ }
+ }
+
+ // Fully call-clobbered values do not survive across EH edges.
+ // In particular, if a call that normally sets a result register
+ // throws an exception, the set of the result register should
+ // not be treated as live on entry to the EH handler.
+ if (has_eh_edge
+ && HARD_REGISTER_NUM_P (regno)
+ && eh_edge_abi.clobbers_full_reg_p (regno)
+ && (EDGE_PRED (cfg_bb, pred_i)->flags & EDGE_EH))
+ input = nullptr;
+
+ pred_reg_indices[pred_i] = reg_i;
+ }
+ m_temp_defs[pred_i] = input;
+ }
+ // Later code works out the correct mode of the phi. Use BLKmode
+ // as a placeholder for now.
+ bi.record_reg_def (regno, finish_phi ({ E_BLKmode, regno }));
+ if (bi.ebb_live_in_for_debug)
+ bitmap_set_bit (bi.ebb_live_in_for_debug, regno);
+ }
+
+ // Repeat the process above for memory.
+ for (unsigned int pred_i = 0; pred_i < num_preds; ++pred_i)
+ {
+ set_info *input = nullptr;
+ if (const bb_live_out_info *pred_live_out = pred_live_outs[pred_i])
+ input = pred_live_out->mem_value;
+ m_temp_defs[pred_i] = input;
+ }
+ bi.record_mem_def (finish_phi (memory));
+
+ m_temp_defs.truncate (0);
+}
+
+// Called while building SSA form using BI.
+//
+// If FLAGS is DF_REF_AT_TOP, create the head insn for BI.current_bb
+// and populate its uses and definitions. If FLAGS is 0, do the same
+// for the end insn.
+void
+function_info::add_artificial_accesses (build_info &bi, df_ref_flags flags)
+{
+ bb_info *bb = bi.current_bb;
+ basic_block cfg_bb = bb->cfg_bb ();
+ auto *lr_info = DF_LR_BB_INFO (cfg_bb);
+ df_ref ref;
+
+ insn_info *insn;
+ if (flags == DF_REF_AT_TOP)
+ {
+ if (cfg_bb->index == EXIT_BLOCK)
+ insn = append_artificial_insn (bb);
+ else
+ insn = append_artificial_insn (bb, bb_note (cfg_bb));
+ bb->set_head_insn (insn);
+ }
+ else
+ {
+ insn = append_artificial_insn (bb);
+ bb->set_end_insn (insn);
+ }
+
+ start_insn_accesses ();
+
+ FOR_EACH_ARTIFICIAL_USE (ref, cfg_bb->index)
+ if ((DF_REF_FLAGS (ref) & DF_REF_AT_TOP) == flags)
+ {
+ unsigned int regno = DF_REF_REGNO (ref);
+ machine_mode mode = GET_MODE (DF_REF_REAL_REG (ref));
+ resource_info resource { mode, regno };
+
+ // A definition must be available.
+ gcc_checking_assert (bitmap_bit_p (&lr_info->in, regno)
+ || (flags != DF_REF_AT_TOP
+ && bitmap_bit_p (&lr_info->def, regno)));
+ set_info *def = bi.current_reg_value (regno);
+ auto *use = allocate<use_info> (insn, resource, def);
+ add_use (use);
+ m_temp_uses.safe_push (use);
+ }
+
+ // Track the return value of memory by adding an artificial use of
+ // memory at the end of the exit block.
+ if (flags == 0 && cfg_bb->index == EXIT_BLOCK)
+ {
+ auto *use = allocate<use_info> (insn, memory, bi.current_mem_value ());
+ add_use (use);
+ m_temp_uses.safe_push (use);
+ }
+
+ FOR_EACH_ARTIFICIAL_DEF (ref, cfg_bb->index)
+ if ((DF_REF_FLAGS (ref) & DF_REF_AT_TOP) == flags)
+ {
+ unsigned int regno = DF_REF_REGNO (ref);
+ machine_mode mode = GET_MODE (DF_REF_REAL_REG (ref));
+ resource_info resource { mode, regno };
+
+ // If the value isn't used later in the block and isn't live
+ // on exit, we could instead represent the definition as a
+ // clobber_info. However, that case should be relatively
+ // rare and set_info is any case more compact than clobber_info.
+ set_info *def = allocate<set_info> (insn, resource);
+ append_def (def);
+ m_temp_defs.safe_push (def);
+ bi.record_reg_def (regno, def);
+ }
+
+ // Model the effect of a memory clobber on an incoming edge by adding
+ // a fake definition of memory at the start of the block. We don't need
+ // to add a use of the phi node because memory is implicitly always live.
+ if (flags == DF_REF_AT_TOP && has_abnormal_call_or_eh_pred_edge_p (cfg_bb))
+ {
+ set_info *def = allocate<set_info> (insn, memory);
+ append_def (def);
+ m_temp_defs.safe_push (def);
+ bi.record_mem_def (def);
+ }
+
+ finish_insn_accesses (insn);
+}
+
+// Called while building SSA form using BI. Create insn_infos for all
+// relevant instructions in BI.current_bb.
+void
+function_info::add_block_contents (build_info &bi)
+{
+ basic_block cfg_bb = bi.current_bb->cfg_bb ();
+ rtx_insn *insn;
+ FOR_BB_INSNS (cfg_bb, insn)
+ if (INSN_P (insn))
+ add_insn_to_block (bi, insn);
+}
+
+// Called while building SSA form using BI. Use BI.bb_live_out to record
+// the values that are live out from BI.current_bb.
+void
+function_info::record_block_live_out (build_info &bi)
+{
+ bb_info *bb = bi.current_bb;
+ ebb_info *ebb = bi.current_ebb;
+ basic_block cfg_bb = bb->cfg_bb ();
+ bb_live_out_info *live_out = &bi.bb_live_out[bb->index ()];
+ auto *lr_info = DF_LR_BB_INFO (bb->cfg_bb ());
+
+ // Calculate which subset of m_potential_phi_regs is live out from EBB
+ // at the end of BB.
+ auto_bitmap live_out_from_ebb;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, cfg_bb->succs)
+ {
+ bb_info *dest_bb = this->bb (e->dest);
+ if (!dest_bb || dest_bb->ebb () != ebb)
+ bitmap_ior_and_into (live_out_from_ebb, DF_LR_IN (e->dest),
+ m_potential_phi_regs);
+ }
+
+ // Record the live-out register values.
+ unsigned int regno;
+ bitmap_iterator out_bi;
+ EXECUTE_IF_AND_IN_BITMAP (&lr_info->out, m_potential_phi_regs,
+ 0, regno, out_bi)
+ if (set_info *value = live_out_value (bb, bi.current_reg_value (regno)))
+ {
+ if (value->ebb () == ebb && bitmap_bit_p (live_out_from_ebb, regno))
+ add_live_out_use (bb, value);
+ obstack_ptr_grow (&m_temp_obstack, value);
+ }
+
+ live_out->num_reg_values = (obstack_object_size (&m_temp_obstack)
+ / sizeof (set_info *));
+ auto *data = obstack_finish (&m_temp_obstack);
+ live_out->reg_values = static_cast<set_info **> (data);
+
+ live_out->mem_value = live_out_value (bb, bi.current_mem_value ());
+}
+
+// Called while building SSA form using BI. Check if BI.current_bb has
+// any outgoing backedges. If so, use the up-to-date contents of
+// BI.bb_live_out to populate the associated inputs of any phi nodes.
+void
+function_info::populate_backedge_phis (build_info &bi)
+{
+ bb_info *bb = bi.current_bb;
+ basic_block cfg_bb = bb->cfg_bb ();
+ const bb_live_out_info *live_out = &bi.bb_live_out[bb->index ()];
+
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, cfg_bb->succs)
+ {
+ // Check if this edge counts as a backedge in the current traversal.
+ bb_info *succ_bb = this->bb (e->dest);
+ if (!succ_bb || !succ_bb->head_insn ())
+ continue;
+
+ // Although the phis do not keep a defined order long-term, they are
+ // still in reverse regno order at this point. We can therefore use
+ // a merge operation on the phis and the live-out values.
+ unsigned int input_i = e->dest_idx;
+ int reg_i = live_out->num_reg_values - 1;
+ for (phi_info *phi : succ_bb->ebb ()->phis ())
+ {
+ set_info *input = nullptr;
+ if (phi->is_mem ())
+ input = live_out->mem_value;
+ else
+ {
+ // Skip over any intervening live-out values.
+ unsigned int regno = phi->regno ();
+ while (reg_i >= 0)
+ {
+ set_info *reg_value = live_out->reg_values[reg_i];
+ if (reg_value->regno () < regno)
+ break;
+ reg_i -= 1;
+ if (reg_value->regno () == regno)
+ {
+ input = reg_value;
+ break;
+ }
+ }
+ }
+ if (input)
+ {
+ use_info *use = phi->input_use (input_i);
+ gcc_assert (!use->def ());
+ use->set_def (input);
+ add_use (use);
+ }
+ }
+ }
+}
+
+// Return true if it would be better to continue an EBB across NEW_EDGE
+// rather than across OLD_EDGE, given that both edges are viable candidates.
+// This is not a total ordering.
+static bool
+better_ebb_edge_p (edge new_edge, edge old_edge)
+{
+ // Prefer the likeliest edge.
+ if (new_edge->probability.initialized_p ()
+ && old_edge->probability.initialized_p ()
+ && !(old_edge->probability == new_edge->probability))
+ return old_edge->probability < new_edge->probability;
+
+ // If both edges are equally likely, prefer a fallthru edge.
+ if (new_edge->flags & EDGE_FALLTHRU)
+ return true;
+ if (old_edge->flags & EDGE_FALLTHRU)
+ return false;
+
+ // Otherwise just stick with OLD_EDGE.
+ return false;
+}
+
+// Pick and return the next basic block in an EBB that currently ends with BB.
+// Return null if the EBB must end with BB.
+static basic_block
+choose_next_block_in_ebb (basic_block bb)
+{
+ // Although there's nothing in principle wrong with having an EBB that
+ // starts with the entry block and includes later blocks, there's not
+ // really much point either. Keeping the entry block separate means
+ // that uses of arguments consistently occur through phi nodes, rather
+ // than the arguments sometimes appearing to come from an EBB-local
+ // definition instead.
+ if (bb->index == ENTRY_BLOCK)
+ return nullptr;
+
+ bool optimize_for_speed_p = optimize_bb_for_speed_p (bb);
+ edge best_edge = nullptr;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if (!(e->flags & EDGE_COMPLEX)
+ && e->dest->index != EXIT_BLOCK
+ && single_pred_p (e->dest)
+ && optimize_for_speed_p == optimize_bb_for_speed_p (e->dest)
+ && (!best_edge || better_ebb_edge_p (e, best_edge)))
+ best_edge = e;
+
+ return best_edge ? best_edge->dest : nullptr;
+}
+
+// Partition the function's blocks into EBBs and build SSA form for all
+// EBBs in the function.
+void
+function_info::process_all_blocks ()
+{
+ auto temps = temp_watermark ();
+ unsigned int num_bb_indices = last_basic_block_for_fn (m_fn);
+
+ // Compute the starting reverse postorder. We tweak this later to try
+ // to get better EBB assignments.
+ auto *postorder = new int[n_basic_blocks_for_fn (m_fn)];
+ unsigned int postorder_num
+ = pre_and_rev_post_order_compute (nullptr, postorder, true);
+ gcc_assert (int (postorder_num) <= n_basic_blocks_for_fn (m_fn));
+
+ // Construct the working state for this function and its subroutines.
+ build_info bi;
+ bi.last_access = XOBNEWVEC (&m_temp_obstack, access_info *, m_num_regs + 1);
+ memset (bi.last_access, 0, (m_num_regs + 1) * sizeof (set_info *));
+
+ // The bb_live_out array shouldn't need to be initialized, since we'll
+ // always write to an entry before reading from it. But poison the
+ // contents when checking, just to make sure we don't accidentally use
+ // an uninitialized value.
+ bi.bb_live_out = XOBNEWVEC (&m_temp_obstack, bb_live_out_info,
+ num_bb_indices);
+ if (flag_checking)
+ memset (bi.bb_live_out, 0xaf,
+ num_bb_indices * sizeof (bb_live_out_info));
+
+ // Only pay the overhead of recording a separate live-in bitmap if
+ // there are debug instructions that might need it.
+ auto_bitmap ebb_live_in;
+ if (MAY_HAVE_DEBUG_INSNS)
+ {
+ bi.ebb_live_in_for_debug = ebb_live_in;
+ // The bitmap is tested using individual bit operations, so optimize
+ // for that case.
+ bitmap_tree_view (ebb_live_in);
+ }
+ else
+ bi.ebb_live_in_for_debug = nullptr;
+
+ // Iterate over the blocks in reverse postorder. In cases where
+ // multiple possible orders exist, prefer orders that chain blocks
+ // together into EBBs. If multiple possible EBBs exist, try to pick
+ // the ones that are most likely to be profitable.
+ auto_vec<bb_info *, 16> ebb;
+ auto_bitmap ebb_use_tmp;
+ auto_bitmap ebb_def_tmp;
+ for (unsigned int i = 0; i < postorder_num; ++i)
+ if (!m_bbs[postorder[i]])
+ {
+ // Choose and create the blocks that should form the next EBB,
+ // and calculate the set of registers that the EBB uses and defines
+ // Only do actual bitmap operations if the EBB contains multiple
+ // blocks.
+ basic_block cfg_bb = BASIC_BLOCK_FOR_FN (m_fn, postorder[i]);
+ bi.ebb_use = &DF_LR_BB_INFO (cfg_bb)->use;
+ bi.ebb_def = &DF_LR_BB_INFO (cfg_bb)->def;
+ ebb.safe_push (create_bb_info (cfg_bb));
+ cfg_bb = choose_next_block_in_ebb (cfg_bb);
+ if (cfg_bb)
+ {
+ // An EBB with two blocks.
+ bitmap_ior (ebb_use_tmp, bi.ebb_use, &DF_LR_BB_INFO (cfg_bb)->use);
+ bitmap_ior (ebb_def_tmp, bi.ebb_def, &DF_LR_BB_INFO (cfg_bb)->def);
+ bi.ebb_use = ebb_use_tmp;
+ bi.ebb_def = ebb_def_tmp;
+ ebb.safe_push (create_bb_info (cfg_bb));
+ cfg_bb = choose_next_block_in_ebb (cfg_bb);
+ while (cfg_bb)
+ {
+ // An EBB with three or more blocks.
+ bitmap_ior_into (bi.ebb_use, &DF_LR_BB_INFO (cfg_bb)->use);
+ bitmap_ior_into (bi.ebb_def, &DF_LR_BB_INFO (cfg_bb)->def);
+ ebb.safe_push (create_bb_info (cfg_bb));
+ cfg_bb = choose_next_block_in_ebb (cfg_bb);
+ }
+ }
+
+ // Create the EBB itself.
+ bi.current_ebb = allocate<ebb_info> (ebb[0], ebb.last ());
+ for (bb_info *bb : ebb)
+ {
+ bb->set_ebb (bi.current_ebb);
+ append_bb (bb);
+ }
+
+ // Populate the contents of the EBB.
+ bi.current_ebb->set_phi_insn (append_artificial_insn (ebb[0]));
+ if (ebb[0]->index () == ENTRY_BLOCK)
+ {
+ gcc_assert (ebb.length () == 1);
+ bi.current_bb = ebb[0];
+ add_entry_block_defs (bi);
+ record_block_live_out (bi);
+ }
+ else if (EDGE_COUNT (ebb[0]->cfg_bb ()->preds) == 0)
+ // Leave unreachable blocks empty, since there is no useful
+ // liveness information for them, and anything they do will
+ // be wasted work. In a cleaned-up cfg, the only unreachable
+ // block we should see is the exit block of a noreturn function.
+ for (bb_info *bb : ebb)
+ {
+ bb->set_head_insn (append_artificial_insn (bb));
+ bb->set_end_insn (append_artificial_insn (bb));
+ }
+ else
+ {
+ add_phi_nodes (bi);
+ for (bb_info *bb : ebb)
+ {
+ bi.current_bb = bb;
+ add_artificial_accesses (bi, DF_REF_AT_TOP);
+ if (bb->index () != EXIT_BLOCK)
+ add_block_contents (bi);
+ add_artificial_accesses (bi, df_ref_flags ());
+ record_block_live_out (bi);
+ populate_backedge_phis (bi);
+ }
+ }
+ ebb.truncate (0);
+ }
+
+ delete[] postorder;
+}
+
+// Print a description of CALL_CLOBBERS to PP.
+void
+rtl_ssa::pp_ebb_call_clobbers (pretty_printer *pp,
+ const ebb_call_clobbers_info *call_clobbers)
+{
+ if (!call_clobbers)
+ pp_string (pp, "<null>");
+ else
+ call_clobbers->print_full (pp);
+}
+
+// Print a description of BB to PP.
+void
+rtl_ssa::pp_bb (pretty_printer *pp, const bb_info *bb)
+{
+ if (!bb)
+ pp_string (pp, "<null>");
+ else
+ bb->print_full (pp);
+}
+
+// Print a description of EBB to PP
+void
+rtl_ssa::pp_ebb (pretty_printer *pp, const ebb_info *ebb)
+{
+ if (!ebb)
+ pp_string (pp, "<null>");
+ else
+ ebb->print_full (pp);
+}
+
+// Print a description of CALL_CLOBBERS to FILE.
+void
+dump (FILE *file, const ebb_call_clobbers_info *call_clobbers)
+{
+ dump_using (file, pp_ebb_call_clobbers, call_clobbers);
+}
+
+// Print a description of BB to FILE.
+void
+dump (FILE *file, const bb_info *bb)
+{
+ dump_using (file, pp_bb, bb);
+}
+
+// Print a description of EBB to FILE.
+void
+dump (FILE *file, const ebb_info *ebb)
+{
+ dump_using (file, pp_ebb, ebb);
+}
+
+// Debug interfaces to the dump routines above.
+void debug (const ebb_call_clobbers_info *x) { dump (stderr, x); }
+void debug (const bb_info *x) { dump (stderr, x); }
+void debug (const ebb_info *x) { dump (stderr, x); }
--- /dev/null
+// Basic-block-related classes for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// SSA-related information about a basic block. Each block contains
+// the following, which are conceptually executed in order:
+//
+// - an artificial "head" insn_info that holds artificial uses and definitions
+// for the start of the block.
+//
+// - one insn_info for each "real" instruction in the block
+// (i.e. those that have an RTL pattern).
+//
+// - an artificial "end" insn_info that holds artificial uses and definitions
+// for the end of the block.
+//
+// Blocks are grouped together into extended basic blocks. In cases where
+// multiple EBBs exist (such as in a full diamond), we try to pick the one
+// that's most frequently executed.
+//
+// Blocks are chained together in reverse postorder. (Rather than use a
+// list, we could instead have stored the index of the block in the overall
+// postorder. However, using lists should make it cheaper to update the
+// information after trivial CFG manipulations.)
+class bb_info
+{
+ // Size: 6 LP64 words.
+ friend class function_info;
+
+public:
+ // Return the previous basic block in reverse postorder, or null if this
+ // is the entry block.
+ bb_info *prev_bb () const { return m_prev_bb; }
+
+ // Return the next basic block in reverse postorder, or null if this
+ // is the exit block.
+ bb_info *next_bb () const { return m_next_bb; }
+
+ // Return true if this block is the function's entry block.
+ bool is_entry_block () const { return !m_prev_bb; }
+
+ // Return true if this block is the function's exit block.
+ bool is_exit_block () const { return !m_next_bb; }
+
+ // Return the underlying basic_block structure.
+ basic_block cfg_bb () const { return m_cfg_bb; }
+
+ // Return the unique identifier of the underlying basic_block. These uids
+ // do not follow any particular order.
+ unsigned int index () const { return m_cfg_bb->index; }
+
+ // Return the EBB that contains this block.
+ ebb_info *ebb () const { return m_ebb; }
+
+ // Return a list of all the instructions in the block, in execution order.
+ // The list includes the head and end instructions described above.
+ //
+ // Iterations over the list will pick up any new instructions that are
+ // inserted after the iterator's current instruction.
+ iterator_range<any_insn_iterator> all_insns () const;
+
+ // Like all_insns (), except that the instructions are in reverse order.
+ //
+ // Iterations over the list will pick up any new instructions that are
+ // inserted before the iterator's current instruction.
+ iterator_range<reverse_any_insn_iterator> reverse_all_insns () const;
+
+ // Like all_insns (), but without the debug instructions.
+ iterator_range<nondebug_insn_iterator> nondebug_insns () const;
+
+ // Like reverse_all_insns (), but without the debug instructions.
+ iterator_range<reverse_nondebug_insn_iterator>
+ reverse_nondebug_insns () const;
+
+ // Like all_insns (), but without the artificial instructions.
+ iterator_range<any_insn_iterator> real_insns () const;
+
+ // Like reverse_all_insns (), but without the artificial instructions.
+ iterator_range<reverse_any_insn_iterator> reverse_real_insns () const;
+
+ // Like real_insns (), but without the debug instructions.
+ iterator_range<nondebug_insn_iterator> real_nondebug_insns () const;
+
+ // Like reverse_real_insns (), but without the debug instructions.
+ iterator_range<reverse_nondebug_insn_iterator>
+ reverse_real_nondebug_insns () const;
+
+ // Return the instruction that holds the artificial uses and
+ // definitions at the head of the block. The associated RTL insn
+ // is the block head note.
+ //
+ // This instruction always exists, even if it has no uses and definitions.
+ insn_info *head_insn () const { return m_head_insn; }
+
+ // Return the instruction that holds the artificial uses and definitions
+ // at the end of the block. There is no associated RTL insn.
+ //
+ // This instruction always exists, even if it has no uses and definitions.
+ insn_info *end_insn () const { return m_end_insn; }
+
+ // Print "bb" + index () to PP.
+ void print_identifier (pretty_printer *pp) const;
+
+ // Print a full description of the block to PP.
+ void print_full (pretty_printer *) const;
+
+private:
+ bb_info (basic_block);
+
+ void set_prev_bb (bb_info *bb) { m_prev_bb = bb; }
+ void set_next_bb (bb_info *bb) { m_next_bb = bb; }
+ void set_cfg_bb (basic_block cfg_bb) { m_cfg_bb = cfg_bb; }
+ void set_ebb (ebb_info *ebb) { m_ebb = ebb; }
+ void set_head_insn (insn_info *insn) { m_head_insn = insn; }
+ void set_end_insn (insn_info *insn) { m_end_insn = insn; }
+
+ // The values returned by the functions above.
+ bb_info *m_prev_bb;
+ bb_info *m_next_bb;
+ basic_block m_cfg_bb;
+ ebb_info *m_ebb;
+ insn_info *m_head_insn;
+ insn_info *m_end_insn;
+};
+
+// Iterators for lists of basic blocks.
+using bb_iterator = list_iterator<bb_info, &bb_info::next_bb>;
+using reverse_bb_iterator = list_iterator<bb_info, &bb_info::prev_bb>;
+
+// This class collects together instructions for which has_call_clobbers ()
+// is true, storing them in a splay tree that follows reverse postorder.
+// Instances of the class form a singly-linked list, with one instance
+// per predefined_function_abi.
+class ebb_call_clobbers_info : public insn_call_clobbers_tree
+{
+ // Size 3 LP64 words.
+ friend class function_info;
+
+public:
+ // Return the next group in the list.
+ ebb_call_clobbers_info *next () const { return m_next; }
+
+ // Return the function abi used by all the calls in the group.
+ const predefined_function_abi *abi () const { return m_abi; }
+
+ // Return true if at least one call in the group should conservatively
+ // be assumed to clobber RESOURCE.
+ bool clobbers (resource_info) const;
+
+ // Print a summary of what the class describes to PP, without printing
+ // the actual instructions.
+ void print_summary (pretty_printer *pp) const;
+
+ // Print a full description of the object to PP, including the
+ // instructions it contains.
+ void print_full (pretty_printer *) const;
+
+private:
+ ebb_call_clobbers_info (const predefined_function_abi *);
+
+ // The values returned by the accessors above.
+ ebb_call_clobbers_info *m_next;
+ const predefined_function_abi *m_abi;
+};
+
+// A list of ebb_call_clobbers_infos.
+using ebb_call_clobbers_iterator
+ = list_iterator<ebb_call_clobbers_info, &ebb_call_clobbers_info::next>;
+
+// Information about an extended basic block.
+//
+// Each EBB has a list of phi nodes and starts with an artificial phi
+// instruction that conceptually "executes" the phi nodes. The phi
+// nodes are independent of one another and so can be executed in any
+// order. The order of the phi nodes in the list is not significant.
+//
+// Each EBB also maintains a list of ebb_call_clobbers_info structures
+// that describe all instructions for which has_call_clobbers () is true.
+// See the comment above that class for details.
+class ebb_info
+{
+ // Size: 5 LP64 words.
+ friend class function_info;
+
+public:
+ // Return the previous EBB in reverse postorder, or null if this EBB
+ // contains the entry block.
+ ebb_info *prev_ebb () const;
+
+ // Return the next EBB in reverse postorder, or null if this EBB contains
+ // the exit block.
+ ebb_info *next_ebb () const;
+
+ // Return the instruction that holds the EBB's phi nodes (and does
+ // nothing else). There is no associated RTL insn.
+ //
+ // This instruction always exists, even if the EBB does not currently
+ // need any phi nodes.
+ insn_info *phi_insn () const { return m_phi_insn; }
+
+ // Return the first and last blocks in the EBB.
+ bb_info *first_bb () const { return m_first_bb; }
+ bb_info *last_bb () const { return m_last_bb; }
+
+ // Return the first of the EBB's phi nodes.
+ phi_info *first_phi () const { return m_first_phi; }
+
+ // Return the head of the list of ebb_call_clobbers_infos.
+ ebb_call_clobbers_info *first_call_clobbers () const;
+
+ // Return the list of ebb_call_clobbers_infos.
+ iterator_range<ebb_call_clobbers_iterator> call_clobbers () const;
+
+ // Return a list of the EBB's phi nodes, in arbitrary order.
+ iterator_range<phi_iterator> phis () const;
+
+ // Return a list of the blocks in the EBB, in execution order.
+ iterator_range<bb_iterator> bbs () const;
+
+ // Return a list of the blocks in the EBB, in reverse execution order.
+ iterator_range<reverse_bb_iterator> reverse_bbs () const;
+
+ // Return a list of all the instructions in the EBB, in execution order.
+ // The list includes phi_insn (), the head and end of each block,
+ // and the real instructions in each block.
+ //
+ // Iterations over the list will pick up any new instructions that are
+ // inserted after the iterator's current instruction.
+ iterator_range<any_insn_iterator> all_insns () const;
+
+ // Like all_insns (), except that the instructions are in reverse order.
+ //
+ // Iterations over the list will pick up any new instructions that are
+ // inserted before the iterator's current instruction.
+ iterator_range<reverse_any_insn_iterator> reverse_all_insns () const;
+
+ // Like all_insns (), but without the debug instructions.
+ iterator_range<nondebug_insn_iterator> nondebug_insns () const;
+
+ // Like reverse_all_insns (), but without the debug instructions.
+ iterator_range<reverse_nondebug_insn_iterator>
+ reverse_nondebug_insns () const;
+
+ // Return an insn_range that covers the same instructions as all_insns ().
+ insn_range_info insn_range () const;
+
+ // Print "ebb" + first_bb ()->index () to PP.
+ void print_identifier (pretty_printer *pp) const;
+
+ // Print a full description of the EBB to PP.
+ void print_full (pretty_printer *pp) const;
+
+private:
+ ebb_info (bb_info *, bb_info *);
+
+ void set_first_phi (phi_info *phi) { m_first_phi = phi; }
+ void set_phi_insn (insn_info *insn) { m_phi_insn = insn; }
+ void set_first_call_clobbers (ebb_call_clobbers_info *);
+
+ // The values returned by the functions above.
+ phi_info *m_first_phi;
+ insn_info *m_phi_insn;
+ bb_info *m_first_bb;
+ bb_info *m_last_bb;
+ ebb_call_clobbers_info *m_first_call_clobbers;
+};
+
+// Iterators for lists of extended basic blocks.
+using ebb_iterator = list_iterator<ebb_info, &ebb_info::next_ebb>;
+using reverse_ebb_iterator = list_iterator<ebb_info, &ebb_info::prev_ebb>;
+
+void pp_bb (pretty_printer *, const bb_info *);
+void pp_ebb_call_clobbers (pretty_printer *, const ebb_call_clobbers_info *);
+void pp_ebb (pretty_printer *, const ebb_info *);
+
+}
+
+void dump (FILE *, const rtl_ssa::bb_info *);
+void dump (FILE *, const rtl_ssa::ebb_call_clobbers_info *);
+void dump (FILE *, const rtl_ssa::ebb_info *);
+
+void DEBUG_FUNCTION debug (const rtl_ssa::bb_info *);
+void DEBUG_FUNCTION debug (const rtl_ssa::ebb_call_clobbers_info *);
+void DEBUG_FUNCTION debug (const rtl_ssa::ebb_info *);
--- /dev/null
+// RTL SSA utility functions for changing instructions -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// Return true if INSN is one of the instructions being changed by CHANGES.
+inline bool
+insn_is_changing (array_slice<insn_change *const> changes,
+ const insn_info *insn)
+{
+ for (const insn_change *change : changes)
+ if (change->insn () == insn)
+ return true;
+ return false;
+}
+
+// Return a closure of insn_is_changing, for use as a predicate.
+// This could be done using local lambdas instead, but the predicate is
+// used often enough that having a class should be more convenient and allow
+// reuse of template instantiations.
+//
+// We don't use std::bind because it would involve an indirect function call,
+// whereas this function is used in relatively performance-critical code.
+inline insn_is_changing_closure
+insn_is_changing (array_slice<insn_change *const> changes)
+{
+ return insn_is_changing_closure (changes);
+}
+
+// Restrict CHANGE.move_range so that the changed instruction can perform
+// all its definitions and uses. Assume that if:
+//
+// - CHANGE contains an access A1 of resource R;
+// - an instruction I2 contains another access A2 to R; and
+// - IGNORE (I2) is true
+//
+// then either:
+//
+// - A2 will be removed; or
+// - something will ensure that A1 and A2 maintain their current order,
+// without this having to be enforced by CHANGE's move range.
+//
+// IGNORE should return true for CHANGE.insn ().
+//
+// Return true on success, otherwise leave CHANGE.move_range in an invalid
+// state.
+//
+// This function only works correctly for instructions that remain within
+// the same extended basic block.
+template<typename IgnorePredicate>
+bool
+restrict_movement_ignoring (insn_change &change, IgnorePredicate ignore)
+{
+ // Uses generally lead to failure quicker, so test those first.
+ return (restrict_movement_for_uses_ignoring (change.move_range,
+ change.new_uses, ignore)
+ && restrict_movement_for_defs_ignoring (change.move_range,
+ change.new_defs, ignore)
+ && canonicalize_move_range (change.move_range, change.insn ()));
+}
+
+// Like restrict_movement_ignoring, but ignore only the instruction
+// that is being changed.
+inline bool
+restrict_movement (insn_change &change)
+{
+ return restrict_movement_ignoring (change, insn_is (change.insn ()));
+}
+
+using add_regno_clobber_fn = std::function<bool (insn_change &,
+ unsigned int)>;
+bool recog_internal (insn_change &, add_regno_clobber_fn);
+
+// Try to recognize the new instruction pattern for CHANGE, potentially
+// tweaking the pattern or adding extra clobbers in order to make it match.
+//
+// When adding an extra clobber for register R, restrict CHANGE.move_range
+// to a range of instructions for which R is not live. When determining
+// whether R is live, ignore accesses made by an instruction I if
+// IGNORE (I) is true. The caller then assumes the responsibility
+// of ensuring that CHANGE and I are placed in a valid order.
+//
+// IGNORE should return true for CHANGE.insn ().
+//
+// Return true on success. Leave CHANGE unmodified on failure.
+template<typename IgnorePredicate>
+inline bool
+recog_ignoring (obstack_watermark &watermark, insn_change &change,
+ IgnorePredicate ignore)
+{
+ auto add_regno_clobber = [&](insn_change &change, unsigned int regno)
+ {
+ return crtl->ssa->add_regno_clobber (watermark, change, regno, ignore);
+ };
+ return recog_internal (change, add_regno_clobber);
+}
+
+// As for recog_ignoring, but ignore only the instruction that is being
+// changed.
+inline bool
+recog (obstack_watermark &watermark, insn_change &change)
+{
+ return recog_ignoring (watermark, change, insn_is (change.insn ()));
+}
+
+// Check whether insn costs indicate that the net effect of the changes
+// in CHANGES is worthwhile. Require a strict improvement if STRICT_P,
+// otherwise allow the new instructions to be the same cost as the old
+// instructions.
+bool changes_are_worthwhile (array_slice<insn_change *const> changes,
+ bool strict_p = false);
+
+// Like changes_are_worthwhile, but for a single change.
+inline bool
+change_is_worthwhile (insn_change &change, bool strict_p = false)
+{
+ insn_change *changes[] = { &change };
+ return changes_are_worthwhile (changes, strict_p);
+}
+
+}
--- /dev/null
+// RTL SSA routines for changing instructions -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#include "rtl-ssa.h"
+#include "rtl-ssa/internals.inl"
+#include "target.h"
+#include "predict.h"
+#include "memmodel.h" // Needed by emit-rtl.h
+#include "emit-rtl.h"
+#include "cfghooks.h"
+#include "cfgrtl.h"
+
+using namespace rtl_ssa;
+
+// See the comment above the declaration.
+void
+insn_change::print (pretty_printer *pp) const
+{
+ if (m_is_deletion)
+ {
+ pp_string (pp, "deletion of ");
+ pp_insn (pp, m_insn);
+ }
+ else
+ {
+ pp_string (pp, "change to ");
+ pp_insn (pp, m_insn);
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "~~~~~~~");
+
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "new cost: ");
+ pp_decimal_int (pp, new_cost);
+
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "new uses:");
+ pp_newline_and_indent (pp, 2);
+ pp_accesses (pp, new_uses);
+ pp_indentation (pp) -= 2;
+
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "new defs:");
+ pp_newline_and_indent (pp, 2);
+ pp_accesses (pp, new_defs);
+ pp_indentation (pp) -= 2;
+
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "first insert-after candidate: ");
+ move_range.first->print_identifier_and_location (pp);
+
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "last insert-after candidate: ");
+ move_range.last->print_identifier_and_location (pp);
+ }
+}
+
+// Return a copy of access_array ACCESSES, allocating it on the
+// temporary obstack.
+access_array
+function_info::temp_access_array (access_array accesses)
+{
+ if (accesses.empty ())
+ return accesses;
+
+ gcc_assert (obstack_object_size (&m_temp_obstack) == 0);
+ obstack_grow (&m_temp_obstack, accesses.begin (), accesses.size_bytes ());
+ return { static_cast<access_info **> (obstack_finish (&m_temp_obstack)),
+ accesses.size () };
+}
+
+// See the comment above the declaration.
+bool
+function_info::verify_insn_changes (array_slice<insn_change *const> changes)
+{
+ HARD_REG_SET defined_hard_regs, clobbered_hard_regs;
+ CLEAR_HARD_REG_SET (defined_hard_regs);
+ CLEAR_HARD_REG_SET (clobbered_hard_regs);
+
+ insn_info *min_insn = m_first_insn;
+ for (insn_change *change : changes)
+ if (!change->is_deletion ())
+ {
+ // Make sure that the changes can be kept in their current order
+ // while honoring all of the move ranges.
+ min_insn = later_insn (min_insn, change->move_range.first);
+ while (min_insn != change->insn () && !can_insert_after (min_insn))
+ min_insn = min_insn->next_nondebug_insn ();
+ if (*min_insn > *change->move_range.last)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "no viable insn position assignment\n");
+ return false;
+ }
+
+ // If recog introduced new clobbers of a register as part of
+ // the matching process, make sure that they don't conflict
+ // with any other new definitions or uses of the register.
+ // (We have already checked that they don't conflict with
+ // unchanging definitions and uses.)
+ for (use_info *use : change->new_uses)
+ {
+ unsigned int regno = use->regno ();
+ if (HARD_REGISTER_NUM_P (regno)
+ && TEST_HARD_REG_BIT (clobbered_hard_regs, regno))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "register %d would be clobbered"
+ " while it is still live\n", regno);
+ return false;
+ }
+ }
+ for (def_info *def : change->new_defs)
+ {
+ unsigned int regno = def->regno ();
+ if (HARD_REGISTER_NUM_P (regno))
+ {
+ if (def->m_is_temp)
+ {
+ // This is a clobber introduced by recog.
+ gcc_checking_assert (is_a<clobber_info *> (def));
+ if (TEST_HARD_REG_BIT (defined_hard_regs, regno))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "conflicting definitions of"
+ " register %d\n", regno);
+ return false;
+ }
+ SET_HARD_REG_BIT (clobbered_hard_regs, regno);
+ }
+ else if (is_a<set_info *> (def))
+ {
+ // REGNO now has a defined value.
+ SET_HARD_REG_BIT (defined_hard_regs, regno);
+ CLEAR_HARD_REG_BIT (clobbered_hard_regs, regno);
+ }
+ }
+ }
+ }
+ return true;
+}
+
+// See the comment above the declaration.
+bool
+rtl_ssa::changes_are_worthwhile (array_slice<insn_change *const> changes,
+ bool strict_p)
+{
+ unsigned int old_cost = 0;
+ unsigned int new_cost = 0;
+ for (insn_change *change : changes)
+ {
+ old_cost += change->old_cost ();
+ if (!change->is_deletion ())
+ {
+ basic_block cfg_bb = change->bb ()->cfg_bb ();
+ change->new_cost = insn_cost (change->rtl (),
+ optimize_bb_for_speed_p (cfg_bb));
+ new_cost += change->new_cost;
+ }
+ }
+ bool ok_p = (strict_p ? new_cost < old_cost : new_cost <= old_cost);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "original cost");
+ char sep = '=';
+ for (const insn_change *change : changes)
+ {
+ fprintf (dump_file, " %c %d", sep, change->old_cost ());
+ sep = '+';
+ }
+ fprintf (dump_file, ", replacement cost");
+ sep = '=';
+ for (const insn_change *change : changes)
+ if (!change->is_deletion ())
+ {
+ fprintf (dump_file, " %c %d", sep, change->new_cost);
+ sep = '+';
+ }
+ fprintf (dump_file, "; %s\n",
+ ok_p ? "keeping replacement" : "rejecting replacement");
+ }
+ if (!ok_p)
+ return false;
+
+ return true;
+}
+
+// Update the REG_NOTES of INSN, whose pattern has just been changed.
+static void
+update_notes (rtx_insn *insn)
+{
+ for (rtx *note_ptr = ®_NOTES (insn); *note_ptr; )
+ {
+ rtx note = *note_ptr;
+ bool keep_p = true;
+ switch (REG_NOTE_KIND (note))
+ {
+ case REG_EQUAL:
+ case REG_EQUIV:
+ case REG_NOALIAS:
+ keep_p = (single_set (insn) != nullptr);
+ break;
+
+ case REG_UNUSED:
+ case REG_DEAD:
+ // These notes are stale. We'll recompute REG_UNUSED notes
+ // after the update.
+ keep_p = false;
+ break;
+
+ default:
+ break;
+ }
+ if (keep_p)
+ note_ptr = &XEXP (*note_ptr, 1);
+ else
+ {
+ *note_ptr = XEXP (*note_ptr, 1);
+ free_EXPR_LIST_node (note);
+ }
+ }
+}
+
+// Pick a location for CHANGE's instruction and return the instruction
+// after which it should be placed.
+static insn_info *
+choose_insn_placement (insn_change &change)
+{
+ gcc_checking_assert (change.move_range);
+
+ insn_info *insn = change.insn ();
+ insn_info *first = change.move_range.first;
+ insn_info *last = change.move_range.last;
+
+ // Quick(ish) exit if there is only one possible choice.
+ if (first == last)
+ return first;
+ if (first == insn->prev_nondebug_insn () && last == insn)
+ return insn;
+
+ // For now just use the closest valid choice to the original instruction.
+ // If the register usage has changed significantly, it might instead be
+ // better to try to take register pressure into account.
+ insn_info *closest = change.move_range.clamp_insn_to_range (insn);
+ while (closest != insn && !can_insert_after (closest))
+ closest = closest->next_nondebug_insn ();
+ return closest;
+}
+
+// Record any changes related to CHANGE that need to be queued for later.
+void
+function_info::possibly_queue_changes (insn_change &change)
+{
+ insn_info *insn = change.insn ();
+ rtx_insn *rtl = insn->rtl ();
+
+ // If the instruction could previously throw, we eventually need to call
+ // purge_dead_edges to check whether things have changed.
+ if (find_reg_note (rtl, REG_EH_REGION, nullptr))
+ bitmap_set_bit (m_need_to_purge_dead_edges, insn->bb ()->index ());
+
+ auto needs_pending_update = [&]()
+ {
+ // If an instruction became a no-op without the pass explicitly
+ // deleting it, queue the deletion for later. Removing the
+ // instruction on the fly would require an update to all instructions
+ // that use the result of the move, which would be a potential source
+ // of quadraticness. Also, definitions shouldn't disappear under
+ // the pass's feet.
+ if (INSN_CODE (rtl) == NOOP_MOVE_INSN_CODE)
+ return true;
+
+ // If any jumps got turned into unconditional jumps or nops, we need
+ // to update the CFG accordingly.
+ if (JUMP_P (rtl)
+ && (returnjump_p (rtl) || any_uncondjump_p (rtl))
+ && !single_succ_p (insn->bb ()->cfg_bb ()))
+ return true;
+
+ // If a previously conditional trap now always fires, execution
+ // terminates at that point.
+ rtx pattern = PATTERN (rtl);
+ if (GET_CODE (pattern) == TRAP_IF
+ && XEXP (pattern, 0) == const1_rtx)
+ return true;
+
+ return false;
+ };
+
+ if (needs_pending_update ()
+ && bitmap_set_bit (m_queued_insn_update_uids, insn->uid ()))
+ {
+ gcc_assert (!change.is_deletion ());
+ m_queued_insn_updates.safe_push (insn);
+ }
+}
+
+// Remove the instruction described by CHANGE from the underlying RTL
+// and from the insn_info list.
+static void
+delete_insn (insn_change &change)
+{
+ insn_info *insn = change.insn ();
+ rtx_insn *rtl = change.rtl ();
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "deleting insn %d\n", insn->uid ());
+ set_insn_deleted (rtl);
+}
+
+// Move the RTL instruction associated with CHANGE so that it comes
+// immediately after AFTER.
+static void
+move_insn (insn_change &change, insn_info *after)
+{
+ rtx_insn *rtl = change.rtl ();
+ rtx_insn *after_rtl = after->rtl ();
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "moving insn %d after insn %d\n",
+ INSN_UID (rtl), INSN_UID (after_rtl));
+
+ // At the moment we don't support moving instructions between EBBs,
+ // but this would be worth adding if it's useful.
+ insn_info *insn = change.insn ();
+ gcc_assert (after->ebb () == insn->ebb ());
+ bb_info *bb = after->bb ();
+ basic_block cfg_bb = bb->cfg_bb ();
+
+ if (insn->bb () != bb)
+ // Force DF to mark the old block as dirty.
+ df_insn_delete (rtl);
+ ::remove_insn (rtl);
+ ::add_insn_after (rtl, after_rtl, cfg_bb);
+}
+
+// The instruction associated with CHANGE is being changed in-place.
+// Update the DF information for its new pattern.
+static void
+update_insn_in_place (insn_change &change)
+{
+ insn_info *insn = change.insn ();
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "updating insn %d in-place\n", insn->uid ());
+ df_insn_rescan (change.rtl ());
+}
+
+// Finalize the new list of definitions and uses in CHANGE, removing
+// any uses and definitions that are no longer needed, and converting
+// pending clobbers into actual definitions.
+void
+function_info::finalize_new_accesses (insn_change &change)
+{
+ insn_info *insn = change.insn ();
+
+ // Get a list of all the things that the instruction now references.
+ vec_rtx_properties properties;
+ properties.add_insn (insn->rtl (), true);
+
+ // Build up the new list of definitions.
+ for (rtx_obj_reference ref : properties.refs ())
+ if (ref.is_write ())
+ {
+ def_info *def = find_access (change.new_defs, ref.regno);
+ gcc_assert (def);
+ if (def->m_is_temp)
+ {
+ // At present, the only temporary instruction definitions we
+ // create are clobbers, such as those added during recog.
+ gcc_assert (is_a<clobber_info *> (def));
+ def = allocate<clobber_info> (change.insn (), ref.regno);
+ }
+ else if (!def->m_has_been_superceded)
+ {
+ // This is a second or subsequent definition.
+ // See function_info::record_def for a discussion of when
+ // this can happen.
+ def->record_reference (ref, false);
+ continue;
+ }
+ else
+ {
+ def->m_has_been_superceded = false;
+
+ // Clobbers can move around, so remove them from their current
+ // position and them back in their final position.
+ //
+ // At the moment, we don't allow sets to move relative to other
+ // definitions of the same resource, so we can leave those where
+ // they are. It might be useful to relax this in future.
+ // The main complication is that removing a set would potentially
+ // fuse two adjoining clobber_groups, and adding the set back
+ // would require the group to be split again.
+ if (is_a<clobber_info *> (def))
+ remove_def (def);
+ else if (ref.is_reg ())
+ def->set_mode (ref.mode);
+ def->set_insn (insn);
+ }
+ def->record_reference (ref, true);
+ m_temp_defs.safe_push (def);
+ }
+
+ // Also keep any explicitly-recorded call clobbers, which are deliberately
+ // excluded from the vec_rtx_properties.
+ for (def_info *def : change.new_defs)
+ if (def->m_has_been_superceded && def->is_call_clobber ())
+ {
+ def->m_has_been_superceded = false;
+ def->set_insn (insn);
+ m_temp_defs.safe_push (def);
+ }
+
+ // Install the new list of definitions in CHANGE.
+ sort_accesses (m_temp_defs);
+ access_array accesses = temp_access_array (m_temp_defs);
+ change.new_defs = def_array (accesses);
+ m_temp_defs.truncate (0);
+
+ // Create temporary copies of use_infos that are already attached to
+ // other insns, which could happen if the uses come from unchanging
+ // insns or if they have been used by earlier changes. Doing this
+ // makes it easier to detect multiple reads below.
+ auto *unshared_uses_base = XOBNEWVEC (&m_temp_obstack, access_info *,
+ change.new_uses.size ());
+ unsigned int i = 0;
+ for (use_info *use : change.new_uses)
+ {
+ if (!use->m_has_been_superceded)
+ {
+ use = allocate_temp<use_info> (insn, use->resource (), use->def ());
+ use->m_has_been_superceded = true;
+ use->m_is_temp = true;
+ }
+ unshared_uses_base[i++] = use;
+ }
+ auto unshared_uses = use_array (unshared_uses_base, change.new_uses.size ());
+
+ // Add (possibly temporary) uses to m_temp_uses for each resource.
+ // If there are multiple references to the same resource, aggregate
+ // information in the modes and flags.
+ for (rtx_obj_reference ref : properties.refs ())
+ if (ref.is_read ())
+ {
+ unsigned int regno = ref.regno;
+ machine_mode mode = ref.is_reg () ? ref.mode : BLKmode;
+ use_info *use = find_access (unshared_uses, ref.regno);
+ gcc_assert (use);
+ if (use->m_has_been_superceded)
+ {
+ // This is the first reference to the resource.
+ bool is_temp = use->m_is_temp;
+ *use = use_info (insn, resource_info { mode, regno }, use->def ());
+ use->m_is_temp = is_temp;
+ use->record_reference (ref, true);
+ m_temp_uses.safe_push (use);
+ }
+ else
+ {
+ // Record the mode of the largest use. The choice is arbitrary if
+ // the instruction (unusually) references the same register in two
+ // different but equal-sized modes.
+ if (HARD_REGISTER_NUM_P (regno)
+ && partial_subreg_p (use->mode (), mode))
+ use->set_mode (mode);
+ use->record_reference (ref, false);
+ }
+ }
+
+ // Replace any temporary uses and definitions with real ones.
+ for (unsigned int i = 0; i < m_temp_uses.length (); ++i)
+ {
+ auto *use = as_a<use_info *> (m_temp_uses[i]);
+ if (use->m_is_temp)
+ {
+ m_temp_uses[i] = use = allocate<use_info> (*use);
+ use->m_is_temp = false;
+ set_info *def = use->def ();
+ // Handle cases in which the value was previously not used
+ // within the block.
+ if (def && def->m_is_temp)
+ {
+ phi_info *phi = as_a<phi_info *> (def);
+ gcc_assert (phi->is_degenerate ());
+ phi = create_degenerate_phi (phi->ebb (), phi->input_value (0));
+ use->set_def (phi);
+ }
+ }
+ }
+
+ // Install the new list of definitions in CHANGE.
+ sort_accesses (m_temp_uses);
+ change.new_uses = use_array (temp_access_array (m_temp_uses));
+ m_temp_uses.truncate (0);
+
+ // Record the new instruction-wide properties.
+ insn->set_properties (properties);
+}
+
+// Copy information from CHANGE to its underlying insn_info, given that
+// the insn_info has already been placed appropriately.
+void
+function_info::apply_changes_to_insn (insn_change &change)
+{
+ insn_info *insn = change.insn ();
+ if (change.is_deletion ())
+ {
+ insn->set_accesses (nullptr, 0, 0);
+ return;
+ }
+
+ // Copy the cost.
+ insn->set_cost (change.new_cost);
+
+ // Add all clobbers. Sets never moved relative to other definitions,
+ // so are OK as-is.
+ for (def_info *def : change.new_defs)
+ if (is_a<clobber_info *> (def))
+ add_def (def);
+
+ // Add all uses, now that their position is final.
+ for (use_info *use : change.new_uses)
+ add_use (use);
+
+ // Copy the uses and definitions.
+ unsigned int num_defs = change.new_defs.size ();
+ unsigned int num_uses = change.new_uses.size ();
+ if (num_defs + num_uses <= insn->num_defs () + insn->num_uses ())
+ insn->copy_accesses (change.new_defs, change.new_uses);
+ else
+ {
+ access_array_builder builder (&m_obstack);
+ builder.reserve (num_defs + num_uses);
+
+ for (def_info *def : change.new_defs)
+ builder.quick_push (def);
+ for (use_info *use : change.new_uses)
+ builder.quick_push (use);
+
+ insn->set_accesses (builder.finish ().begin (), num_defs, num_uses);
+ }
+
+ add_reg_unused_notes (insn);
+}
+
+// Add a temporary placeholder instruction after AFTER.
+insn_info *
+function_info::add_placeholder_after (insn_info *after)
+{
+ insn_info *insn = allocate_temp<insn_info> (after->bb (), nullptr, -1);
+ add_insn_after (insn, after);
+ return insn;
+}
+
+// See the comment above the declaration.
+void
+function_info::change_insns (array_slice<insn_change *> changes)
+{
+ auto watermark = temp_watermark ();
+
+ insn_info *min_insn = m_first_insn;
+ for (insn_change *change : changes)
+ {
+ // Tentatively mark all the old uses and definitions for deletion.
+ for (use_info *use : change->old_uses ())
+ {
+ use->m_has_been_superceded = true;
+ remove_use (use);
+ }
+ for (def_info *def : change->old_defs ())
+ def->m_has_been_superceded = true;
+
+ if (!change->is_deletion ())
+ {
+ // Remove any notes that are no longer relevant.
+ update_notes (change->rtl ());
+
+ // Make sure that the placement of this instruction would still
+ // leave room for previous instructions.
+ change->move_range = move_later_than (change->move_range, min_insn);
+ if (!canonicalize_move_range (change->move_range, change->insn ()))
+ // verify_insn_changes is supposed to make sure that this holds.
+ gcc_unreachable ();
+ min_insn = later_insn (min_insn, change->move_range.first);
+ }
+ }
+
+ // Walk backwards through the changes, allocating specific positions
+ // to each one. Update the underlying RTL and its associated DF
+ // information.
+ insn_info *following_insn = nullptr;
+ auto_vec<insn_info *, 16> placeholders;
+ placeholders.safe_grow_cleared (changes.size ());
+ for (unsigned int i = changes.size (); i-- > 0;)
+ {
+ insn_change &change = *changes[i];
+ insn_info *placeholder = nullptr;
+ possibly_queue_changes (change);
+ if (change.is_deletion ())
+ delete_insn (change);
+ else
+ {
+ // Make sure that this instruction comes before later ones.
+ if (following_insn)
+ {
+ change.move_range = move_earlier_than (change.move_range,
+ following_insn);
+ if (!canonicalize_move_range (change.move_range,
+ change.insn ()))
+ // verify_insn_changes is supposed to make sure that this
+ // holds.
+ gcc_unreachable ();
+ }
+
+ // Decide which instruction INSN should go after.
+ insn_info *after = choose_insn_placement (change);
+
+ // If INSN is moving, insert a placeholder insn_info at the
+ // new location. We can't move INSN itself yet because it
+ // might still be referenced by earlier move ranges.
+ insn_info *insn = change.insn ();
+ if (after == insn || after == insn->prev_nondebug_insn ())
+ {
+ update_insn_in_place (change);
+ following_insn = insn;
+ }
+ else
+ {
+ move_insn (change, after);
+ placeholder = add_placeholder_after (after);
+ following_insn = placeholder;
+ }
+
+ // Finalize the new list of accesses for the change. Don't install
+ // them yet, so that we still have access to the old lists below.
+ finalize_new_accesses (change);
+ }
+ placeholders[i] = placeholder;
+ }
+
+ // Remove all definitions that are no longer needed. After the above,
+ // such definitions should no longer have any registered users.
+ //
+ // In particular, this means that consumers must handle debug
+ // instructions before removing a set.
+ for (insn_change *change : changes)
+ for (def_info *def : change->old_defs ())
+ if (def->m_has_been_superceded)
+ {
+ auto *set = dyn_cast<set_info *> (def);
+ gcc_assert (!set || !set->has_any_uses ());
+ remove_def (def);
+ }
+
+ // Move the insn_infos to their new locations.
+ for (unsigned int i = 0; i < changes.size (); ++i)
+ {
+ insn_change &change = *changes[i];
+ insn_info *insn = change.insn ();
+ if (change.is_deletion ())
+ remove_insn (insn);
+ else if (insn_info *placeholder = placeholders[i])
+ {
+ // Check if earlier movements turned a move into a no-op.
+ if (placeholder->prev_nondebug_insn () == insn
+ || placeholder->next_nondebug_insn () == insn)
+ {
+ remove_insn (placeholder);
+ placeholders[i] = nullptr;
+ }
+ else
+ {
+ // Remove the placeholder first so that we have a wider range of
+ // program points when inserting INSN.
+ insn_info *after = placeholder->prev_any_insn ();
+ remove_insn (insn);
+ remove_insn (placeholder);
+ insn->set_bb (after->bb ());
+ add_insn_after (insn, after);
+ }
+ }
+ }
+
+ // Finally apply the changes to the underlying insn_infos.
+ for (insn_change *change : changes)
+ apply_changes_to_insn (*change);
+}
+
+// See the comment above the declaration.
+void
+function_info::change_insn (insn_change &change)
+{
+ insn_change *changes[] = { &change };
+ return change_insns (changes);
+}
+
+// Try to adjust CHANGE so that its pattern can include clobber rtx CLOBBER.
+// Return true on success.
+//
+// ADD_REGNO_CLOBBER is a specialization of function_info::add_regno_clobber
+// for a specific caller-provided predicate.
+static bool
+add_clobber (insn_change &change, add_regno_clobber_fn add_regno_clobber,
+ rtx clobber)
+{
+ rtx pat = PATTERN (change.rtl ());
+ gcc_assert (GET_CODE (clobber) == CLOBBER);
+ rtx dest = XEXP (clobber, 0);
+ if (GET_CODE (dest) == SCRATCH)
+ {
+ if (reload_completed)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ // ??? Maybe we could try to do some RA here?
+ fprintf (dump_file, "instruction requires a scratch"
+ " after reload:\n");
+ print_rtl_single (dump_file, pat);
+ }
+ return false;
+ }
+ return true;
+ }
+
+ gcc_assert (REG_P (dest));
+ for (unsigned int regno = REGNO (dest); regno != END_REGNO (dest); ++regno)
+ if (!add_regno_clobber (change, regno))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "cannot clobber live register %d in:\n",
+ regno);
+ print_rtl_single (dump_file, pat);
+ }
+ return false;
+ }
+ return true;
+}
+
+// Try to recognize the new form of the insn associated with CHANGE,
+// adding any clobbers that are necessary to make the instruction match
+// an .md pattern. Return true on success.
+//
+// ADD_REGNO_CLOBBER is a specialization of function_info::add_regno_clobber
+// for a specific caller-provided predicate.
+static bool
+recog_level2 (insn_change &change, add_regno_clobber_fn add_regno_clobber)
+{
+ insn_change_watermark insn_watermark;
+ rtx_insn *rtl = change.rtl ();
+ rtx pat = PATTERN (rtl);
+ int num_clobbers = 0;
+ int icode = -1;
+ bool asm_p = asm_noperands (pat) >= 0;
+ if (asm_p)
+ {
+ if (!check_asm_operands (pat))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "failed to match this asm instruction:\n");
+ print_rtl_single (dump_file, pat);
+ }
+ return false;
+ }
+ }
+ else if (noop_move_p (rtl))
+ {
+ INSN_CODE (rtl) = NOOP_MOVE_INSN_CODE;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "instruction becomes a no-op:\n");
+ print_rtl_single (dump_file, pat);
+ }
+ insn_watermark.keep ();
+ return true;
+ }
+ else
+ {
+ icode = ::recog (pat, rtl, &num_clobbers);
+ if (icode < 0)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "failed to match this instruction:\n");
+ print_rtl_single (dump_file, pat);
+ }
+ return false;
+ }
+ }
+
+ auto prev_new_defs = change.new_defs;
+ auto prev_move_range = change.move_range;
+ if (num_clobbers > 0)
+ {
+ // ??? It would be good to have a way of recycling the rtxes on failure,
+ // but any attempt to cache old PARALLELs would at best be a half
+ // measure, since add_clobbers would still generate fresh clobbers
+ // each time. It would be better to have a more general recycling
+ // mechanism that all rtx passes can use.
+ rtvec newvec;
+ int oldlen;
+ if (GET_CODE (pat) == PARALLEL)
+ {
+ oldlen = XVECLEN (pat, 0);
+ newvec = rtvec_alloc (num_clobbers + oldlen);
+ for (int i = 0; i < oldlen; ++i)
+ RTVEC_ELT (newvec, i) = XVECEXP (pat, 0, i);
+ }
+ else
+ {
+ oldlen = 1;
+ newvec = rtvec_alloc (num_clobbers + oldlen);
+ RTVEC_ELT (newvec, 0) = pat;
+ }
+ rtx newpat = gen_rtx_PARALLEL (VOIDmode, newvec);
+ add_clobbers (newpat, icode);
+ validate_change (rtl, &PATTERN (rtl), newpat, true);
+ for (int i = 0; i < num_clobbers; ++i)
+ if (!add_clobber (change, add_regno_clobber,
+ XVECEXP (newpat, 0, oldlen + i)))
+ {
+ change.new_defs = prev_new_defs;
+ change.move_range = prev_move_range;
+ return false;
+ }
+
+ pat = newpat;
+ }
+
+ INSN_CODE (rtl) = icode;
+ if (reload_completed)
+ {
+ extract_insn (rtl);
+ if (!constrain_operands (1, get_preferred_alternatives (rtl)))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (asm_p)
+ fprintf (dump_file, "asm does not match its constraints:\n");
+ else if (const char *name = get_insn_name (icode))
+ fprintf (dump_file, "instruction does not match the"
+ " constraints for %s:\n", name);
+ else
+ fprintf (dump_file, "instruction does not match its"
+ " constraints:\n");
+ print_rtl_single (dump_file, pat);
+ }
+ change.new_defs = prev_new_defs;
+ change.move_range = prev_move_range;
+ return false;
+ }
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ const char *name;
+ if (!asm_p && (name = get_insn_name (icode)))
+ fprintf (dump_file, "successfully matched this instruction "
+ "to %s:\n", name);
+ else
+ fprintf (dump_file, "successfully matched this instruction:\n");
+ print_rtl_single (dump_file, pat);
+ }
+
+ insn_watermark.keep ();
+ return true;
+}
+
+// Try to recognize the new form of the insn associated with CHANGE,
+// adding and removing clobbers as necessary to make the instruction
+// match an .md pattern. Return true on success, otherwise leave
+// CHANGE as it was on entry.
+//
+// ADD_REGNO_CLOBBER is a specialization of function_info::add_regno_clobber
+// for a specific caller-provided predicate.
+bool
+rtl_ssa::recog_internal (insn_change &change,
+ add_regno_clobber_fn add_regno_clobber)
+{
+ // Accept all changes to debug instructions.
+ insn_info *insn = change.insn ();
+ if (insn->is_debug_insn ())
+ return true;
+
+ rtx_insn *rtl = insn->rtl ();
+ rtx pat = PATTERN (rtl);
+ if (GET_CODE (pat) == PARALLEL && asm_noperands (pat) < 0)
+ {
+ // Try to remove trailing (clobber (scratch)) rtxes, since the new form
+ // of the instruction might not need those scratches. recog will add
+ // back any that are needed.
+ int len = XVECLEN (pat, 0);
+ int new_len = len;
+ while (new_len > 0
+ && GET_CODE (XVECEXP (pat, 0, new_len - 1)) == CLOBBER
+ && GET_CODE (XEXP (XVECEXP (pat, 0, new_len - 1), 0)) == SCRATCH)
+ new_len -= 1;
+
+ int old_num_changes = num_validated_changes ();
+ validate_change_xveclen (rtl, &PATTERN (rtl), new_len, true);
+ if (recog_level2 (change, add_regno_clobber))
+ return true;
+ cancel_changes (old_num_changes);
+
+ // Try to remove all trailing clobbers. For example, a pattern that
+ // used to clobber the flags might no longer need to do so.
+ int prev_len = new_len;
+ while (new_len > 0
+ && GET_CODE (XVECEXP (pat, 0, new_len - 1)) == CLOBBER)
+ new_len -= 1;
+ if (new_len != prev_len)
+ {
+ validate_change_xveclen (rtl, &PATTERN (rtl), new_len, true);
+ if (recog_level2 (change, add_regno_clobber))
+ return true;
+ cancel_changes (old_num_changes);
+ }
+ return false;
+ }
+
+ return recog_level2 (change, add_regno_clobber);
+}
+
+// See the comment above the declaration.
+bool
+function_info::perform_pending_updates ()
+{
+ bool changed_cfg = false;
+ bool changed_jumps = false;
+ for (insn_info *insn : m_queued_insn_updates)
+ {
+ rtx_insn *rtl = insn->rtl ();
+ if (JUMP_P (rtl))
+ {
+ if (INSN_CODE (rtl) == NOOP_MOVE_INSN_CODE)
+ {
+ ::delete_insn (rtl);
+ bitmap_set_bit (m_need_to_purge_dead_edges,
+ insn->bb ()->index ());
+ }
+ else if (returnjump_p (rtl) || any_uncondjump_p (rtl))
+ {
+ mark_jump_label (PATTERN (rtl), rtl, 0);
+ update_cfg_for_uncondjump (rtl);
+ changed_cfg = true;
+ changed_jumps = true;
+ }
+ }
+ else if (INSN_CODE (rtl) == NOOP_MOVE_INSN_CODE)
+ ::delete_insn (rtl);
+ else
+ {
+ rtx pattern = PATTERN (rtl);
+ if (GET_CODE (pattern) == TRAP_IF
+ && XEXP (pattern, 0) == const1_rtx)
+ {
+ remove_edge (split_block (BLOCK_FOR_INSN (rtl), rtl));
+ emit_barrier_after_bb (BLOCK_FOR_INSN (rtl));
+ changed_cfg = true;
+ }
+ }
+ }
+
+ unsigned int index;
+ bitmap_iterator bi;
+ EXECUTE_IF_SET_IN_BITMAP (m_need_to_purge_dead_edges, 0, index, bi)
+ if (purge_dead_edges (BASIC_BLOCK_FOR_FN (m_fn, index)))
+ changed_cfg = true;
+
+ if (changed_jumps)
+ // This uses its own timevar internally, so we don't need to push
+ // one ourselves.
+ rebuild_jump_labels (get_insns ());
+
+ bitmap_clear (m_need_to_purge_dead_edges);
+ bitmap_clear (m_queued_insn_update_uids);
+ m_queued_insn_updates.truncate (0);
+
+ if (changed_cfg)
+ {
+ free_dominance_info (CDI_DOMINATORS);
+ free_dominance_info (CDI_POST_DOMINATORS);
+ }
+
+ return changed_cfg;
+}
+
+// Print a description of CHANGE to PP.
+void
+rtl_ssa::pp_insn_change (pretty_printer *pp, const insn_change &change)
+{
+ change.print (pp);
+}
+
+// Print a description of CHANGE to FILE.
+void
+dump (FILE *file, const insn_change &change)
+{
+ dump_using (file, pp_insn_change, change);
+}
+
+// Debug interface to the dump routine above.
+void debug (const insn_change &x) { dump (stderr, x); }
--- /dev/null
+// RTL SSA classes related to changing instructions -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// A class that describes a change that we're considering making to an
+// instruction. There are three choices:
+//
+// (1) delete the instruction
+// (2) replace the instruction with a new instruction in-place
+// (3) replace the instruction with a new instruction at a different location
+//
+// Anything related to the "new instruction" is irrelevant for (1).
+//
+// The class doesn't actually change anything itself, it simply records
+// something that we might do.
+class insn_change
+{
+public:
+ enum delete_action { DELETE };
+
+ // Construct a possible change to INSN.
+ insn_change (insn_info *insn);
+
+ // Construct a possible deletion of INSN.
+ insn_change (insn_info *insn, delete_action);
+
+ // The instruction that we would change.
+ insn_info *insn () const { return m_insn; }
+
+ // The rtx_insn of the instruction that we would change.
+ rtx_insn *rtl () const { return m_insn->rtl (); }
+
+ // The basic block that contains insn ().
+ bb_info *bb () const { return m_insn->bb (); }
+
+ // The extended basic block that contains insn ().
+ ebb_info *ebb () const { return m_insn->ebb (); }
+
+ // The uid of the instruction that we would change.
+ unsigned int insn_uid () const { return m_insn->uid (); }
+
+ // The list of things that the original instruction defined and used.
+ def_array old_defs () const { return m_insn->defs (); }
+ use_array old_uses () const { return m_insn->uses (); }
+
+ // The cost of the original instruction, as calculated by the target.
+ unsigned int old_cost () const { return m_insn->cost (); }
+
+ // Return true if the original instruction would simply be deleted,
+ // rather than being replaced by a new instruction.
+ bool is_deletion () const { return m_is_deletion; }
+
+ // Print a description of the change to PP.
+ void print (pretty_printer *pp) const;
+
+ // Return an insn_change for deleting INSN.
+ static insn_change delete_insn (insn_info *insn) { return { insn, DELETE }; }
+
+private:
+ // The value returned by insn ().
+ insn_info *m_insn;
+
+public:
+ // The list of things that the new instruction would define and use.
+ def_array new_defs;
+ use_array new_uses;
+
+ // The range of instructions after which the instruction could be placed.
+ // The range can include INSN itself: placing the instruction after either
+ // INSN or INSN->prev_nondebug_insn () is equivalent to not moving the
+ // instruction.
+ insn_range_info move_range;
+
+ // The cost that the new instruction would have, as calculated by the target.
+ unsigned int new_cost;
+
+private:
+ // The value returned by is_deletion ().
+ bool m_is_deletion;
+};
+
+// A class that represents a closure of the two-argument form of
+// insn_is_changing. See the comment above the one-argument form
+// for details.
+class insn_is_changing_closure
+{
+public:
+ insn_is_changing_closure (array_slice<insn_change *const> changes);
+ bool operator() (const insn_info *) const;
+
+private:
+ array_slice<insn_change *const> m_changes;
+};
+
+void pp_insn_change (pretty_printer *, const insn_change &);
+
+}
+
+void dump (FILE *, const rtl_ssa::insn_change &);
+
+void DEBUG_FUNCTION debug (const rtl_ssa::insn_change &);
--- /dev/null
+// Implementation of function-related RTL SSA functions -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#include "rtl-ssa.h"
+#include "rtl-ssa/internals.inl"
+
+using namespace rtl_ssa;
+
+function_info::function_info (function *fn)
+ : m_fn (fn)
+{
+ // Force the alignment to be obstack_alignment. Everything else is normal.
+ obstack_specify_allocation (&m_obstack, OBSTACK_CHUNK_SIZE,
+ obstack_alignment, obstack_chunk_alloc,
+ obstack_chunk_free);
+ obstack_specify_allocation (&m_temp_obstack, OBSTACK_CHUNK_SIZE,
+ obstack_alignment, obstack_chunk_alloc,
+ obstack_chunk_free);
+
+ // Record the start of the obstacks.
+ m_obstack_start = XOBNEWVAR (&m_obstack, char, 0);
+ m_temp_obstack_start = XOBNEWVAR (&m_temp_obstack, char, 0);
+
+ init_function_data ();
+ process_all_blocks ();
+ simplify_phis ();
+}
+
+function_info::~function_info ()
+{
+ // Anything using the temporary obstack should free it afterwards,
+ // preferably via temp_watermark ().
+ gcc_assert (XOBNEWVAR (&m_temp_obstack, char, 0) == m_temp_obstack_start);
+
+ obstack_free (&m_temp_obstack, nullptr);
+ obstack_free (&m_obstack, nullptr);
+}
+
+// See the comment above the declaration.
+void
+function_info::print (pretty_printer *pp) const
+{
+ pp_string (pp, "Function: ");
+ pp_string (pp, function_name (m_fn));
+ for (ebb_info *ebb : ebbs ())
+ {
+ pp_newline (pp);
+ pp_newline_and_indent (pp, 0);
+ pp_ebb (pp, ebb);
+ }
+}
+
+// Calculate m_potential_phi_regs.
+void
+function_info::calculate_potential_phi_regs ()
+{
+ auto *lr_info = DF_LR_BB_INFO (ENTRY_BLOCK_PTR_FOR_FN (m_fn));
+ for (unsigned int regno = 0; regno < m_num_regs; ++regno)
+ if (regno >= DF_REG_SIZE (DF)
+ // Exclude registers that have a single definition that dominates
+ // all uses. If the definition does not dominate all uses,
+ // the register will be exposed upwards to the entry block but
+ // will not be defined by the entry block.
+ || DF_REG_DEF_COUNT (regno) > 1
+ || (!bitmap_bit_p (&lr_info->def, regno)
+ && bitmap_bit_p (&lr_info->out, regno)))
+ bitmap_set_bit (m_potential_phi_regs, regno);
+}
+
+// Initialize all member variables in preparation for (re)building
+// SSA form from scratch.
+void
+function_info::init_function_data ()
+{
+ m_next_artificial_uid = -1;
+ m_next_phi_uid = 0;
+ m_num_regs = max_reg_num ();
+ m_defs.safe_grow_cleared (m_num_regs + 1);
+ m_bbs.safe_grow_cleared (last_basic_block_for_fn (m_fn));
+ m_first_bb = nullptr;
+ m_last_bb = nullptr;
+ m_first_insn = nullptr;
+ m_last_insn = nullptr;
+ m_last_nondebug_insn = nullptr;
+ m_free_phis = nullptr;
+
+ calculate_potential_phi_regs ();
+}
+
+// The initial phase of the phi simplification process. The cumulative
+// effect of the initial phase is to set up ASSUMED_VALUES such that,
+// for a phi P with uid ID:
+//
+// - if we think all inputs to P have the same value, ASSUMED_VALUES[ID]
+// is that value
+//
+// - otherwise, ASSUMED_VALUES[ID] is P.
+//
+// This has already been done for phis with a lower uid than PHI,
+// initially making optimistic assumptions about backedge inputs.
+// Now do the same for PHI. If this might invalidate any assumptions
+// made for earlier phis, add the uids of those phis to WORKLIST.
+void
+function_info::simplify_phi_setup (phi_info *phi, set_info **assumed_values,
+ bitmap worklist)
+{
+ // If all non-backedge inputs have the same value, set NEW_VALUE
+ // to that value. Otherwise set NEW_VALUE to PHI, to indicate
+ // that PHI cannot be simplified.
+ unsigned int phi_uid = phi->uid ();
+ bool is_first_input = true;
+ set_info *new_value = nullptr;
+ machine_mode phi_mode = phi->mode ();
+ for (use_info *input : phi->inputs ())
+ {
+ set_info *def = input->def ();
+
+ if (auto *input_phi = safe_dyn_cast<phi_info *> (def))
+ {
+ // Ignore backedges for now.
+ unsigned int input_phi_uid = input_phi->uid ();
+ if (phi_uid <= input_phi_uid)
+ continue;
+
+ def = assumed_values[input_phi_uid];
+ }
+
+ // Compare this definition with previous ones.
+ if (is_first_input)
+ {
+ new_value = def;
+ is_first_input = false;
+ }
+ else if (new_value != def)
+ new_value = phi;
+
+ // If the input has a known mode (i.e. not BLKmode), make sure
+ // that the phi's mode is at least as large.
+ if (def)
+ phi_mode = combine_modes (phi_mode, def->mode ());
+ }
+ if (phi->mode () != phi_mode)
+ phi->set_mode (phi_mode);
+
+ // Since we use a reverse postorder traversal, no phi can consist
+ // entirely of backedges.
+ gcc_checking_assert (!is_first_input);
+ assumed_values[phi_uid] = new_value;
+
+ // See whether any assumptions for earlier phis are now invalid.
+ simplify_phi_propagate (phi, assumed_values, nullptr, worklist);
+}
+
+// The propagation phase of the phi simplification process, with
+// ASSUMED_VALUES as described above simplify_phi_setup. Iteratively
+// update the phis that use PHI based on PHI's entry in ASSUMED_VALUES.
+// If CURR_WORKLIST is null, consider only phi uses with a lower uid
+// than PHI, otherwise consider all phi uses.
+//
+// If a phi with a higher uid than PHI needs updating, add its uid to
+// CURR_WORKLIST; if a phi with a lower uid than PHI needs updating,
+// add its uid to NEXT_WORKLIST.
+void
+function_info::simplify_phi_propagate (phi_info *phi,
+ set_info **assumed_values,
+ bitmap curr_worklist,
+ bitmap next_worklist)
+{
+ // Go through each phi user of PHI to see whether it needs updating.
+ unsigned int phi_uid = phi->uid ();
+ machine_mode phi_mode = phi->mode ();
+ set_info *phi_value = assumed_values[phi_uid];
+ for (use_info *use : phi->phi_uses ())
+ {
+ phi_info *user_phi = use->phi ();
+
+ // Propagate the phi's new mode to all phi users. Insn uses should
+ // not be updated, since their modes reflect a property of the insns
+ // rather than the phi.
+ if (use->mode () != phi_mode)
+ use->set_mode (phi_mode);
+
+ if (user_phi == phi)
+ continue;
+
+ // If this is a phi we should be looking at, see whether it needs
+ // an update.
+ unsigned int user_phi_uid = user_phi->uid ();
+ if (user_phi_uid < phi_uid || curr_worklist)
+ {
+ bool needs_update = false;
+
+ // Make sure that USER_PHI's mode is at least as big as PHI_MODE.
+ machine_mode user_phi_mode = user_phi->mode ();
+ machine_mode new_mode = combine_modes (user_phi_mode, phi_mode);
+ if (user_phi_mode != new_mode)
+ {
+ user_phi->set_mode (new_mode);
+ needs_update = true;
+ }
+
+ // If USER_PHI optimistically assumed an incorrect value,
+ // adjust it now.
+ if (assumed_values[user_phi_uid] != user_phi
+ && assumed_values[user_phi_uid] != phi_value)
+ {
+ assumed_values[user_phi_uid] = user_phi;
+ needs_update = true;
+ }
+
+ if (needs_update)
+ {
+ if (user_phi_uid < phi_uid)
+ bitmap_set_bit (next_worklist, user_phi_uid);
+ else
+ bitmap_set_bit (curr_worklist, user_phi_uid);
+ }
+ }
+ }
+}
+
+// Update the modes of all phis so that they are at least as big as
+// all inputs. Remove any non-degenerate phis whose inputs are all equal.
+void
+function_info::simplify_phis ()
+{
+ auto temps = temp_watermark ();
+
+ // See the comment above simplify_phi_setup for details about this array.
+ auto *assumed_values = XOBNEWVEC (&m_temp_obstack, set_info *,
+ m_next_phi_uid);
+
+ // An array of all phis, indexed by uid.
+ auto *phis = XOBNEWVEC (&m_temp_obstack, phi_info *, m_next_phi_uid);
+
+ // Which phi uids are actually in use.
+ auto_sbitmap valid_phi_uids (m_next_phi_uid);
+ bitmap_clear (valid_phi_uids);
+
+ // Bitmaps used for the main double-queue propagation phase.
+ auto_bitmap worklist1;
+ auto_bitmap worklist2;
+ bitmap curr_worklist = worklist1;
+ bitmap next_worklist = worklist2;
+
+ // Perform the set-up phase; see simplify_phi_setup for details.
+ for (ebb_info *ebb : ebbs ())
+ for (phi_info *phi : ebb->phis ())
+ {
+ bitmap_set_bit (valid_phi_uids, phi->uid ());
+ phis[phi->uid ()] = phi;
+ simplify_phi_setup (phi, assumed_values, curr_worklist);
+ }
+
+ // Iteratively process any phis that need updating; see
+ // simplify_phi_propagate for details. Using a double queue
+ // should reduce the number of times that any given phi node
+ // needs to be revisited.
+ while (!bitmap_empty_p (curr_worklist))
+ {
+ do
+ {
+ unsigned int uid = bitmap_first_set_bit (curr_worklist);
+ bitmap_clear_bit (curr_worklist, uid);
+ simplify_phi_propagate (phis[uid], assumed_values,
+ curr_worklist, next_worklist);
+ }
+ while (!bitmap_empty_p (curr_worklist));
+ std::swap (next_worklist, curr_worklist);
+ }
+
+ // Make sure that assumed_values is a transitive closure. This ensures
+ // that each use_info is only updated once.
+ if (flag_checking)
+ for (unsigned int i = 0; i < m_next_phi_uid; ++i)
+ if (bitmap_bit_p (valid_phi_uids, i))
+ if (auto *new_phi = safe_dyn_cast<phi_info *> (assumed_values[i]))
+ gcc_assert (assumed_values[new_phi->uid ()] == new_phi);
+
+ // Update any phis that turned out to be equivalent to a single input.
+ for (unsigned int i = 0; i < m_next_phi_uid; ++i)
+ if (bitmap_bit_p (valid_phi_uids, i) && phis[i] != assumed_values[i])
+ replace_phi (phis[i], assumed_values[i]);
+}
+
+// Print a description of FUNCTION to PP.
+void
+rtl_ssa::pp_function (pretty_printer *pp, const function_info *function)
+{
+ function->print (pp);
+}
+
+// Print a description of FUNCTION to FILE.
+void
+dump (FILE *file, const function_info *function)
+{
+ dump_using (file, pp_function, function);
+}
+
+// Debug interface to the dump routine above.
+void debug (const function_info *x) { dump (stderr, x); }
--- /dev/null
+// Function-related RTL SSA classes -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// SSA-related information about a function. It contains three levels
+// of information, each in reverse postorder:
+//
+// - a list of extended basic blocks
+// - a list of basic blocks
+// - a list of instructions
+//
+// It also maintains a list of definitions of memory, and a list of
+// definitions of each register.
+//
+// See doc/rtl.texi for more details about the way this information
+// is organized and how changes to it are made.
+class function_info
+{
+ // The default obstack alignment takes long double into account.
+ // Since we have no use for that here, and since we allocate many
+ // relatively small objects, it's better to specify an alignment
+ // explicitly. The allocation routines assert that the alignment
+ // is enough for the objects being allocated.
+ //
+ // Because various structures use pointer_mux, we need at least 2 bytes
+ // of alignment.
+ static const size_t obstack_alignment = sizeof (void *);
+
+public:
+ // Construct SSA form for function FN.
+ function_info (function *fn);
+ ~function_info ();
+
+ // Return a list of all the extended basic blocks in the function, in reverse
+ // postorder. The list includes the entry and exit blocks.
+ iterator_range<ebb_iterator> ebbs () const;
+
+ // Like ebbs (), but in the reverse order.
+ iterator_range<reverse_ebb_iterator> reverse_ebbs () const;
+
+ // Return a list of all the basic blocks in the function, in reverse
+ // postorder. The list includes the entry and exit blocks.
+ iterator_range<bb_iterator> bbs () const;
+
+ // Like bbs (), but in the reverse order.
+ iterator_range<reverse_bb_iterator> reverse_bbs () const;
+
+ // Return the SSA information for the basic block with index INDEX.
+ bb_info *bb (unsigned int index) const { return m_bbs[index]; }
+
+ // Return the SSA information for CFG_BB.
+ bb_info *bb (basic_block cfg_bb) const { return m_bbs[cfg_bb->index]; }
+
+ // Return a list of all the instructions in the function, in reverse
+ // postorder. The list includes both real and artificial instructions.
+ //
+ // Iterations over the list will pick up any new instructions that are
+ // inserted after the iterator's current instruction.
+ iterator_range<any_insn_iterator> all_insns () const;
+
+ // Like all_insns (), but in the reverse order.
+ //
+ // Iterations over the list will pick up any new instructions that are
+ // inserted before the iterator's current instruction.
+ iterator_range<reverse_any_insn_iterator> reverse_all_insns () const;
+
+ // Like all_insns (), but without the debug instructions.
+ iterator_range<nondebug_insn_iterator> nondebug_insns () const;
+
+ // Like reverse_all_insns (), but without the debug instructions.
+ iterator_range<reverse_nondebug_insn_iterator>
+ reverse_nondebug_insns () const;
+
+ // Return the first and last instructions in insns ().
+ insn_info *first_insn () const { return m_first_insn; }
+ insn_info *last_insn () const { return m_last_insn; }
+
+ // Return a list of all definitions of memory, in reverse postorder.
+ // This includes both real stores by instructions and artificial
+ // definitions by things like phi nodes.
+ iterator_range<def_iterator> mem_defs () const;
+
+ // Return a list of all definitions of register REGNO, in reverse postorder.
+ // This includes both real stores by instructions and artificial
+ // definitions by things like phi nodes.
+ iterator_range<def_iterator> ref_defs (unsigned int regno) const;
+
+ // Check if all uses of register REGNO are either unconditionally undefined
+ // or use the same single dominating definition. Return the definition
+ // if so, otherwise return null.
+ set_info *single_dominating_def (unsigned int regno) const;
+
+ // Look for a definition of RESOURCE at INSN. Return the result of the
+ // search as a def_lookup; see the comments there for more details.
+ def_lookup find_def (resource_info resource, insn_info *insn);
+
+ // Return an RAII object that owns all temporary RTL SSA memory
+ // allocated during a change attempt. The object should remain in
+ // scope until the change has been aborted or successfully completed.
+ obstack_watermark new_change_attempt () { return &m_temp_obstack; }
+
+ // Make a best attempt to check whether the values used by USES are
+ // available on entry to BB, without solving a full dataflow problem.
+ // If all the values are already live on entry to BB or can be made
+ // available there, return a use_array that describes the uses as
+ // if they occured at the start of BB. These uses are purely temporary,
+ // and will not become permanent unless applied using change_insns.
+ //
+ // If the operation fails, return an invalid use_array.
+ //
+ // WATERMARK is a watermark returned by new_change_attempt ().
+ use_array make_uses_available (obstack_watermark &watermark,
+ use_array uses, bb_info *bb);
+
+ // If CHANGE doesn't already clobber REGNO, try to add such a clobber,
+ // limiting the movement range in order to make the clobber valid.
+ // When determining whether REGNO is live, ignore accesses made by an
+ // instruction I if IGNORE (I) is true. The caller then assumes the
+ // responsibility of ensuring that CHANGE and I are placed in a valid order.
+ //
+ // Return true on success. Leave CHANGE unmodified when returning false.
+ //
+ // WATERMARK is a watermark returned by new_change_attempt ().
+ template<typename IgnorePredicate>
+ bool add_regno_clobber (obstack_watermark &watermark, insn_change &change,
+ unsigned int regno, IgnorePredicate ignore);
+
+ // Return true if change_insns will be able to perform the changes
+ // described by CHANGES.
+ bool verify_insn_changes (array_slice<insn_change *const> changes);
+
+ // Perform all the changes in CHANGES, keeping the instructions in the
+ // order specified by the CHANGES array. On return, the SSA information
+ // remains up-to-date. The same is true for instruction-level DF
+ // information, although the block-level DF information might be
+ // marked dirty.
+ void change_insns (array_slice<insn_change *> changes);
+
+ // Like change_insns, but for a single change CHANGE.
+ void change_insn (insn_change &change);
+
+ // If the changes that have been made to instructions require updates
+ // to the CFG, perform those updates now. Return true if something changed.
+ // If it did:
+ //
+ // - The SSA information is now invalid and needs to be recomputed.
+ //
+ // - Dominance information is no longer available (in either direction).
+ //
+ // - The caller will need to call cleanup_cfg at some point.
+ //
+ // ??? We could probably update the SSA information for simple updates,
+ // but currently nothing would benefit. These late CFG changes are
+ // relatively rare anyway, since gimple optimisers should remove most
+ // unnecessary control flow.
+ bool perform_pending_updates ();
+
+ // Print the contents of the function to PP.
+ void print (pretty_printer *pp) const;
+
+private:
+ // Information about the values that are live on exit from a basic block.
+ // This class is only used when constructing the SSA form, it isn't
+ // designed for being kept up-to-date.
+ class bb_live_out_info
+ {
+ public:
+ // REG_VALUES contains all the registers that live out from the block,
+ // in order of increasing register number. There are NUM_REG_VALUES
+ // in total. Registers do not appear here if their values are known
+ // to be completely undefined; in that sense, the information is
+ // closer to DF_LIVE than to DF_LR.
+ unsigned int num_reg_values;
+ set_info **reg_values;
+
+ // The memory value that is live on exit from the block.
+ set_info *mem_value;
+ };
+
+ // Information used while constructing the SSA form and discarded
+ // afterwards.
+ class build_info
+ {
+ public:
+ set_info *current_reg_value (unsigned int) const;
+ set_info *current_mem_value () const;
+
+ void record_reg_def (unsigned int, def_info *);
+ void record_mem_def (def_info *);
+
+ // The block that we're currently processing.
+ bb_info *current_bb;
+
+ // The EBB that contains CURRENT_BB.
+ ebb_info *current_ebb;
+
+ // Except for the local exception noted below:
+ //
+ // - If register R has been defined in the current EBB, LAST_ACCESS[R + 1]
+ // is the last definition of R in the EBB.
+ //
+ // - If register R is currently live but has not yet been defined
+ // in the EBB, LAST_ACCESS[R + 1] is the current value of R,
+ // or null if the register's value is completely undefined.
+ //
+ // - The contents are not meaningful for other registers.
+ //
+ // Similarly:
+ //
+ // - If the current EBB has defined memory, LAST_ACCESS[0] is the last
+ // definition of memory in the EBB.
+ //
+ // - Otherwise LAST_ACCESS[0] is the value of memory that is live on
+ // - entry to the EBB.
+ //
+ // The exception is that while building instructions, LAST_ACCESS[I]
+ // can temporarily be the use of regno I - 1 by that instruction.
+ access_info **last_access;
+
+ // A bitmap of registers that are live on entry to this EBB, with a tree
+ // view for quick lookup. Only used if MAY_HAVE_DEBUG_INSNS.
+ bitmap ebb_live_in_for_debug;
+
+ // A conservative superset of the registers that are used by
+ // instructions in CURRENT_EBB. That is, all used registers
+ // are in the set, but some unused registers might be too.
+ bitmap ebb_use;
+
+ // A similarly conservative superset of the registers that are defined
+ // by instructions in CURRENT_EBB.
+ bitmap ebb_def;
+
+ // BB_LIVE_OUT[BI] gives the live-out values for the basic block
+ // with index BI.
+ bb_live_out_info *bb_live_out;
+ };
+
+ // Return an RAII object that owns all objects allocated by
+ // allocate_temp during its lifetime.
+ obstack_watermark temp_watermark () { return &m_temp_obstack; }
+
+ template<typename T, typename... Ts>
+ T *allocate (Ts... args);
+
+ template<typename T, typename... Ts>
+ T *allocate_temp (Ts... args);
+
+ access_array temp_access_array (access_array accesses);
+
+ clobber_group *need_clobber_group (clobber_info *);
+ def_node *need_def_node (def_info *);
+ def_splay_tree need_def_splay_tree (def_info *);
+
+ use_info *make_use_available (use_info *, bb_info *);
+ def_array insert_temp_clobber (obstack_watermark &, insn_info *,
+ unsigned int, def_array);
+
+ void insert_def_before (def_info *, def_info *);
+ void insert_def_after (def_info *, def_info *);
+ void remove_def_from_list (def_info *);
+
+ void add_clobber (clobber_info *, clobber_group *);
+ void remove_clobber (clobber_info *, clobber_group *);
+ void prepend_clobber_to_group (clobber_info *, clobber_group *);
+ void append_clobber_to_group (clobber_info *, clobber_group *);
+ void merge_clobber_groups (clobber_info *, clobber_info *,
+ def_info *);
+ clobber_info *split_clobber_group (clobber_group *, insn_info *);
+
+ void append_def (def_info *);
+ void add_def (def_info *);
+ void remove_def (def_info *);
+
+ void need_use_splay_tree (set_info *);
+
+ static void insert_use_before (use_info *, use_info *);
+ static void insert_use_after (use_info *, use_info *);
+
+ void add_use (use_info *);
+ void remove_use (use_info *);
+
+ insn_info::order_node *need_order_node (insn_info *);
+
+ void add_insn_after (insn_info *, insn_info *);
+ void append_insn (insn_info *);
+ void remove_insn (insn_info *);
+
+ insn_info *append_artificial_insn (bb_info *, rtx_insn * = nullptr);
+
+ void start_insn_accesses ();
+ void finish_insn_accesses (insn_info *);
+
+ void record_use (build_info &, insn_info *, rtx_obj_reference);
+ void record_call_clobbers (build_info &, insn_info *, rtx_call_insn *);
+ void record_def (build_info &, insn_info *, rtx_obj_reference);
+ void add_insn_to_block (build_info &, rtx_insn *);
+
+ void add_reg_unused_notes (insn_info *);
+
+ void add_live_out_use (bb_info *, set_info *);
+ set_info *live_out_value (bb_info *, set_info *);
+
+ void append_phi (ebb_info *, phi_info *);
+ void remove_phi (phi_info *);
+ void delete_phi (phi_info *);
+ void replace_phi (phi_info *, set_info *);
+ phi_info *create_phi (ebb_info *, resource_info, access_info **,
+ unsigned int);
+ phi_info *create_degenerate_phi (ebb_info *, set_info *);
+
+ bb_info *create_bb_info (basic_block);
+ void append_bb (bb_info *);
+ void calculate_potential_phi_regs ();
+
+ insn_info *add_placeholder_after (insn_info *);
+ void possibly_queue_changes (insn_change &);
+ void finalize_new_accesses (insn_change &);
+ void apply_changes_to_insn (insn_change &);
+
+ void init_function_data ();
+ void add_entry_block_defs (build_info &);
+ void add_phi_nodes (build_info &);
+ void add_artificial_accesses (build_info &, df_ref_flags);
+ void add_block_contents (build_info &);
+ void record_block_live_out (build_info &);
+ void populate_backedge_phis (build_info &);
+ void process_all_blocks ();
+
+ void simplify_phi_setup (phi_info *, set_info **, bitmap);
+ void simplify_phi_propagate (phi_info *, set_info **, bitmap, bitmap);
+ void simplify_phis ();
+
+ // The function that this object describes.
+ function *m_fn;
+
+ // The lowest (negative) in-use artificial insn uid minus one.
+ int m_next_artificial_uid;
+
+ // The highest in-use phi uid plus one.
+ unsigned int m_next_phi_uid;
+
+ // The highest in-use register number plus one.
+ unsigned int m_num_regs;
+
+ // M_DEFS[R] is the first definition of register R - 1 in a reverse
+ // postorder traversal of the function, or null if the function has
+ // no definition of R. Applying last () gives the last definition of R.
+ //
+ // M_DEFS[0] is for memory; MEM_REGNO + 1 == 0.
+ auto_vec<def_info *> m_defs;
+
+ // M_BBS[BI] gives the SSA information about the block with index BI.
+ auto_vec<bb_info *> m_bbs;
+
+ // An obstack used to allocate the main RTL SSA information.
+ obstack m_obstack;
+
+ // An obstack used for temporary work, such as while building up a list
+ // of possible instruction changes.
+ obstack m_temp_obstack;
+
+ // The start of each obstack, so that all memory in them can be freed.
+ char *m_obstack_start;
+ char *m_temp_obstack_start;
+
+ // The entry and exit blocks.
+ bb_info *m_first_bb;
+ bb_info *m_last_bb;
+
+ // The first and last instructions in a reverse postorder traversal
+ // of the function.
+ insn_info *m_first_insn;
+ insn_info *m_last_insn;
+
+ // The last nondebug instruction in the list of instructions.
+ // This is only different from m_last_insn when building the initial
+ // SSA information; after that, the last instruction is always a
+ // BB end instruction.
+ insn_info *m_last_nondebug_insn;
+
+ // Temporary working state when building up lists of definitions and uses.
+ // Keeping them around should reduce the number of unnecessary reallocations.
+ auto_vec<access_info *> m_temp_defs;
+ auto_vec<access_info *> m_temp_uses;
+
+ // The set of registers that might need to have phis associated with them.
+ // Registers outside this set are known to have a single definition that
+ // dominates all uses.
+ //
+ // Before RA, about 5% of registers are typically in the set.
+ auto_bitmap m_potential_phi_regs;
+
+ // A list of phis that are no longer in use. Their uids are still unique
+ // and so can be recycled.
+ phi_info *m_free_phis;
+
+ // A list of instructions that have been changed in ways that need
+ // further processing later, such as removing dead instructions or
+ // altering the CFG.
+ auto_vec<insn_info *> m_queued_insn_updates;
+
+ // The INSN_UIDs of all instructions in M_QUEUED_INSN_UPDATES.
+ auto_bitmap m_queued_insn_update_uids;
+
+ // A basic_block is in this bitmap if we need to call purge_dead_edges
+ // on it. As with M_QUEUED_INSN_UPDATES, these updates are queued until
+ // a convenient point.
+ auto_bitmap m_need_to_purge_dead_edges;
+};
+
+void pp_function (pretty_printer *, const function_info *);
+}
+
+void dump (FILE *, const rtl_ssa::function_info *);
+
+void DEBUG_FUNCTION debug (const rtl_ssa::function_info *);
--- /dev/null
+// Instruction-related utilities for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// Return whichever of INSN1 and INSN2 occurs earlier in the function's
+// reverse postorder.
+inline insn_info *
+earlier_insn (insn_info *insn1, insn_info *insn2)
+{
+ return *insn1 < *insn2 ? insn1 : insn2;
+}
+
+// Return whichever of INSN1 and INSN2 occurs later in the function's
+// reverse postorder.
+inline insn_info *
+later_insn (insn_info *insn1, insn_info *insn2)
+{
+ return *insn1 < *insn2 ? insn2 : insn1;
+}
+
+// Return a closure of operator== for INSN. See insn_is_changing for
+// the rationale for defining the function this way.
+inline insn_is_closure
+insn_is (const insn_info *insn)
+{
+ return insn_is_closure (insn);
+}
+
+}
--- /dev/null
+// Implementation of instruction-related RTL SSA functions -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+#define INCLUDE_ALGORITHM
+#define INCLUDE_FUNCTIONAL
+#include "config.h"
+#include "system.h"
+#include "coretypes.h"
+#include "backend.h"
+#include "rtl.h"
+#include "df.h"
+#include "rtl-ssa.h"
+#include "rtl-ssa/internals.inl"
+#include "predict.h"
+#include "print-rtl.h"
+#include "rtl-iter.h"
+
+using namespace rtl_ssa;
+
+// The gap to leave between program points when building up the list
+// of instructions for the first time. Using 2 allows an instruction
+// to be inserted between two others without resorting to splay tree
+// ordering. Using 0 is useful as a debugging aid to stress the
+// splay tree code.
+static const unsigned int POINT_INCREASE = 2;
+
+// Calculate and record the cost of the instruction, based on the
+// form it had before any in-progress changes were made.
+void
+insn_info::calculate_cost () const
+{
+ basic_block cfg_bb = BLOCK_FOR_INSN (m_rtl);
+ temporarily_undo_changes (0);
+ m_cost_or_uid = insn_cost (m_rtl, optimize_bb_for_speed_p (cfg_bb));
+ redo_changes (0);
+}
+
+// Add NOTE to the instruction's notes.
+void
+insn_info::add_note (insn_note *note)
+{
+ insn_note **ptr = &m_first_note;
+ // Always put the order node first, since it's the one that's likely
+ // to be used most often.
+ if (*ptr && (*ptr)->kind () == insn_note_kind::ORDER_NODE)
+ ptr = &(*ptr)->m_next_note;
+ note->m_next_note = *ptr;
+ *ptr = note;
+}
+
+// Implement compare_with for the case in which this insn and OTHER
+// have the same program point.
+int
+insn_info::slow_compare_with (const insn_info &other) const
+{
+ return order_splay_tree::compare_nodes (get_known_order_node (),
+ other.get_known_order_node ());
+}
+
+// Print insn uid UID to PP, where UID has the same form as insn_info::uid.
+void
+insn_info::print_uid (pretty_printer *pp, int uid)
+{
+ char tmp[3 * sizeof (uid) + 2];
+ if (uid < 0)
+ // An artificial instruction.
+ snprintf (tmp, sizeof (tmp), "a%d", -uid);
+ else
+ // A real RTL instruction.
+ snprintf (tmp, sizeof (tmp), "i%d", uid);
+ pp_string (pp, tmp);
+}
+
+// See comment above declaration.
+void
+insn_info::print_identifier (pretty_printer *pp) const
+{
+ print_uid (pp, uid ());
+}
+
+// See comment above declaration.
+void
+insn_info::print_location (pretty_printer *pp) const
+{
+ if (bb_info *bb = this->bb ())
+ {
+ ebb_info *ebb = bb->ebb ();
+ if (ebb && is_phi ())
+ ebb->print_identifier (pp);
+ else
+ bb->print_identifier (pp);
+ pp_string (pp, " at point ");
+ pp_decimal_int (pp, m_point);
+ }
+ else
+ pp_string (pp, "<unknown location>");
+}
+
+// See comment above declaration.
+void
+insn_info::print_identifier_and_location (pretty_printer *pp) const
+{
+ if (m_is_asm)
+ pp_string (pp, "asm ");
+ if (m_is_debug_insn)
+ pp_string (pp, "debug ");
+ pp_string (pp, "insn ");
+ print_identifier (pp);
+ pp_string (pp, " in ");
+ print_location (pp);
+}
+
+// See comment above declaration.
+void
+insn_info::print_full (pretty_printer *pp) const
+{
+ print_identifier_and_location (pp);
+ pp_colon (pp);
+ if (is_real ())
+ {
+ pp_newline_and_indent (pp, 2);
+ if (has_been_deleted ())
+ pp_string (pp, "deleted");
+ else
+ {
+ // Print the insn pattern to a temporary printer.
+ pretty_printer sub_pp;
+ print_insn_with_notes (&sub_pp, rtl ());
+ const char *text = pp_formatted_text (&sub_pp);
+
+ // Calculate the length of the maximum line in the pattern.
+ unsigned int max_len = 0;
+ const char *start = text;
+ while (const char *end = strchr (start, '\n'))
+ {
+ max_len = MAX (max_len, (unsigned int) (end - start));
+ start = end + 1;
+ }
+
+ // Print a separator before or after the pattern.
+ auto print_top_bottom = [&]()
+ {
+ pp_character (pp, '+');
+ for (unsigned int i = 0; i < max_len + 2; ++i)
+ pp_character (pp, '-');
+ };
+
+ print_top_bottom ();
+ start = text;
+ while (const char *end = strchr (start, '\n'))
+ {
+ pp_newline_and_indent (pp, 0);
+ pp_character (pp, '|');
+ // Each line of the pattern already starts with a space.
+ // so we don't need to add another one here.
+ pp_append_text (pp, start, end);
+ start = end + 1;
+ }
+ pp_newline_and_indent (pp, 0);
+ print_top_bottom ();
+
+ if (m_cost_or_uid != UNKNOWN_COST)
+ {
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "cost: ");
+ pp_decimal_int (pp, m_cost_or_uid);
+ }
+ if (m_has_pre_post_modify)
+ {
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "has pre/post-modify operations");
+ }
+ if (m_has_volatile_refs)
+ {
+ pp_newline_and_indent (pp, 0);
+ pp_string (pp, "has volatile refs");
+ }
+ }
+ pp_indentation (pp) -= 2;
+ }
+
+ auto print_accesses = [&](const char *heading, access_array accesses,
+ unsigned int flags)
+ {
+ if (!accesses.empty ())
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, heading);
+ pp_newline_and_indent (pp, 2);
+ pp_accesses (pp, accesses, flags);
+ pp_indentation (pp) -= 4;
+ }
+ };
+
+ print_accesses ("uses:", uses (), PP_ACCESS_USER);
+ auto *call_clobbers_note = find_note<insn_call_clobbers_note> ();
+ if (call_clobbers_note)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "has call clobbers for ABI ");
+ pp_decimal_int (pp, call_clobbers_note->abi_id ());
+ pp_indentation (pp) -= 2;
+ }
+ print_accesses ("defines:", defs (), PP_ACCESS_SETTER);
+ if (num_uses () == 0 && !call_clobbers_note && num_defs () == 0)
+ {
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "has no uses or defs");
+ pp_indentation (pp) -= 2;
+ }
+
+ if (order_node *node = get_order_node ())
+ {
+ while (node->m_parent)
+ node = node->m_parent;
+
+ pp_newline_and_indent (pp, 2);
+ pp_string (pp, "insn order: ");
+ pp_newline_and_indent (pp, 2);
+ auto print_order = [](pretty_printer *pp, order_node *node)
+ {
+ print_uid (pp, node->uid ());
+ };
+ order_splay_tree::print (pp, node, print_order);
+ pp_indentation (pp) -= 4;
+ }
+}
+
+// Return an insn_info::order_node for INSN, creating one if necessary.
+insn_info::order_node *
+function_info::need_order_node (insn_info *insn)
+{
+ insn_info::order_node *order = insn->get_order_node ();
+ if (!order)
+ {
+ order = allocate<insn_info::order_node> (insn->uid ());
+ insn->add_note (order);
+ }
+ return order;
+}
+
+// Add instruction INSN immediately after AFTER in the reverse postorder list.
+// INSN is not currently in the list.
+void
+function_info::add_insn_after (insn_info *insn, insn_info *after)
+{
+ gcc_checking_assert (!insn->has_insn_links ());
+
+ insn->copy_next_from (after);
+ after->set_next_any_insn (insn);
+
+ // The prev link is easy if AFTER and INSN are the same type.
+ // Handle the other cases below.
+ if (after->is_debug_insn () == insn->is_debug_insn ())
+ insn->set_prev_sametype_insn (after);
+
+ if (insn_info *next = insn->next_any_insn ())
+ {
+ if (insn->is_debug_insn () == next->is_debug_insn ())
+ {
+ // INSN might now be the start of the subsequence of debug insns,
+ // and so its prev pointer might point to the end of the subsequence
+ // instead of AFTER.
+ insn->copy_prev_from (next);
+ next->set_prev_sametype_insn (insn);
+ }
+ else if (insn->is_debug_insn ()) // && !next->is_debug_insn ()
+ {
+ // INSN ends a subsequence of debug instructions. Find the
+ // first debug instruction in the subsequence, which might
+ // be INSN itself. (If it isn't, then AFTER is also a debug
+ // instruction and we updated INSN's prev link above.)
+ insn_info *first = next->prev_nondebug_insn ()->next_any_insn ();
+ first->set_last_debug_insn (insn);
+ }
+ else // !insn->is_debug_insn () && next->is_debug_insn ()
+ // At present we don't (need to) support inserting a nondebug
+ // instruction between two existing debug instructions.
+ gcc_assert (!after->is_debug_insn ());
+
+ // If AFTER and NEXT are separated by at least two points, we can
+ // use a unique point number for INSN. Otherwise INSN will have
+ // the same point number as AFTER.
+ insn->set_point ((next->point () + after->point ()) / 2);
+ }
+ else
+ {
+ if (!insn->is_debug_insn ())
+ {
+ insn->set_prev_sametype_insn (m_last_nondebug_insn);
+ m_last_nondebug_insn = insn;
+ }
+ else
+ // There is now at least one debug instruction after
+ // m_last_nondebug_insn: either INSN itself, or the start of
+ // a longer subsequence of debug insns that now ends with AFTER
+ // followed by INSN.
+ m_last_nondebug_insn->next_any_insn ()->set_last_debug_insn (insn);
+ m_last_insn = insn;
+
+ insn->set_point (after->point () + POINT_INCREASE);
+ }
+
+ // If INSN's program point is the same as AFTER's, we need to use the
+ // splay tree to record their relative order.
+ if (insn->point () == after->point ())
+ {
+ insn_info::order_node *after_node = need_order_node (after);
+ insn_info::order_node *insn_node = need_order_node (insn);
+ insn_info::order_splay_tree::insert_child (after_node, 1, insn_node);
+ }
+}
+
+// Remove INSN from the function's list of instructions.
+void
+function_info::remove_insn (insn_info *insn)
+{
+ if (insn_info::order_node *order = insn->get_order_node ())
+ insn_info::order_splay_tree::remove_node (order);
+
+ if (auto *note = insn->find_note<insn_call_clobbers_note> ())
+ {
+ ebb_call_clobbers_info *ecc = insn->ebb ()->first_call_clobbers ();
+ while (ecc->abi ()->id () != note->abi_id ())
+ ecc = ecc->next ();
+ int comparison = lookup_call_clobbers (*ecc, insn);
+ gcc_assert (comparison == 0);
+ ecc->remove_root ();
+ }
+
+ insn_info *prev = insn->prev_any_insn ();
+ insn_info *next = insn->next_any_insn ();
+ insn_info *prev_nondebug = insn->prev_nondebug_insn ();
+ insn_info *next_nondebug = insn->next_nondebug_insn ();
+
+ // We should never remove the entry or exit block's instructions.
+ // At present we also don't remove entire blocks, so should never
+ // remove debug instructions.
+ gcc_checking_assert (prev_nondebug
+ && next_nondebug
+ && !insn->is_debug_insn ());
+
+ if (prev->is_debug_insn () && next->is_debug_insn ())
+ {
+ // We need to stitch together two subsequences of debug insns.
+ insn_info *last = next->last_debug_insn ();
+ next->set_prev_sametype_insn (prev);
+ prev_nondebug->next_any_insn ()->set_last_debug_insn (last);
+ }
+ prev->set_next_any_insn (next);
+ next_nondebug->set_prev_sametype_insn (prev_nondebug);
+
+ insn->clear_insn_links ();
+}
+
+// Create an artificial instruction for BB, associating it with RTL (which can
+// be null). Add the new instruction to the end of the function's list and
+// return the new instruction.
+insn_info *
+function_info::append_artificial_insn (bb_info *bb, rtx_insn *rtl)
+{
+ insn_info *insn = allocate<insn_info> (bb, rtl, m_next_artificial_uid);
+ m_next_artificial_uid -= 1;
+ append_insn (insn);
+ return insn;
+}
+
+// Finish building a new list of uses and definitions for instruction INSN.
+void
+function_info::finish_insn_accesses (insn_info *insn)
+{
+ unsigned int num_defs = m_temp_defs.length ();
+ unsigned int num_uses = m_temp_uses.length ();
+ obstack_make_room (&m_obstack, num_defs + num_uses);
+ if (num_defs)
+ {
+ sort_accesses (m_temp_defs);
+ obstack_grow (&m_obstack, m_temp_defs.address (),
+ num_defs * sizeof (access_info *));
+ m_temp_defs.truncate (0);
+ }
+ if (num_uses)
+ {
+ sort_accesses (m_temp_uses);
+ obstack_grow (&m_obstack, m_temp_uses.address (),
+ num_uses * sizeof (access_info *));
+ m_temp_uses.truncate (0);
+ }
+ void *addr = obstack_finish (&m_obstack);
+ insn->set_accesses (static_cast<access_info **> (addr), num_defs, num_uses);
+}
+
+// Called while building SSA form using BI. Record that INSN contains
+// read reference REF. If this requires new entries to be added to
+// INSN->uses (), add those entries to the list we're building in
+// m_temp_uses.
+void
+function_info::record_use (build_info &bi, insn_info *insn,
+ rtx_obj_reference ref)
+{
+ unsigned int regno = ref.regno;
+ machine_mode mode = ref.is_reg () ? ref.mode : BLKmode;
+ access_info *access = bi.last_access[ref.regno + 1];
+ use_info *use = safe_dyn_cast<use_info *> (access);
+ if (!use)
+ {
+ set_info *value = safe_dyn_cast<set_info *> (access);
+ // In order to ensure that -g doesn't affect codegen, uses in debug
+ // instructions do not affect liveness, either in DF or here.
+ // This means that there might be no correct definition of the resource
+ // available (e.g. if it would require a phi node that the nondebug
+ // code doesn't need). Perhaps we could have "debug phi nodes" as
+ // well as "debug instructions", but that would require a method
+ // of building phi nodes that didn't depend on DF liveness information,
+ // and so might be significantly more expensive.
+ //
+ // Therefore, the only value we try to attach to a use by a debug
+ // instruction is VALUE itself (as we would for nondebug instructions).
+ // We then need to make a conservative check for whether VALUE is
+ // actually correct.
+ auto value_is_valid = [&]()
+ {
+ // Memmory always has a valid definition.
+ if (ref.is_mem ())
+ return true;
+
+ // If VALUE would lead to an uninitialized use anyway, there's
+ // nothing to check.
+ if (!value)
+ return false;
+
+ // If the previous definition occurs in the same EBB then it
+ // is certainly correct.
+ if (value->ebb () == bi.current_ebb)
+ return true;
+
+ // If the register is live on entry to the EBB but not used
+ // within it, VALUE is the correct live-in value.
+ if (bitmap_bit_p (bi.ebb_live_in_for_debug, regno))
+ return true;
+
+ // Check if VALUE is the function's only definition of REGNO
+ // and if it dominates the use.
+ if (regno != MEM_REGNO
+ && regno < DF_REG_SIZE (DF)
+ && DF_REG_DEF_COUNT (regno) == 1
+ && dominated_by_p (CDI_DOMINATORS, insn->bb ()->cfg_bb (),
+ value->bb ()->cfg_bb ()))
+ return true;
+
+ // Punt for other cases.
+ return false;
+ };
+ if (insn->is_debug_insn () && !value_is_valid ())
+ value = nullptr;
+
+ use = allocate<use_info> (insn, resource_info { mode, regno }, value);
+ add_use (use);
+ m_temp_uses.safe_push (use);
+ bi.last_access[ref.regno + 1] = use;
+ use->record_reference (ref, true);
+ }
+ else
+ {
+ // Record the mode of the largest use. The choice is arbitrary if
+ // the instruction (unusually) references the same register in two
+ // different but equal-sized modes.
+ gcc_checking_assert (use->insn () == insn);
+ if (HARD_REGISTER_NUM_P (regno)
+ && partial_subreg_p (use->mode (), mode))
+ use->set_mode (mode);
+ use->record_reference (ref, false);
+ }
+}
+
+// Called while building SSA form for INSN using BI. Record the effect
+// of call clobbers in RTL. We have already added the explicit sets and
+// clobbers for RTL, which have priority over any call clobbers.
+void
+function_info::record_call_clobbers (build_info &bi, insn_info *insn,
+ rtx_call_insn *rtl)
+{
+ // See whether we should record this call in the EBB's list of
+ // call clobbers. Three things affect this choice:
+ //
+ // (1) The list is the only way we have of recording partial clobbers.
+ // All calls that only partially clobber registers must therefore
+ // be in the list.
+ //
+ // (2) Adding calls to the list is much more memory-efficient than
+ // creating a long list of clobber_infos.
+ //
+ // (3) Adding calls to the list limits the ability to move definitions
+ // of registers that are normally fully or partially clobbered
+ // by the associated predefined ABI. So adding calls to the list
+ // can hamper optimization if (thanks to -fipa-ra) the number of
+ // clobbers is much smaller than the usual set.
+ //
+ // The trade-off that we currently take is to use the list if there
+ // are some registers that the call only partially clobbers or if
+ // the set of clobbers is the standard set.
+ function_abi abi = insn_callee_abi (rtl);
+ if (abi.base_abi ().full_reg_clobbers () == abi.full_reg_clobbers ()
+ || abi.full_and_partial_reg_clobbers () != abi.full_reg_clobbers ())
+ {
+ // Find an entry for this predefined ABI, creating one if necessary.
+ ebb_call_clobbers_info *ecc = bi.current_ebb->first_call_clobbers ();
+ while (ecc && ecc->abi () != &abi.base_abi ())
+ ecc = ecc->next ();
+ if (!ecc)
+ {
+ ecc = allocate<ebb_call_clobbers_info> (&abi.base_abi ());
+ ecc->m_next = bi.current_ebb->first_call_clobbers ();
+ bi.current_ebb->set_first_call_clobbers (ecc);
+ }
+
+ auto abi_id = abi.base_abi ().id ();
+ auto *insn_clobbers = allocate<insn_call_clobbers_note> (abi_id, insn);
+ insn->add_note (insn_clobbers);
+
+ ecc->insert_max_node (insn_clobbers);
+ }
+ else
+ for (unsigned int regno = 0; regno < FIRST_PSEUDO_REGISTER; ++regno)
+ if (TEST_HARD_REG_BIT (abi.full_reg_clobbers (), regno))
+ {
+ def_info *def = m_defs[regno + 1];
+ if (!def || def->last_def ()->insn () != insn)
+ {
+ def = allocate<clobber_info> (insn, regno);
+ def->m_is_call_clobber = true;
+ append_def (def);
+ m_temp_defs.safe_push (def);
+ bi.last_access[regno + 1] = def;
+ }
+ }
+}
+
+// Called while building SSA form using BI. Record that INSN contains
+// write reference REF. Add associated def_infos to the list of accesses
+// that we're building in m_temp_defs. Record the register's new live
+// value in BI.
+void
+function_info::record_def (build_info &bi, insn_info *insn,
+ rtx_obj_reference ref)
+{
+ // Punt if we see multiple definitions of the same resource.
+ // This can happen for several reasons:
+ //
+ // - An instruction might store two values to memory at once, giving two
+ // distinct memory references.
+ //
+ // - An instruction might assign to multiple pieces of a wide pseudo
+ // register. For example, on 32-bit targets, an instruction might
+ // assign to both the upper and lower halves of a 64-bit pseudo register.
+ //
+ // - It's possible for the same register to be clobbered by the
+ // CALL_INSN_FUNCTION_USAGE and to be set by the main instruction
+ // pattern as well. In that case, the clobber conceptually happens
+ // before the set and can essentially be ignored.
+ //
+ // - Similarly, global registers are implicitly set by a call but can
+ // be explicitly set or clobbered as well. In that situation, the sets
+ // are listed first and should win over a clobber.
+ unsigned int regno = ref.regno;
+ machine_mode mode = ref.is_reg () ? ref.mode : BLKmode;
+ def_info *def = safe_dyn_cast<def_info *> (bi.last_access[ref.regno + 1]);
+ if (def && def->insn () == insn)
+ {
+ if (!ref.is_clobber ())
+ {
+ gcc_checking_assert (!is_a<clobber_info *> (def));
+ def->record_reference (ref, false);
+ }
+ return;
+ }
+
+ // Memory is always well-defined, so only use clobber_infos for registers.
+ if (ref.is_reg () && ref.is_clobber ())
+ def = allocate<clobber_info> (insn, regno);
+ else
+ def = allocate<set_info> (insn, resource_info { mode, regno });
+ def->record_reference (ref, true);
+ append_def (def);
+ m_temp_defs.safe_push (def);
+ bi.last_access[ref.regno + 1] = def;
+}
+
+// Called while building SSA form using BI. Add an insn_info for RTL
+// to the block that we're current building.
+void
+function_info::add_insn_to_block (build_info &bi, rtx_insn *rtl)
+{
+ insn_info *insn = allocate<insn_info> (bi.current_bb, rtl, UNKNOWN_COST);
+ append_insn (insn);
+
+ vec_rtx_properties properties;
+ properties.add_insn (rtl, true);
+ insn->set_properties (properties);
+
+ start_insn_accesses ();
+
+ // Record the uses.
+ for (rtx_obj_reference ref : properties.refs ())
+ if (ref.is_read ())
+ record_use (bi, insn, ref);
+
+ // Restore the contents of bi.last_access, which we used as a cache
+ // when assembling the uses.
+ for (access_info *access : m_temp_uses)
+ {
+ unsigned int regno = access->regno ();
+ gcc_checking_assert (bi.last_access[regno + 1] == access);
+ bi.last_access[regno + 1] = as_a<use_info *> (access)->def ();
+ }
+
+ // Record the definitions.
+ for (rtx_obj_reference ref : properties.refs ())
+ if (ref.is_write ())
+ record_def (bi, insn, ref);
+
+ // Logically these happen before the explicit definitions, but if the
+ // explicit definitions and call clobbers reference the same register,
+ // the explicit definition should win.
+ if (auto *call_rtl = dyn_cast<rtx_call_insn *> (rtl))
+ record_call_clobbers (bi, insn, call_rtl);
+
+ finish_insn_accesses (insn);
+}
+
+// Check whether INSN sets any registers that are never subsequently used.
+// If so, add REG_UNUSED notes for them. The caller has already removed
+// any previous REG_UNUSED notes.
+void
+function_info::add_reg_unused_notes (insn_info *insn)
+{
+ rtx_insn *rtl = insn->rtl ();
+
+ auto handle_potential_set = [&](rtx pattern)
+ {
+ if (GET_CODE (pattern) != SET)
+ return;
+
+ rtx dest = SET_DEST (pattern);
+ if (!REG_P (dest))
+ return;
+
+ def_array defs = insn->defs ();
+ unsigned int index = find_access_index (defs, REGNO (dest));
+ for (unsigned int i = 0; i < REG_NREGS (dest); ++i)
+ {
+ def_info *def = defs[index + i];
+ gcc_checking_assert (def->regno () == REGNO (dest) + i);
+ set_info *set = dyn_cast<set_info *> (def);
+ if (set && set->has_nondebug_uses ())
+ return;
+ }
+ add_reg_note (rtl, REG_UNUSED, dest);
+ };
+
+ rtx pattern = PATTERN (rtl);
+ if (GET_CODE (pattern) == PARALLEL)
+ for (int i = 0; i < XVECLEN (pattern, 0); ++i)
+ handle_potential_set (XVECEXP (pattern, 0, i));
+ else
+ handle_potential_set (pattern);
+}
+
+// Search TREE for call clobbers at INSN. Return:
+//
+// - less than zero if INSN occurs before the root of TREE
+// - 0 if INSN is the root of TREE
+// - greater than zero if INSN occurs after the root of TREE
+int
+rtl_ssa::lookup_call_clobbers (insn_call_clobbers_tree &tree, insn_info *insn)
+{
+ auto compare = [&](insn_call_clobbers_note *clobbers)
+ {
+ return insn->compare_with (clobbers->insn ());
+ };
+ return tree.lookup (compare);
+}
+
+// Print a description of INSN to PP.
+void
+rtl_ssa::pp_insn (pretty_printer *pp, const insn_info *insn)
+{
+ if (!insn)
+ pp_string (pp, "<null>");
+ else
+ insn->print_full (pp);
+}
+
+// Print a description of INSN to FILE.
+void
+dump (FILE *file, const insn_info *insn)
+{
+ dump_using (file, pp_insn, insn);
+}
+
+// Debug interface to the dump routine above.
+void debug (const insn_info *x) { dump (stderr, x); }
--- /dev/null
+// Instruction-related RTL SSA classes -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// A fake cost for instructions that we haven't costed yet.
+const int UNKNOWN_COST = INT_MAX;
+
+// Enumerates the kinds of note that can be added to an instruction.
+// See the comment above insn_info for details.
+enum class insn_note_kind : uint8_t
+{
+ ORDER_NODE,
+ CALL_CLOBBERS
+};
+
+// The base class for notes that can be added to an instruction.
+// See the comment above insn_info for details.
+class insn_note
+{
+ // Size: 2 LP64 words.
+ friend class insn_info;
+ friend class function_info;
+
+public:
+ // Return what kind of note this is.
+ insn_note_kind kind () const { return m_kind; }
+
+ // Return the next note in the list, or null if none.
+ insn_note *next_note () const { return m_next_note; }
+
+ // Used with T = Derived *, where Derived is derived from insn_note.
+ // Convert the note to Derived, asserting that it has the right kind.
+ template<typename T>
+ T as_a ();
+
+ // Used with T = Derived *, where Derived is derived from insn_note.
+ // If the note is a Derived note, return it in that form, otherwise
+ // return null.
+ template<typename T>
+ T dyn_cast ();
+
+protected:
+ // Construct a note with the given kind.
+ insn_note (insn_note_kind);
+
+private:
+ // The next note in the list, or null if none.
+ insn_note *m_next_note;
+
+ // The kind of note this is.
+ insn_note_kind m_kind : 8;
+
+protected:
+ // Fill in the remaining LP64 word with data that derived classes can use.
+ unsigned int m_data8 : 8;
+ unsigned int m_data16 : 16;
+ unsigned int m_data32 : 32;
+};
+
+// Instructions have one of these notes if insn_info::has_call_clobbers ()
+// is true. All such instructions in an EBB are first grouped together
+// by the predefined_function_abis of the functions that they call.
+// Then, for each such predefined ABI, the call_clobbers notes are put
+// into a splay tree whose nodes follow execution order.
+class insn_call_clobbers_note : public insn_note
+{
+ friend class function_info;
+ friend class default_splay_tree_accessors<insn_call_clobbers_note *>;
+
+public:
+ static const insn_note_kind kind = insn_note_kind::CALL_CLOBBERS;
+
+ // Return the identifier of the predefined_function_abi.
+ unsigned int abi_id () const { return m_data32; }
+
+ // Return the instruction to which the note is attached.
+ insn_info *insn () const { return m_insn; }
+
+protected:
+ insn_call_clobbers_note (unsigned int abi_id, insn_info *insn);
+
+ // The splay tree pointers.
+ insn_call_clobbers_note *m_children[2];
+
+ // The value returned by insn ().
+ insn_info *m_insn;
+};
+
+// A splay tree of insn_call_clobbers_notes.
+using insn_call_clobbers_tree = default_splay_tree<insn_call_clobbers_note *>;
+
+// SSA-related information about an instruction. It also represents
+// artificial instructions that are added to make the dataflow correct;
+// these artificial instructions fall into three categories:
+//
+// - Instructions that hold the phi nodes for an extended basic block (is_phi).
+//
+// - Instructions that represent the head of a basic block and that hold
+// all the associated artificial uses and definitions.
+//
+// - Instructions that represent the end of a basic block and that again
+// hold all the associated artificial uses and definitions.
+//
+// Dataflow-wise, each instruction goes through three stages:
+//
+// (1) Use all the values in uses ().
+//
+// (2) If has_call_clobbers (), clobber the registers indicated by
+// insn_callee_abi.
+//
+// (3) Define all the values in defs ().
+//
+// Having stage (2) is a trade-off: it makes processing the instructions
+// more complicated, but it saves having to allocate memory for every
+// individual call clobber. Without it, clobbers for calls would often
+// make up a large proportion of the total definitions in a function.
+//
+// All the instructions in a function are chained together in a list
+// that follows a reverse postorder traversal of the CFG. The list
+// contains both debug and nondebug instructions, but it is possible
+// to hop from one nondebug instruction to the next with constant complexity.
+//
+// Instructions can have supplemental information attached in the form
+// of "notes", a bit like REG_NOTES for the underlying RTL insns.
+class insn_info
+{
+ // Size: 8 LP64 words.
+ friend class ebb_info;
+ friend class function_info;
+
+public:
+ // Compare instructions by their positions in the function list described
+ // above. Thus for two instructions in the same basic block, I1 < I2 if
+ // I1 comes before I2 in the block.
+ bool operator< (const insn_info &) const;
+ bool operator<= (const insn_info &) const;
+ bool operator>= (const insn_info &) const;
+ bool operator> (const insn_info &) const;
+
+ // Return -1 if this instruction comes before INSN in the reverse
+ // postorder, 0 if this instruction is INSN, or 1 if this instruction
+ // comes after INSN in the reverse postorder.
+ int compare_with (const insn_info *insn) const;
+
+ // Return the previous and next instructions in the list described above,
+ // or null if there are no such instructions.
+ insn_info *prev_any_insn () const;
+ insn_info *next_any_insn () const;
+
+ // Only valid if !is_debug_insn (). Return the previous and next
+ // nondebug instructions in the list described above, skipping over
+ // any intervening debug instructions. These are constant-time operations.
+ insn_info *prev_nondebug_insn () const;
+ insn_info *next_nondebug_insn () const;
+
+ // Return the underlying RTL insn. This instruction is null if is_phi ()
+ // or is_bb_end () are true. The instruction is a basic block note if
+ // is_bb_head () is true.
+ rtx_insn *rtl () const { return m_rtl; }
+
+ // Return true if the instruction is a real insn with an rtl pattern.
+ // Return false if it is an artificial instruction that represents the
+ // phi nodes in an extended basic block or the head or end of a basic block.
+ bool is_real () const { return m_cost_or_uid >= 0; }
+
+ // Return the opposite of is_real ().
+ bool is_artificial () const { return m_cost_or_uid < 0; }
+
+ // Return true if the instruction was a real instruction but has now
+ // been deleted. In this case the instruction is no longer part of
+ // the SSA information.
+ bool has_been_deleted () const { return m_rtl && !INSN_P (m_rtl); }
+
+ // Return true if the instruction is a debug instruction (and thus
+ // also a real instruction).
+ bool is_debug_insn () const { return m_is_debug_insn; }
+
+ // Return true if the instruction is something that we can optimize.
+ // This implies that it is a real instruction that contains an asm
+ // or that contains something that matches an .md define_insn pattern.
+ bool can_be_optimized () const { return m_can_be_optimized; }
+
+ // Return true if the instruction is a call instruction.
+ //
+ // ??? We could cache this information, but since most callers would
+ // go on to access PATTERN (rtl ()), a cache might not be helpful and
+ // could even be counterproductive.
+ bool is_call () const { return CALL_P (m_rtl); }
+
+ // Return true if the instruction is a jump instruction.
+ //
+ // ??? See is_call for the reason we don't cache this.
+ bool is_jump () const { return JUMP_P (m_rtl); }
+
+ // Return true if the instruction is real and contains an inline asm.
+ bool is_asm () const { return m_is_asm; }
+
+ // Return true if the instruction is real and includes an RTX_AUTOINC
+ // operation.
+ bool has_pre_post_modify () const { return m_has_pre_post_modify; }
+
+ // Return true if the instruction is real and has volatile references,
+ // in the sense of volatile_refs_p. This includes volatile memory,
+ // volatile asms and UNSPEC_VOLATILEs.
+ bool has_volatile_refs () const { return m_has_volatile_refs; }
+
+ // Return true if the instruction is aritificial and if its (sole)
+ // purpose is to hold the phi nodes in an extended basic block.
+ bool is_phi () const;
+
+ // Return true if the instruction is artificial and if it represents
+ // the head of a basic block. If so, the instruction conceptually
+ // executes before the real instructions in the block. The uses
+ // and definitions represent the df_get_artificial_uses and
+ // df_get_artificial_defs entries for the head of the block.
+ bool is_bb_head () const;
+
+ // Return true if the instruction is artificial and if it represents
+ // the end of a basic block. The uses and definitions represent the
+ // the df_get_artificial_uses and df_get_artificial_defs entries for
+ // the end of the block.
+ bool is_bb_end () const;
+
+ // Return the basic block that the instruction is in.
+ bb_info *bb () const { return m_bb; }
+
+ // Return the extended basic block that the instruction is in;
+ // see bb_info for details.
+ ebb_info *ebb () const;
+
+ // If the instruction is real, return the unique identifier of the
+ // underlying RTL insn. If the instruction is artificial, return
+ // a unique negative identifier for the instructions.
+ //
+ // Note that the identifiers are not linear: it can be the case that
+ // an instruction with a higher uid comes earlier in a block than an
+ // instruction with a lower uid. The identifiers are however persistent;
+ // the identifier remains the same after the instruction has been moved
+ // or changed.
+ int uid () const;
+
+ // Return the list of things that this instruction uses. Registers
+ // come first, in register number order, followed by memory.
+ use_array uses () const;
+
+ // Return true if the instruction is a call and if the clobbers
+ // described by insn_callee_abi have been omitted from the list
+ // of definitions.
+ bool has_call_clobbers () const;
+
+ // Return the list of things that this instruction sets or clobbers.
+ // Registers come first, in register number order, followed by memory.
+ //
+ // If has_call_clobbers () is true, the list omits both the full and
+ // partial register clobbers described by insn_callee_abi.
+ def_array defs () const;
+
+ // The number of entries in uses ().
+ unsigned int num_uses () const { return m_num_uses; }
+
+ // The number of entries in defs ().
+ unsigned int num_defs () const { return m_num_defs; }
+
+ // Return the cost of the instruction, as calculated by the target.
+ // For performance reasons, the cost is evaluated lazily on first use.
+ //
+ // Artificial instructions have a cost of 0.
+ unsigned int cost () const;
+
+ // Return the first insn_note attached to the instruction, or null
+ // if none.
+ insn_note *first_note () const { return m_first_note; }
+
+ // See if a note of type T is attached to the instruction. Return it
+ // if so, otherwise return null.
+ template<typename T>
+ const T *find_note () const;
+
+ // Print "i" + uid () for real instructions and "a" + -uid () for
+ // artificial instructions.
+ void print_identifier (pretty_printer *) const;
+
+ // Print a short(ish) description of where the instruction is.
+ void print_location (pretty_printer *) const;
+
+ // Combine print_identifier and print_location.
+ void print_identifier_and_location (pretty_printer *) const;
+
+ // Print a full description of the instruction.
+ void print_full (pretty_printer *) const;
+
+private:
+ // The first-order way of representing the order between instructions
+ // is to assign "program points", with higher point numbers coming
+ // later in the reverse postorder than lower point numbers. However,
+ // after a sequence of instruction movements, we may end up in a situation
+ // that adjacent instructions have the same program point.
+ //
+ // When that happens, we put the instructions into a splay tree that
+ // records their relative order. Each node of the splay tree is an
+ // order_node note that is attached to its respective instruction.
+ // The root of the splay tree is not stored, since the only thing
+ // we need the tree for is to compare two nodes.
+ class order_node : public insn_note
+ {
+ public:
+ static const insn_note_kind kind = insn_note_kind::ORDER_NODE;
+
+ order_node (int uid);
+
+ // Return the uid of the instruction that this node describes.
+ int uid () const { return m_data32; }
+
+ // The splay tree pointers.
+ order_node *m_children[2];
+ order_node *m_parent;
+ };
+ using order_splay_tree = default_rootless_splay_tree<order_node *>;
+
+ // prev_insn_or_last_debug_insn represents a choice between two things:
+ //
+ // (1) A pointer to the previous instruction in the list that has the
+ // same is_debug_insn () value, or null if no such instruction exists.
+ //
+ // (2) A pointer to the end of a sublist of debug instructions.
+ //
+ // (2) is used if this instruction is a debug instruction and the
+ // previous instruction is not. (1) is used otherwise.
+ //
+ // next_nondebug_or_debug_insn points to the next instruction but also
+ // records whether that next instruction is a debug instruction or a
+ // nondebug instruction.
+ //
+ // Thus the list is chained as follows:
+ //
+ // ----> ----> ----> ----> ---->
+ // NONDEBUG NONDEBUG DEBUG DEBUG DEBUG NONDEBUG ...
+ // <---- ^ +-- <---- <---- ^ +--
+ // | | | |
+ // | +------------------------+ |
+ // | |
+ // +-----------------------------------+
+ using prev_insn_or_last_debug_insn = pointer_mux<insn_info>;
+ using next_nondebug_or_debug_insn = pointer_mux<insn_info>;
+
+ insn_info (bb_info *bb, rtx_insn *rtl, int cost_or_uid);
+
+ static void print_uid (pretty_printer *, int);
+
+ void calculate_cost () const;
+ void set_properties (const rtx_properties &);
+ void set_accesses (access_info **, unsigned int, unsigned int);
+ void copy_accesses (access_array, access_array);
+ void set_cost (unsigned int cost) { m_cost_or_uid = cost; }
+ void set_bb (bb_info *bb) { m_bb = bb; }
+
+ void add_note (insn_note *note);
+
+ order_node *get_order_node () const;
+ order_node *get_known_order_node () const;
+ int slow_compare_with (const insn_info &) const;
+
+ insn_info *last_debug_insn () const;
+
+ unsigned int point () const { return m_point; }
+ void copy_prev_from (insn_info *);
+ void copy_next_from (insn_info *);
+ void set_prev_sametype_insn (insn_info *);
+ void set_last_debug_insn (insn_info *);
+ void set_next_any_insn (insn_info *);
+ void set_point (unsigned int point) { m_point = point; }
+ void clear_insn_links ();
+ bool has_insn_links ();
+
+ // The values returned by the accessors above.
+ prev_insn_or_last_debug_insn m_prev_insn_or_last_debug_insn;
+ next_nondebug_or_debug_insn m_next_nondebug_or_debug_insn;
+ bb_info *m_bb;
+ rtx_insn *m_rtl;
+
+ // The list of definitions followed by the list of uses.
+ access_info **m_accesses;
+
+ // The number of definitions and the number uses. FIRST_PSEUDO_REGISTER + 1
+ // is the maximum number of accesses to hard registers and memory, and
+ // MAX_RECOG_OPERANDS is the maximum number of pseudos that can be
+ // defined by an instruction, so the number of definitions should fit
+ // easily in 16 bits.
+ unsigned int m_num_uses;
+ unsigned int m_num_defs : 16;
+
+ // Flags returned by the accessors above.
+ unsigned int m_is_debug_insn : 1;
+ unsigned int m_can_be_optimized : 1;
+ unsigned int m_is_asm : 1;
+ unsigned int m_has_pre_post_modify : 1;
+ unsigned int m_has_volatile_refs : 1;
+
+ // For future expansion.
+ unsigned int m_spare : 11;
+
+ // The program point at which the instruction occurs.
+ //
+ // Note that the values of the program points are influenced by -g
+ // and so should not used to make codegen decisions.
+ unsigned int m_point;
+
+ // Negative if the instruction is artificial, nonnegative if it is real.
+ //
+ // For real instructions: the cost of the instruction, or UNKNOWN_COST
+ // if we haven't measured it yet.
+ //
+ // For artificial instructions: the (negative) unique identifier of the
+ // instruction.
+ mutable int m_cost_or_uid;
+
+ // The list of notes that have been attached to the instruction.
+ insn_note *m_first_note;
+};
+
+// Iterators for unfiltered lists of instructions.
+using any_insn_iterator = list_iterator<insn_info, &insn_info::next_any_insn>;
+using reverse_any_insn_iterator
+ = list_iterator<insn_info, &insn_info::prev_any_insn>;
+
+// Iterators for nondebug instructions only.
+using nondebug_insn_iterator
+ = list_iterator<insn_info, &insn_info::next_nondebug_insn>;
+using reverse_nondebug_insn_iterator
+ = list_iterator<insn_info, &insn_info::prev_nondebug_insn>;
+
+// A class that describes an inclusive range of instructions.
+class insn_range_info
+{
+public:
+ insn_range_info () = default;
+
+ // Create a range that contains a singleton instruction.
+ insn_range_info (insn_info *insn) : first (insn), last (insn) {}
+
+ // Create a range [FIRST, LAST], given that *FIRST <= *LAST.
+ insn_range_info (insn_info *first, insn_info *last);
+
+ // Return true if the range contains at least one instruction.
+ explicit operator bool () const { return *first <= *last; }
+
+ bool operator== (const insn_range_info &) const;
+ bool operator!= (const insn_range_info &) const;
+
+ // If the range contains a single instruction, return that instruction,
+ // otherwise return null.
+ insn_info *singleton () const;
+
+ // Return true if the range includes INSN.
+ bool includes (insn_info *insn) const;
+
+ // If INSN is inside the range, return INSN, otherwise return the
+ // nearest in-range instruction.
+ insn_info *clamp_insn_to_range (insn_info *insn) const;
+
+ // Return true if this range is a subrange of OTHER, i.e. if OTHER
+ // includes every instruction that this range does.
+ bool is_subrange_of (const insn_range_info &other) const;
+
+ // The lower and upper bounds of the range.
+ insn_info *first;
+ insn_info *last;
+};
+
+// A class that represents a closure of operator== for instructions.
+// This is used by insn_is; see there for details.
+class insn_is_closure
+{
+public:
+ insn_is_closure (const insn_info *insn) : m_insn (insn) {}
+ bool operator() (const insn_info *other) const { return m_insn == other; }
+
+private:
+ const insn_info *m_insn;
+};
+
+void pp_insn (pretty_printer *, const insn_info *);
+
+}
+
+void dump (FILE *, const rtl_ssa::insn_info *);
+
+void DEBUG_FUNCTION debug (const rtl_ssa::insn_info *);
--- /dev/null
+// Implementation of private inline member functions for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// Construct a new access with the given resource () and kind () values.
+inline access_info::access_info (resource_info resource, access_kind kind)
+ : m_regno (resource.regno),
+ m_kind (kind),
+ m_is_artificial (false),
+ m_is_set_with_nondebug_insn_uses (false),
+ m_is_pre_post_modify (false),
+ m_is_call_clobber (false),
+ m_is_live_out_use (false),
+ m_includes_address_uses (false),
+ m_includes_read_writes (false),
+ m_includes_subregs (false),
+ m_includes_multiregs (false),
+ m_only_occurs_in_notes (false),
+ m_is_last_nondebug_insn_use (false),
+ m_is_in_debug_insn_or_phi (false),
+ m_has_been_superceded (false),
+ m_is_temp (false),
+ m_spare (0),
+ m_mode (resource.mode)
+{
+}
+
+// Construct a use of RESOURCE in LOCATION. The resource's value is provided
+// by DEF, or is completely undefined if DEF is null.
+inline use_info::use_info (insn_or_phi location, resource_info resource,
+ set_info *definition)
+ : access_info (resource, access_kind::USE),
+ m_insn_or_phi (location),
+ m_last_use_or_prev_use (nullptr),
+ m_last_nondebug_insn_use_or_next_use (nullptr),
+ m_def (definition)
+{
+ if (m_insn_or_phi.is_second ())
+ {
+ m_is_in_debug_insn_or_phi = true;
+ m_is_artificial = true;
+ }
+ else
+ {
+ insn_info *insn = m_insn_or_phi.known_first ();
+ m_is_in_debug_insn_or_phi = insn->is_debug_insn ();
+ m_is_artificial = insn->is_artificial ();
+ }
+}
+
+// Return the correct (uncached) value of m_is_last_nondebug_insn_use.
+inline bool
+use_info::calculate_is_last_nondebug_insn_use () const
+{
+ use_info *next = next_use ();
+ return is_in_nondebug_insn () && (!next || next->is_in_debug_insn_or_phi ());
+}
+
+// Accumulate any properties about REF that are also stored in use_infos.
+// IS_FIRST is true if REF is the first access to resource () that we have
+// recorded in this way, false if we have already recorded previous
+// references.
+inline void
+use_info::record_reference (rtx_obj_reference ref, bool is_first)
+{
+ if (is_first)
+ {
+ m_includes_address_uses = ref.in_address ();
+ m_includes_read_writes = ref.is_write ();
+ m_includes_subregs = ref.in_subreg ();
+ m_includes_multiregs = ref.is_multireg ();
+ m_only_occurs_in_notes = ref.in_note ();
+ }
+ else
+ {
+ m_includes_address_uses |= ref.in_address ();
+ m_includes_read_writes |= ref.is_write ();
+ m_includes_subregs |= ref.in_subreg ();
+ m_includes_multiregs |= ref.is_multireg ();
+ m_only_occurs_in_notes &= ref.in_note ();
+ }
+}
+
+// Change the value of insn () to INSN.
+inline void
+use_info::set_insn (insn_info *insn)
+{
+ m_insn_or_phi = insn;
+ m_is_artificial = insn->is_artificial ();
+}
+
+// Copy the overloaded prev link from OTHER.
+inline void
+use_info::copy_prev_from (use_info *other)
+{
+ m_last_use_or_prev_use = other->m_last_use_or_prev_use;
+}
+
+// Copy the overloaded next link from OTHER.
+inline void
+use_info::copy_next_from (use_info *other)
+{
+ m_last_nondebug_insn_use_or_next_use
+ = other->m_last_nondebug_insn_use_or_next_use;
+ m_is_last_nondebug_insn_use = calculate_is_last_nondebug_insn_use ();
+}
+
+// Record that this use is the first in the list and that the last use is LAST.
+inline void
+use_info::set_last_use (use_info *last_use)
+{
+ m_last_use_or_prev_use.set_first (last_use);
+}
+
+// Record that this use is not the first in the list and that the previous
+// use is PREV.
+inline void
+use_info::set_prev_use (use_info *prev_use)
+{
+ m_last_use_or_prev_use.set_second (prev_use);
+}
+
+// Record that this use is the last use in the list. If USE is nonnull,
+// record that USE is the last use in the list by a nondebug instruction,
+// otherwise record that there are no uses by nondebug instructions
+// in the list.
+inline void
+use_info::set_last_nondebug_insn_use (use_info *use)
+{
+ m_last_nondebug_insn_use_or_next_use.set_first (use);
+ m_is_last_nondebug_insn_use = (use == this);
+}
+
+// Record that this use is not the last in the list and that the next
+// use is NEXT_USE.
+inline void
+use_info::set_next_use (use_info *next_use)
+{
+ m_last_nondebug_insn_use_or_next_use.set_second (next_use);
+ m_is_last_nondebug_insn_use = calculate_is_last_nondebug_insn_use ();
+}
+
+// Clear any information relating to the position of the use in its
+// definition's list.
+inline void
+use_info::clear_use_links ()
+{
+ m_last_use_or_prev_use = nullptr;
+ m_last_nondebug_insn_use_or_next_use = nullptr;
+ m_is_last_nondebug_insn_use = false;
+}
+
+// Return true if the use has any links to other uses. This is mostly
+// for assert checking.
+inline bool
+use_info::has_use_links ()
+{
+ return (m_last_use_or_prev_use
+ || m_last_nondebug_insn_use_or_next_use
+ || m_is_last_nondebug_insn_use);
+}
+
+// Construct a definition of RESOURCE in INSN, giving it kind KIND.
+inline def_info::def_info (insn_info *insn, resource_info resource,
+ access_kind kind)
+ : access_info (resource, kind),
+ m_insn (insn),
+ m_last_def_or_prev_def (nullptr),
+ m_splay_root_or_next_def (nullptr)
+{
+ m_is_artificial = insn->is_artificial ();
+}
+
+// Record any properties about REF that are also stored in def_infos.
+// IS_FIRST is true if REF is the first access to resource () that we have
+// recorded in this way, false if we have already recorded previous
+// references.
+inline void
+def_info::record_reference (rtx_obj_reference ref, bool is_first)
+{
+ if (is_first)
+ {
+ m_is_pre_post_modify = ref.is_pre_post_modify ();
+ m_includes_read_writes = ref.is_read ();
+ m_includes_subregs = ref.in_subreg ();
+ m_includes_multiregs = ref.is_multireg ();
+ }
+ else
+ {
+ m_is_pre_post_modify |= ref.is_pre_post_modify ();
+ m_includes_read_writes |= ref.is_read ();
+ m_includes_subregs |= ref.in_subreg ();
+ m_includes_multiregs |= ref.is_multireg ();
+ }
+}
+
+// Return the last definition in the list. Only valid when is_first ()
+// is true.
+inline def_info *
+def_info::last_def () const
+{
+ return m_last_def_or_prev_def.known_first ();
+}
+
+// Return the root of the splay tree of definitions of resource (),
+// or null if no splay tree has been created for this resource.
+// Only valid when is_last () is true.
+inline def_node *
+def_info::splay_root () const
+{
+ return m_splay_root_or_next_def.known_first ();
+}
+
+// Copy the overloaded prev link from OTHER.
+inline void
+def_info::copy_prev_from (def_info *other)
+{
+ m_last_def_or_prev_def
+ = other->m_last_def_or_prev_def;
+}
+
+// Copy the overloaded next link from OTHER.
+inline void
+def_info::copy_next_from (def_info *other)
+{
+ m_splay_root_or_next_def = other->m_splay_root_or_next_def;
+}
+
+// Record that this definition is the first in the list and that the last
+// definition is LAST.
+inline void
+def_info::set_last_def (def_info *last_def)
+{
+ m_last_def_or_prev_def.set_first (last_def);
+}
+
+// Record that this definition is not the first in the list and that the
+// previous definition is PREV.
+inline void
+def_info::set_prev_def (def_info *prev_def)
+{
+ m_last_def_or_prev_def.set_second (prev_def);
+}
+
+// Record that this definition is the last in the list and that the root
+// of the splay tree associated with resource () is ROOT.
+inline void
+def_info::set_splay_root (def_node *root)
+{
+ m_splay_root_or_next_def = root;
+}
+
+// Record that this definition is not the last in the list and that the
+// next definition is NEXT.
+inline void
+def_info::set_next_def (def_info *next_def)
+{
+ m_splay_root_or_next_def = next_def;
+}
+
+// Clear the prev and next links
+inline void
+def_info::clear_def_links ()
+{
+ m_last_def_or_prev_def = nullptr;
+ m_splay_root_or_next_def = nullptr;
+}
+
+// Return true if the definition has any links to other definitions.
+// This is mostly for assert checking.
+inline bool
+def_info::has_def_links ()
+{
+ return m_last_def_or_prev_def || m_splay_root_or_next_def;
+}
+
+// Construct a clobber of register REGNO in insn INSN.
+inline clobber_info::clobber_info (insn_info *insn, unsigned int regno)
+ : def_info (insn, { E_BLKmode, regno }, access_kind::CLOBBER),
+ m_children (),
+ m_parent (nullptr),
+ m_group (nullptr)
+{
+}
+
+// Set the containing group to GROUP, if it isn't already. The main
+// use of this function is to update the new root of GROUP's splay tree.
+inline void
+clobber_info::update_group (clobber_group *group)
+{
+ if (__builtin_expect (m_group != group, 0))
+ m_group = group;
+}
+
+// Cconstruct a set_info for a store to RESOURCE in INSN, giving it
+// kind KIND.
+inline set_info::set_info (insn_info *insn, resource_info resource,
+ access_kind kind)
+ : def_info (insn, resource, kind),
+ m_first_use (nullptr)
+{
+}
+
+// Cconstruct a set_info for a store to RESOURCE in INSN.
+inline set_info::set_info (insn_info *insn, resource_info resource)
+ : set_info (insn, resource, access_kind::SET)
+{
+}
+
+// Record that USE is the first use of this definition.
+inline void
+set_info::set_first_use (use_info *first_use)
+{
+ m_first_use = first_use;
+ m_is_set_with_nondebug_insn_uses
+ = (first_use && first_use->is_in_nondebug_insn ());
+}
+
+// Construct a phi for RESOURCE in INSN, giving it identifier UID.
+inline phi_info::phi_info (insn_info *insn, resource_info resource,
+ unsigned int uid)
+ : set_info (insn, resource, access_kind::PHI),
+ m_uid (uid),
+ m_num_inputs (0),
+ m_prev_phi (nullptr),
+ m_next_phi (nullptr)
+{
+}
+
+// Turn the phi into a degenerate phi, with INPUT representing the
+// value of the resource on all incoming edges.
+inline void
+phi_info::make_degenerate (use_info *input)
+{
+ m_num_inputs = 1;
+ m_single_input = input;
+}
+
+// Set the inputs of the phi to INPUTS.
+inline void
+phi_info::set_inputs (use_array inputs)
+{
+ m_num_inputs = inputs.size ();
+ if (inputs.size () == 1)
+ m_single_input = inputs[0];
+ else
+ m_inputs = access_array (inputs).begin ();
+}
+
+// Construct a definition splay tree node for FIRST_DEF, which is either
+// the first clobber_info in a group or a standalone set_info.
+inline def_node::def_node (clobber_or_set first_def)
+ : m_clobber_or_set (first_def),
+ m_children ()
+{
+}
+
+// Construct a new group of clobber_infos that initially contains just CLOBBER.
+inline clobber_group::clobber_group (clobber_info *clobber)
+ : def_node (clobber),
+ m_last_clobber (clobber),
+ m_clobber_tree (clobber)
+{
+ clobber->m_group = this;
+}
+
+// Construct a node for the instruction with uid UID.
+inline insn_info::order_node::order_node (int uid)
+ : insn_note (kind),
+ m_children (),
+ m_parent (nullptr)
+{
+ m_data32 = uid;
+}
+
+// Construct a note for instruction INSN, giving it abi_id () value ABI_ID.
+inline insn_call_clobbers_note::insn_call_clobbers_note (unsigned int abi_id,
+ insn_info *insn)
+ : insn_note (kind),
+ m_children (),
+ m_insn (insn)
+{
+ m_data32 = abi_id;
+}
+
+// Construct an instruction with the given bb () and rtl () values.
+// If the instruction is real, COST_OR_UID is the value of cost (),
+// otherwise it is the value of uid ().
+inline insn_info::insn_info (bb_info *bb, rtx_insn *rtl, int cost_or_uid)
+ : m_prev_insn_or_last_debug_insn (nullptr),
+ m_next_nondebug_or_debug_insn (nullptr),
+ m_bb (bb),
+ m_rtl (rtl),
+ m_accesses (nullptr),
+ m_num_uses (0),
+ m_num_defs (0),
+ m_is_debug_insn (rtl && DEBUG_INSN_P (rtl)),
+ m_can_be_optimized (false),
+ m_is_asm (false),
+ m_has_pre_post_modify (false),
+ m_has_volatile_refs (false),
+ m_spare (0),
+ m_point (0),
+ m_cost_or_uid (cost_or_uid),
+ m_first_note (nullptr)
+{
+}
+
+// Copy any insn properties from PROPERTIES that are also stored in an
+// insn_info.
+inline void
+insn_info::set_properties (const rtx_properties &properties)
+{
+ m_is_asm = properties.has_asm;
+ m_has_pre_post_modify = properties.has_pre_post_modify;
+ m_has_volatile_refs = properties.has_volatile_refs;
+ // Not strictly related to the properties we've been given, but it's
+ // a convenient location to do this.
+ m_can_be_optimized = (NONDEBUG_INSN_P (m_rtl)
+ & (GET_CODE (PATTERN (m_rtl)) != USE)
+ & (GET_CODE (PATTERN (m_rtl)) != CLOBBER));
+}
+
+// Change the list of instruction accesses to ACCESSES, which contains
+// NUM_DEFS definitions followed by NUM_USES uses.
+inline void
+insn_info::set_accesses (access_info **accesses,
+ unsigned int num_defs, unsigned int num_uses)
+{
+ m_accesses = accesses;
+ m_num_defs = num_defs;
+ gcc_assert (num_defs == m_num_defs);
+ m_num_uses = num_uses;
+}
+
+// Change defs () and uses () to DEFS and USES respectively, given that
+// the existing m_accesses array has enough room for them.
+inline void
+insn_info::copy_accesses (access_array defs, access_array uses)
+{
+ gcc_assert (defs.size () + uses.size () <= m_num_defs + m_num_uses);
+ memcpy (m_accesses, defs.begin (), defs.size_bytes ());
+ memcpy (m_accesses + defs.size (), uses.begin (), uses.size_bytes ());
+ m_num_defs = defs.size ();
+ gcc_assert (m_num_defs == defs.size ());
+ m_num_uses = uses.size ();
+}
+
+// If the instruction has an insn_info::order_node, return the node,
+// otherwise return null.
+inline insn_info::order_node *
+insn_info::get_order_node () const
+{
+ // The order_node always comes first.
+ if (insn_note *note = first_note ())
+ return note->dyn_cast<insn_info::order_node *> ();
+ return nullptr;
+}
+
+// Like get_order_node (), but the node is known to exist.
+inline insn_info::order_node *
+insn_info::get_known_order_node () const
+{
+ // The order_node always comes first.
+ return first_note ()->as_a<insn_info::order_node *> ();
+}
+
+// Copy the overloaded prev link from OTHER.
+inline void
+insn_info::copy_prev_from (insn_info *other)
+{
+ m_prev_insn_or_last_debug_insn = other->m_prev_insn_or_last_debug_insn;
+}
+
+// Copy the overloaded next link from OTHER.
+inline void
+insn_info::copy_next_from (insn_info *other)
+{
+ m_next_nondebug_or_debug_insn = other->m_next_nondebug_or_debug_insn;
+}
+
+// If this is a nondebug instruction, record that the previous nondebug
+// instruction is PREV. (There might be intervening debug instructions.)
+//
+// If this is a debug instruction, record that the previous instruction
+// is debug instruction PREV.
+inline void
+insn_info::set_prev_sametype_insn (insn_info *prev)
+{
+ m_prev_insn_or_last_debug_insn.set_first (prev);
+}
+
+// Only valid for debug instructions. Record that this instruction starts
+// a subsequence of debug instructions that ends with LAST.
+inline void
+insn_info::set_last_debug_insn (insn_info *last)
+{
+ m_prev_insn_or_last_debug_insn.set_second (last);
+}
+
+// Record that the next instruction of any kind is NEXT.
+inline void
+insn_info::set_next_any_insn (insn_info *next)
+{
+ if (next && next->is_debug_insn ())
+ m_next_nondebug_or_debug_insn.set_second (next);
+ else
+ m_next_nondebug_or_debug_insn.set_first (next);
+}
+
+// Clear the list links and point number for this instruction.
+inline void
+insn_info::clear_insn_links ()
+{
+ m_prev_insn_or_last_debug_insn = nullptr;
+ m_next_nondebug_or_debug_insn = nullptr;
+ m_point = 0;
+}
+
+// Return true if the instruction contains any list information.
+// This is used by assert checking.
+inline bool
+insn_info::has_insn_links ()
+{
+ return (m_prev_insn_or_last_debug_insn
+ || m_next_nondebug_or_debug_insn
+ || m_point);
+}
+
+// Construct a representation of basic block CFG_BB.
+inline bb_info::bb_info (basic_block cfg_bb)
+ : m_prev_bb (nullptr),
+ m_next_bb (nullptr),
+ m_cfg_bb (cfg_bb),
+ m_ebb (nullptr),
+ m_head_insn (nullptr),
+ m_end_insn (nullptr)
+{
+}
+
+// Construct a tree of call clobbers for the given ABI.
+inline ebb_call_clobbers_info::
+ebb_call_clobbers_info (const predefined_function_abi *abi)
+ : m_next (nullptr),
+ m_abi (abi)
+{
+}
+
+// Construct an EBB whose first block is FIRST_BB and whose last block
+// is LAST_BB.
+inline ebb_info::ebb_info (bb_info *first_bb, bb_info *last_bb)
+ : m_first_phi (nullptr),
+ m_phi_insn (nullptr),
+ m_first_bb (first_bb),
+ m_last_bb (last_bb),
+ m_first_call_clobbers (nullptr)
+{
+}
+
+// Set the contents of last_access for register REGNO to DEF.
+inline void
+function_info::build_info::record_reg_def (unsigned int regno, def_info *def)
+{
+ last_access[regno + 1] = def;
+}
+
+// Set the contents of last_access for memory to DEF.
+inline void
+function_info::build_info::record_mem_def (def_info *def)
+{
+ last_access[0] = def;
+}
+
+// Return the current value of live register REGNO, or null if the register's
+// value is completedly undefined.
+inline set_info *
+function_info::build_info::current_reg_value (unsigned int regno) const
+{
+ return safe_dyn_cast<set_info *> (last_access[regno + 1]);
+}
+
+// Return the current value of memory.
+inline set_info *
+function_info::build_info::current_mem_value () const
+{
+ return as_a<set_info *> (last_access[0]);
+}
+
+// Allocate a T on the function's main obstack, passing ARGS
+// to its constructor.
+template<typename T, typename... Ts>
+inline T *
+function_info::allocate (Ts... args)
+{
+ static_assert (std::is_trivially_destructible<T>::value,
+ "destructor won't be called");
+ static_assert (alignof (T) <= obstack_alignment,
+ "too much alignment required");
+ void *addr = obstack_alloc (&m_obstack, sizeof (T));
+ return new (addr) T (std::forward<Ts> (args)...);
+}
+
+// Allocate a T on the function's temporary obstack, passing ARGS
+// to its constructor.
+template<typename T, typename... Ts>
+inline T *
+function_info::allocate_temp (Ts... args)
+{
+ static_assert (std::is_trivially_destructible<T>::value,
+ "destructor won't be called");
+ static_assert (alignof (T) <= obstack_alignment,
+ "too much alignment required");
+ void *addr = obstack_alloc (&m_temp_obstack, sizeof (T));
+ return new (addr) T (std::forward<Ts> (args)...);
+}
+
+// Add INSN to the end of the function's list of instructions.
+inline void
+function_info::append_insn (insn_info *insn)
+{
+ gcc_checking_assert (!insn->has_insn_links ());
+ if (insn_info *after = m_last_insn)
+ add_insn_after (insn, after);
+ else
+ // The first instruction is for the entry block and is always a nondebug
+ // insn
+ m_first_insn = m_last_insn = m_last_nondebug_insn = insn;
+}
+
+// Start building a new list of uses and definitions for an instruction.
+inline void
+function_info::start_insn_accesses ()
+{
+ gcc_checking_assert (m_temp_defs.is_empty ()
+ && m_temp_uses.is_empty ());
+}
+
+// Return a mode that encapsulates two distinct references to a register,
+// one with mode MODE1 and one with mode MODE2. Treat BLKmode as a
+// "don't know" wildcard.
+inline machine_mode
+combine_modes (machine_mode mode1, machine_mode mode2)
+{
+ if (mode1 == E_BLKmode)
+ return mode2;
+
+ if (mode2 == E_BLKmode)
+ return mode1;
+
+ return wider_subreg_mode (mode1, mode2);
+}
+
+// PRINTER (PP, ARGS...) prints ARGS... to a pretty_printer PP. Use it
+// to print ARGS... to FILE.
+template<typename Printer, typename... Args>
+inline void
+dump_using (FILE *file, Printer printer, Args... args)
+{
+ pretty_printer pp;
+ printer (&pp, args...);
+ pp_newline (&pp);
+ fprintf (file, "%s", pp_formatted_text (&pp));
+}
+
+}
--- /dev/null
+// is_a<> support for RTL SSA classes -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+template<>
+struct is_a_helper<rtl_ssa::def_info *>
+ : static_is_a_helper<rtl_ssa::def_info *>
+{
+ static inline bool
+ test (const rtl_ssa::access_info *ref)
+ {
+ return (ref->kind () == rtl_ssa::access_kind::SET
+ || ref->kind () == rtl_ssa::access_kind::PHI
+ || ref->kind () == rtl_ssa::access_kind::CLOBBER);
+ }
+};
+
+template<>
+struct is_a_helper<rtl_ssa::clobber_info *>
+ : static_is_a_helper<rtl_ssa::clobber_info *>
+{
+ static inline bool
+ test (const rtl_ssa::access_info *ref)
+ {
+ return ref->kind () == rtl_ssa::access_kind::CLOBBER;
+ }
+};
+
+template<>
+struct is_a_helper<rtl_ssa::use_info *>
+ : static_is_a_helper<rtl_ssa::use_info *>
+{
+ static inline bool
+ test (const rtl_ssa::access_info *ref)
+ {
+ return ref->kind () == rtl_ssa::access_kind::USE;
+ }
+};
+
+template<>
+struct is_a_helper<rtl_ssa::set_info *>
+ : static_is_a_helper<rtl_ssa::set_info *>
+{
+ static inline bool
+ test (const rtl_ssa::access_info *ref)
+ {
+ return (ref->kind () == rtl_ssa::access_kind::SET
+ || ref->kind () == rtl_ssa::access_kind::PHI);
+ }
+};
+
+template<>
+struct is_a_helper<rtl_ssa::phi_info *>
+ : static_is_a_helper<rtl_ssa::phi_info *>
+{
+ static inline bool
+ test (const rtl_ssa::access_info *ref)
+ {
+ return ref->kind () == rtl_ssa::access_kind::PHI;
+ }
+};
+
+template<>
+struct is_a_helper<rtl_ssa::set_node *>
+ : static_is_a_helper<rtl_ssa::set_node *>
+{
+ static inline bool
+ test (const rtl_ssa::def_node *node)
+ {
+ return node->contains_set ();
+ }
+};
+
+template<>
+struct is_a_helper<rtl_ssa::clobber_group *>
+ : static_is_a_helper<rtl_ssa::clobber_group *>
+{
+ static inline bool
+ test (const rtl_ssa::def_node *node)
+ {
+ return node->contains_clobber ();
+ }
+};
--- /dev/null
+// Implementation of public inline member functions for RTL SSA -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+// This file contains inline implementations of public member functions that
+// are too large to be written in the class definition. It also contains
+// some non-inline template definitions of public member functions.
+// See the comments above the function declarations for details.
+//
+// The file also contains the bare minimum of private and protected inline
+// member functions that are needed to make the public functions compile.
+namespace rtl_ssa {
+
+inline void
+access_array_builder::reserve (unsigned int num_accesses)
+{
+ obstack_make_room (m_obstack, num_accesses * sizeof (access_info *));
+}
+
+inline void
+access_array_builder::quick_push (access_info *access)
+{
+ obstack_ptr_grow_fast (m_obstack, access);
+}
+
+inline array_slice<access_info *>
+access_array_builder::finish ()
+{
+ auto num_accesses = obstack_object_size (m_obstack) / sizeof (access_info *);
+ if (num_accesses == 0)
+ return {};
+
+ auto **base = static_cast<access_info **> (obstack_finish (m_obstack));
+ keep ();
+ return { base, num_accesses };
+}
+
+inline bool
+access_info::is_set_with_nondebug_insn_uses () const
+{
+ return m_is_set_with_nondebug_insn_uses;
+}
+
+inline bool
+use_info::is_in_debug_insn () const
+{
+ return m_insn_or_phi.is_first () && m_is_in_debug_insn_or_phi;
+}
+
+inline bb_info *
+use_info::bb () const
+{
+ if (m_insn_or_phi.is_first ())
+ return m_insn_or_phi.known_first ()->bb ();
+ return m_insn_or_phi.known_second ()->bb ();
+}
+
+inline ebb_info *
+use_info::ebb () const
+{
+ return bb ()->ebb ();
+}
+
+inline use_info *
+use_info::prev_use () const
+{
+ return m_last_use_or_prev_use.second_or_null ();
+}
+
+inline use_info *
+use_info::next_use () const
+{
+ return m_last_nondebug_insn_use_or_next_use.second_or_null ();
+}
+
+inline bool
+use_info::is_first_use () const
+{
+ return m_last_use_or_prev_use.is_first ();
+}
+
+inline bool
+use_info::is_last_use () const
+{
+ return m_last_nondebug_insn_use_or_next_use.is_first ();
+}
+
+inline use_info *
+use_info::next_nondebug_insn_use () const
+{
+ if (m_is_last_nondebug_insn_use)
+ return nullptr;
+ return m_last_nondebug_insn_use_or_next_use.known_second ();
+}
+
+inline use_info *
+use_info::next_any_insn_use () const
+{
+ // This is used less often than next_nondebug_insn_use, so it doesn't
+ // seem worth having an m_is_last_nondebug_insn_use-style end marker.
+ if (use_info *use = next_use ())
+ if (use->is_in_any_insn ())
+ return use;
+ return nullptr;
+}
+
+inline use_info *
+use_info::prev_phi_use () const
+{
+ // This is used less often than next_nondebug_insn_use, so it doesn't
+ // seem worth having an m_is_last_nondebug_insn_use-style end marker.
+ if (use_info *use = prev_use ())
+ if (use->is_in_phi ())
+ return use;
+ return nullptr;
+}
+
+// Return the last use of any kind in the list. Only valid when is_first ()
+// is true.
+inline use_info *
+use_info::last_use () const
+{
+ return m_last_use_or_prev_use.known_first ();
+}
+
+// Return the last nondebug insn use in the list, or null if none. Only valid
+// when is_last_use () is true.
+inline use_info *
+use_info::last_nondebug_insn_use () const
+{
+ return m_last_nondebug_insn_use_or_next_use.known_first ();
+}
+
+inline def_info *
+def_info::prev_def () const
+{
+ return m_last_def_or_prev_def.second_or_null ();
+}
+
+inline def_info *
+def_info::next_def () const
+{
+ return m_splay_root_or_next_def.second_or_null ();
+}
+
+inline bool
+def_info::is_first_def () const
+{
+ return m_last_def_or_prev_def.is_first ();
+}
+
+inline bool
+def_info::is_last_def () const
+{
+ return m_splay_root_or_next_def.is_first ();
+}
+
+inline bb_info *
+def_info::bb () const
+{
+ return m_insn->bb ();
+}
+
+inline ebb_info *
+def_info::ebb () const
+{
+ return m_insn->ebb ();
+}
+
+inline clobber_group *
+clobber_info::group () const
+{
+ if (!m_group || !m_group->has_been_superceded ())
+ return m_group;
+ return const_cast<clobber_info *> (this)->recompute_group ();
+}
+
+inline use_info *
+set_info::last_use () const
+{
+ return m_first_use ? m_first_use->last_use () : nullptr;
+}
+
+inline use_info *
+set_info::first_nondebug_insn_use () const
+{
+ if (m_is_set_with_nondebug_insn_uses)
+ return m_first_use;
+ return nullptr;
+}
+
+inline use_info *
+set_info::last_nondebug_insn_use () const
+{
+ if (m_is_set_with_nondebug_insn_uses)
+ return m_first_use->last_use ()->last_nondebug_insn_use ();
+ return nullptr;
+}
+
+inline use_info *
+set_info::first_any_insn_use () const
+{
+ if (m_first_use->is_in_any_insn ())
+ return m_first_use;
+ return nullptr;
+}
+
+inline use_info *
+set_info::last_phi_use () const
+{
+ if (m_first_use)
+ {
+ use_info *last = m_first_use->last_use ();
+ if (last->is_in_phi ())
+ return last;
+ }
+ return nullptr;
+}
+
+inline bool
+set_info::has_nondebug_uses () const
+{
+ return has_nondebug_insn_uses () || has_phi_uses ();
+}
+
+inline bool
+set_info::has_nondebug_insn_uses () const
+{
+ return m_is_set_with_nondebug_insn_uses;
+}
+
+inline bool
+set_info::has_phi_uses () const
+{
+ return m_first_use && m_first_use->last_use ()->is_in_phi ();
+}
+
+inline bool
+set_info::is_local_to_ebb () const
+{
+ if (!m_first_use)
+ return true;
+
+ use_info *last = m_first_use->last_use ();
+ if (last->is_in_phi ())
+ return false;
+
+ last = last->last_nondebug_insn_use ();
+ return !last || last->ebb () == ebb ();
+}
+
+inline iterator_range<use_iterator>
+set_info::all_uses () const
+{
+ return { m_first_use, nullptr };
+}
+
+inline iterator_range<reverse_use_iterator>
+set_info::reverse_all_uses () const
+{
+ return { last_use (), nullptr };
+}
+
+inline iterator_range<nondebug_insn_use_iterator>
+set_info::nondebug_insn_uses () const
+{
+ return { first_nondebug_insn_use (), nullptr };
+}
+
+inline iterator_range<reverse_use_iterator>
+set_info::reverse_nondebug_insn_uses () const
+{
+ return { last_nondebug_insn_use (), nullptr };
+}
+
+inline iterator_range<any_insn_use_iterator>
+set_info::all_insn_uses () const
+{
+ return { first_any_insn_use (), nullptr };
+}
+
+inline iterator_range<phi_use_iterator>
+set_info::phi_uses () const
+{
+ return { last_phi_use (), nullptr };
+}
+
+inline use_array
+phi_info::inputs () const
+{
+ if (m_num_inputs == 1)
+ return use_array (&m_single_input, 1);
+ return use_array (m_inputs, m_num_inputs);
+}
+
+inline use_info *
+phi_info::input_use (unsigned int i) const
+{
+ if (m_num_inputs == 1)
+ return as_a<use_info *> (m_single_input);
+ return as_a<use_info *> (m_inputs[i]);
+}
+
+inline set_info *
+phi_info::input_value (unsigned int i) const
+{
+ return input_use (i)->def ();
+}
+
+inline def_info *
+def_node::first_def () const
+{
+ // This should get optimized into an AND with -2.
+ if (m_clobber_or_set.is_first ())
+ return m_clobber_or_set.known_first ();
+ return m_clobber_or_set.known_second ();
+}
+
+inline clobber_info *
+clobber_group::first_clobber () const
+{
+ return m_clobber_or_set.known_first ();
+}
+
+inline iterator_range<def_iterator>
+clobber_group::clobbers () const
+{
+ return { first_clobber (), m_last_clobber->next_def () };
+}
+
+inline def_info *
+def_mux::first_def () const
+{
+ if (is_first ())
+ return known_first ();
+ return known_second ()->first_def ();
+}
+
+inline def_info *
+def_mux::last_def () const
+{
+ if (is_first ())
+ return known_first ();
+
+ def_node *node = known_second ();
+ if (auto *clobber = ::dyn_cast<clobber_group *> (node))
+ return clobber->last_clobber ();
+
+ return node->first_def ();
+}
+
+inline set_info *
+def_mux::set () const
+{
+ if (is_first ())
+ return ::safe_dyn_cast<set_info *> (known_first ());
+ return ::dyn_cast<set_info *> (known_second ()->first_def ());
+}
+
+inline def_info *
+def_lookup::prev_def () const
+{
+ if (!mux)
+ return nullptr;
+
+ if (comparison > 0)
+ return mux.last_def ();
+
+ return mux.first_def ()->prev_def ();
+}
+
+inline def_info *
+def_lookup::next_def () const
+{
+ if (!mux)
+ return nullptr;
+
+ if (comparison < 0)
+ return mux.first_def ();
+
+ return mux.last_def ()->next_def ();
+}
+
+inline set_info *
+def_lookup::matching_set () const
+{
+ if (comparison == 0)
+ return mux.set ();
+ return nullptr;
+}
+
+inline def_info *
+def_lookup::matching_or_prev_def () const
+{
+ if (set_info *set = matching_set ())
+ return set;
+ return prev_def ();
+}
+
+inline def_info *
+def_lookup::matching_or_next_def () const
+{
+ if (set_info *set = matching_set ())
+ return set;
+ return next_def ();
+}
+
+inline insn_note::insn_note (insn_note_kind kind)
+ : m_next_note (nullptr),
+ m_kind (kind),
+ m_data8 (0),
+ m_data16 (0),
+ m_data32 (0)
+{
+}
+
+template<typename T>
+inline T
+insn_note::as_a ()
+{
+ using deref_type = decltype (*std::declval<T> ());
+ using derived = typename std::remove_reference<deref_type>::type;
+ gcc_checking_assert (m_kind == derived::kind);
+ return static_cast<T> (this);
+}
+
+template<typename T>
+inline T
+insn_note::dyn_cast ()
+{
+ using deref_type = decltype (*std::declval<T> ());
+ using derived = typename std::remove_reference<deref_type>::type;
+ if (m_kind == derived::kind)
+ return static_cast<T> (this);
+ return nullptr;
+}
+
+inline bool
+insn_info::operator< (const insn_info &other) const
+{
+ if (this == &other)
+ return false;
+
+ if (__builtin_expect (m_point != other.m_point, 1))
+ return m_point < other.m_point;
+
+ return slow_compare_with (other) < 0;
+}
+
+inline bool
+insn_info::operator> (const insn_info &other) const
+{
+ return other < *this;
+}
+
+inline bool
+insn_info::operator<= (const insn_info &other) const
+{
+ return !(other < *this);
+}
+
+inline bool
+insn_info::operator>= (const insn_info &other) const
+{
+ return !(*this < other);
+}
+
+inline int
+insn_info::compare_with (const insn_info *other) const
+{
+ if (this == other)
+ return 0;
+
+ if (__builtin_expect (m_point != other->m_point, 1))
+ // Assume that points remain in [0, INT_MAX].
+ return m_point - other->m_point;
+
+ return slow_compare_with (*other);
+}
+
+inline insn_info *
+insn_info::prev_nondebug_insn () const
+{
+ gcc_checking_assert (!is_debug_insn ());
+ return m_prev_insn_or_last_debug_insn.known_first ();
+}
+
+inline insn_info *
+insn_info::next_nondebug_insn () const
+{
+ gcc_checking_assert (!is_debug_insn ());
+ const insn_info *from = this;
+ if (insn_info *first_debug = m_next_nondebug_or_debug_insn.second_or_null ())
+ from = first_debug->last_debug_insn ();
+ return from->m_next_nondebug_or_debug_insn.known_first ();
+}
+
+inline insn_info *
+insn_info::prev_any_insn () const
+{
+ const insn_info *from = this;
+ if (insn_info *last_debug = m_prev_insn_or_last_debug_insn.second_or_null ())
+ // This instruction is the first in a subsequence of debug instructions.
+ // Move to the following nondebug instruction.
+ from = last_debug->m_next_nondebug_or_debug_insn.known_first ();
+ return from->m_prev_insn_or_last_debug_insn.known_first ();
+}
+
+inline insn_info *
+insn_info::next_any_insn () const
+{
+ // This should get optimized into an AND with -2.
+ if (m_next_nondebug_or_debug_insn.is_first ())
+ return m_next_nondebug_or_debug_insn.known_first ();
+ return m_next_nondebug_or_debug_insn.known_second ();
+}
+
+inline bool
+insn_info::is_phi () const
+{
+ return this == ebb ()->phi_insn ();
+}
+
+inline bool
+insn_info::is_bb_head () const
+{
+ return this == m_bb->head_insn ();
+}
+
+inline bool
+insn_info::is_bb_end () const
+{
+ return this == m_bb->end_insn ();
+}
+
+inline ebb_info *
+insn_info::ebb () const
+{
+ return m_bb->ebb ();
+}
+
+inline int
+insn_info::uid () const
+{
+ return m_cost_or_uid < 0 ? m_cost_or_uid : INSN_UID (m_rtl);
+}
+
+inline use_array
+insn_info::uses () const
+{
+ return use_array (m_accesses + m_num_defs, m_num_uses);
+}
+
+inline bool
+insn_info::has_call_clobbers () const
+{
+ return find_note<insn_call_clobbers_note> ();
+}
+
+inline def_array
+insn_info::defs () const
+{
+ return def_array (m_accesses, m_num_defs);
+}
+
+inline unsigned int
+insn_info::cost () const
+{
+ if (m_cost_or_uid < 0)
+ return 0;
+ if (m_cost_or_uid == UNKNOWN_COST)
+ calculate_cost ();
+ return m_cost_or_uid;
+}
+
+template<typename T>
+inline const T *
+insn_info::find_note () const
+{
+ // We could break if the note kind is > T::kind, but since the number
+ // of notes should be very small, the check is unlikely to pay for itself.
+ for (const insn_note *note = first_note (); note; note = note->next_note ())
+ if (note->kind () == T::kind)
+ return static_cast<const T *> (note);
+ return nullptr;
+}
+
+// Only valid for debug instructions that come after a nondebug instruction,
+// and so start a subsequence of debug instructions. Return the last debug
+// instruction in the subsequence.
+inline insn_info *
+insn_info::last_debug_insn () const
+{
+ return m_prev_insn_or_last_debug_insn.known_second ();
+}
+
+inline insn_range_info::insn_range_info (insn_info *first, insn_info *last)
+ : first (first), last (last)
+{
+}
+
+inline bool
+insn_range_info::operator== (const insn_range_info &other) const
+{
+ return first == other.first && last == other.last;
+}
+
+inline bool
+insn_range_info::operator!= (const insn_range_info &other) const
+{
+ return first != other.first || last != other.last;
+}
+
+inline insn_info *
+insn_range_info::singleton () const
+{
+ return first == last ? last : nullptr;
+}
+
+inline bool
+insn_range_info::includes (insn_info *insn) const
+{
+ return *insn >= *first && *insn <= *last;
+}
+
+inline insn_info *
+insn_range_info::clamp_insn_to_range (insn_info *insn) const
+{
+ if (*first > *insn)
+ return first;
+ if (*last < *insn)
+ return last;
+ return insn;
+}
+
+inline bool
+insn_range_info::is_subrange_of (const insn_range_info &other) const
+{
+ return *first >= *other.first && *last <= *other.last;
+}
+
+inline iterator_range<any_insn_iterator>
+bb_info::all_insns () const
+{
+ return { m_head_insn, m_end_insn->next_any_insn () };
+}
+
+inline iterator_range<reverse_any_insn_iterator>
+bb_info::reverse_all_insns () const
+{
+ return { m_end_insn, m_head_insn->prev_any_insn () };
+}
+
+inline iterator_range<nondebug_insn_iterator>
+bb_info::nondebug_insns () const
+{
+ return { m_head_insn, m_end_insn->next_nondebug_insn () };
+}
+
+inline iterator_range<reverse_nondebug_insn_iterator>
+bb_info::reverse_nondebug_insns () const
+{
+ return { m_end_insn, m_head_insn->prev_nondebug_insn () };
+}
+
+inline iterator_range<any_insn_iterator>
+bb_info::real_insns () const
+{
+ return { m_head_insn->next_any_insn (), m_end_insn };
+}
+
+inline iterator_range<reverse_any_insn_iterator>
+bb_info::reverse_real_insns () const
+{
+ return { m_end_insn->prev_any_insn (), m_head_insn };
+}
+
+inline iterator_range<nondebug_insn_iterator>
+bb_info::real_nondebug_insns () const
+{
+ return { m_head_insn->next_nondebug_insn (), m_end_insn };
+}
+
+inline iterator_range<reverse_nondebug_insn_iterator>
+bb_info::reverse_real_nondebug_insns () const
+{
+ return { m_end_insn->prev_nondebug_insn (), m_head_insn };
+}
+
+inline bool
+ebb_call_clobbers_info::clobbers (resource_info resource) const
+{
+ // Only register clobbers are tracked this way. Other clobbers are
+ // recorded explicitly.
+ return (resource.is_reg ()
+ && m_abi->clobbers_reg_p (resource.mode, resource.regno));
+}
+
+inline ebb_info *
+ebb_info::prev_ebb () const
+{
+ if (bb_info *prev_bb = m_first_bb->prev_bb ())
+ return prev_bb->ebb ();
+ return nullptr;
+}
+
+inline ebb_info *
+ebb_info::next_ebb () const
+{
+ if (bb_info *next_bb = m_last_bb->next_bb ())
+ return next_bb->ebb ();
+ return nullptr;
+}
+
+inline iterator_range<phi_iterator>
+ebb_info::phis () const
+{
+ return { m_first_phi, nullptr };
+}
+
+inline iterator_range<bb_iterator>
+ebb_info::bbs () const
+{
+ return { m_first_bb, m_last_bb->next_bb () };
+}
+
+inline iterator_range<reverse_bb_iterator>
+ebb_info::reverse_bbs () const
+{
+ return { m_last_bb, m_first_bb->prev_bb () };
+}
+
+inline iterator_range<any_insn_iterator>
+ebb_info::all_insns () const
+{
+ return { m_phi_insn, m_last_bb->end_insn ()->next_any_insn () };
+}
+
+inline iterator_range<reverse_any_insn_iterator>
+ebb_info::reverse_all_insns () const
+{
+ return { m_last_bb->end_insn (), m_phi_insn->prev_any_insn () };
+}
+
+inline iterator_range<nondebug_insn_iterator>
+ebb_info::nondebug_insns () const
+{
+ return { m_phi_insn, m_last_bb->end_insn ()->next_nondebug_insn () };
+}
+
+inline iterator_range<reverse_nondebug_insn_iterator>
+ebb_info::reverse_nondebug_insns () const
+{
+ return { m_last_bb->end_insn (), m_phi_insn->prev_nondebug_insn () };
+}
+
+inline insn_range_info
+ebb_info::insn_range () const
+{
+ return { m_phi_insn, m_last_bb->end_insn () };
+}
+
+inline void
+ebb_info::set_first_call_clobbers (ebb_call_clobbers_info *call_clobbers)
+{
+ m_first_call_clobbers = call_clobbers;
+}
+
+inline ebb_call_clobbers_info *
+ebb_info::first_call_clobbers () const
+{
+ return m_first_call_clobbers;
+}
+
+inline iterator_range<ebb_call_clobbers_iterator>
+ebb_info::call_clobbers () const
+{
+ return { m_first_call_clobbers, nullptr };
+}
+
+inline insn_change::insn_change (insn_info *insn)
+ : m_insn (insn),
+ new_defs (insn->defs ()),
+ new_uses (insn->uses ()),
+ move_range (insn),
+ new_cost (UNKNOWN_COST),
+ m_is_deletion (false)
+{
+}
+
+inline insn_change::insn_change (insn_info *insn, delete_action)
+ : m_insn (insn),
+ new_defs (),
+ new_uses (),
+ move_range (insn),
+ new_cost (0),
+ m_is_deletion (true)
+{
+}
+
+inline insn_is_changing_closure::
+insn_is_changing_closure (array_slice<insn_change *const> changes)
+ : m_changes (changes)
+{
+}
+
+inline bool
+insn_is_changing_closure::operator() (const insn_info *insn) const
+{
+ for (const insn_change *change : m_changes)
+ if (change->insn () == insn)
+ return true;
+ return false;
+}
+
+inline iterator_range<bb_iterator>
+function_info::bbs () const
+{
+ return { m_first_bb, nullptr };
+}
+
+inline iterator_range<reverse_bb_iterator>
+function_info::reverse_bbs () const
+{
+ return { m_last_bb, nullptr };
+}
+
+inline iterator_range<ebb_iterator>
+function_info::ebbs () const
+{
+ return { m_first_bb->ebb (), nullptr };
+}
+
+inline iterator_range<reverse_ebb_iterator>
+function_info::reverse_ebbs () const
+{
+ return { m_last_bb->ebb (), nullptr };
+}
+
+inline iterator_range<any_insn_iterator>
+function_info::all_insns () const
+{
+ return { m_first_insn, nullptr };
+}
+
+inline iterator_range<reverse_any_insn_iterator>
+function_info::reverse_all_insns () const
+{
+ return { m_last_insn, nullptr };
+}
+
+inline iterator_range<nondebug_insn_iterator>
+function_info::nondebug_insns () const
+{
+ return { m_first_insn, nullptr };
+}
+
+inline iterator_range<reverse_nondebug_insn_iterator>
+function_info::reverse_nondebug_insns () const
+{
+ return { m_last_insn, nullptr };
+}
+
+inline iterator_range<def_iterator>
+function_info::mem_defs () const
+{
+ return { m_defs[0], nullptr };
+}
+
+inline iterator_range<def_iterator>
+function_info::ref_defs (unsigned int regno) const
+{
+ return { m_defs[regno + 1], nullptr };
+}
+
+inline set_info *
+function_info::single_dominating_def (unsigned int regno) const
+{
+ if (set_info *set = safe_dyn_cast<set_info *> (m_defs[regno + 1]))
+ if (is_single_dominating_def (set))
+ return set;
+ return nullptr;
+}
+
+template<typename IgnorePredicate>
+bool
+function_info::add_regno_clobber (obstack_watermark &watermark,
+ insn_change &change, unsigned int regno,
+ IgnorePredicate ignore)
+{
+ // Check whether CHANGE already clobbers REGNO.
+ if (find_access (change.new_defs, regno))
+ return true;
+
+ // Get the closest position to INSN at which the new instruction
+ // could be placed.
+ insn_info *insn = change.move_range.clamp_insn_to_range (change.insn ());
+ def_array new_defs = insert_temp_clobber (watermark, insn, regno,
+ change.new_defs);
+ if (!new_defs.is_valid ())
+ return false;
+
+ // Find a definition at or neighboring INSN.
+ insn_range_info move_range = change.move_range;
+ if (!restrict_movement_for_dead_range (move_range, regno, insn, ignore))
+ return false;
+
+ change.new_defs = new_defs;
+ change.move_range = move_range;
+ return true;
+}
+
+}
--- /dev/null
+// RTL SSA utilities relating to instruction movement -*- C++ -*-
+// Copyright (C) 2020 Free Software Foundation, Inc.
+//
+// This file is part of GCC.
+//
+// GCC is free software; you can redistribute it and/or modify it under
+// the terms of the GNU General Public License as published by the Free
+// Software Foundation; either version 3, or (at your option) any later
+// version.
+//
+// GCC is distributed in the hope that it will be useful, but WITHOUT ANY
+// WARRANTY; without even the implied warranty of MERCHANTABILITY or
+// FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+// for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with GCC; see the file COPYING3. If not see
+// <http://www.gnu.org/licenses/>.
+
+namespace rtl_ssa {
+
+// Restrict movement range RANGE so that the instruction is placed later
+// than INSN. (The movement range is the range of instructions after which
+// an instruction can be placed.)
+inline insn_range_info
+move_later_than (insn_range_info range, insn_info *insn)
+{
+ return { later_insn (range.first, insn), range.last };
+}
+
+// Restrict movement range RANGE so that the instruction is placed no earlier
+// than INSN. (The movement range is the range of instructions after which
+// an instruction can be placed.)
+inline insn_range_info
+move_no_earlier_than (insn_range_info range, insn_info *insn)
+{
+ insn_info *first = later_insn (range.first, insn->prev_nondebug_insn ());
+ return { first, range.last };
+}
+
+// Restrict movement range RANGE so that the instruction is placed no later
+// than INSN. (The movement range is the range of instructions after which
+// an instruction can be placed.)
+inline insn_range_info
+move_no_later_than (insn_range_info range, insn_info *insn)
+{
+ return { range.first, earlier_insn (range.last, insn) };
+}
+
+// Restrict movement range RANGE so that the instruction is placed earlier
+// than INSN. (The movement range is the range of instructions after which
+// an instruction can be placed.)
+inline insn_range_info
+move_earlier_than (insn_range_info range, insn_info *insn)
+{
+ insn_info *last = earlier_insn (range.last, insn->prev_nondebug_insn ());
+ return { range.first, last };
+}
+
+// Return true if it is possible to insert a new instruction after INSN.
+inline bool
+can_insert_after (insn_info *insn)
+{
+ return insn->is_bb_head () || (insn->is_real () && !insn->is_jump ());
+}
+
+// Try to restrict move range MOVE_RANGE so that it is possible to
+// insert INSN after both of the end points. Return true on success,
+// otherwise leave MOVE_RANGE in an invalid state.
+inline bool
+canonicalize_move_range (insn_range_info &move_range, insn_info *insn)
+{
+ while (move_range.first != insn && !can_insert_after (move_range.first))
+ move_range.first = move_range.first->next_nondebug_insn ();
+ while (move_range.last != insn && !can_insert_after (move_range.last))
+ move_range.last = move_range.last->prev_nondebug_insn ();
+ return bool (move_range);
+}
+
+// Try to restrict movement range MOVE_RANGE of INSN so that it can set
+// or clobber REGNO. Assume that if:
+//
+// - an instruction I2 contains another access A to REGNO; and
+// - IGNORE (I2) is true
+//
+// then either:
+//
+// - A will be removed; or
+// - something will ensure that the new definition of REGNO does not
+// interfere with A, without this having to be enforced by I1's move range.
+//
+// Return true on success, otherwise leave MOVE_RANGE in an invalid state.
+//
+// This function only works correctly for instructions that remain within
+// the same extended basic block.
+template<typename IgnorePredicate>
+bool
+restrict_movement_for_dead_range (insn_range_info &move_range,
+ unsigned int regno, insn_info *insn,
+ IgnorePredicate ignore)
+{
+ // Find a definition at or neighboring INSN.
+ resource_info resource = full_register (regno);
+ def_lookup dl = crtl->ssa->find_def (resource, insn);
+
+ def_info *prev = dl.prev_def ();
+ ebb_info *ebb = insn->ebb ();
+ if (!prev || prev->ebb () != ebb)
+ {
+ // REGNO is not defined or used in EBB before INSN, but it
+ // might be live on entry. To keep complexity under control,
+ // handle only these cases:
+ //
+ // - If the register is not live on entry to EBB, the register is
+ // free from the start of EBB to the first definition in EBB.
+ //
+ // - Otherwise, if the register is live on entry to BB, refuse
+ // to allocate the register. We could in principle try to move
+ // the instruction to later blocks in the EBB, but it's rarely
+ // worth the effort, and could lead to linear complexity.
+ //
+ // - Otherwise, don't allow INSN to move earlier than its current
+ // block. Again, we could in principle look backwards to find where
+ // REGNO dies, but it's rarely worth the effort.
+ bb_info *bb = insn->bb ();
+ insn_info *limit;
+ if (!bitmap_bit_p (DF_LR_IN (ebb->first_bb ()->cfg_bb ()), regno))
+ limit = ebb->phi_insn ();
+ else if (bitmap_bit_p (DF_LR_IN (bb->cfg_bb ()), regno))
+ return false;
+ else
+ limit = bb->head_insn ();
+ move_range = move_later_than (move_range, limit);
+ }
+ else
+ {
+ // Stop the instruction moving beyond the previous relevant access
+ // to REGNO.
+ access_info *prev_access
+ = last_access_ignoring (prev, ignore_clobbers::YES, ignore);
+ if (prev_access)
+ move_range = move_later_than (move_range, access_insn (prev_access));
+ }
+
+ // Stop the instruction moving beyond the next relevant definition of REGNO.
+ def_info *next = first_def_ignoring (dl.matching_or_next_def (),
+ ignore_clobbers::YES, ignore);
+ if (next)
+ move_range = move_earlier_than (move_range, next->insn ());
+
+ return canonicalize_move_range (move_range, insn);
+}
+
+// Try to restrict movement range MOVE_RANGE so that it is possible for the
+// instruction being moved ("instruction I1") to perform all the definitions
+// in DEFS while still preserving dependencies between those definitions
+// and surrounding instructions. Assume that if:
+//
+// - DEFS contains a definition D of resource R;
+// - an instruction I2 contains another access A to R; and
+// - IGNORE (I2) is true
+//
+// then either:
+//
+// - A will be removed; or
+// - something will ensure that D and A maintain their current order,
+// without this having to be enforced by I1's move range.
+//
+// Return true on success, otherwise leave MOVE_RANGE in an invalid state.
+//
+// This function only works correctly for instructions that remain within
+// the same extended basic block.
+template<typename IgnorePredicate>
+bool
+restrict_movement_for_defs_ignoring (insn_range_info &move_range,
+ def_array defs, IgnorePredicate ignore)
+{
+ for (def_info *def : defs)
+ {
+ // If the definition is a clobber, we can move it with respect
+ // to other clobbers.
+ //
+ // ??? We could also do this if a definition and all its uses
+ // are being moved at once.
+ bool is_clobber = is_a<clobber_info *> (def);
+
+ // Search back for the first unfiltered use or definition of the
+ // same resource.
+ access_info *access;
+ access = prev_access_ignoring (def, ignore_clobbers (is_clobber),
+ ignore);
+ if (access)
+ move_range = move_later_than (move_range, access_insn (access));
+
+ // Search forward for the first unfiltered use of DEF,
+ // or the first unfiltered definition that follows DEF.
+ //
+ // We don't need to consider uses of following definitions, since
+ // if IGNORE (D->insn ()) is true for some definition D, the caller
+ // is guarantees that either
+ //
+ // - D will be removed, and thus its uses will be removed; or
+ // - D will occur after DEF, and thus D's uses will also occur
+ // after DEF.
+ //
+ // This is purely a simplification: we could also process D's uses,
+ // but we don't need to.
+ access = next_access_ignoring (def, ignore_clobbers (is_clobber),
+ ignore);
+ if (access)
+ move_range = move_earlier_than (move_range, access_insn (access));
+
+ // If DEF sets a hard register, take any call clobbers
+ // into account.
+ unsigned int regno = def->regno ();
+ if (!HARD_REGISTER_NUM_P (regno) || is_clobber)
+ continue;
+
+ ebb_info *ebb = def->ebb ();
+ for (ebb_call_clobbers_info *call_group : ebb->call_clobbers ())
+ {
+ if (!call_group->clobbers (def->resource ()))
+ continue;
+
+ // Exit now if we've already failed, and if the splay accesses
+ // below would be wasted work.
+ if (!move_range)
+ return false;
+
+ insn_info *insn;
+ insn = prev_call_clobbers_ignoring (*call_group, def->insn (),
+ ignore);
+ if (insn)
+ move_range = move_later_than (move_range, insn);
+
+ insn = next_call_clobbers_ignoring (*call_group, def->insn (),
+ ignore);
+ if (insn)
+ move_range = move_earlier_than (move_range, insn);
+ }
+ }
+
+ // Make sure that we don't move stores between basic blocks, since we
+ // don't have enough information to tell whether it's safe.
+ if (def_info *def = memory_access (defs))
+ {
+ move_range = move_later_than (move_range, def->bb ()->head_insn ());
+ move_range = move_earlier_than (move_range, def->bb ()->end_insn ());
+ }
+
+ return bool (move_range);
+}
+
+// Like restrict_movement_for_defs_ignoring, but for the uses in USES.
+template<typename IgnorePredicate>
+bool
+restrict_movement_for_uses_ignoring (insn_range_info &move_range,
+ use_array uses, IgnorePredicate ignore)
+{
+ for (const use_info *use : uses)
+ {
+ // Ignore uses of undefined values.
+ set_info *set = use->def ();
+ if (!set)
+ continue;
+
+ // Ignore uses by debug instructions. Debug instructions are
+ // never supposed to move, and uses by debug instructions are
+ // never supposed to be transferred elsewhere, so we know that
+ // the caller must be changing the uses on the debug instruction
+ // and checking whether all new uses are available at the debug
+ // instruction's original location.
+ if (use->is_in_debug_insn ())
+ continue;
+
+ // If the used value is defined by an instruction I2 for which
+ // IGNORE (I2) is true, the caller guarantees that I2 will occur
+ // before change.insn (). Otherwise, make sure that the use occurs
+ // after the definition.
+ insn_info *insn = set->insn ();
+ if (!ignore (insn))
+ move_range = move_later_than (move_range, insn);
+
+ // Search forward for the first unfiltered definition that follows SET.
+ //
+ // We don't need to consider the uses of these definitions, since
+ // if IGNORE (D->insn ()) is true for some definition D, the caller
+ // is guarantees that either
+ //
+ // - D will be removed, and thus its uses will be removed; or
+ // - D will occur after USE, and thus D's uses will also occur
+ // after USE.
+ //
+ // This is purely a simplification: we could also process D's uses,
+ // but we don't need to.
+ def_info *def;
+ def = first_def_ignoring (set->next_def (), ignore_clobbers::NO,
+ ignore);
+ if (def)
+ move_range = move_earlier_than (move_range, def->insn ());
+
+ // If USE uses a hard register, take any call clobbers into account too.
+ // SET will necessarily occur after any previous call clobber, so we
+ // only need to check for later clobbers.
+ unsigned int regno = use->regno ();
+ if (!HARD_REGISTER_NUM_P (regno))
+ continue;
+
+ ebb_info *ebb = use->ebb ();
+ for (ebb_call_clobbers_info *call_group : ebb->call_clobbers ())
+ {
+ if (!call_group->clobbers (use->resource ()))
+ continue;
+
+ if (!move_range)
+ return false;
+
+ insn_info *insn = next_call_clobbers_ignoring (*call_group,
+ use->insn (), ignore);
+ if (insn)
+ move_range = move_earlier_than (move_range, insn);
+ }
+ }
+
+ // Make sure that we don't move loads into an earlier basic block.
+ //
+ // ??? It would be good to relax this for loads that can be safely
+ // speculated.
+ if (use_info *use = memory_access (uses))
+ move_range = move_later_than (move_range, use->bb ()->head_insn ());
+
+ return bool (move_range);
+}
+
+}
#ifdef INCLUDE_ARRAY
# include <array>
#endif
+#ifdef INCLUDE_FUNCTIONAL
+# include <functional>
+#endif
# include <cstring>
# include <new>
# include <utility>
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