/* SCC value numbering for trees
- Copyright (C) 2006-2018 Free Software Foundation, Inc.
+ Copyright (C) 2006-2019 Free Software Foundation, Inc.
Contributed by Daniel Berlin <dan@dberlin.org>
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
+#include "splay-tree.h"
#include "backend.h"
#include "rtl.h"
#include "tree.h"
#include "gimple.h"
-#include "alloc-pool.h"
#include "ssa.h"
#include "expmed.h"
#include "insn-config.h"
#include "tree-cfgcleanup.h"
#include "tree-ssa-loop.h"
#include "tree-scalar-evolution.h"
+#include "tree-ssa-loop-niter.h"
+#include "builtins.h"
#include "tree-ssa-sccvn.h"
/* This algorithm is based on the SCC algorithm presented by Keith
structure copies.
*/
+/* There's no BB_EXECUTABLE but we can use BB_VISITED. */
+#define BB_EXECUTABLE BB_VISITED
-static tree *last_vuse_ptr;
-static vn_lookup_kind vn_walk_kind;
static vn_lookup_kind default_vn_walk_kind;
-bitmap const_parms;
/* vn_nary_op hashtable helpers. */
inline bool
vn_nary_op_hasher::equal (const vn_nary_op_s *vno1, const vn_nary_op_s *vno2)
{
- return vn_nary_op_eq (vno1, vno2);
+ return vno1 == vno2 || vn_nary_op_eq (vno1, vno2);
}
typedef hash_table<vn_nary_op_hasher> vn_nary_op_table_type;
static int
vn_phi_eq (const_vn_phi_t const vp1, const_vn_phi_t const vp2);
-struct vn_phi_hasher : pointer_hash <vn_phi_s>
+struct vn_phi_hasher : nofree_ptr_hash <vn_phi_s>
{
static inline hashval_t hash (const vn_phi_s *);
static inline bool equal (const vn_phi_s *, const vn_phi_s *);
- static inline void remove (vn_phi_s *);
};
/* Return the computed hashcode for phi operation P1. */
inline bool
vn_phi_hasher::equal (const vn_phi_s *vp1, const vn_phi_s *vp2)
{
- return vn_phi_eq (vp1, vp2);
-}
-
-/* Free a phi operation structure VP. */
-
-inline void
-vn_phi_hasher::remove (vn_phi_s *phi)
-{
- phi->phiargs.release ();
+ return vp1 == vp2 || vn_phi_eq (vp1, vp2);
}
typedef hash_table<vn_phi_hasher> vn_phi_table_type;
/* vn_reference hashtable helpers. */
-struct vn_reference_hasher : pointer_hash <vn_reference_s>
+struct vn_reference_hasher : nofree_ptr_hash <vn_reference_s>
{
static inline hashval_t hash (const vn_reference_s *);
static inline bool equal (const vn_reference_s *, const vn_reference_s *);
- static inline void remove (vn_reference_s *);
};
/* Return the hashcode for a given reference operation P1. */
inline bool
vn_reference_hasher::equal (const vn_reference_s *v, const vn_reference_s *c)
{
- return vn_reference_eq (v, c);
-}
-
-inline void
-vn_reference_hasher::remove (vn_reference_s *v)
-{
- free_reference (v);
+ return v == c || vn_reference_eq (v, c);
}
typedef hash_table<vn_reference_hasher> vn_reference_table_type;
typedef vn_reference_table_type::iterator vn_reference_iterator_type;
-/* The set of hashtables and alloc_pool's for their items. */
+/* The set of VN hashtables. */
typedef struct vn_tables_s
{
vn_nary_op_table_type *nary;
vn_phi_table_type *phis;
vn_reference_table_type *references;
- struct obstack nary_obstack;
- object_allocator<vn_phi_s> *phis_pool;
- object_allocator<vn_reference_s> *references_pool;
} *vn_tables_t;
static bitmap constant_value_ids;
+/* Obstack we allocate the vn-tables elements from. */
+static obstack vn_tables_obstack;
+/* Special obstack we never unwind. */
+static obstack vn_tables_insert_obstack;
+
+static vn_reference_t last_inserted_ref;
+static vn_phi_t last_inserted_phi;
+static vn_nary_op_t last_inserted_nary;
+
/* Valid hashtables storing information we have proven to be
correct. */
-
static vn_tables_t valid_info;
-/* Optimistic hashtables storing information we are making assumptions about
- during iterations. */
-
-static vn_tables_t optimistic_info;
-
-/* Pointer to the set of hashtables that is currently being used.
- Should always point to either the optimistic_info, or the
- valid_info. */
-
-static vn_tables_t current_info;
-
-
-/* Reverse post order index for each basic block. */
-
-static int *rpo_numbers;
-#define SSA_VAL(x) (VN_INFO ((x))->valnum)
+/* Valueization hook. Valueize NAME if it is an SSA name, otherwise
+ just return it. */
+tree (*vn_valueize) (tree);
-/* Return the SSA value of the VUSE x, supporting released VDEFs
- during elimination which will value-number the VDEF to the
- associated VUSE (but not substitute in the whole lattice). */
-
-static inline tree
-vuse_ssa_val (tree x)
-{
- if (!x)
- return NULL_TREE;
-
- do
- {
- tree tem = SSA_VAL (x);
- /* stmt walking can walk over a backedge and reach code we didn't
- value-number yet. */
- if (tem == VN_TOP)
- return x;
- x = tem;
- }
- while (SSA_NAME_IN_FREE_LIST (x));
-
- return x;
-}
/* This represents the top of the VN lattice, which is the universal
value. */
static unsigned int next_value_id;
-/* Next DFS number and the stack for strongly connected component
- detection. */
-
-static unsigned int next_dfs_num;
-static vec<tree> sccstack;
-
-
/* Table of vn_ssa_aux_t's, one per ssa_name. The vn_ssa_aux_t objects
are allocated on an obstack for locality reasons, and to free them
without looping over the vec. */
-static vec<vn_ssa_aux_t> vn_ssa_aux_table;
+struct vn_ssa_aux_hasher : typed_noop_remove <vn_ssa_aux_t>
+{
+ typedef vn_ssa_aux_t value_type;
+ typedef tree compare_type;
+ static inline hashval_t hash (const value_type &);
+ static inline bool equal (const value_type &, const compare_type &);
+ static inline void mark_deleted (value_type &) {}
+ static inline void mark_empty (value_type &e) { e = NULL; }
+ static inline bool is_deleted (value_type &) { return false; }
+ static inline bool is_empty (value_type &e) { return e == NULL; }
+};
+
+hashval_t
+vn_ssa_aux_hasher::hash (const value_type &entry)
+{
+ return SSA_NAME_VERSION (entry->name);
+}
+
+bool
+vn_ssa_aux_hasher::equal (const value_type &entry, const compare_type &name)
+{
+ return name == entry->name;
+}
+
+static hash_table<vn_ssa_aux_hasher> *vn_ssa_aux_hash;
+typedef hash_table<vn_ssa_aux_hasher>::iterator vn_ssa_aux_iterator_type;
static struct obstack vn_ssa_aux_obstack;
+static vn_nary_op_t vn_nary_op_insert_stmt (gimple *, tree);
+static unsigned int vn_nary_length_from_stmt (gimple *);
+static vn_nary_op_t alloc_vn_nary_op_noinit (unsigned int, obstack *);
+static vn_nary_op_t vn_nary_op_insert_into (vn_nary_op_t,
+ vn_nary_op_table_type *, bool);
+static void init_vn_nary_op_from_stmt (vn_nary_op_t, gimple *);
+static void init_vn_nary_op_from_pieces (vn_nary_op_t, unsigned int,
+ enum tree_code, tree, tree *);
+static tree vn_lookup_simplify_result (gimple_match_op *);
+static vn_reference_t vn_reference_lookup_or_insert_for_pieces
+ (tree, alias_set_type, tree, vec<vn_reference_op_s, va_heap>, tree);
+
/* Return whether there is value numbering information for a given SSA name. */
bool
has_VN_INFO (tree name)
{
- if (SSA_NAME_VERSION (name) < vn_ssa_aux_table.length ())
- return vn_ssa_aux_table[SSA_NAME_VERSION (name)] != NULL;
- return false;
+ return vn_ssa_aux_hash->find_with_hash (name, SSA_NAME_VERSION (name));
}
-/* Return the value numbering information for a given SSA name. */
-
vn_ssa_aux_t
VN_INFO (tree name)
{
- vn_ssa_aux_t res = vn_ssa_aux_table[SSA_NAME_VERSION (name)];
- gcc_checking_assert (res);
- return res;
+ vn_ssa_aux_t *res
+ = vn_ssa_aux_hash->find_slot_with_hash (name, SSA_NAME_VERSION (name),
+ INSERT);
+ if (*res != NULL)
+ return *res;
+
+ vn_ssa_aux_t newinfo = *res = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux);
+ memset (newinfo, 0, sizeof (struct vn_ssa_aux));
+ newinfo->name = name;
+ newinfo->valnum = VN_TOP;
+ /* We are using the visited flag to handle uses with defs not within the
+ region being value-numbered. */
+ newinfo->visited = false;
+
+ /* Given we create the VN_INFOs on-demand now we have to do initialization
+ different than VN_TOP here. */
+ if (SSA_NAME_IS_DEFAULT_DEF (name))
+ switch (TREE_CODE (SSA_NAME_VAR (name)))
+ {
+ case VAR_DECL:
+ /* All undefined vars are VARYING. */
+ newinfo->valnum = name;
+ newinfo->visited = true;
+ break;
+
+ case PARM_DECL:
+ /* Parameters are VARYING but we can record a condition
+ if we know it is a non-NULL pointer. */
+ newinfo->visited = true;
+ newinfo->valnum = name;
+ if (POINTER_TYPE_P (TREE_TYPE (name))
+ && nonnull_arg_p (SSA_NAME_VAR (name)))
+ {
+ tree ops[2];
+ ops[0] = name;
+ ops[1] = build_int_cst (TREE_TYPE (name), 0);
+ vn_nary_op_t nary;
+ /* Allocate from non-unwinding stack. */
+ nary = alloc_vn_nary_op_noinit (2, &vn_tables_insert_obstack);
+ init_vn_nary_op_from_pieces (nary, 2, NE_EXPR,
+ boolean_type_node, ops);
+ nary->predicated_values = 0;
+ nary->u.result = boolean_true_node;
+ vn_nary_op_insert_into (nary, valid_info->nary, true);
+ gcc_assert (nary->unwind_to == NULL);
+ /* Also do not link it into the undo chain. */
+ last_inserted_nary = nary->next;
+ nary->next = (vn_nary_op_t)(void *)-1;
+ nary = alloc_vn_nary_op_noinit (2, &vn_tables_insert_obstack);
+ init_vn_nary_op_from_pieces (nary, 2, EQ_EXPR,
+ boolean_type_node, ops);
+ nary->predicated_values = 0;
+ nary->u.result = boolean_false_node;
+ vn_nary_op_insert_into (nary, valid_info->nary, true);
+ gcc_assert (nary->unwind_to == NULL);
+ last_inserted_nary = nary->next;
+ nary->next = (vn_nary_op_t)(void *)-1;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Recording ");
+ print_generic_expr (dump_file, name, TDF_SLIM);
+ fprintf (dump_file, " != 0\n");
+ }
+ }
+ break;
+
+ case RESULT_DECL:
+ /* If the result is passed by invisible reference the default
+ def is initialized, otherwise it's uninitialized. Still
+ undefined is varying. */
+ newinfo->visited = true;
+ newinfo->valnum = name;
+ break;
+
+ default:
+ gcc_unreachable ();
+ }
+ return newinfo;
}
-/* Set the value numbering info for a given SSA name to a given
- value. */
+/* Return the SSA value of X. */
-static inline void
-VN_INFO_SET (tree name, vn_ssa_aux_t value)
+inline tree
+SSA_VAL (tree x, bool *visited = NULL)
{
- vn_ssa_aux_table[SSA_NAME_VERSION (name)] = value;
+ vn_ssa_aux_t tem = vn_ssa_aux_hash->find_with_hash (x, SSA_NAME_VERSION (x));
+ if (visited)
+ *visited = tem && tem->visited;
+ return tem && tem->visited ? tem->valnum : x;
}
-/* Initialize the value numbering info for a given SSA name.
- This should be called just once for every SSA name. */
+/* Return the SSA value of the VUSE x, supporting released VDEFs
+ during elimination which will value-number the VDEF to the
+ associated VUSE (but not substitute in the whole lattice). */
-vn_ssa_aux_t
-VN_INFO_GET (tree name)
+static inline tree
+vuse_ssa_val (tree x)
{
- vn_ssa_aux_t newinfo;
+ if (!x)
+ return NULL_TREE;
- gcc_assert (SSA_NAME_VERSION (name) >= vn_ssa_aux_table.length ()
- || vn_ssa_aux_table[SSA_NAME_VERSION (name)] == NULL);
- newinfo = XOBNEW (&vn_ssa_aux_obstack, struct vn_ssa_aux);
- memset (newinfo, 0, sizeof (struct vn_ssa_aux));
- if (SSA_NAME_VERSION (name) >= vn_ssa_aux_table.length ())
- vn_ssa_aux_table.safe_grow_cleared (SSA_NAME_VERSION (name) + 1);
- vn_ssa_aux_table[SSA_NAME_VERSION (name)] = newinfo;
- return newinfo;
+ do
+ {
+ x = SSA_VAL (x);
+ gcc_assert (x != VN_TOP);
+ }
+ while (SSA_NAME_IN_FREE_LIST (x));
+
+ return x;
+}
+
+/* Similar to the above but used as callback for walk_non_aliases_vuses
+ and thus should stop at unvisited VUSE to not walk across region
+ boundaries. */
+
+static tree
+vuse_valueize (tree vuse)
+{
+ do
+ {
+ bool visited;
+ vuse = SSA_VAL (vuse, &visited);
+ if (!visited)
+ return NULL_TREE;
+ gcc_assert (vuse != VN_TOP);
+ }
+ while (SSA_NAME_IN_FREE_LIST (vuse));
+ return vuse;
}
struct vn_constant_s vc;
vn_constant_t vcp;
+ /* If the hashtable isn't initialized we're not running from PRE and thus
+ do not need value-ids. */
+ if (!constant_to_value_id)
+ return 0;
+
vc.hashcode = vn_hash_constant_with_type (constant);
vc.constant = constant;
slot = constant_to_value_id->find_slot (&vc, INSERT);
static void
copy_reference_ops_from_ref (tree ref, vec<vn_reference_op_s> *result)
{
- if (TREE_CODE (ref) == TARGET_MEM_REF)
- {
- vn_reference_op_s temp;
-
- result->reserve (3);
-
- memset (&temp, 0, sizeof (temp));
- temp.type = TREE_TYPE (ref);
- temp.opcode = TREE_CODE (ref);
- temp.op0 = TMR_INDEX (ref);
- temp.op1 = TMR_STEP (ref);
- temp.op2 = TMR_OFFSET (ref);
- temp.off = -1;
- temp.clique = MR_DEPENDENCE_CLIQUE (ref);
- temp.base = MR_DEPENDENCE_BASE (ref);
- result->quick_push (temp);
-
- memset (&temp, 0, sizeof (temp));
- temp.type = NULL_TREE;
- temp.opcode = ERROR_MARK;
- temp.op0 = TMR_INDEX2 (ref);
- temp.off = -1;
- result->quick_push (temp);
-
- memset (&temp, 0, sizeof (temp));
- temp.type = NULL_TREE;
- temp.opcode = TREE_CODE (TMR_BASE (ref));
- temp.op0 = TMR_BASE (ref);
- temp.off = -1;
- result->quick_push (temp);
- return;
- }
-
/* For non-calls, store the information that makes up the address. */
tree orig = ref;
while (ref)
temp.base = MR_DEPENDENCE_BASE (ref);
temp.reverse = REF_REVERSE_STORAGE_ORDER (ref);
break;
+ case TARGET_MEM_REF:
+ /* The base address gets its own vn_reference_op_s structure. */
+ temp.op0 = TMR_INDEX (ref);
+ temp.op1 = TMR_STEP (ref);
+ temp.op2 = TMR_OFFSET (ref);
+ temp.clique = MR_DEPENDENCE_CLIQUE (ref);
+ temp.base = MR_DEPENDENCE_BASE (ref);
+ result->safe_push (temp);
+ memset (&temp, 0, sizeof (temp));
+ temp.type = NULL_TREE;
+ temp.opcode = ERROR_MARK;
+ temp.op0 = TMR_INDEX2 (ref);
+ temp.off = -1;
+ break;
case BIT_FIELD_REF:
/* Record bits, position and storage order. */
temp.op0 = TREE_OPERAND (ref, 1);
/* Copy the type, opcode, function, static chain and EH region, if any. */
memset (&temp, 0, sizeof (temp));
- temp.type = gimple_call_return_type (call);
+ temp.type = gimple_call_fntype (call);
temp.opcode = CALL_EXPR;
temp.op0 = gimple_call_fn (call);
temp.op1 = gimple_call_chain (call);
- if (stmt_could_throw_p (call) && (lr = lookup_stmt_eh_lp (call)) > 0)
+ if (stmt_could_throw_p (cfun, call) && (lr = lookup_stmt_eh_lp (call)) > 0)
temp.op2 = size_int (lr);
temp.off = -1;
result->safe_push (temp);
vn_reference_maybe_forwprop_address (vec<vn_reference_op_s> *ops,
unsigned int *i_p)
{
- unsigned int i = *i_p;
- vn_reference_op_t op = &(*ops)[i];
- vn_reference_op_t mem_op = &(*ops)[i - 1];
- gimple *def_stmt;
- enum tree_code code;
- poly_offset_int off;
-
- def_stmt = SSA_NAME_DEF_STMT (op->op0);
- if (!is_gimple_assign (def_stmt))
- return false;
-
- code = gimple_assign_rhs_code (def_stmt);
- if (code != ADDR_EXPR
- && code != POINTER_PLUS_EXPR)
- return false;
-
- off = poly_offset_int::from (wi::to_poly_wide (mem_op->op0), SIGNED);
+ bool changed = false;
+ vn_reference_op_t op;
- /* The only thing we have to do is from &OBJ.foo.bar add the offset
- from .foo.bar to the preceding MEM_REF offset and replace the
- address with &OBJ. */
- if (code == ADDR_EXPR)
+ do
{
- tree addr, addr_base;
- poly_int64 addr_offset;
-
- addr = gimple_assign_rhs1 (def_stmt);
- addr_base = get_addr_base_and_unit_offset (TREE_OPERAND (addr, 0),
- &addr_offset);
- /* If that didn't work because the address isn't invariant propagate
- the reference tree from the address operation in case the current
- dereference isn't offsetted. */
- if (!addr_base
- && *i_p == ops->length () - 1
- && known_eq (off, 0)
- /* This makes us disable this transform for PRE where the
- reference ops might be also used for code insertion which
- is invalid. */
- && default_vn_walk_kind == VN_WALKREWRITE)
+ unsigned int i = *i_p;
+ op = &(*ops)[i];
+ vn_reference_op_t mem_op = &(*ops)[i - 1];
+ gimple *def_stmt;
+ enum tree_code code;
+ poly_offset_int off;
+
+ def_stmt = SSA_NAME_DEF_STMT (op->op0);
+ if (!is_gimple_assign (def_stmt))
+ return changed;
+
+ code = gimple_assign_rhs_code (def_stmt);
+ if (code != ADDR_EXPR
+ && code != POINTER_PLUS_EXPR)
+ return changed;
+
+ off = poly_offset_int::from (wi::to_poly_wide (mem_op->op0), SIGNED);
+
+ /* The only thing we have to do is from &OBJ.foo.bar add the offset
+ from .foo.bar to the preceding MEM_REF offset and replace the
+ address with &OBJ. */
+ if (code == ADDR_EXPR)
{
- auto_vec<vn_reference_op_s, 32> tem;
- copy_reference_ops_from_ref (TREE_OPERAND (addr, 0), &tem);
- /* Make sure to preserve TBAA info. The only objects not
- wrapped in MEM_REFs that can have their address taken are
- STRING_CSTs. */
- if (tem.length () >= 2
- && tem[tem.length () - 2].opcode == MEM_REF)
+ tree addr, addr_base;
+ poly_int64 addr_offset;
+
+ addr = gimple_assign_rhs1 (def_stmt);
+ addr_base = get_addr_base_and_unit_offset (TREE_OPERAND (addr, 0),
+ &addr_offset);
+ /* If that didn't work because the address isn't invariant propagate
+ the reference tree from the address operation in case the current
+ dereference isn't offsetted. */
+ if (!addr_base
+ && *i_p == ops->length () - 1
+ && known_eq (off, 0)
+ /* This makes us disable this transform for PRE where the
+ reference ops might be also used for code insertion which
+ is invalid. */
+ && default_vn_walk_kind == VN_WALKREWRITE)
{
- vn_reference_op_t new_mem_op = &tem[tem.length () - 2];
- new_mem_op->op0
- = wide_int_to_tree (TREE_TYPE (mem_op->op0),
- wi::to_poly_wide (new_mem_op->op0));
+ auto_vec<vn_reference_op_s, 32> tem;
+ copy_reference_ops_from_ref (TREE_OPERAND (addr, 0), &tem);
+ /* Make sure to preserve TBAA info. The only objects not
+ wrapped in MEM_REFs that can have their address taken are
+ STRING_CSTs. */
+ if (tem.length () >= 2
+ && tem[tem.length () - 2].opcode == MEM_REF)
+ {
+ vn_reference_op_t new_mem_op = &tem[tem.length () - 2];
+ new_mem_op->op0
+ = wide_int_to_tree (TREE_TYPE (mem_op->op0),
+ wi::to_poly_wide (new_mem_op->op0));
+ }
+ else
+ gcc_assert (tem.last ().opcode == STRING_CST);
+ ops->pop ();
+ ops->pop ();
+ ops->safe_splice (tem);
+ --*i_p;
+ return true;
}
- else
- gcc_assert (tem.last ().opcode == STRING_CST);
- ops->pop ();
- ops->pop ();
- ops->safe_splice (tem);
- --*i_p;
- return true;
+ if (!addr_base
+ || TREE_CODE (addr_base) != MEM_REF
+ || (TREE_CODE (TREE_OPERAND (addr_base, 0)) == SSA_NAME
+ && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (addr_base,
+ 0))))
+ return changed;
+
+ off += addr_offset;
+ off += mem_ref_offset (addr_base);
+ op->op0 = TREE_OPERAND (addr_base, 0);
+ }
+ else
+ {
+ tree ptr, ptroff;
+ ptr = gimple_assign_rhs1 (def_stmt);
+ ptroff = gimple_assign_rhs2 (def_stmt);
+ if (TREE_CODE (ptr) != SSA_NAME
+ || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)
+ /* Make sure to not endlessly recurse.
+ See gcc.dg/tree-ssa/20040408-1.c for an example. Can easily
+ happen when we value-number a PHI to its backedge value. */
+ || SSA_VAL (ptr) == op->op0
+ || !poly_int_tree_p (ptroff))
+ return changed;
+
+ off += wi::to_poly_offset (ptroff);
+ op->op0 = ptr;
}
- if (!addr_base
- || TREE_CODE (addr_base) != MEM_REF
- || (TREE_CODE (TREE_OPERAND (addr_base, 0)) == SSA_NAME
- && SSA_NAME_OCCURS_IN_ABNORMAL_PHI (TREE_OPERAND (addr_base, 0))))
- return false;
-
- off += addr_offset;
- off += mem_ref_offset (addr_base);
- op->op0 = TREE_OPERAND (addr_base, 0);
- }
- else
- {
- tree ptr, ptroff;
- ptr = gimple_assign_rhs1 (def_stmt);
- ptroff = gimple_assign_rhs2 (def_stmt);
- if (TREE_CODE (ptr) != SSA_NAME
- || SSA_NAME_OCCURS_IN_ABNORMAL_PHI (ptr)
- || !poly_int_tree_p (ptroff))
- return false;
- off += wi::to_poly_offset (ptroff);
- op->op0 = ptr;
+ mem_op->op0 = wide_int_to_tree (TREE_TYPE (mem_op->op0), off);
+ if (tree_fits_shwi_p (mem_op->op0))
+ mem_op->off = tree_to_shwi (mem_op->op0);
+ else
+ mem_op->off = -1;
+ /* ??? Can end up with endless recursion here!?
+ gcc.c-torture/execute/strcmp-1.c */
+ if (TREE_CODE (op->op0) == SSA_NAME)
+ op->op0 = SSA_VAL (op->op0);
+ if (TREE_CODE (op->op0) != SSA_NAME)
+ op->opcode = TREE_CODE (op->op0);
+
+ changed = true;
}
+ /* Tail-recurse. */
+ while (TREE_CODE (op->op0) == SSA_NAME);
- mem_op->op0 = wide_int_to_tree (TREE_TYPE (mem_op->op0), off);
- if (tree_fits_shwi_p (mem_op->op0))
- mem_op->off = tree_to_shwi (mem_op->op0);
- else
- mem_op->off = -1;
- if (TREE_CODE (op->op0) == SSA_NAME)
- op->op0 = SSA_VAL (op->op0);
- if (TREE_CODE (op->op0) != SSA_NAME)
- op->opcode = TREE_CODE (op->op0);
-
- /* And recurse. */
- if (TREE_CODE (op->op0) == SSA_NAME)
- vn_reference_maybe_forwprop_address (ops, i_p);
- else if (TREE_CODE (op->op0) == ADDR_EXPR)
+ /* Fold a remaining *&. */
+ if (TREE_CODE (op->op0) == ADDR_EXPR)
vn_reference_fold_indirect (ops, i_p);
- return true;
+
+ return changed;
}
/* Optimize the reference REF to a constant if possible or return
if (op->opcode == CALL_EXPR
&& TREE_CODE (op->op0) == ADDR_EXPR
&& TREE_CODE (TREE_OPERAND (op->op0, 0)) == FUNCTION_DECL
- && DECL_BUILT_IN (TREE_OPERAND (op->op0, 0))
+ && fndecl_built_in_p (TREE_OPERAND (op->op0, 0))
&& operands.length () >= 2
&& operands.length () <= 3)
{
/* Simplify reads from constants or constant initializers. */
else if (BITS_PER_UNIT == 8
- && is_gimple_reg_type (ref->type)
- && (!INTEGRAL_TYPE_P (ref->type)
- || TYPE_PRECISION (ref->type) % BITS_PER_UNIT == 0))
+ && COMPLETE_TYPE_P (ref->type)
+ && is_gimple_reg_type (ref->type))
{
poly_int64 off = 0;
HOST_WIDE_INT size;
if (INTEGRAL_TYPE_P (ref->type))
size = TYPE_PRECISION (ref->type);
- else
+ else if (tree_fits_shwi_p (TYPE_SIZE (ref->type)))
size = tree_to_shwi (TYPE_SIZE (ref->type));
+ else
+ return NULL_TREE;
if (size % BITS_PER_UNIT != 0
|| size > MAX_BITSIZE_MODE_ANY_MODE)
return NULL_TREE;
whether any operands were valueized. */
static vec<vn_reference_op_s>
-valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything)
+valueize_refs_1 (vec<vn_reference_op_s> orig, bool *valueized_anything,
+ bool with_avail = false)
{
vn_reference_op_t vro;
unsigned int i;
if (vro->opcode == SSA_NAME
|| (vro->op0 && TREE_CODE (vro->op0) == SSA_NAME))
{
- tree tem = SSA_VAL (vro->op0);
+ tree tem = with_avail ? vn_valueize (vro->op0) : SSA_VAL (vro->op0);
if (tem != vro->op0)
{
*valueized_anything = true;
}
if (vro->op1 && TREE_CODE (vro->op1) == SSA_NAME)
{
- tree tem = SSA_VAL (vro->op1);
+ tree tem = with_avail ? vn_valueize (vro->op1) : SSA_VAL (vro->op1);
if (tem != vro->op1)
{
*valueized_anything = true;
}
if (vro->op2 && TREE_CODE (vro->op2) == SSA_NAME)
{
- tree tem = SSA_VAL (vro->op2);
+ tree tem = with_avail ? vn_valueize (vro->op2) : SSA_VAL (vro->op2);
if (tem != vro->op2)
{
*valueized_anything = true;
hashval_t hash;
hash = vr->hashcode;
- slot = current_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
- if (!slot && current_info == optimistic_info)
- slot = valid_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
+ slot = valid_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
if (slot)
{
if (vnresult)
return NULL_TREE;
}
+
+/* Partial definition tracking support. */
+
+struct pd_range
+{
+ HOST_WIDE_INT offset;
+ HOST_WIDE_INT size;
+};
+
+struct pd_data
+{
+ tree rhs;
+ HOST_WIDE_INT offset;
+ HOST_WIDE_INT size;
+};
+
+/* Context for alias walking. */
+
+struct vn_walk_cb_data
+{
+ vn_walk_cb_data (vn_reference_t vr_, tree orig_ref_, tree *last_vuse_ptr_,
+ vn_lookup_kind vn_walk_kind_, bool tbaa_p_)
+ : vr (vr_), last_vuse_ptr (last_vuse_ptr_),
+ vn_walk_kind (vn_walk_kind_), tbaa_p (tbaa_p_), known_ranges (NULL)
+ {
+ ao_ref_init (&orig_ref, orig_ref_);
+ }
+ ~vn_walk_cb_data ();
+ void *push_partial_def (const pd_data& pd, tree, HOST_WIDE_INT);
+
+ vn_reference_t vr;
+ ao_ref orig_ref;
+ tree *last_vuse_ptr;
+ vn_lookup_kind vn_walk_kind;
+ bool tbaa_p;
+
+ /* The VDEFs of partial defs we come along. */
+ auto_vec<pd_data, 2> partial_defs;
+ /* The first defs range to avoid splay tree setup in most cases. */
+ pd_range first_range;
+ tree first_vuse;
+ splay_tree known_ranges;
+ obstack ranges_obstack;
+};
+
+vn_walk_cb_data::~vn_walk_cb_data ()
+{
+ if (known_ranges)
+ {
+ splay_tree_delete (known_ranges);
+ obstack_free (&ranges_obstack, NULL);
+ }
+}
+
+/* pd_range splay-tree helpers. */
+
+static int
+pd_range_compare (splay_tree_key offset1p, splay_tree_key offset2p)
+{
+ HOST_WIDE_INT offset1 = *(HOST_WIDE_INT *)offset1p;
+ HOST_WIDE_INT offset2 = *(HOST_WIDE_INT *)offset2p;
+ if (offset1 < offset2)
+ return -1;
+ else if (offset1 > offset2)
+ return 1;
+ return 0;
+}
+
+static void *
+pd_tree_alloc (int size, void *data_)
+{
+ vn_walk_cb_data *data = (vn_walk_cb_data *)data_;
+ return obstack_alloc (&data->ranges_obstack, size);
+}
+
+static void
+pd_tree_dealloc (void *, void *)
+{
+}
+
+/* Push PD to the vector of partial definitions returning a
+ value when we are ready to combine things with VUSE and MAXSIZEI,
+ NULL when we want to continue looking for partial defs or -1
+ on failure. */
+
+void *
+vn_walk_cb_data::push_partial_def (const pd_data &pd, tree vuse,
+ HOST_WIDE_INT maxsizei)
+{
+ if (partial_defs.is_empty ())
+ {
+ partial_defs.safe_push (pd);
+ first_range.offset = pd.offset;
+ first_range.size = pd.size;
+ first_vuse = vuse;
+ last_vuse_ptr = NULL;
+ /* Continue looking for partial defs. */
+ return NULL;
+ }
+
+ if (!known_ranges)
+ {
+ /* ??? Optimize the case where the 2nd partial def completes things. */
+ gcc_obstack_init (&ranges_obstack);
+ known_ranges = splay_tree_new_with_allocator (pd_range_compare, 0, 0,
+ pd_tree_alloc,
+ pd_tree_dealloc, this);
+ splay_tree_insert (known_ranges,
+ (splay_tree_key)&first_range.offset,
+ (splay_tree_value)&first_range);
+ }
+
+ pd_range newr = { pd.offset, pd.size };
+ splay_tree_node n;
+ pd_range *r;
+ /* Lookup the predecessor of offset + 1 and see if we need to merge. */
+ HOST_WIDE_INT loffset = newr.offset + 1;
+ if ((n = splay_tree_predecessor (known_ranges, (splay_tree_key)&loffset))
+ && ((r = (pd_range *)n->value), true)
+ && ranges_known_overlap_p (r->offset, r->size + 1,
+ newr.offset, newr.size))
+ {
+ /* Ignore partial defs already covered. */
+ if (known_subrange_p (newr.offset, newr.size, r->offset, r->size))
+ return NULL;
+ r->size = MAX (r->offset + r->size, newr.offset + newr.size) - r->offset;
+ }
+ else
+ {
+ /* newr.offset wasn't covered yet, insert the range. */
+ r = XOBNEW (&ranges_obstack, pd_range);
+ *r = newr;
+ splay_tree_insert (known_ranges, (splay_tree_key)&r->offset,
+ (splay_tree_value)r);
+ }
+ /* Merge r which now contains newr and is a member of the splay tree with
+ adjacent overlapping ranges. */
+ pd_range *rafter;
+ while ((n = splay_tree_successor (known_ranges, (splay_tree_key)&r->offset))
+ && ((rafter = (pd_range *)n->value), true)
+ && ranges_known_overlap_p (r->offset, r->size + 1,
+ rafter->offset, rafter->size))
+ {
+ r->size = MAX (r->offset + r->size,
+ rafter->offset + rafter->size) - r->offset;
+ splay_tree_remove (known_ranges, (splay_tree_key)&rafter->offset);
+ }
+ partial_defs.safe_push (pd);
+
+ /* Now we have merged newr into the range tree. When we have covered
+ [offseti, sizei] then the tree will contain exactly one node which has
+ the desired properties and it will be 'r'. */
+ if (!known_subrange_p (0, maxsizei / BITS_PER_UNIT, r->offset, r->size))
+ /* Continue looking for partial defs. */
+ return NULL;
+
+ /* Now simply native encode all partial defs in reverse order. */
+ unsigned ndefs = partial_defs.length ();
+ /* We support up to 512-bit values (for V8DFmode). */
+ unsigned char buffer[64];
+ int len;
+
+ while (!partial_defs.is_empty ())
+ {
+ pd_data pd = partial_defs.pop ();
+ if (TREE_CODE (pd.rhs) == CONSTRUCTOR)
+ /* Empty CONSTRUCTOR. */
+ memset (buffer + MAX (0, pd.offset),
+ 0, MIN ((HOST_WIDE_INT)sizeof (buffer) - MAX (0, pd.offset),
+ pd.size + MIN (0, pd.offset)));
+ else
+ {
+ unsigned pad = 0;
+ if (BYTES_BIG_ENDIAN
+ && is_a <scalar_mode> (TYPE_MODE (TREE_TYPE (pd.rhs))))
+ {
+ /* On big-endian the padding is at the 'front' so just skip
+ the initial bytes. */
+ fixed_size_mode mode
+ = as_a <fixed_size_mode> (TYPE_MODE (TREE_TYPE (pd.rhs)));
+ pad = GET_MODE_SIZE (mode) - pd.size;
+ }
+ len = native_encode_expr (pd.rhs, buffer + MAX (0, pd.offset),
+ sizeof (buffer) - MAX (0, pd.offset),
+ MAX (0, -pd.offset) + pad);
+ if (len <= 0 || len < (pd.size - MAX (0, -pd.offset)))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Failed to encode %u "
+ "partial definitions\n", ndefs);
+ return (void *)-1;
+ }
+ }
+ }
+
+ tree type = vr->type;
+ /* Make sure to interpret in a type that has a range covering the whole
+ access size. */
+ if (INTEGRAL_TYPE_P (vr->type) && maxsizei != TYPE_PRECISION (vr->type))
+ type = build_nonstandard_integer_type (maxsizei, TYPE_UNSIGNED (type));
+ tree val = native_interpret_expr (type, buffer, maxsizei / BITS_PER_UNIT);
+ /* If we chop off bits because the types precision doesn't match the memory
+ access size this is ok when optimizing reads but not when called from
+ the DSE code during elimination. */
+ if (val && type != vr->type)
+ {
+ if (! int_fits_type_p (val, vr->type))
+ val = NULL_TREE;
+ else
+ val = fold_convert (vr->type, val);
+ }
+
+ if (val)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Successfully combined %u partial definitions\n", ndefs);
+ return vn_reference_lookup_or_insert_for_pieces
+ (first_vuse, vr->set, vr->type, vr->operands, val);
+ }
+ else
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "Failed to interpret %u encoded partial definitions\n", ndefs);
+ return (void *)-1;
+ }
+}
+
/* Callback for walk_non_aliased_vuses. Adjusts the vn_reference_t VR_
with the current VUSE and performs the expression lookup. */
static void *
-vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse,
- unsigned int cnt, void *vr_)
+vn_reference_lookup_2 (ao_ref *op ATTRIBUTE_UNUSED, tree vuse, void *data_)
{
- vn_reference_t vr = (vn_reference_t)vr_;
+ vn_walk_cb_data *data = (vn_walk_cb_data *)data_;
+ vn_reference_t vr = data->vr;
vn_reference_s **slot;
hashval_t hash;
- /* This bounds the stmt walks we perform on reference lookups
- to O(1) instead of O(N) where N is the number of dominating
- stores. */
- if (cnt > (unsigned) PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS))
- return (void *)-1;
+ /* If we have partial definitions recorded we have to go through
+ vn_reference_lookup_3. */
+ if (!data->partial_defs.is_empty ())
+ return NULL;
- if (last_vuse_ptr)
- *last_vuse_ptr = vuse;
+ if (data->last_vuse_ptr)
+ *data->last_vuse_ptr = vuse;
/* Fixup vuse and hash. */
if (vr->vuse)
vr->hashcode = vr->hashcode + SSA_NAME_VERSION (vr->vuse);
hash = vr->hashcode;
- slot = current_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
- if (!slot && current_info == optimistic_info)
- slot = valid_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
+ slot = valid_info->references->find_slot_with_hash (vr, hash, NO_INSERT);
if (slot)
return *slot;
operands.copy (), value, value_id);
}
-static vn_nary_op_t vn_nary_op_insert_stmt (gimple *stmt, tree result);
-
-/* Hook for maybe_push_res_to_seq, lookup the expression in the VN tables. */
+/* Return a value-number for RCODE OPS... either by looking up an existing
+ value-number for the simplified result or by inserting the operation if
+ INSERT is true. */
static tree
-vn_lookup_simplify_result (gimple_match_op *res_op)
-{
- if (!res_op->code.is_tree_code ())
- return NULL_TREE;
- tree *ops = res_op->ops;
- unsigned int length = res_op->num_ops;
- if (res_op->code == CONSTRUCTOR
- /* ??? We're arriving here with SCCVNs view, decomposed CONSTRUCTOR
- and GIMPLEs / match-and-simplifies, CONSTRUCTOR as GENERIC tree. */
- && TREE_CODE (res_op->ops[0]) == CONSTRUCTOR)
- {
- length = CONSTRUCTOR_NELTS (res_op->ops[0]);
- ops = XALLOCAVEC (tree, length);
- for (unsigned i = 0; i < length; ++i)
- ops[i] = CONSTRUCTOR_ELT (res_op->ops[0], i)->value;
- }
- vn_nary_op_t vnresult = NULL;
- return vn_nary_op_lookup_pieces (length, (tree_code) res_op->code,
- res_op->type, ops, &vnresult);
-}
-
-/* Return a value-number for RCODE OPS... either by looking up an existing
- value-number for the simplified result or by inserting the operation if
- INSERT is true. */
-
-static tree
-vn_nary_build_or_lookup_1 (gimple_match_op *res_op, bool insert)
+vn_nary_build_or_lookup_1 (gimple_match_op *res_op, bool insert)
{
tree result = NULL_TREE;
/* We will be creating a value number for
RCODE (OPS...).
So first simplify and lookup this expression to see if it
is already available. */
- mprts_hook = vn_lookup_simplify_result;
+ /* For simplification valueize. */
+ unsigned i;
+ for (i = 0; i < res_op->num_ops; ++i)
+ if (TREE_CODE (res_op->ops[i]) == SSA_NAME)
+ {
+ tree tem = vn_valueize (res_op->ops[i]);
+ if (!tem)
+ break;
+ res_op->ops[i] = tem;
+ }
+ /* If valueization of an operand fails (it is not available), skip
+ simplification. */
bool res = false;
- switch (TREE_CODE_LENGTH ((tree_code) res_op->code))
+ if (i == res_op->num_ops)
{
- case 1:
- res = gimple_resimplify1 (NULL, res_op, vn_valueize);
- break;
- case 2:
- res = gimple_resimplify2 (NULL, res_op, vn_valueize);
- break;
- case 3:
- res = gimple_resimplify3 (NULL, res_op, vn_valueize);
- break;
+ mprts_hook = vn_lookup_simplify_result;
+ res = res_op->resimplify (NULL, vn_valueize);
+ mprts_hook = NULL;
}
- mprts_hook = NULL;
gimple *new_stmt = NULL;
if (res
&& gimple_simplified_result_is_gimple_val (res_op))
- /* The expression is already available. */
- result = res_op->ops[0];
+ {
+ /* The expression is already available. */
+ result = res_op->ops[0];
+ /* Valueize it, simplification returns sth in AVAIL only. */
+ if (TREE_CODE (result) == SSA_NAME)
+ result = SSA_VAL (result);
+ }
else
{
tree val = vn_lookup_simplify_result (res_op);
/* The expression is not yet available, value-number lhs to
the new SSA_NAME we created. */
/* Initialize value-number information properly. */
- VN_INFO_GET (result)->valnum = result;
- VN_INFO (result)->value_id = get_next_value_id ();
+ vn_ssa_aux_t result_info = VN_INFO (result);
+ result_info->valnum = result;
+ result_info->value_id = get_next_value_id ();
+ result_info->visited = 1;
gimple_seq_add_stmt_without_update (&VN_INFO (result)->expr,
new_stmt);
- VN_INFO (result)->needs_insertion = true;
+ result_info->needs_insertion = true;
/* ??? PRE phi-translation inserts NARYs without corresponding
SSA name result. Re-use those but set their result according
to the stmt we just built. */
vn_nary_op_lookup_stmt (new_stmt, &nary);
if (nary)
{
- gcc_assert (nary->result == NULL_TREE);
- nary->result = gimple_assign_lhs (new_stmt);
+ gcc_assert (! nary->predicated_values && nary->u.result == NULL_TREE);
+ nary->u.result = gimple_assign_lhs (new_stmt);
}
/* As all "inserted" statements are singleton SCCs, insert
to the valid table. This is strictly needed to
optimistic table gets cleared after each iteration).
We do not need to insert into the optimistic table, as
lookups there will fall back to the valid table. */
- else if (current_info == optimistic_info)
+ else
{
- current_info = valid_info;
- vn_nary_op_insert_stmt (new_stmt, result);
- current_info = optimistic_info;
+ unsigned int length = vn_nary_length_from_stmt (new_stmt);
+ vn_nary_op_t vno1
+ = alloc_vn_nary_op_noinit (length, &vn_tables_insert_obstack);
+ vno1->value_id = result_info->value_id;
+ vno1->length = length;
+ vno1->predicated_values = 0;
+ vno1->u.result = result;
+ init_vn_nary_op_from_stmt (vno1, new_stmt);
+ vn_nary_op_insert_into (vno1, valid_info->nary, true);
+ /* Also do not link it into the undo chain. */
+ last_inserted_nary = vno1->next;
+ vno1->next = (vn_nary_op_t)(void *)-1;
}
- else
- vn_nary_op_insert_stmt (new_stmt, result);
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Inserting name ");
return vn_nary_build_or_lookup_1 (&op, false);
}
+/* Elimination engine. */
+
+class eliminate_dom_walker : public dom_walker
+{
+public:
+ eliminate_dom_walker (cdi_direction, bitmap);
+ ~eliminate_dom_walker ();
+
+ virtual edge before_dom_children (basic_block);
+ virtual void after_dom_children (basic_block);
+
+ virtual tree eliminate_avail (basic_block, tree op);
+ virtual void eliminate_push_avail (basic_block, tree op);
+ tree eliminate_insert (basic_block, gimple_stmt_iterator *gsi, tree val);
+
+ void eliminate_stmt (basic_block, gimple_stmt_iterator *);
+
+ unsigned eliminate_cleanup (bool region_p = false);
+
+ bool do_pre;
+ unsigned int el_todo;
+ unsigned int eliminations;
+ unsigned int insertions;
+
+ /* SSA names that had their defs inserted by PRE if do_pre. */
+ bitmap inserted_exprs;
+
+ /* Blocks with statements that have had their EH properties changed. */
+ bitmap need_eh_cleanup;
+
+ /* Blocks with statements that have had their AB properties changed. */
+ bitmap need_ab_cleanup;
+
+ /* Local state for the eliminate domwalk. */
+ auto_vec<gimple *> to_remove;
+ auto_vec<gimple *> to_fixup;
+ auto_vec<tree> avail;
+ auto_vec<tree> avail_stack;
+};
+
+/* Adaptor to the elimination engine using RPO availability. */
+
+class rpo_elim : public eliminate_dom_walker
+{
+public:
+ rpo_elim(basic_block entry_)
+ : eliminate_dom_walker (CDI_DOMINATORS, NULL), entry (entry_),
+ m_avail_freelist (NULL) {}
+
+ virtual tree eliminate_avail (basic_block, tree op);
+
+ virtual void eliminate_push_avail (basic_block, tree);
+
+ basic_block entry;
+ /* Freelist of avail entries which are allocated from the vn_ssa_aux
+ obstack. */
+ vn_avail *m_avail_freelist;
+};
+
+/* Global RPO state for access from hooks. */
+static rpo_elim *rpo_avail;
+basic_block vn_context_bb;
+
+/* Return true if BASE1 and BASE2 can be adjusted so they have the
+ same address and adjust *OFFSET1 and *OFFSET2 accordingly.
+ Otherwise return false. */
+
+static bool
+adjust_offsets_for_equal_base_address (tree base1, poly_int64 *offset1,
+ tree base2, poly_int64 *offset2)
+{
+ poly_int64 soff;
+ if (TREE_CODE (base1) == MEM_REF
+ && TREE_CODE (base2) == MEM_REF)
+ {
+ if (mem_ref_offset (base1).to_shwi (&soff))
+ {
+ base1 = TREE_OPERAND (base1, 0);
+ *offset1 += soff * BITS_PER_UNIT;
+ }
+ if (mem_ref_offset (base2).to_shwi (&soff))
+ {
+ base2 = TREE_OPERAND (base2, 0);
+ *offset2 += soff * BITS_PER_UNIT;
+ }
+ return operand_equal_p (base1, base2, 0);
+ }
+ return operand_equal_p (base1, base2, OEP_ADDRESS_OF);
+}
/* Callback for walk_non_aliased_vuses. Tries to perform a lookup
from the statement defining VUSE and if not successful tries to
*DISAMBIGUATE_ONLY is set to true. */
static void *
-vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_,
- bool *disambiguate_only)
+vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *data_,
+ translate_flags *disambiguate_only)
{
- vn_reference_t vr = (vn_reference_t)vr_;
+ vn_walk_cb_data *data = (vn_walk_cb_data *)data_;
+ vn_reference_t vr = data->vr;
gimple *def_stmt = SSA_NAME_DEF_STMT (vuse);
tree base = ao_ref_base (ref);
HOST_WIDE_INT offseti, maxsizei;
bool lhs_ref_ok = false;
poly_int64 copy_size;
- /* If the reference is based on a parameter that was determined as
- pointing to readonly memory it doesn't change. */
- if (TREE_CODE (base) == MEM_REF
- && TREE_CODE (TREE_OPERAND (base, 0)) == SSA_NAME
- && SSA_NAME_IS_DEFAULT_DEF (TREE_OPERAND (base, 0))
- && bitmap_bit_p (const_parms,
- SSA_NAME_VERSION (TREE_OPERAND (base, 0))))
- {
- *disambiguate_only = true;
- return NULL;
- }
-
/* First try to disambiguate after value-replacing in the definitions LHS. */
if (is_gimple_assign (def_stmt))
{
bool valueized_anything = false;
/* Avoid re-allocation overhead. */
lhs_ops.truncate (0);
- copy_reference_ops_from_ref (lhs, &lhs_ops);
- lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything);
+ basic_block saved_rpo_bb = vn_context_bb;
+ vn_context_bb = gimple_bb (def_stmt);
+ if (*disambiguate_only <= TR_VALUEIZE_AND_DISAMBIGUATE)
+ {
+ copy_reference_ops_from_ref (lhs, &lhs_ops);
+ lhs_ops = valueize_refs_1 (lhs_ops, &valueized_anything, true);
+ }
+ vn_context_bb = saved_rpo_bb;
if (valueized_anything)
{
lhs_ref_ok = ao_ref_init_from_vn_reference (&lhs_ref,
get_alias_set (lhs),
TREE_TYPE (lhs), lhs_ops);
if (lhs_ref_ok
- && !refs_may_alias_p_1 (ref, &lhs_ref, true))
+ && !refs_may_alias_p_1 (ref, &lhs_ref, data->tbaa_p))
{
- *disambiguate_only = true;
+ *disambiguate_only = TR_VALUEIZE_AND_DISAMBIGUATE;
return NULL;
}
}
lhs_ref_ok = true;
}
+ /* Besides valueizing the LHS we can also use access-path based
+ disambiguation on the original non-valueized ref. */
+ if (!ref->ref
+ && lhs_ref_ok
+ && data->orig_ref.ref)
+ {
+ /* We want to use the non-valueized LHS for this, but avoid redundant
+ work. */
+ ao_ref *lref = &lhs_ref;
+ ao_ref lref_alt;
+ if (valueized_anything)
+ {
+ ao_ref_init (&lref_alt, lhs);
+ lref = &lref_alt;
+ }
+ if (!refs_may_alias_p_1 (&data->orig_ref, lref, data->tbaa_p))
+ {
+ *disambiguate_only = (valueized_anything
+ ? TR_VALUEIZE_AND_DISAMBIGUATE
+ : TR_DISAMBIGUATE);
+ return NULL;
+ }
+ }
+
/* If we reach a clobbering statement try to skip it and see if
we find a VN result with exactly the same value as the
possible clobber. In this case we can ignore the clobber
- and return the found value.
- Note that we don't need to worry about partial overlapping
- accesses as we then can use TBAA to disambiguate against the
- clobbering statement when looking up a load (thus the
- VN_WALKREWRITE guard). */
- if (vn_walk_kind == VN_WALKREWRITE
- && is_gimple_reg_type (TREE_TYPE (lhs))
- && types_compatible_p (TREE_TYPE (lhs), vr->type))
+ and return the found value. */
+ if (is_gimple_reg_type (TREE_TYPE (lhs))
+ && types_compatible_p (TREE_TYPE (lhs), vr->type)
+ && ref->ref)
{
- tree *saved_last_vuse_ptr = last_vuse_ptr;
+ tree *saved_last_vuse_ptr = data->last_vuse_ptr;
/* Do not update last_vuse_ptr in vn_reference_lookup_2. */
- last_vuse_ptr = NULL;
+ data->last_vuse_ptr = NULL;
tree saved_vuse = vr->vuse;
hashval_t saved_hashcode = vr->hashcode;
- void *res = vn_reference_lookup_2 (ref,
- gimple_vuse (def_stmt), 0, vr);
+ void *res = vn_reference_lookup_2 (ref, gimple_vuse (def_stmt), data);
/* Need to restore vr->vuse and vr->hashcode. */
vr->vuse = saved_vuse;
vr->hashcode = saved_hashcode;
- last_vuse_ptr = saved_last_vuse_ptr;
+ data->last_vuse_ptr = saved_last_vuse_ptr;
if (res && res != (void *)-1)
{
vn_reference_t vnresult = (vn_reference_t) res;
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = SSA_VAL (rhs);
if (vnresult->result
- && operand_equal_p (vnresult->result,
- gimple_assign_rhs1 (def_stmt), 0))
+ && operand_equal_p (vnresult->result, rhs, 0)
+ /* We have to honor our promise about union type punning
+ and also support arbitrary overlaps with
+ -fno-strict-aliasing. So simply resort to alignment to
+ rule out overlaps. Do this check last because it is
+ quite expensive compared to the hash-lookup above. */
+ && multiple_p (get_object_alignment (ref->ref), ref->size)
+ && multiple_p (get_object_alignment (lhs), ref->size))
return res;
}
}
}
- else if (gimple_call_builtin_p (def_stmt, BUILT_IN_NORMAL)
+ else if (*disambiguate_only <= TR_VALUEIZE_AND_DISAMBIGUATE
+ && gimple_call_builtin_p (def_stmt, BUILT_IN_NORMAL)
&& gimple_call_num_args (def_stmt) <= 4)
{
/* For builtin calls valueize its arguments and call the
gimple_call_set_arg (def_stmt, i, oldargs[i]);
if (!res)
{
- *disambiguate_only = true;
+ *disambiguate_only = TR_VALUEIZE_AND_DISAMBIGUATE;
return NULL;
}
}
}
- if (*disambiguate_only)
+ /* If we are looking for redundant stores do not create new hashtable
+ entries from aliasing defs with made up alias-sets. */
+ if (*disambiguate_only > TR_TRANSLATE || !data->tbaa_p)
return (void *)-1;
/* If we cannot constrain the size of the reference we cannot
else
return (void *)-1;
tree len = gimple_call_arg (def_stmt, 2);
- if (known_subrange_p (offset, maxsize, offset2,
- wi::to_poly_offset (len) << LOG2_BITS_PER_UNIT))
+ HOST_WIDE_INT leni, offset2i, offseti;
+ if (data->partial_defs.is_empty ()
+ && known_subrange_p (offset, maxsize, offset2,
+ wi::to_poly_offset (len) << LOG2_BITS_PER_UNIT))
{
tree val;
if (integer_zerop (gimple_call_arg (def_stmt, 1)))
return vn_reference_lookup_or_insert_for_pieces
(vuse, vr->set, vr->type, vr->operands, val);
}
+ /* For now handle clearing memory with partial defs. */
+ else if (known_eq (ref->size, maxsize)
+ && integer_zerop (gimple_call_arg (def_stmt, 1))
+ && tree_to_poly_int64 (len).is_constant (&leni)
+ && offset.is_constant (&offseti)
+ && offset2.is_constant (&offset2i)
+ && maxsize.is_constant (&maxsizei))
+ {
+ pd_data pd;
+ pd.rhs = build_constructor (NULL_TREE, NULL);
+ pd.offset = (offset2i - offseti) / BITS_PER_UNIT;
+ pd.size = leni;
+ return data->push_partial_def (pd, vuse, maxsizei);
+ }
}
/* 2) Assignment from an empty CONSTRUCTOR. */
&& gimple_assign_rhs_code (def_stmt) == CONSTRUCTOR
&& CONSTRUCTOR_NELTS (gimple_assign_rhs1 (def_stmt)) == 0)
{
+ tree lhs = gimple_assign_lhs (def_stmt);
tree base2;
poly_int64 offset2, size2, maxsize2;
+ HOST_WIDE_INT offset2i, size2i;
bool reverse;
- base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
- &offset2, &size2, &maxsize2, &reverse);
+ if (lhs_ref_ok)
+ {
+ base2 = ao_ref_base (&lhs_ref);
+ offset2 = lhs_ref.offset;
+ size2 = lhs_ref.size;
+ maxsize2 = lhs_ref.max_size;
+ reverse = reverse_storage_order_for_component_p (lhs);
+ }
+ else
+ base2 = get_ref_base_and_extent (lhs,
+ &offset2, &size2, &maxsize2, &reverse);
if (known_size_p (maxsize2)
- && operand_equal_p (base, base2, 0)
- && known_subrange_p (offset, maxsize, offset2, size2))
+ && known_eq (maxsize2, size2)
+ && adjust_offsets_for_equal_base_address (base, &offset,
+ base2, &offset2))
{
- tree val = build_zero_cst (vr->type);
- return vn_reference_lookup_or_insert_for_pieces
- (vuse, vr->set, vr->type, vr->operands, val);
+ if (data->partial_defs.is_empty ()
+ && known_subrange_p (offset, maxsize, offset2, size2))
+ {
+ tree val = build_zero_cst (vr->type);
+ return vn_reference_lookup_or_insert_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
+ }
+ else if (known_eq (ref->size, maxsize)
+ && maxsize.is_constant (&maxsizei)
+ && maxsizei % BITS_PER_UNIT == 0
+ && offset.is_constant (&offseti)
+ && offseti % BITS_PER_UNIT == 0
+ && offset2.is_constant (&offset2i)
+ && offset2i % BITS_PER_UNIT == 0
+ && size2.is_constant (&size2i)
+ && size2i % BITS_PER_UNIT == 0)
+ {
+ pd_data pd;
+ pd.rhs = gimple_assign_rhs1 (def_stmt);
+ pd.offset = (offset2i - offseti) / BITS_PER_UNIT;
+ pd.size = size2i / BITS_PER_UNIT;
+ return data->push_partial_def (pd, vuse, maxsizei);
+ }
}
}
|| (TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
&& is_gimple_min_invariant (SSA_VAL (gimple_assign_rhs1 (def_stmt))))))
{
+ tree lhs = gimple_assign_lhs (def_stmt);
tree base2;
- HOST_WIDE_INT offset2, size2;
+ poly_int64 offset2, size2, maxsize2;
+ HOST_WIDE_INT offset2i, size2i;
bool reverse;
- base2 = get_ref_base_and_extent_hwi (gimple_assign_lhs (def_stmt),
- &offset2, &size2, &reverse);
+ if (lhs_ref_ok)
+ {
+ base2 = ao_ref_base (&lhs_ref);
+ offset2 = lhs_ref.offset;
+ size2 = lhs_ref.size;
+ maxsize2 = lhs_ref.max_size;
+ reverse = reverse_storage_order_for_component_p (lhs);
+ }
+ else
+ base2 = get_ref_base_and_extent (lhs,
+ &offset2, &size2, &maxsize2, &reverse);
if (base2
&& !reverse
- && size2 % BITS_PER_UNIT == 0
- && offset2 % BITS_PER_UNIT == 0
- && operand_equal_p (base, base2, 0)
- && known_subrange_p (offseti, maxsizei, offset2, size2))
+ && known_eq (maxsize2, size2)
+ && multiple_p (size2, BITS_PER_UNIT)
+ && multiple_p (offset2, BITS_PER_UNIT)
+ && adjust_offsets_for_equal_base_address (base, &offset,
+ base2, &offset2)
+ && offset.is_constant (&offseti)
+ && offset2.is_constant (&offset2i)
+ && size2.is_constant (&size2i))
{
- /* We support up to 512-bit values (for V8DFmode). */
- unsigned char buffer[64];
- int len;
-
- tree rhs = gimple_assign_rhs1 (def_stmt);
- if (TREE_CODE (rhs) == SSA_NAME)
- rhs = SSA_VAL (rhs);
- len = native_encode_expr (gimple_assign_rhs1 (def_stmt),
- buffer, sizeof (buffer),
- (offseti - offset2) / BITS_PER_UNIT);
- if (len > 0 && len * BITS_PER_UNIT >= maxsizei)
+ if (data->partial_defs.is_empty ()
+ && known_subrange_p (offseti, maxsizei, offset2, size2))
{
- tree type = vr->type;
- /* Make sure to interpret in a type that has a range
- covering the whole access size. */
- if (INTEGRAL_TYPE_P (vr->type)
- && maxsizei != TYPE_PRECISION (vr->type))
- type = build_nonstandard_integer_type (maxsizei,
- TYPE_UNSIGNED (type));
- tree val = native_interpret_expr (type, buffer,
- maxsizei / BITS_PER_UNIT);
- /* If we chop off bits because the types precision doesn't
- match the memory access size this is ok when optimizing
- reads but not when called from the DSE code during
- elimination. */
- if (val
- && type != vr->type)
+ /* We support up to 512-bit values (for V8DFmode). */
+ unsigned char buffer[64];
+ int len;
+
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = SSA_VAL (rhs);
+ unsigned pad = 0;
+ if (BYTES_BIG_ENDIAN
+ && is_a <scalar_mode> (TYPE_MODE (TREE_TYPE (rhs))))
{
- if (! int_fits_type_p (val, vr->type))
- val = NULL_TREE;
- else
- val = fold_convert (vr->type, val);
+ /* On big-endian the padding is at the 'front' so
+ just skip the initial bytes. */
+ fixed_size_mode mode
+ = as_a <fixed_size_mode> (TYPE_MODE (TREE_TYPE (rhs)));
+ pad = GET_MODE_SIZE (mode) - size2i / BITS_PER_UNIT;
}
+ len = native_encode_expr (rhs,
+ buffer, sizeof (buffer),
+ ((offseti - offset2i) / BITS_PER_UNIT
+ + pad));
+ if (len > 0 && len * BITS_PER_UNIT >= maxsizei)
+ {
+ tree type = vr->type;
+ /* Make sure to interpret in a type that has a range
+ covering the whole access size. */
+ if (INTEGRAL_TYPE_P (vr->type)
+ && maxsizei != TYPE_PRECISION (vr->type))
+ type = build_nonstandard_integer_type (maxsizei,
+ TYPE_UNSIGNED (type));
+ tree val = native_interpret_expr (type, buffer,
+ maxsizei / BITS_PER_UNIT);
+ /* If we chop off bits because the types precision doesn't
+ match the memory access size this is ok when optimizing
+ reads but not when called from the DSE code during
+ elimination. */
+ if (val
+ && type != vr->type)
+ {
+ if (! int_fits_type_p (val, vr->type))
+ val = NULL_TREE;
+ else
+ val = fold_convert (vr->type, val);
+ }
- if (val)
- return vn_reference_lookup_or_insert_for_pieces
- (vuse, vr->set, vr->type, vr->operands, val);
+ if (val)
+ return vn_reference_lookup_or_insert_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
+ }
+ }
+ else if (ranges_known_overlap_p (offseti, maxsizei, offset2i, size2i))
+ {
+ pd_data pd;
+ tree rhs = gimple_assign_rhs1 (def_stmt);
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = SSA_VAL (rhs);
+ pd.rhs = rhs;
+ pd.offset = (offset2i - offseti) / BITS_PER_UNIT;
+ pd.size = size2i / BITS_PER_UNIT;
+ return data->push_partial_def (pd, vuse, maxsizei);
}
}
}
&& is_gimple_reg_type (vr->type)
&& !contains_storage_order_barrier_p (vr->operands)
&& gimple_assign_single_p (def_stmt)
- && TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME)
+ && TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME
+ /* A subset of partial defs from non-constants can be handled
+ by for example inserting a CONSTRUCTOR, a COMPLEX_EXPR or
+ even a (series of) BIT_INSERT_EXPR hoping for simplifications
+ downstream, not so much for actually doing the insertion. */
+ && data->partial_defs.is_empty ())
{
+ tree lhs = gimple_assign_lhs (def_stmt);
tree base2;
poly_int64 offset2, size2, maxsize2;
bool reverse;
- base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt),
- &offset2, &size2, &maxsize2,
- &reverse);
+ if (lhs_ref_ok)
+ {
+ base2 = ao_ref_base (&lhs_ref);
+ offset2 = lhs_ref.offset;
+ size2 = lhs_ref.size;
+ maxsize2 = lhs_ref.max_size;
+ reverse = reverse_storage_order_for_component_p (lhs);
+ }
+ else
+ base2 = get_ref_base_and_extent (lhs,
+ &offset2, &size2, &maxsize2, &reverse);
+ tree def_rhs = gimple_assign_rhs1 (def_stmt);
if (!reverse
&& known_size_p (maxsize2)
&& known_eq (maxsize2, size2)
- && operand_equal_p (base, base2, 0)
+ && adjust_offsets_for_equal_base_address (base, &offset,
+ base2, &offset2)
&& known_subrange_p (offset, maxsize, offset2, size2)
/* ??? We can't handle bitfield precision extracts without
either using an alternate type for the BIT_FIELD_REF and
according to endianness. */
&& (! INTEGRAL_TYPE_P (vr->type)
|| known_eq (ref->size, TYPE_PRECISION (vr->type)))
- && multiple_p (ref->size, BITS_PER_UNIT))
+ && multiple_p (ref->size, BITS_PER_UNIT)
+ && (! INTEGRAL_TYPE_P (TREE_TYPE (def_rhs))
+ || type_has_mode_precision_p (TREE_TYPE (def_rhs))))
{
gimple_match_op op (gimple_match_cond::UNCOND,
BIT_FIELD_REF, vr->type,
- SSA_VAL (gimple_assign_rhs1 (def_stmt)),
+ vn_valueize (def_rhs),
bitsize_int (ref->size),
bitsize_int (offset - offset2));
tree val = vn_nary_build_or_lookup (&op);
/* 5) For aggregate copies translate the reference through them if
the copy kills ref. */
- else if (vn_walk_kind == VN_WALKREWRITE
+ else if (data->vn_walk_kind == VN_WALKREWRITE
&& gimple_assign_single_p (def_stmt)
&& (DECL_P (gimple_assign_rhs1 (def_stmt))
|| TREE_CODE (gimple_assign_rhs1 (def_stmt)) == MEM_REF
/* Try folding the new reference to a constant. */
tree val = fully_constant_vn_reference_p (vr);
if (val)
- return vn_reference_lookup_or_insert_for_pieces
- (vuse, vr->set, vr->type, vr->operands, val);
+ {
+ if (data->partial_defs.is_empty ())
+ return vn_reference_lookup_or_insert_for_pieces
+ (vuse, vr->set, vr->type, vr->operands, val);
+ /* This is the only interesting case for partial-def handling
+ coming from targets that like to gimplify init-ctors as
+ aggregate copies from constant data like aarch64 for
+ PR83518. */
+ if (maxsize.is_constant (&maxsizei)
+ && known_eq (ref->size, maxsize))
+ {
+ pd_data pd;
+ pd.rhs = val;
+ pd.offset = 0;
+ pd.size = maxsizei / BITS_PER_UNIT;
+ return data->push_partial_def (pd, vuse, maxsizei);
+ }
+ }
+
+ /* Continuing with partial defs isn't easily possible here, we
+ have to find a full def from further lookups from here. Probably
+ not worth the special-casing everywhere. */
+ if (!data->partial_defs.is_empty ())
+ return (void *)-1;
/* Adjust *ref from the new operands. */
if (!ao_ref_init_from_vn_reference (&r, vr->set, vr->type, vr->operands))
*ref = r;
/* Do not update last seen VUSE after translating. */
- last_vuse_ptr = NULL;
+ data->last_vuse_ptr = NULL;
+ /* Invalidate the original access path since it now contains
+ the wrong base. */
+ data->orig_ref.ref = NULL_TREE;
/* Keep looking for the adjusted *REF / VR pair. */
return NULL;
/* 6) For memcpy copies translate the reference through them if
the copy kills ref. */
- else if (vn_walk_kind == VN_WALKREWRITE
+ else if (data->vn_walk_kind == VN_WALKREWRITE
&& is_gimple_reg_type (vr->type)
/* ??? Handle BCOPY as well. */
&& (gimple_call_builtin_p (def_stmt, BUILT_IN_MEMCPY)
|| TREE_CODE (gimple_call_arg (def_stmt, 0)) == SSA_NAME)
&& (TREE_CODE (gimple_call_arg (def_stmt, 1)) == ADDR_EXPR
|| TREE_CODE (gimple_call_arg (def_stmt, 1)) == SSA_NAME)
- && poly_int_tree_p (gimple_call_arg (def_stmt, 2), ©_size))
+ && poly_int_tree_p (gimple_call_arg (def_stmt, 2), ©_size)
+ /* Handling this is more complicated, give up for now. */
+ && data->partial_defs.is_empty ())
{
tree lhs, rhs;
ao_ref r;
lhs_offset = 0;
if (TREE_CODE (lhs) == SSA_NAME)
{
- lhs = SSA_VAL (lhs);
+ lhs = vn_valueize (lhs);
if (TREE_CODE (lhs) == SSA_NAME)
{
gimple *def_stmt = SSA_NAME_DEF_STMT (lhs);
{
lhs = TREE_OPERAND (tem, 0);
if (TREE_CODE (lhs) == SSA_NAME)
- lhs = SSA_VAL (lhs);
+ lhs = vn_valueize (lhs);
lhs_offset += mem_offset;
}
else if (DECL_P (tem))
rhs = gimple_call_arg (def_stmt, 1);
rhs_offset = 0;
if (TREE_CODE (rhs) == SSA_NAME)
- rhs = SSA_VAL (rhs);
+ rhs = vn_valueize (rhs);
if (TREE_CODE (rhs) == ADDR_EXPR)
{
tree tem = get_addr_base_and_unit_offset (TREE_OPERAND (rhs, 0),
else
return (void *)-1;
}
- if (TREE_CODE (rhs) != SSA_NAME
- && TREE_CODE (rhs) != ADDR_EXPR)
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = SSA_VAL (rhs);
+ else if (TREE_CODE (rhs) != ADDR_EXPR)
return (void *)-1;
/* The bases of the destination and the references have to agree. */
*ref = r;
/* Do not update last seen VUSE after translating. */
- last_vuse_ptr = NULL;
+ data->last_vuse_ptr = NULL;
+ /* Invalidate the original access path since it now contains
+ the wrong base. */
+ data->orig_ref.ref = NULL_TREE;
/* Keep looking for the adjusted *REF / VR pair. */
return NULL;
&& vr1.vuse)
{
ao_ref r;
- vn_walk_kind = kind;
+ unsigned limit = PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS);
+ vn_walk_cb_data data (&vr1, NULL_TREE, NULL, kind, true);
if (ao_ref_init_from_vn_reference (&r, set, type, vr1.operands))
*vnresult =
- (vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse,
+ (vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse, true,
vn_reference_lookup_2,
vn_reference_lookup_3,
- vuse_ssa_val, &vr1);
+ vuse_valueize, limit, &data);
gcc_checking_assert (vr1.operands == shared_lookup_references);
}
not exist in the hash table or if the result field of the structure
was NULL.. VNRESULT will be filled in with the vn_reference_t
stored in the hashtable if one exists. When TBAA_P is false assume
- we are looking up a store and treat it as having alias-set zero. */
+ we are looking up a store and treat it as having alias-set zero.
+ *LAST_VUSE_PTR will be updated with the VUSE the value lookup succeeded. */
tree
vn_reference_lookup (tree op, tree vuse, vn_lookup_kind kind,
- vn_reference_t *vnresult, bool tbaa_p)
+ vn_reference_t *vnresult, bool tbaa_p, tree *last_vuse_ptr)
{
vec<vn_reference_op_s> operands;
struct vn_reference_s vr1;
vr1.operands = operands
= valueize_shared_reference_ops_from_ref (op, &valuezied_anything);
vr1.type = TREE_TYPE (op);
- vr1.set = tbaa_p ? get_alias_set (op) : 0;
+ vr1.set = get_alias_set (op);
vr1.hashcode = vn_reference_compute_hash (&vr1);
if ((cst = fully_constant_vn_reference_p (&vr1)))
return cst;
{
vn_reference_t wvnresult;
ao_ref r;
+ unsigned limit = PARAM_VALUE (PARAM_SCCVN_MAX_ALIAS_QUERIES_PER_ACCESS);
/* Make sure to use a valueized reference if we valueized anything.
Otherwise preserve the full reference for advanced TBAA. */
if (!valuezied_anything
|| !ao_ref_init_from_vn_reference (&r, vr1.set, vr1.type,
vr1.operands))
ao_ref_init (&r, op);
- if (! tbaa_p)
- r.ref_alias_set = r.base_alias_set = 0;
- vn_walk_kind = kind;
+ vn_walk_cb_data data (&vr1, r.ref ? NULL_TREE : op,
+ last_vuse_ptr, kind, tbaa_p);
wvnresult =
- (vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse,
+ (vn_reference_t)walk_non_aliased_vuses (&r, vr1.vuse, tbaa_p,
vn_reference_lookup_2,
vn_reference_lookup_3,
- vuse_ssa_val, &vr1);
+ vuse_valueize, limit, &data);
gcc_checking_assert (vr1.operands == shared_lookup_references);
if (wvnresult)
{
vn_reference_lookup_1 (vr, vnresult);
}
-/* Insert OP into the current hash table with a value number of
- RESULT, and return the resulting reference structure we created. */
+/* Insert OP into the current hash table with a value number of RESULT. */
-static vn_reference_t
+static void
vn_reference_insert (tree op, tree result, tree vuse, tree vdef)
{
vn_reference_s **slot;
vn_reference_t vr1;
bool tem;
- vr1 = current_info->references_pool->allocate ();
+ vr1 = XOBNEW (&vn_tables_obstack, vn_reference_s);
if (TREE_CODE (result) == SSA_NAME)
vr1->value_id = VN_INFO (result)->value_id;
else
vr1->value_id = get_or_alloc_constant_value_id (result);
- vr1->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
+ vr1->vuse = vuse_ssa_val (vuse);
vr1->operands = valueize_shared_reference_ops_from_ref (op, &tem).copy ();
vr1->type = TREE_TYPE (op);
vr1->set = get_alias_set (op);
vr1->result = TREE_CODE (result) == SSA_NAME ? SSA_VAL (result) : result;
vr1->result_vdef = vdef;
- slot = current_info->references->find_slot_with_hash (vr1, vr1->hashcode,
- INSERT);
+ slot = valid_info->references->find_slot_with_hash (vr1, vr1->hashcode,
+ INSERT);
- /* Because we lookup stores using vuses, and value number failures
- using the vdefs (see visit_reference_op_store for how and why),
- it's possible that on failure we may try to insert an already
- inserted store. This is not wrong, there is no ssa name for a
- store that we could use as a differentiator anyway. Thus, unlike
- the other lookup functions, you cannot gcc_assert (!*slot)
- here. */
-
- /* But free the old slot in case of a collision. */
+ /* Because IL walking on reference lookup can end up visiting
+ a def that is only to be visited later in iteration order
+ when we are about to make an irreducible region reducible
+ the def can be effectively processed and its ref being inserted
+ by vn_reference_lookup_3 already. So we cannot assert (!*slot)
+ but save a lookup if we deal with already inserted refs here. */
if (*slot)
- free_reference (*slot);
+ {
+ /* We cannot assert that we have the same value either because
+ when disentangling an irreducible region we may end up visiting
+ a use before the corresponding def. That's a missed optimization
+ only though. See gcc.dg/tree-ssa/pr87126.c for example. */
+ if (dump_file && (dump_flags & TDF_DETAILS)
+ && !operand_equal_p ((*slot)->result, vr1->result, 0))
+ {
+ fprintf (dump_file, "Keeping old value ");
+ print_generic_expr (dump_file, (*slot)->result);
+ fprintf (dump_file, " because of collision\n");
+ }
+ free_reference (vr1);
+ obstack_free (&vn_tables_obstack, vr1);
+ return;
+ }
*slot = vr1;
- return vr1;
+ vr1->next = last_inserted_ref;
+ last_inserted_ref = vr1;
}
/* Insert a reference by it's pieces into the current hash table with
vn_reference_s **slot;
vn_reference_t vr1;
- vr1 = current_info->references_pool->allocate ();
+ vr1 = XOBNEW (&vn_tables_obstack, vn_reference_s);
vr1->value_id = value_id;
- vr1->vuse = vuse ? SSA_VAL (vuse) : NULL_TREE;
+ vr1->vuse = vuse_ssa_val (vuse);
vr1->operands = valueize_refs (operands);
vr1->type = type;
vr1->set = set;
result = SSA_VAL (result);
vr1->result = result;
- slot = current_info->references->find_slot_with_hash (vr1, vr1->hashcode,
- INSERT);
+ slot = valid_info->references->find_slot_with_hash (vr1, vr1->hashcode,
+ INSERT);
/* At this point we should have all the things inserted that we have
seen before, and we should never try inserting something that
already exists. */
gcc_assert (!*slot);
- if (*slot)
- free_reference (*slot);
*slot = vr1;
+ vr1->next = last_inserted_ref;
+ last_inserted_ref = vr1;
return vr1;
}
memcpy (&vno->op[0], ops, sizeof (tree) * length);
}
-/* Initialize VNO from OP. */
-
-static void
-init_vn_nary_op_from_op (vn_nary_op_t vno, tree op)
-{
- unsigned i;
-
- vno->opcode = TREE_CODE (op);
- vno->length = TREE_CODE_LENGTH (TREE_CODE (op));
- vno->type = TREE_TYPE (op);
- for (i = 0; i < vno->length; ++i)
- vno->op[i] = TREE_OPERAND (op, i);
-}
-
/* Return the number of operands for a vn_nary ops structure from STMT. */
static unsigned int
*vnresult = NULL;
vno->hashcode = vn_nary_op_compute_hash (vno);
- slot = current_info->nary->find_slot_with_hash (vno, vno->hashcode,
- NO_INSERT);
- if (!slot && current_info == optimistic_info)
- slot = valid_info->nary->find_slot_with_hash (vno, vno->hashcode,
- NO_INSERT);
+ slot = valid_info->nary->find_slot_with_hash (vno, vno->hashcode, NO_INSERT);
if (!slot)
return NULL_TREE;
if (vnresult)
*vnresult = *slot;
- return (*slot)->result;
+ return (*slot)->predicated_values ? NULL_TREE : (*slot)->u.result;
}
/* Lookup a n-ary operation by its pieces and return the resulting value
return vn_nary_op_lookup_1 (vno1, vnresult);
}
-/* Lookup OP in the current hash table, and return the resulting value
- number if it exists in the hash table. Return NULL_TREE if it does
- not exist in the hash table or if the result field of the operation
- is NULL. VNRESULT will contain the vn_nary_op_t from the hashtable
- if it exists. */
-
-tree
-vn_nary_op_lookup (tree op, vn_nary_op_t *vnresult)
-{
- vn_nary_op_t vno1
- = XALLOCAVAR (struct vn_nary_op_s,
- sizeof_vn_nary_op (TREE_CODE_LENGTH (TREE_CODE (op))));
- init_vn_nary_op_from_op (vno1, op);
- return vn_nary_op_lookup_1 (vno1, vnresult);
-}
-
/* Lookup the rhs of STMT in the current hash table, and return the resulting
value number if it exists in the hash table. Return NULL_TREE if
it does not exist in the hash table. VNRESULT will contain the
static vn_nary_op_t
alloc_vn_nary_op (unsigned int length, tree result, unsigned int value_id)
{
- vn_nary_op_t vno1 = alloc_vn_nary_op_noinit (length,
- ¤t_info->nary_obstack);
+ vn_nary_op_t vno1 = alloc_vn_nary_op_noinit (length, &vn_tables_obstack);
vno1->value_id = value_id;
vno1->length = length;
- vno1->result = result;
+ vno1->predicated_values = 0;
+ vno1->u.result = result;
return vno1;
}
vn_nary_op_s **slot;
if (compute_hash)
- vno->hashcode = vn_nary_op_compute_hash (vno);
+ {
+ vno->hashcode = vn_nary_op_compute_hash (vno);
+ gcc_assert (! vno->predicated_values
+ || (! vno->u.values->next
+ && vno->u.values->n == 1));
+ }
slot = table->find_slot_with_hash (vno, vno->hashcode, INSERT);
- /* While we do not want to insert things twice it's awkward to
- avoid it in the case where visit_nary_op pattern-matches stuff
- and ends up simplifying the replacement to itself. We then
- get two inserts, one from visit_nary_op and one from
- vn_nary_build_or_lookup.
- So allow inserts with the same value number. */
- if (*slot && (*slot)->result == vno->result)
- return *slot;
+ vno->unwind_to = *slot;
+ if (*slot)
+ {
+ /* Prefer non-predicated values.
+ ??? Only if those are constant, otherwise, with constant predicated
+ value, turn them into predicated values with entry-block validity
+ (??? but we always find the first valid result currently). */
+ if ((*slot)->predicated_values
+ && ! vno->predicated_values)
+ {
+ /* ??? We cannot remove *slot from the unwind stack list.
+ For the moment we deal with this by skipping not found
+ entries but this isn't ideal ... */
+ *slot = vno;
+ /* ??? Maintain a stack of states we can unwind in
+ vn_nary_op_s? But how far do we unwind? In reality
+ we need to push change records somewhere... Or not
+ unwind vn_nary_op_s and linking them but instead
+ unwind the results "list", linking that, which also
+ doesn't move on hashtable resize. */
+ /* We can also have a ->unwind_to recording *slot there.
+ That way we can make u.values a fixed size array with
+ recording the number of entries but of course we then
+ have always N copies for each unwind_to-state. Or we
+ make sure to only ever append and each unwinding will
+ pop off one entry (but how to deal with predicated
+ replaced with non-predicated here?) */
+ vno->next = last_inserted_nary;
+ last_inserted_nary = vno;
+ return vno;
+ }
+ else if (vno->predicated_values
+ && ! (*slot)->predicated_values)
+ return *slot;
+ else if (vno->predicated_values
+ && (*slot)->predicated_values)
+ {
+ /* ??? Factor this all into a insert_single_predicated_value
+ routine. */
+ gcc_assert (!vno->u.values->next && vno->u.values->n == 1);
+ basic_block vno_bb
+ = BASIC_BLOCK_FOR_FN (cfun, vno->u.values->valid_dominated_by_p[0]);
+ vn_pval *nval = vno->u.values;
+ vn_pval **next = &vno->u.values;
+ bool found = false;
+ for (vn_pval *val = (*slot)->u.values; val; val = val->next)
+ {
+ if (expressions_equal_p (val->result, vno->u.values->result))
+ {
+ found = true;
+ for (unsigned i = 0; i < val->n; ++i)
+ {
+ basic_block val_bb
+ = BASIC_BLOCK_FOR_FN (cfun,
+ val->valid_dominated_by_p[i]);
+ if (dominated_by_p (CDI_DOMINATORS, vno_bb, val_bb))
+ /* Value registered with more generic predicate. */
+ return *slot;
+ else if (dominated_by_p (CDI_DOMINATORS, val_bb, vno_bb))
+ /* Shouldn't happen, we insert in RPO order. */
+ gcc_unreachable ();
+ }
+ /* Append value. */
+ *next = (vn_pval *) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_pval)
+ + val->n * sizeof (int));
+ (*next)->next = NULL;
+ (*next)->result = val->result;
+ (*next)->n = val->n + 1;
+ memcpy ((*next)->valid_dominated_by_p,
+ val->valid_dominated_by_p,
+ val->n * sizeof (int));
+ (*next)->valid_dominated_by_p[val->n] = vno_bb->index;
+ next = &(*next)->next;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Appending predicate to value.\n");
+ continue;
+ }
+ /* Copy other predicated values. */
+ *next = (vn_pval *) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_pval)
+ + (val->n-1) * sizeof (int));
+ memcpy (*next, val, sizeof (vn_pval) + (val->n-1) * sizeof (int));
+ (*next)->next = NULL;
+ next = &(*next)->next;
+ }
+ if (!found)
+ *next = nval;
+
+ *slot = vno;
+ vno->next = last_inserted_nary;
+ last_inserted_nary = vno;
+ return vno;
+ }
+
+ /* While we do not want to insert things twice it's awkward to
+ avoid it in the case where visit_nary_op pattern-matches stuff
+ and ends up simplifying the replacement to itself. We then
+ get two inserts, one from visit_nary_op and one from
+ vn_nary_build_or_lookup.
+ So allow inserts with the same value number. */
+ if ((*slot)->u.result == vno->u.result)
+ return *slot;
+ }
+
+ /* ??? There's also optimistic vs. previous commited state merging
+ that is problematic for the case of unwinding. */
+ /* ??? We should return NULL if we do not use 'vno' and have the
+ caller release it. */
gcc_assert (!*slot);
*slot = vno;
+ vno->next = last_inserted_nary;
+ last_inserted_nary = vno;
return vno;
}
{
vn_nary_op_t vno1 = alloc_vn_nary_op (length, result, value_id);
init_vn_nary_op_from_pieces (vno1, length, code, type, ops);
- return vn_nary_op_insert_into (vno1, current_info->nary, true);
+ return vn_nary_op_insert_into (vno1, valid_info->nary, true);
}
-/* Insert OP into the current hash table with a value number of
- RESULT. Return the vn_nary_op_t structure we created and put in
- the hashtable. */
-
-vn_nary_op_t
-vn_nary_op_insert (tree op, tree result)
+static vn_nary_op_t
+vn_nary_op_insert_pieces_predicated (unsigned int length, enum tree_code code,
+ tree type, tree *ops,
+ tree result, unsigned int value_id,
+ edge pred_e)
{
- unsigned length = TREE_CODE_LENGTH (TREE_CODE (op));
- vn_nary_op_t vno1;
+ /* ??? Currently tracking BBs. */
+ if (! single_pred_p (pred_e->dest))
+ {
+ /* Never record for backedges. */
+ if (pred_e->flags & EDGE_DFS_BACK)
+ return NULL;
+ edge_iterator ei;
+ edge e;
+ int cnt = 0;
+ /* Ignore backedges. */
+ FOR_EACH_EDGE (e, ei, pred_e->dest->preds)
+ if (! dominated_by_p (CDI_DOMINATORS, e->src, e->dest))
+ cnt++;
+ if (cnt != 1)
+ return NULL;
+ }
+ if (dump_file && (dump_flags & TDF_DETAILS)
+ /* ??? Fix dumping, but currently we only get comparisons. */
+ && TREE_CODE_CLASS (code) == tcc_comparison)
+ {
+ fprintf (dump_file, "Recording on edge %d->%d ", pred_e->src->index,
+ pred_e->dest->index);
+ print_generic_expr (dump_file, ops[0], TDF_SLIM);
+ fprintf (dump_file, " %s ", get_tree_code_name (code));
+ print_generic_expr (dump_file, ops[1], TDF_SLIM);
+ fprintf (dump_file, " == %s\n",
+ integer_zerop (result) ? "false" : "true");
+ }
+ vn_nary_op_t vno1 = alloc_vn_nary_op (length, NULL_TREE, value_id);
+ init_vn_nary_op_from_pieces (vno1, length, code, type, ops);
+ vno1->predicated_values = 1;
+ vno1->u.values = (vn_pval *) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_pval));
+ vno1->u.values->next = NULL;
+ vno1->u.values->result = result;
+ vno1->u.values->n = 1;
+ vno1->u.values->valid_dominated_by_p[0] = pred_e->dest->index;
+ return vn_nary_op_insert_into (vno1, valid_info->nary, true);
+}
- vno1 = alloc_vn_nary_op (length, result, VN_INFO (result)->value_id);
- init_vn_nary_op_from_op (vno1, op);
- return vn_nary_op_insert_into (vno1, current_info->nary, true);
+static bool
+dominated_by_p_w_unex (basic_block bb1, basic_block bb2);
+
+static tree
+vn_nary_op_get_predicated_value (vn_nary_op_t vno, basic_block bb)
+{
+ if (! vno->predicated_values)
+ return vno->u.result;
+ for (vn_pval *val = vno->u.values; val; val = val->next)
+ for (unsigned i = 0; i < val->n; ++i)
+ if (dominated_by_p_w_unex (bb,
+ BASIC_BLOCK_FOR_FN
+ (cfun, val->valid_dominated_by_p[i])))
+ return val->result;
+ return NULL_TREE;
}
/* Insert the rhs of STMT into the current hash table with a value number of
= alloc_vn_nary_op (vn_nary_length_from_stmt (stmt),
result, VN_INFO (result)->value_id);
init_vn_nary_op_from_stmt (vno1, stmt);
- return vn_nary_op_insert_into (vno1, current_info->nary, true);
+ return vn_nary_op_insert_into (vno1, valid_info->nary, true);
}
/* Compute a hashcode for PHI operation VP1 and return it. */
static inline hashval_t
vn_phi_compute_hash (vn_phi_t vp1)
{
- inchash::hash hstate (vp1->phiargs.length () > 2
- ? vp1->block->index : vp1->phiargs.length ());
+ inchash::hash hstate (EDGE_COUNT (vp1->block->preds) > 2
+ ? vp1->block->index : EDGE_COUNT (vp1->block->preds));
tree phi1op;
tree type;
edge e;
if (vp1->block != vp2->block)
{
- if (vp1->phiargs.length () != vp2->phiargs.length ())
+ if (EDGE_COUNT (vp1->block->preds) != EDGE_COUNT (vp2->block->preds))
return false;
- switch (vp1->phiargs.length ())
+ switch (EDGE_COUNT (vp1->block->preds))
{
case 1:
/* Single-arg PHIs are just copies. */
/* Any phi in the same block will have it's arguments in the
same edge order, because of how we store phi nodes. */
- int i;
- tree phi1op;
- FOR_EACH_VEC_ELT (vp1->phiargs, i, phi1op)
+ for (unsigned i = 0; i < EDGE_COUNT (vp1->block->preds); ++i)
{
+ tree phi1op = vp1->phiargs[i];
tree phi2op = vp2->phiargs[i];
if (phi1op == VN_TOP || phi2op == VN_TOP)
continue;
return true;
}
-static vec<tree> shared_lookup_phiargs;
-
/* Lookup PHI in the current hash table, and return the resulting
value number if it exists in the hash table. Return NULL_TREE if
it does not exist in the hash table. */
static tree
-vn_phi_lookup (gimple *phi)
+vn_phi_lookup (gimple *phi, bool backedges_varying_p)
{
vn_phi_s **slot;
- struct vn_phi_s vp1;
+ struct vn_phi_s *vp1;
edge e;
edge_iterator ei;
- shared_lookup_phiargs.truncate (0);
- shared_lookup_phiargs.safe_grow (gimple_phi_num_args (phi));
+ vp1 = XALLOCAVAR (struct vn_phi_s,
+ sizeof (struct vn_phi_s)
+ + (gimple_phi_num_args (phi) - 1) * sizeof (tree));
/* Canonicalize the SSA_NAME's to their value number. */
FOR_EACH_EDGE (e, ei, gimple_bb (phi)->preds)
{
tree def = PHI_ARG_DEF_FROM_EDGE (phi, e);
- def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
- shared_lookup_phiargs[e->dest_idx] = def;
+ if (TREE_CODE (def) == SSA_NAME
+ && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK)))
+ def = SSA_VAL (def);
+ vp1->phiargs[e->dest_idx] = def;
}
- vp1.type = TREE_TYPE (gimple_phi_result (phi));
- vp1.phiargs = shared_lookup_phiargs;
- vp1.block = gimple_bb (phi);
+ vp1->type = TREE_TYPE (gimple_phi_result (phi));
+ vp1->block = gimple_bb (phi);
/* Extract values of the controlling condition. */
- vp1.cclhs = NULL_TREE;
- vp1.ccrhs = NULL_TREE;
- basic_block idom1 = get_immediate_dominator (CDI_DOMINATORS, vp1.block);
+ vp1->cclhs = NULL_TREE;
+ vp1->ccrhs = NULL_TREE;
+ basic_block idom1 = get_immediate_dominator (CDI_DOMINATORS, vp1->block);
if (EDGE_COUNT (idom1->succs) == 2)
if (gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1)))
{
- vp1.cclhs = vn_valueize (gimple_cond_lhs (last1));
- vp1.ccrhs = vn_valueize (gimple_cond_rhs (last1));
+ /* ??? We want to use SSA_VAL here. But possibly not
+ allow VN_TOP. */
+ vp1->cclhs = vn_valueize (gimple_cond_lhs (last1));
+ vp1->ccrhs = vn_valueize (gimple_cond_rhs (last1));
}
- vp1.hashcode = vn_phi_compute_hash (&vp1);
- slot = current_info->phis->find_slot_with_hash (&vp1, vp1.hashcode,
- NO_INSERT);
- if (!slot && current_info == optimistic_info)
- slot = valid_info->phis->find_slot_with_hash (&vp1, vp1.hashcode,
- NO_INSERT);
+ vp1->hashcode = vn_phi_compute_hash (vp1);
+ slot = valid_info->phis->find_slot_with_hash (vp1, vp1->hashcode, NO_INSERT);
if (!slot)
return NULL_TREE;
return (*slot)->result;
RESULT. */
static vn_phi_t
-vn_phi_insert (gimple *phi, tree result)
+vn_phi_insert (gimple *phi, tree result, bool backedges_varying_p)
{
vn_phi_s **slot;
- vn_phi_t vp1 = current_info->phis_pool->allocate ();
- vec<tree> args = vNULL;
+ vn_phi_t vp1 = (vn_phi_t) obstack_alloc (&vn_tables_obstack,
+ sizeof (vn_phi_s)
+ + ((gimple_phi_num_args (phi) - 1)
+ * sizeof (tree)));
edge e;
edge_iterator ei;
- args.safe_grow (gimple_phi_num_args (phi));
-
/* Canonicalize the SSA_NAME's to their value number. */
FOR_EACH_EDGE (e, ei, gimple_bb (phi)->preds)
{
tree def = PHI_ARG_DEF_FROM_EDGE (phi, e);
- def = TREE_CODE (def) == SSA_NAME ? SSA_VAL (def) : def;
- args[e->dest_idx] = def;
+ if (TREE_CODE (def) == SSA_NAME
+ && (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK)))
+ def = SSA_VAL (def);
+ vp1->phiargs[e->dest_idx] = def;
}
vp1->value_id = VN_INFO (result)->value_id;
vp1->type = TREE_TYPE (gimple_phi_result (phi));
- vp1->phiargs = args;
vp1->block = gimple_bb (phi);
/* Extract values of the controlling condition. */
vp1->cclhs = NULL_TREE;
if (EDGE_COUNT (idom1->succs) == 2)
if (gcond *last1 = safe_dyn_cast <gcond *> (last_stmt (idom1)))
{
+ /* ??? We want to use SSA_VAL here. But possibly not
+ allow VN_TOP. */
vp1->cclhs = vn_valueize (gimple_cond_lhs (last1));
vp1->ccrhs = vn_valueize (gimple_cond_rhs (last1));
}
vp1->result = result;
vp1->hashcode = vn_phi_compute_hash (vp1);
- slot = current_info->phis->find_slot_with_hash (vp1, vp1->hashcode, INSERT);
+ slot = valid_info->phis->find_slot_with_hash (vp1, vp1->hashcode, INSERT);
+ gcc_assert (!*slot);
- /* Because we iterate over phi operations more than once, it's
- possible the slot might already exist here, hence no assert.*/
*slot = vp1;
+ vp1->next = last_inserted_phi;
+ last_inserted_phi = vp1;
return vp1;
}
-/* Print set of components in strongly connected component SCC to OUT. */
-
-static void
-print_scc (FILE *out, vec<tree> scc)
-{
- tree var;
- unsigned int i;
-
- fprintf (out, "SCC consists of %u:", scc.length ());
- FOR_EACH_VEC_ELT (scc, i, var)
- {
- fprintf (out, " ");
- print_generic_expr (out, var);
- }
- fprintf (out, "\n");
-}
-
/* Return true if BB1 is dominated by BB2 taking into account edges
that are not executable. */
static inline bool
set_ssa_val_to (tree from, tree to)
{
- tree currval = SSA_VAL (from);
+ vn_ssa_aux_t from_info = VN_INFO (from);
+ tree currval = from_info->valnum; // SSA_VAL (from)
poly_int64 toff, coff;
/* The only thing we allow as value numbers are ssa_names
get VN_TOP on valueization. */
if (to == VN_TOP)
{
+ /* ??? When iterating and visiting PHI <undef, backedge-value>
+ for the first time we rightfully get VN_TOP and we need to
+ preserve that to optimize for example gcc.dg/tree-ssa/ssa-sccvn-2.c.
+ With SCCVN we were simply lucky we iterated the other PHI
+ cycles first and thus visited the backedge-value DEF. */
+ if (currval == VN_TOP)
+ goto set_and_exit;
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, "Forcing value number to varying on "
"receiving VN_TOP\n");
to = from;
}
- gcc_assert (to != NULL_TREE
- && ((TREE_CODE (to) == SSA_NAME
- && (to == from || SSA_VAL (to) == to))
- || is_gimple_min_invariant (to)));
+ gcc_checking_assert (to != NULL_TREE
+ && ((TREE_CODE (to) == SSA_NAME
+ && (to == from || SSA_VAL (to) == to))
+ || is_gimple_min_invariant (to)));
if (from != to)
{
}
return false;
}
- else if (currval != VN_TOP
- && ! is_gimple_min_invariant (currval)
- && is_gimple_min_invariant (to))
+ bool curr_invariant = is_gimple_min_invariant (currval);
+ bool curr_undefined = (TREE_CODE (currval) == SSA_NAME
+ && ssa_undefined_value_p (currval, false));
+ if (currval != VN_TOP
+ && !curr_invariant
+ && !curr_undefined
+ && is_gimple_min_invariant (to))
{
if (dump_file && (dump_flags & TDF_DETAILS))
{
}
to = from;
}
+ else if (currval != VN_TOP
+ && !curr_undefined
+ && TREE_CODE (to) == SSA_NAME
+ && ssa_undefined_value_p (to, false))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Forcing VARYING instead of changing "
+ "value number of ");
+ print_generic_expr (dump_file, from);
+ fprintf (dump_file, " from ");
+ print_generic_expr (dump_file, currval);
+ fprintf (dump_file, " (non-undefined) to ");
+ print_generic_expr (dump_file, to);
+ fprintf (dump_file, " (undefined)\n");
+ }
+ to = from;
+ }
else if (TREE_CODE (to) == SSA_NAME
&& SSA_NAME_OCCURS_IN_ABNORMAL_PHI (to))
to = from;
}
+set_and_exit:
if (dump_file && (dump_flags & TDF_DETAILS))
{
fprintf (dump_file, "Setting value number of ");
{
if (dump_file && (dump_flags & TDF_DETAILS))
fprintf (dump_file, " (changed)\n");
-
- /* If we equate two SSA names we have to make the side-band info
- of the leader conservative (and remember whatever original value
- was present). */
- if (TREE_CODE (to) == SSA_NAME)
- {
- if (INTEGRAL_TYPE_P (TREE_TYPE (to))
- && SSA_NAME_RANGE_INFO (to))
- {
- if (SSA_NAME_IS_DEFAULT_DEF (to)
- || dominated_by_p_w_unex
- (gimple_bb (SSA_NAME_DEF_STMT (from)),
- gimple_bb (SSA_NAME_DEF_STMT (to))))
- /* Keep the info from the dominator. */
- ;
- else
- {
- /* Save old info. */
- if (! VN_INFO (to)->info.range_info)
- {
- VN_INFO (to)->info.range_info = SSA_NAME_RANGE_INFO (to);
- VN_INFO (to)->range_info_anti_range_p
- = SSA_NAME_ANTI_RANGE_P (to);
- }
- /* Rather than allocating memory and unioning the info
- just clear it. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "clearing range info of ");
- print_generic_expr (dump_file, to);
- fprintf (dump_file, "\n");
- }
- SSA_NAME_RANGE_INFO (to) = NULL;
- }
- }
- else if (POINTER_TYPE_P (TREE_TYPE (to))
- && SSA_NAME_PTR_INFO (to))
- {
- if (SSA_NAME_IS_DEFAULT_DEF (to)
- || dominated_by_p_w_unex
- (gimple_bb (SSA_NAME_DEF_STMT (from)),
- gimple_bb (SSA_NAME_DEF_STMT (to))))
- /* Keep the info from the dominator. */
- ;
- else if (! SSA_NAME_PTR_INFO (from)
- /* Handle the case of trivially equivalent info. */
- || memcmp (SSA_NAME_PTR_INFO (to),
- SSA_NAME_PTR_INFO (from),
- sizeof (ptr_info_def)) != 0)
- {
- /* Save old info. */
- if (! VN_INFO (to)->info.ptr_info)
- VN_INFO (to)->info.ptr_info = SSA_NAME_PTR_INFO (to);
- /* Rather than allocating memory and unioning the info
- just clear it. */
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "clearing points-to info of ");
- print_generic_expr (dump_file, to);
- fprintf (dump_file, "\n");
- }
- SSA_NAME_PTR_INFO (to) = NULL;
- }
- }
- }
-
- VN_INFO (from)->valnum = to;
- return true;
- }
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "\n");
- return false;
-}
-
-/* Mark as processed all the definitions in the defining stmt of USE, or
- the USE itself. */
-
-static void
-mark_use_processed (tree use)
-{
- ssa_op_iter iter;
- def_operand_p defp;
- gimple *stmt = SSA_NAME_DEF_STMT (use);
-
- if (SSA_NAME_IS_DEFAULT_DEF (use) || gimple_code (stmt) == GIMPLE_PHI)
- {
- VN_INFO (use)->use_processed = true;
- return;
- }
-
- FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_ALL_DEFS)
- {
- tree def = DEF_FROM_PTR (defp);
-
- VN_INFO (def)->use_processed = true;
- }
-}
+ from_info->valnum = to;
+ return true;
+ }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "\n");
+ return false;
+}
/* Set all definitions in STMT to value number to themselves.
Return true if a value number changed. */
valueized_wider_op (tree wide_type, tree op)
{
if (TREE_CODE (op) == SSA_NAME)
- op = SSA_VAL (op);
+ op = vn_valueize (op);
/* Either we have the op widened available. */
tree ops[3] = {};
if (useless_type_conversion_p (wide_type, TREE_TYPE (tem)))
{
if (TREE_CODE (tem) == SSA_NAME)
- tem = SSA_VAL (tem);
+ tem = vn_valueize (tem);
return tem;
}
}
static bool
visit_nary_op (tree lhs, gassign *stmt)
{
- tree result = vn_nary_op_lookup_stmt (stmt, NULL);
+ vn_nary_op_t vnresult;
+ tree result = vn_nary_op_lookup_stmt (stmt, &vnresult);
+ if (! result && vnresult)
+ result = vn_nary_op_get_predicated_value (vnresult, gimple_bb (stmt));
if (result)
return set_ssa_val_to (lhs, result);
operation. */
if (INTEGRAL_TYPE_P (type)
&& TREE_CODE (rhs1) == SSA_NAME
- /* We only handle sign-changes or zero-extension -> & mask. */
- && ((TYPE_UNSIGNED (TREE_TYPE (rhs1))
+ /* We only handle sign-changes, zero-extension -> & mask or
+ sign-extension if we know the inner operation doesn't
+ overflow. */
+ && (((TYPE_UNSIGNED (TREE_TYPE (rhs1))
+ || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (rhs1))))
&& TYPE_PRECISION (type) > TYPE_PRECISION (TREE_TYPE (rhs1)))
|| TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (rhs1))))
{
ops[0] = vn_nary_op_lookup_pieces
(2, gimple_assign_rhs_code (def), type, ops, NULL);
/* We have wider operation available. */
- if (ops[0])
+ if (ops[0]
+ /* If the leader is a wrapping operation we can
+ insert it for code hoisting w/o introducing
+ undefined overflow. If it is not it has to
+ be available. See PR86554. */
+ && (TYPE_OVERFLOW_WRAPS (TREE_TYPE (ops[0]))
+ || (rpo_avail && vn_context_bb
+ && rpo_avail->eliminate_avail (vn_context_bb,
+ ops[0]))))
{
unsigned lhs_prec = TYPE_PRECISION (type);
unsigned rhs_prec = TYPE_PRECISION (TREE_TYPE (rhs1));
- if (lhs_prec == rhs_prec)
+ if (lhs_prec == rhs_prec
+ || (INTEGRAL_TYPE_P (TREE_TYPE (rhs1))
+ && TYPE_OVERFLOW_UNDEFINED (TREE_TYPE (rhs1))))
{
gimple_match_op match_op (gimple_match_cond::UNCOND,
NOP_EXPR, type, ops[0]);
}
if (lhs)
changed |= set_ssa_val_to (lhs, lhs);
- vr2 = current_info->references_pool->allocate ();
+ vr2 = XOBNEW (&vn_tables_obstack, vn_reference_s);
vr2->vuse = vr1.vuse;
/* As we are not walking the virtual operand chain we know the
shared_lookup_references are still original so we can re-use
vr2->hashcode = vr1.hashcode;
vr2->result = lhs;
vr2->result_vdef = vdef_val;
- slot = current_info->references->find_slot_with_hash (vr2, vr2->hashcode,
- INSERT);
+ vr2->value_id = 0;
+ slot = valid_info->references->find_slot_with_hash (vr2, vr2->hashcode,
+ INSERT);
gcc_assert (!*slot);
*slot = vr2;
+ vr2->next = last_inserted_ref;
+ last_inserted_ref = vr2;
}
return changed;
tree result;
last_vuse = gimple_vuse (stmt);
- last_vuse_ptr = &last_vuse;
result = vn_reference_lookup (op, gimple_vuse (stmt),
- default_vn_walk_kind, NULL, true);
- last_vuse_ptr = NULL;
+ default_vn_walk_kind, NULL, true, &last_vuse);
/* We handle type-punning through unions by value-numbering based
on offset and size of the access. Be prepared to handle a
gimple_match_op res_op (gimple_match_cond::UNCOND,
VIEW_CONVERT_EXPR, TREE_TYPE (op), result);
result = vn_nary_build_or_lookup (&res_op);
+ /* When building the conversion fails avoid inserting the reference
+ again. */
+ if (!result)
+ return set_ssa_val_to (lhs, lhs);
}
if (result)
&& vnresult->result)
{
tree result = vnresult->result;
- if (TREE_CODE (result) == SSA_NAME)
- result = SSA_VAL (result);
+ gcc_checking_assert (TREE_CODE (result) != SSA_NAME
+ || result == SSA_VAL (result));
resultsame = expressions_equal_p (result, op);
if (resultsame)
{
vn_reference_lookup (assign, vuse, VN_NOWALK, &vnresult, false);
if (vnresult)
{
- VN_INFO (vdef)->use_processed = true;
+ VN_INFO (vdef)->visited = true;
return set_ssa_val_to (vdef, vnresult->result_vdef);
}
}
}
/* Visit and value number PHI, return true if the value number
- changed. */
+ changed. When BACKEDGES_VARYING_P is true then assume all
+ backedge values are varying. When INSERTED is not NULL then
+ this is just a ahead query for a possible iteration, set INSERTED
+ to true if we'd insert into the hashtable. */
static bool
-visit_phi (gimple *phi)
+visit_phi (gimple *phi, bool *inserted, bool backedges_varying_p)
{
tree result, sameval = VN_TOP, seen_undef = NULL_TREE;
+ tree backedge_val = NULL_TREE;
+ bool seen_non_backedge = false;
+ tree sameval_base = NULL_TREE;
+ poly_int64 soff, doff;
unsigned n_executable = 0;
- bool allsame = true;
edge_iterator ei;
edge e;
- /* TODO: We could check for this in init_sccvn, and replace this
+ /* TODO: We could check for this in initialization, and replace this
with a gcc_assert. */
if (SSA_NAME_OCCURS_IN_ABNORMAL_PHI (PHI_RESULT (phi)))
return set_ssa_val_to (PHI_RESULT (phi), PHI_RESULT (phi));
+ /* We track whether a PHI was CSEd to to avoid excessive iterations
+ that would be necessary only because the PHI changed arguments
+ but not value. */
+ if (!inserted)
+ gimple_set_plf (phi, GF_PLF_1, false);
+
/* See if all non-TOP arguments have the same value. TOP is
equivalent to everything, so we can ignore it. */
FOR_EACH_EDGE (e, ei, gimple_bb (phi)->preds)
++n_executable;
if (TREE_CODE (def) == SSA_NAME)
- def = SSA_VAL (def);
+ {
+ if (!backedges_varying_p || !(e->flags & EDGE_DFS_BACK))
+ def = SSA_VAL (def);
+ if (e->flags & EDGE_DFS_BACK)
+ backedge_val = def;
+ }
+ if (!(e->flags & EDGE_DFS_BACK))
+ seen_non_backedge = true;
if (def == VN_TOP)
;
/* Ignore undefined defs for sameval but record one. */
else if (TREE_CODE (def) == SSA_NAME
+ && ! virtual_operand_p (def)
&& ssa_undefined_value_p (def, false))
seen_undef = def;
else if (sameval == VN_TOP)
sameval = def;
else if (!expressions_equal_p (def, sameval))
{
- allsame = false;
+ /* We know we're arriving only with invariant addresses here,
+ try harder comparing them. We can do some caching here
+ which we cannot do in expressions_equal_p. */
+ if (TREE_CODE (def) == ADDR_EXPR
+ && TREE_CODE (sameval) == ADDR_EXPR
+ && sameval_base != (void *)-1)
+ {
+ if (!sameval_base)
+ sameval_base = get_addr_base_and_unit_offset
+ (TREE_OPERAND (sameval, 0), &soff);
+ if (!sameval_base)
+ sameval_base = (tree)(void *)-1;
+ else if ((get_addr_base_and_unit_offset
+ (TREE_OPERAND (def, 0), &doff) == sameval_base)
+ && known_eq (soff, doff))
+ continue;
+ }
+ sameval = NULL_TREE;
break;
}
}
-
+ /* If the value we want to use is flowing over the backedge and we
+ should take it as VARYING but it has a non-VARYING value drop to
+ VARYING.
+ If we value-number a virtual operand never value-number to the
+ value from the backedge as that confuses the alias-walking code.
+ See gcc.dg/torture/pr87176.c. If the value is the same on a
+ non-backedge everything is OK though. */
+ bool visited_p;
+ if ((backedge_val
+ && !seen_non_backedge
+ && TREE_CODE (backedge_val) == SSA_NAME
+ && sameval == backedge_val
+ && (SSA_NAME_IS_VIRTUAL_OPERAND (backedge_val)
+ || SSA_VAL (backedge_val) != backedge_val))
+ /* Do not value-number a virtual operand to sth not visited though
+ given that allows us to escape a region in alias walking. */
+ || (sameval
+ && TREE_CODE (sameval) == SSA_NAME
+ && !SSA_NAME_IS_DEFAULT_DEF (sameval)
+ && SSA_NAME_IS_VIRTUAL_OPERAND (sameval)
+ && (SSA_VAL (sameval, &visited_p), !visited_p)))
+ /* Note this just drops to VARYING without inserting the PHI into
+ the hashes. */
+ result = PHI_RESULT (phi);
/* If none of the edges was executable keep the value-number at VN_TOP,
if only a single edge is exectuable use its value. */
- if (n_executable <= 1)
+ else if (n_executable <= 1)
result = seen_undef ? seen_undef : sameval;
/* If we saw only undefined values and VN_TOP use one of the
undefined values. */
result = seen_undef ? seen_undef : sameval;
/* First see if it is equivalent to a phi node in this block. We prefer
this as it allows IV elimination - see PRs 66502 and 67167. */
- else if ((result = vn_phi_lookup (phi)))
- ;
+ else if ((result = vn_phi_lookup (phi, backedges_varying_p)))
+ {
+ if (!inserted
+ && TREE_CODE (result) == SSA_NAME
+ && gimple_code (SSA_NAME_DEF_STMT (result)) == GIMPLE_PHI)
+ {
+ gimple_set_plf (SSA_NAME_DEF_STMT (result), GF_PLF_1, true);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Marking CSEd to PHI node ");
+ print_gimple_expr (dump_file, SSA_NAME_DEF_STMT (result),
+ 0, TDF_SLIM);
+ fprintf (dump_file, "\n");
+ }
+ }
+ }
/* If all values are the same use that, unless we've seen undefined
values as well and the value isn't constant.
CCP/copyprop have the same restriction to not remove uninit warnings. */
- else if (allsame
+ else if (sameval
&& (! seen_undef || is_gimple_min_invariant (sameval)))
result = sameval;
else
/* Only insert PHIs that are varying, for constant value numbers
we mess up equivalences otherwise as we are only comparing
the immediate controlling predicates. */
- vn_phi_insert (phi, result);
+ vn_phi_insert (phi, result, backedges_varying_p);
+ if (inserted)
+ *inserted = true;
}
return set_ssa_val_to (PHI_RESULT (phi), result);
return NULL_TREE;
}
-/* Visit and value number USE, return true if the value number
- changed. */
+/* Visit and value number STMT, return true if the value number
+ changed. */
static bool
-visit_use (tree use)
+visit_stmt (gimple *stmt, bool backedges_varying_p = false)
{
bool changed = false;
- gimple *stmt = SSA_NAME_DEF_STMT (use);
-
- mark_use_processed (use);
-
- gcc_assert (!SSA_NAME_IN_FREE_LIST (use)
- && !SSA_NAME_IS_DEFAULT_DEF (use));
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "Value numbering ");
- print_generic_expr (dump_file, use);
- fprintf (dump_file, " stmt = ");
+ fprintf (dump_file, "Value numbering stmt = ");
print_gimple_stmt (dump_file, stmt, 0);
}
if (gimple_code (stmt) == GIMPLE_PHI)
- changed = visit_phi (stmt);
+ changed = visit_phi (stmt, NULL, backedges_varying_p);
else if (gimple_has_volatile_ops (stmt))
changed = defs_to_varying (stmt);
else if (gassign *ass = dyn_cast <gassign *> (stmt))
return changed;
}
-/* Compare two operands by reverse postorder index */
-static int
-compare_ops (const void *pa, const void *pb)
-{
- const tree opa = *((const tree *)pa);
- const tree opb = *((const tree *)pb);
- gimple *opstmta = SSA_NAME_DEF_STMT (opa);
- gimple *opstmtb = SSA_NAME_DEF_STMT (opb);
- basic_block bba;
- basic_block bbb;
-
- if (gimple_nop_p (opstmta) && gimple_nop_p (opstmtb))
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- else if (gimple_nop_p (opstmta))
- return -1;
- else if (gimple_nop_p (opstmtb))
- return 1;
+/* Allocate a value number table. */
- bba = gimple_bb (opstmta);
- bbb = gimple_bb (opstmtb);
+static void
+allocate_vn_table (vn_tables_t table, unsigned size)
+{
+ table->phis = new vn_phi_table_type (size);
+ table->nary = new vn_nary_op_table_type (size);
+ table->references = new vn_reference_table_type (size);
+}
- if (!bba && !bbb)
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- else if (!bba)
- return -1;
- else if (!bbb)
- return 1;
+/* Free a value number table. */
- if (bba == bbb)
- {
- if (gimple_code (opstmta) == GIMPLE_PHI
- && gimple_code (opstmtb) == GIMPLE_PHI)
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- else if (gimple_code (opstmta) == GIMPLE_PHI)
- return -1;
- else if (gimple_code (opstmtb) == GIMPLE_PHI)
- return 1;
- else if (gimple_uid (opstmta) != gimple_uid (opstmtb))
- return gimple_uid (opstmta) - gimple_uid (opstmtb);
- else
- return SSA_NAME_VERSION (opa) - SSA_NAME_VERSION (opb);
- }
- return rpo_numbers[bba->index] - rpo_numbers[bbb->index];
+static void
+free_vn_table (vn_tables_t table)
+{
+ /* Walk over elements and release vectors. */
+ vn_reference_iterator_type hir;
+ vn_reference_t vr;
+ FOR_EACH_HASH_TABLE_ELEMENT (*table->references, vr, vn_reference_t, hir)
+ vr->operands.release ();
+ delete table->phis;
+ table->phis = NULL;
+ delete table->nary;
+ table->nary = NULL;
+ delete table->references;
+ table->references = NULL;
}
-/* Sort an array containing members of a strongly connected component
- SCC so that the members are ordered by RPO number.
- This means that when the sort is complete, iterating through the
- array will give you the members in RPO order. */
+/* Set *ID according to RESULT. */
static void
-sort_scc (vec<tree> scc)
+set_value_id_for_result (tree result, unsigned int *id)
{
- scc.qsort (compare_ops);
+ if (result && TREE_CODE (result) == SSA_NAME)
+ *id = VN_INFO (result)->value_id;
+ else if (result && is_gimple_min_invariant (result))
+ *id = get_or_alloc_constant_value_id (result);
+ else
+ *id = get_next_value_id ();
}
-/* Insert the no longer used nary ONARY to the hash INFO. */
+/* Set the value ids in the valid hash tables. */
static void
-copy_nary (vn_nary_op_t onary, vn_tables_t info)
+set_hashtable_value_ids (void)
{
- size_t size = sizeof_vn_nary_op (onary->length);
- vn_nary_op_t nary = alloc_vn_nary_op_noinit (onary->length,
- &info->nary_obstack);
- memcpy (nary, onary, size);
- vn_nary_op_insert_into (nary, info->nary, false);
+ vn_nary_op_iterator_type hin;
+ vn_phi_iterator_type hip;
+ vn_reference_iterator_type hir;
+ vn_nary_op_t vno;
+ vn_reference_t vr;
+ vn_phi_t vp;
+
+ /* Now set the value ids of the things we had put in the hash
+ table. */
+
+ FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->nary, vno, vn_nary_op_t, hin)
+ if (! vno->predicated_values)
+ set_value_id_for_result (vno->u.result, &vno->value_id);
+
+ FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->phis, vp, vn_phi_t, hip)
+ set_value_id_for_result (vp->result, &vp->value_id);
+
+ FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->references, vr, vn_reference_t,
+ hir)
+ set_value_id_for_result (vr->result, &vr->value_id);
}
-/* Insert the no longer used phi OPHI to the hash INFO. */
+/* Return the maximum value id we have ever seen. */
-static void
-copy_phi (vn_phi_t ophi, vn_tables_t info)
+unsigned int
+get_max_value_id (void)
{
- vn_phi_t phi = info->phis_pool->allocate ();
- vn_phi_s **slot;
- memcpy (phi, ophi, sizeof (*phi));
- ophi->phiargs.create (0);
- slot = info->phis->find_slot_with_hash (phi, phi->hashcode, INSERT);
- gcc_assert (!*slot);
- *slot = phi;
+ return next_value_id;
}
-/* Insert the no longer used reference OREF to the hash INFO. */
+/* Return the next unique value id. */
-static void
-copy_reference (vn_reference_t oref, vn_tables_t info)
+unsigned int
+get_next_value_id (void)
{
- vn_reference_t ref;
- vn_reference_s **slot;
- ref = info->references_pool->allocate ();
- memcpy (ref, oref, sizeof (*ref));
- oref->operands.create (0);
- slot = info->references->find_slot_with_hash (ref, ref->hashcode, INSERT);
- if (*slot)
- free_reference (*slot);
- *slot = ref;
+ return next_value_id++;
}
-/* Process a strongly connected component in the SSA graph. */
-static void
-process_scc (vec<tree> scc)
+/* Compare two expressions E1 and E2 and return true if they are equal. */
+
+bool
+expressions_equal_p (tree e1, tree e2)
{
- tree var;
- unsigned int i;
- unsigned int iterations = 0;
- bool changed = true;
- vn_nary_op_iterator_type hin;
- vn_phi_iterator_type hip;
- vn_reference_iterator_type hir;
- vn_nary_op_t nary;
- vn_phi_t phi;
- vn_reference_t ref;
+ /* The obvious case. */
+ if (e1 == e2)
+ return true;
- /* If the SCC has a single member, just visit it. */
- if (scc.length () == 1)
- {
- tree use = scc[0];
- if (VN_INFO (use)->use_processed)
- return;
- /* We need to make sure it doesn't form a cycle itself, which can
- happen for self-referential PHI nodes. In that case we would
- end up inserting an expression with VN_TOP operands into the
- valid table which makes us derive bogus equivalences later.
- The cheapest way to check this is to assume it for all PHI nodes. */
- if (gimple_code (SSA_NAME_DEF_STMT (use)) == GIMPLE_PHI)
- /* Fallthru to iteration. */ ;
- else
- {
- visit_use (use);
- return;
- }
- }
+ /* If either one is VN_TOP consider them equal. */
+ if (e1 == VN_TOP || e2 == VN_TOP)
+ return true;
- if (dump_file && (dump_flags & TDF_DETAILS))
- print_scc (dump_file, scc);
+ /* If only one of them is null, they cannot be equal. */
+ if (!e1 || !e2)
+ return false;
- /* Iterate over the SCC with the optimistic table until it stops
- changing. */
- current_info = optimistic_info;
- while (changed)
- {
- changed = false;
- iterations++;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Starting iteration %d\n", iterations);
- /* As we are value-numbering optimistically we have to
- clear the expression tables and the simplified expressions
- in each iteration until we converge. */
- optimistic_info->nary->empty ();
- optimistic_info->phis->empty ();
- optimistic_info->references->empty ();
- obstack_free (&optimistic_info->nary_obstack, NULL);
- gcc_obstack_init (&optimistic_info->nary_obstack);
- optimistic_info->phis_pool->release ();
- optimistic_info->references_pool->release ();
- FOR_EACH_VEC_ELT (scc, i, var)
- gcc_assert (!VN_INFO (var)->needs_insertion
- && VN_INFO (var)->expr == NULL);
- FOR_EACH_VEC_ELT (scc, i, var)
- changed |= visit_use (var);
- }
+ /* Now perform the actual comparison. */
+ if (TREE_CODE (e1) == TREE_CODE (e2)
+ && operand_equal_p (e1, e2, OEP_PURE_SAME))
+ return true;
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Processing SCC needed %d iterations\n", iterations);
- statistics_histogram_event (cfun, "SCC iterations", iterations);
-
- /* Finally, copy the contents of the no longer used optimistic
- table to the valid table. */
- FOR_EACH_HASH_TABLE_ELEMENT (*optimistic_info->nary, nary, vn_nary_op_t, hin)
- copy_nary (nary, valid_info);
- FOR_EACH_HASH_TABLE_ELEMENT (*optimistic_info->phis, phi, vn_phi_t, hip)
- copy_phi (phi, valid_info);
- FOR_EACH_HASH_TABLE_ELEMENT (*optimistic_info->references,
- ref, vn_reference_t, hir)
- copy_reference (ref, valid_info);
-
- current_info = valid_info;
+ return false;
}
-/* Pop the components of the found SCC for NAME off the SCC stack
- and process them. Returns true if all went well, false if
- we run into resource limits. */
+/* Return true if the nary operation NARY may trap. This is a copy
+ of stmt_could_throw_1_p adjusted to the SCCVN IL. */
-static void
-extract_and_process_scc_for_name (tree name)
+bool
+vn_nary_may_trap (vn_nary_op_t nary)
{
- auto_vec<tree> scc;
- tree x;
-
- /* Found an SCC, pop the components off the SCC stack and
- process them. */
- do
- {
- x = sccstack.pop ();
-
- VN_INFO (x)->on_sccstack = false;
- scc.safe_push (x);
- } while (x != name);
+ tree type;
+ tree rhs2 = NULL_TREE;
+ bool honor_nans = false;
+ bool honor_snans = false;
+ bool fp_operation = false;
+ bool honor_trapv = false;
+ bool handled, ret;
+ unsigned i;
- /* Drop all defs in the SCC to varying in case a SCC turns out to be
- incredibly large.
- ??? Just switch to a non-optimistic mode that avoids any iteration. */
- if (scc.length () > (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE))
+ if (TREE_CODE_CLASS (nary->opcode) == tcc_comparison
+ || TREE_CODE_CLASS (nary->opcode) == tcc_unary
+ || TREE_CODE_CLASS (nary->opcode) == tcc_binary)
{
- if (dump_file)
- {
- print_scc (dump_file, scc);
- fprintf (dump_file, "WARNING: Giving up value-numbering SCC due to "
- "size %u exceeding %u\n", scc.length (),
- (unsigned)PARAM_VALUE (PARAM_SCCVN_MAX_SCC_SIZE));
- }
- tree var;
- unsigned i;
- FOR_EACH_VEC_ELT (scc, i, var)
+ type = nary->type;
+ fp_operation = FLOAT_TYPE_P (type);
+ if (fp_operation)
{
- gimple *def = SSA_NAME_DEF_STMT (var);
- mark_use_processed (var);
- if (SSA_NAME_IS_DEFAULT_DEF (var)
- || gimple_code (def) == GIMPLE_PHI)
- set_ssa_val_to (var, var);
- else
- defs_to_varying (def);
+ honor_nans = flag_trapping_math && !flag_finite_math_only;
+ honor_snans = flag_signaling_nans != 0;
}
- return;
+ else if (INTEGRAL_TYPE_P (type)
+ && TYPE_OVERFLOW_TRAPS (type))
+ honor_trapv = true;
}
+ if (nary->length >= 2)
+ rhs2 = nary->op[1];
+ ret = operation_could_trap_helper_p (nary->opcode, fp_operation,
+ honor_trapv,
+ honor_nans, honor_snans, rhs2,
+ &handled);
+ if (handled
+ && ret)
+ return true;
- if (scc.length () > 1)
- sort_scc (scc);
+ for (i = 0; i < nary->length; ++i)
+ if (tree_could_trap_p (nary->op[i]))
+ return true;
- process_scc (scc);
+ return false;
}
-/* Depth first search on NAME to discover and process SCC's in the SSA
- graph.
- Execution of this algorithm relies on the fact that the SCC's are
- popped off the stack in topological order.
- Returns true if successful, false if we stopped processing SCC's due
- to resource constraints. */
+/* Return true if the reference operation REF may trap. */
-static void
-DFS (tree name)
+bool
+vn_reference_may_trap (vn_reference_t ref)
{
- auto_vec<ssa_op_iter> itervec;
- auto_vec<tree> namevec;
- use_operand_p usep = NULL;
- gimple *defstmt;
- tree use;
- ssa_op_iter iter;
-
-start_over:
- /* SCC info */
- VN_INFO (name)->dfsnum = next_dfs_num++;
- VN_INFO (name)->visited = true;
- VN_INFO (name)->low = VN_INFO (name)->dfsnum;
-
- sccstack.safe_push (name);
- VN_INFO (name)->on_sccstack = true;
- defstmt = SSA_NAME_DEF_STMT (name);
-
- /* Recursively DFS on our operands, looking for SCC's. */
- if (!gimple_nop_p (defstmt))
+ switch (ref->operands[0].opcode)
{
- /* Push a new iterator. */
- if (gphi *phi = dyn_cast <gphi *> (defstmt))
- usep = op_iter_init_phiuse (&iter, phi, SSA_OP_ALL_USES);
- else
- usep = op_iter_init_use (&iter, defstmt, SSA_OP_ALL_USES);
+ case MODIFY_EXPR:
+ case CALL_EXPR:
+ /* We do not handle calls. */
+ case ADDR_EXPR:
+ /* And toplevel address computations never trap. */
+ return false;
+ default:;
}
- else
- clear_and_done_ssa_iter (&iter);
- while (1)
+ vn_reference_op_t op;
+ unsigned i;
+ FOR_EACH_VEC_ELT (ref->operands, i, op)
{
- /* If we are done processing uses of a name, go up the stack
- of iterators and process SCCs as we found them. */
- if (op_iter_done (&iter))
- {
- /* See if we found an SCC. */
- if (VN_INFO (name)->low == VN_INFO (name)->dfsnum)
- extract_and_process_scc_for_name (name);
-
- /* Check if we are done. */
- if (namevec.is_empty ())
- return;
-
- /* Restore the last use walker and continue walking there. */
- use = name;
- name = namevec.pop ();
- memcpy (&iter, &itervec.last (),
- sizeof (ssa_op_iter));
- itervec.pop ();
- goto continue_walking;
- }
-
- use = USE_FROM_PTR (usep);
-
- /* Since we handle phi nodes, we will sometimes get
- invariants in the use expression. */
- if (TREE_CODE (use) == SSA_NAME)
+ switch (op->opcode)
{
- if (! (VN_INFO (use)->visited))
- {
- /* Recurse by pushing the current use walking state on
- the stack and starting over. */
- itervec.safe_push (iter);
- namevec.safe_push (name);
- name = use;
- goto start_over;
-
-continue_walking:
- VN_INFO (name)->low = MIN (VN_INFO (name)->low,
- VN_INFO (use)->low);
- }
- if (VN_INFO (use)->dfsnum < VN_INFO (name)->dfsnum
- && VN_INFO (use)->on_sccstack)
- {
- VN_INFO (name)->low = MIN (VN_INFO (use)->dfsnum,
- VN_INFO (name)->low);
- }
+ case WITH_SIZE_EXPR:
+ case TARGET_MEM_REF:
+ /* Always variable. */
+ return true;
+ case COMPONENT_REF:
+ if (op->op1 && TREE_CODE (op->op1) == SSA_NAME)
+ return true;
+ break;
+ case ARRAY_RANGE_REF:
+ case ARRAY_REF:
+ if (TREE_CODE (op->op0) == SSA_NAME)
+ return true;
+ break;
+ case MEM_REF:
+ /* Nothing interesting in itself, the base is separate. */
+ break;
+ /* The following are the address bases. */
+ case SSA_NAME:
+ return true;
+ case ADDR_EXPR:
+ if (op->op0)
+ return tree_could_trap_p (TREE_OPERAND (op->op0, 0));
+ return false;
+ default:;
}
-
- usep = op_iter_next_use (&iter);
}
+ return false;
}
-/* Allocate a value number table. */
-
-static void
-allocate_vn_table (vn_tables_t table)
+eliminate_dom_walker::eliminate_dom_walker (cdi_direction direction,
+ bitmap inserted_exprs_)
+ : dom_walker (direction), do_pre (inserted_exprs_ != NULL),
+ el_todo (0), eliminations (0), insertions (0),
+ inserted_exprs (inserted_exprs_)
{
- table->phis = new vn_phi_table_type (23);
- table->nary = new vn_nary_op_table_type (23);
- table->references = new vn_reference_table_type (23);
-
- gcc_obstack_init (&table->nary_obstack);
- table->phis_pool = new object_allocator<vn_phi_s> ("VN phis");
- table->references_pool = new object_allocator<vn_reference_s>
- ("VN references");
+ need_eh_cleanup = BITMAP_ALLOC (NULL);
+ need_ab_cleanup = BITMAP_ALLOC (NULL);
}
-/* Free a value number table. */
-
-static void
-free_vn_table (vn_tables_t table)
+eliminate_dom_walker::~eliminate_dom_walker ()
{
- delete table->phis;
- table->phis = NULL;
- delete table->nary;
- table->nary = NULL;
- delete table->references;
- table->references = NULL;
- obstack_free (&table->nary_obstack, NULL);
- delete table->phis_pool;
- delete table->references_pool;
+ BITMAP_FREE (need_eh_cleanup);
+ BITMAP_FREE (need_ab_cleanup);
}
-static void
-init_scc_vn (void)
-{
- int j;
- int *rpo_numbers_temp;
+/* Return a leader for OP that is available at the current point of the
+ eliminate domwalk. */
- calculate_dominance_info (CDI_DOMINATORS);
- mark_dfs_back_edges ();
+tree
+eliminate_dom_walker::eliminate_avail (basic_block, tree op)
+{
+ tree valnum = VN_INFO (op)->valnum;
+ if (TREE_CODE (valnum) == SSA_NAME)
+ {
+ if (SSA_NAME_IS_DEFAULT_DEF (valnum))
+ return valnum;
+ if (avail.length () > SSA_NAME_VERSION (valnum))
+ return avail[SSA_NAME_VERSION (valnum)];
+ }
+ else if (is_gimple_min_invariant (valnum))
+ return valnum;
+ return NULL_TREE;
+}
- sccstack.create (0);
- constant_to_value_id = new hash_table<vn_constant_hasher> (23);
+/* At the current point of the eliminate domwalk make OP available. */
- constant_value_ids = BITMAP_ALLOC (NULL);
+void
+eliminate_dom_walker::eliminate_push_avail (basic_block, tree op)
+{
+ tree valnum = VN_INFO (op)->valnum;
+ if (TREE_CODE (valnum) == SSA_NAME)
+ {
+ if (avail.length () <= SSA_NAME_VERSION (valnum))
+ avail.safe_grow_cleared (SSA_NAME_VERSION (valnum) + 1);
+ tree pushop = op;
+ if (avail[SSA_NAME_VERSION (valnum)])
+ pushop = avail[SSA_NAME_VERSION (valnum)];
+ avail_stack.safe_push (pushop);
+ avail[SSA_NAME_VERSION (valnum)] = op;
+ }
+}
- next_dfs_num = 1;
- next_value_id = 1;
+/* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
+ the leader for the expression if insertion was successful. */
- vn_ssa_aux_table.create (num_ssa_names + 1);
- /* VEC_alloc doesn't actually grow it to the right size, it just
- preallocates the space to do so. */
- vn_ssa_aux_table.safe_grow_cleared (num_ssa_names + 1);
- gcc_obstack_init (&vn_ssa_aux_obstack);
+tree
+eliminate_dom_walker::eliminate_insert (basic_block bb,
+ gimple_stmt_iterator *gsi, tree val)
+{
+ /* We can insert a sequence with a single assignment only. */
+ gimple_seq stmts = VN_INFO (val)->expr;
+ if (!gimple_seq_singleton_p (stmts))
+ return NULL_TREE;
+ gassign *stmt = dyn_cast <gassign *> (gimple_seq_first_stmt (stmts));
+ if (!stmt
+ || (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt))
+ && gimple_assign_rhs_code (stmt) != VIEW_CONVERT_EXPR
+ && gimple_assign_rhs_code (stmt) != BIT_FIELD_REF
+ && (gimple_assign_rhs_code (stmt) != BIT_AND_EXPR
+ || TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)))
+ return NULL_TREE;
- shared_lookup_phiargs.create (0);
- shared_lookup_references.create (0);
- rpo_numbers = XNEWVEC (int, last_basic_block_for_fn (cfun));
- rpo_numbers_temp =
- XNEWVEC (int, n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS);
- pre_and_rev_post_order_compute (NULL, rpo_numbers_temp, false);
+ tree op = gimple_assign_rhs1 (stmt);
+ if (gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR
+ || gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
+ op = TREE_OPERAND (op, 0);
+ tree leader = TREE_CODE (op) == SSA_NAME ? eliminate_avail (bb, op) : op;
+ if (!leader)
+ return NULL_TREE;
- /* RPO numbers is an array of rpo ordering, rpo[i] = bb means that
- the i'th block in RPO order is bb. We want to map bb's to RPO
- numbers, so we need to rearrange this array. */
- for (j = 0; j < n_basic_blocks_for_fn (cfun) - NUM_FIXED_BLOCKS; j++)
- rpo_numbers[rpo_numbers_temp[j]] = j;
+ tree res;
+ stmts = NULL;
+ if (gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
+ res = gimple_build (&stmts, BIT_FIELD_REF,
+ TREE_TYPE (val), leader,
+ TREE_OPERAND (gimple_assign_rhs1 (stmt), 1),
+ TREE_OPERAND (gimple_assign_rhs1 (stmt), 2));
+ else if (gimple_assign_rhs_code (stmt) == BIT_AND_EXPR)
+ res = gimple_build (&stmts, BIT_AND_EXPR,
+ TREE_TYPE (val), leader, gimple_assign_rhs2 (stmt));
+ else
+ res = gimple_build (&stmts, gimple_assign_rhs_code (stmt),
+ TREE_TYPE (val), leader);
+ if (TREE_CODE (res) != SSA_NAME
+ || SSA_NAME_IS_DEFAULT_DEF (res)
+ || gimple_bb (SSA_NAME_DEF_STMT (res)))
+ {
+ gimple_seq_discard (stmts);
- XDELETE (rpo_numbers_temp);
+ /* During propagation we have to treat SSA info conservatively
+ and thus we can end up simplifying the inserted expression
+ at elimination time to sth not defined in stmts. */
+ /* But then this is a redundancy we failed to detect. Which means
+ res now has two values. That doesn't play well with how
+ we track availability here, so give up. */
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ if (TREE_CODE (res) == SSA_NAME)
+ res = eliminate_avail (bb, res);
+ if (res)
+ {
+ fprintf (dump_file, "Failed to insert expression for value ");
+ print_generic_expr (dump_file, val);
+ fprintf (dump_file, " which is really fully redundant to ");
+ print_generic_expr (dump_file, res);
+ fprintf (dump_file, "\n");
+ }
+ }
- VN_TOP = build_decl (UNKNOWN_LOCATION, VAR_DECL,
- get_identifier ("VN_TOP"), error_mark_node);
+ return NULL_TREE;
+ }
+ else
+ {
+ gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
+ VN_INFO (res)->valnum = val;
+ VN_INFO (res)->visited = true;
+ }
- renumber_gimple_stmt_uids ();
+ insertions++;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Inserted ");
+ print_gimple_stmt (dump_file, SSA_NAME_DEF_STMT (res), 0);
+ }
- /* Create the valid and optimistic value numbering tables. */
- valid_info = XCNEW (struct vn_tables_s);
- allocate_vn_table (valid_info);
- optimistic_info = XCNEW (struct vn_tables_s);
- allocate_vn_table (optimistic_info);
- current_info = valid_info;
-
- /* Create the VN_INFO structures, and initialize value numbers to
- TOP or VARYING for parameters. */
- size_t i;
- tree name;
+ return res;
+}
- FOR_EACH_SSA_NAME (i, name, cfun)
+void
+eliminate_dom_walker::eliminate_stmt (basic_block b, gimple_stmt_iterator *gsi)
+{
+ tree sprime = NULL_TREE;
+ gimple *stmt = gsi_stmt (*gsi);
+ tree lhs = gimple_get_lhs (stmt);
+ if (lhs && TREE_CODE (lhs) == SSA_NAME
+ && !gimple_has_volatile_ops (stmt)
+ /* See PR43491. Do not replace a global register variable when
+ it is a the RHS of an assignment. Do replace local register
+ variables since gcc does not guarantee a local variable will
+ be allocated in register.
+ ??? The fix isn't effective here. This should instead
+ be ensured by not value-numbering them the same but treating
+ them like volatiles? */
+ && !(gimple_assign_single_p (stmt)
+ && (TREE_CODE (gimple_assign_rhs1 (stmt)) == VAR_DECL
+ && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt))
+ && is_global_var (gimple_assign_rhs1 (stmt)))))
{
- VN_INFO_GET (name)->valnum = VN_TOP;
- VN_INFO (name)->needs_insertion = false;
- VN_INFO (name)->expr = NULL;
- VN_INFO (name)->value_id = 0;
+ sprime = eliminate_avail (b, lhs);
+ if (!sprime)
+ {
+ /* If there is no existing usable leader but SCCVN thinks
+ it has an expression it wants to use as replacement,
+ insert that. */
+ tree val = VN_INFO (lhs)->valnum;
+ if (val != VN_TOP
+ && TREE_CODE (val) == SSA_NAME
+ && VN_INFO (val)->needs_insertion
+ && VN_INFO (val)->expr != NULL
+ && (sprime = eliminate_insert (b, gsi, val)) != NULL_TREE)
+ eliminate_push_avail (b, sprime);
+ }
- if (!SSA_NAME_IS_DEFAULT_DEF (name))
- continue;
+ /* If this now constitutes a copy duplicate points-to
+ and range info appropriately. This is especially
+ important for inserted code. See tree-ssa-copy.c
+ for similar code. */
+ if (sprime
+ && TREE_CODE (sprime) == SSA_NAME)
+ {
+ basic_block sprime_b = gimple_bb (SSA_NAME_DEF_STMT (sprime));
+ if (POINTER_TYPE_P (TREE_TYPE (lhs))
+ && SSA_NAME_PTR_INFO (lhs)
+ && ! SSA_NAME_PTR_INFO (sprime))
+ {
+ duplicate_ssa_name_ptr_info (sprime,
+ SSA_NAME_PTR_INFO (lhs));
+ if (b != sprime_b)
+ mark_ptr_info_alignment_unknown
+ (SSA_NAME_PTR_INFO (sprime));
+ }
+ else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
+ && SSA_NAME_RANGE_INFO (lhs)
+ && ! SSA_NAME_RANGE_INFO (sprime)
+ && b == sprime_b)
+ duplicate_ssa_name_range_info (sprime,
+ SSA_NAME_RANGE_TYPE (lhs),
+ SSA_NAME_RANGE_INFO (lhs));
+ }
- switch (TREE_CODE (SSA_NAME_VAR (name)))
+ /* Inhibit the use of an inserted PHI on a loop header when
+ the address of the memory reference is a simple induction
+ variable. In other cases the vectorizer won't do anything
+ anyway (either it's loop invariant or a complicated
+ expression). */
+ if (sprime
+ && TREE_CODE (sprime) == SSA_NAME
+ && do_pre
+ && (flag_tree_loop_vectorize || flag_tree_parallelize_loops > 1)
+ && loop_outer (b->loop_father)
+ && has_zero_uses (sprime)
+ && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))
+ && gimple_assign_load_p (stmt))
{
- case VAR_DECL:
- /* All undefined vars are VARYING. */
- VN_INFO (name)->valnum = name;
- VN_INFO (name)->visited = true;
- break;
+ gimple *def_stmt = SSA_NAME_DEF_STMT (sprime);
+ basic_block def_bb = gimple_bb (def_stmt);
+ if (gimple_code (def_stmt) == GIMPLE_PHI
+ && def_bb->loop_father->header == def_bb)
+ {
+ loop_p loop = def_bb->loop_father;
+ ssa_op_iter iter;
+ tree op;
+ bool found = false;
+ FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
+ {
+ affine_iv iv;
+ def_bb = gimple_bb (SSA_NAME_DEF_STMT (op));
+ if (def_bb
+ && flow_bb_inside_loop_p (loop, def_bb)
+ && simple_iv (loop, loop, op, &iv, true))
+ {
+ found = true;
+ break;
+ }
+ }
+ if (found)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Not replacing ");
+ print_gimple_expr (dump_file, stmt, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, " which would add a loop"
+ " carried dependence to loop %d\n",
+ loop->num);
+ }
+ /* Don't keep sprime available. */
+ sprime = NULL_TREE;
+ }
+ }
+ }
- case PARM_DECL:
- /* Parameters are VARYING but we can record a condition
- if we know it is a non-NULL pointer. */
- VN_INFO (name)->visited = true;
- VN_INFO (name)->valnum = name;
- if (POINTER_TYPE_P (TREE_TYPE (name))
- && nonnull_arg_p (SSA_NAME_VAR (name)))
+ if (sprime)
+ {
+ /* If we can propagate the value computed for LHS into
+ all uses don't bother doing anything with this stmt. */
+ if (may_propagate_copy (lhs, sprime))
{
- tree ops[2];
- ops[0] = name;
- ops[1] = build_int_cst (TREE_TYPE (name), 0);
- vn_nary_op_insert_pieces (2, NE_EXPR, boolean_type_node, ops,
- boolean_true_node, 0);
+ /* Mark it for removal. */
+ to_remove.safe_push (stmt);
+
+ /* ??? Don't count copy/constant propagations. */
+ if (gimple_assign_single_p (stmt)
+ && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ || gimple_assign_rhs1 (stmt) == sprime))
+ return;
+
if (dump_file && (dump_flags & TDF_DETAILS))
{
- fprintf (dump_file, "Recording ");
- print_generic_expr (dump_file, name, TDF_SLIM);
- fprintf (dump_file, " != 0\n");
+ fprintf (dump_file, "Replaced ");
+ print_gimple_expr (dump_file, stmt, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, " in all uses of ");
+ print_gimple_stmt (dump_file, stmt, 0);
}
+
+ eliminations++;
+ return;
}
- break;
- case RESULT_DECL:
- /* If the result is passed by invisible reference the default
- def is initialized, otherwise it's uninitialized. Still
- undefined is varying. */
- VN_INFO (name)->visited = true;
- VN_INFO (name)->valnum = name;
- break;
+ /* If this is an assignment from our leader (which
+ happens in the case the value-number is a constant)
+ then there is nothing to do. */
+ if (gimple_assign_single_p (stmt)
+ && sprime == gimple_assign_rhs1 (stmt))
+ return;
- default:
- gcc_unreachable ();
+ /* Else replace its RHS. */
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced ");
+ print_gimple_expr (dump_file, stmt, 0);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, " in ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
+ eliminations++;
+
+ bool can_make_abnormal_goto = (is_gimple_call (stmt)
+ && stmt_can_make_abnormal_goto (stmt));
+ gimple *orig_stmt = stmt;
+ if (!useless_type_conversion_p (TREE_TYPE (lhs),
+ TREE_TYPE (sprime)))
+ {
+ /* We preserve conversions to but not from function or method
+ types. This asymmetry makes it necessary to re-instantiate
+ conversions here. */
+ if (POINTER_TYPE_P (TREE_TYPE (lhs))
+ && FUNC_OR_METHOD_TYPE_P (TREE_TYPE (TREE_TYPE (lhs))))
+ sprime = fold_convert (TREE_TYPE (lhs), sprime);
+ else
+ gcc_unreachable ();
+ }
+ tree vdef = gimple_vdef (stmt);
+ tree vuse = gimple_vuse (stmt);
+ propagate_tree_value_into_stmt (gsi, sprime);
+ stmt = gsi_stmt (*gsi);
+ update_stmt (stmt);
+ /* In case the VDEF on the original stmt was released, value-number
+ it to the VUSE. This is to make vuse_ssa_val able to skip
+ released virtual operands. */
+ if (vdef != gimple_vdef (stmt))
+ {
+ gcc_assert (SSA_NAME_IN_FREE_LIST (vdef));
+ VN_INFO (vdef)->valnum = vuse;
+ }
+
+ /* If we removed EH side-effects from the statement, clean
+ its EH information. */
+ if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
+ {
+ bitmap_set_bit (need_eh_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed EH side-effects.\n");
+ }
+
+ /* Likewise for AB side-effects. */
+ if (can_make_abnormal_goto
+ && !stmt_can_make_abnormal_goto (stmt))
+ {
+ bitmap_set_bit (need_ab_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed AB side-effects.\n");
+ }
+
+ return;
}
}
-}
-/* Restore SSA info that has been reset on value leaders. */
+ /* If the statement is a scalar store, see if the expression
+ has the same value number as its rhs. If so, the store is
+ dead. */
+ if (gimple_assign_single_p (stmt)
+ && !gimple_has_volatile_ops (stmt)
+ && !is_gimple_reg (gimple_assign_lhs (stmt))
+ && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
+ || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+ {
+ tree val;
+ tree rhs = gimple_assign_rhs1 (stmt);
+ vn_reference_t vnresult;
+ val = vn_reference_lookup (lhs, gimple_vuse (stmt), VN_WALKREWRITE,
+ &vnresult, false);
+ if (TREE_CODE (rhs) == SSA_NAME)
+ rhs = VN_INFO (rhs)->valnum;
+ if (val
+ && operand_equal_p (val, rhs, 0))
+ {
+ /* We can only remove the later store if the former aliases
+ at least all accesses the later one does or if the store
+ was to readonly memory storing the same value. */
+ alias_set_type set = get_alias_set (lhs);
+ if (! vnresult
+ || vnresult->set == set
+ || alias_set_subset_of (set, vnresult->set))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Deleted redundant store ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
-void
-scc_vn_restore_ssa_info (void)
-{
- unsigned i;
- tree name;
+ /* Queue stmt for removal. */
+ to_remove.safe_push (stmt);
+ return;
+ }
+ }
+ }
- FOR_EACH_SSA_NAME (i, name, cfun)
+ /* If this is a control statement value numbering left edges
+ unexecuted on force the condition in a way consistent with
+ that. */
+ if (gcond *cond = dyn_cast <gcond *> (stmt))
{
- if (has_VN_INFO (name))
+ if ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE)
+ ^ (EDGE_SUCC (b, 1)->flags & EDGE_EXECUTABLE))
{
- if (VN_INFO (name)->needs_insertion)
- ;
- else if (POINTER_TYPE_P (TREE_TYPE (name))
- && VN_INFO (name)->info.ptr_info)
- SSA_NAME_PTR_INFO (name) = VN_INFO (name)->info.ptr_info;
- else if (INTEGRAL_TYPE_P (TREE_TYPE (name))
- && VN_INFO (name)->info.range_info)
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- SSA_NAME_RANGE_INFO (name) = VN_INFO (name)->info.range_info;
- SSA_NAME_ANTI_RANGE_P (name)
- = VN_INFO (name)->range_info_anti_range_p;
+ fprintf (dump_file, "Removing unexecutable edge from ");
+ print_gimple_stmt (dump_file, stmt, 0);
}
+ if (((EDGE_SUCC (b, 0)->flags & EDGE_TRUE_VALUE) != 0)
+ == ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE) != 0))
+ gimple_cond_make_true (cond);
+ else
+ gimple_cond_make_false (cond);
+ update_stmt (cond);
+ el_todo |= TODO_cleanup_cfg;
+ return;
}
}
-}
-void
-free_scc_vn (void)
-{
- size_t i;
- tree name;
-
- delete constant_to_value_id;
- constant_to_value_id = NULL;
- BITMAP_FREE (constant_value_ids);
- shared_lookup_phiargs.release ();
- shared_lookup_references.release ();
- XDELETEVEC (rpo_numbers);
+ bool can_make_abnormal_goto = stmt_can_make_abnormal_goto (stmt);
+ bool was_noreturn = (is_gimple_call (stmt)
+ && gimple_call_noreturn_p (stmt));
+ tree vdef = gimple_vdef (stmt);
+ tree vuse = gimple_vuse (stmt);
- FOR_EACH_SSA_NAME (i, name, cfun)
+ /* If we didn't replace the whole stmt (or propagate the result
+ into all uses), replace all uses on this stmt with their
+ leaders. */
+ bool modified = false;
+ use_operand_p use_p;
+ ssa_op_iter iter;
+ FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
{
- if (has_VN_INFO (name)
- && VN_INFO (name)->needs_insertion)
- release_ssa_name (name);
+ tree use = USE_FROM_PTR (use_p);
+ /* ??? The call code above leaves stmt operands un-updated. */
+ if (TREE_CODE (use) != SSA_NAME)
+ continue;
+ tree sprime;
+ if (SSA_NAME_IS_DEFAULT_DEF (use))
+ /* ??? For default defs BB shouldn't matter, but we have to
+ solve the inconsistency between rpo eliminate and
+ dom eliminate avail valueization first. */
+ sprime = eliminate_avail (b, use);
+ else
+ /* Look for sth available at the definition block of the argument.
+ This avoids inconsistencies between availability there which
+ decides if the stmt can be removed and availability at the
+ use site. The SSA property ensures that things available
+ at the definition are also available at uses. */
+ sprime = eliminate_avail (gimple_bb (SSA_NAME_DEF_STMT (use)), use);
+ if (sprime && sprime != use
+ && may_propagate_copy (use, sprime)
+ /* We substitute into debug stmts to avoid excessive
+ debug temporaries created by removed stmts, but we need
+ to avoid doing so for inserted sprimes as we never want
+ to create debug temporaries for them. */
+ && (!inserted_exprs
+ || TREE_CODE (sprime) != SSA_NAME
+ || !is_gimple_debug (stmt)
+ || !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))))
+ {
+ propagate_value (use_p, sprime);
+ modified = true;
+ }
}
- obstack_free (&vn_ssa_aux_obstack, NULL);
- vn_ssa_aux_table.release ();
- sccstack.release ();
- free_vn_table (valid_info);
- XDELETE (valid_info);
- free_vn_table (optimistic_info);
- XDELETE (optimistic_info);
+ /* Fold the stmt if modified, this canonicalizes MEM_REFs we propagated
+ into which is a requirement for the IPA devirt machinery. */
+ gimple *old_stmt = stmt;
+ if (modified)
+ {
+ /* If a formerly non-invariant ADDR_EXPR is turned into an
+ invariant one it was on a separate stmt. */
+ if (gimple_assign_single_p (stmt)
+ && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
+ recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
+ gimple_stmt_iterator prev = *gsi;
+ gsi_prev (&prev);
+ if (fold_stmt (gsi))
+ {
+ /* fold_stmt may have created new stmts inbetween
+ the previous stmt and the folded stmt. Mark
+ all defs created there as varying to not confuse
+ the SCCVN machinery as we're using that even during
+ elimination. */
+ if (gsi_end_p (prev))
+ prev = gsi_start_bb (b);
+ else
+ gsi_next (&prev);
+ if (gsi_stmt (prev) != gsi_stmt (*gsi))
+ do
+ {
+ tree def;
+ ssa_op_iter dit;
+ FOR_EACH_SSA_TREE_OPERAND (def, gsi_stmt (prev),
+ dit, SSA_OP_ALL_DEFS)
+ /* As existing DEFs may move between stmts
+ only process new ones. */
+ if (! has_VN_INFO (def))
+ {
+ VN_INFO (def)->valnum = def;
+ VN_INFO (def)->visited = true;
+ }
+ if (gsi_stmt (prev) == gsi_stmt (*gsi))
+ break;
+ gsi_next (&prev);
+ }
+ while (1);
+ }
+ stmt = gsi_stmt (*gsi);
+ /* In case we folded the stmt away schedule the NOP for removal. */
+ if (gimple_nop_p (stmt))
+ to_remove.safe_push (stmt);
+ }
- BITMAP_FREE (const_parms);
-}
+ /* Visit indirect calls and turn them into direct calls if
+ possible using the devirtualization machinery. Do this before
+ checking for required EH/abnormal/noreturn cleanup as devird
+ may expose more of those. */
+ if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
+ {
+ tree fn = gimple_call_fn (call_stmt);
+ if (fn
+ && flag_devirtualize
+ && virtual_method_call_p (fn))
+ {
+ tree otr_type = obj_type_ref_class (fn);
+ unsigned HOST_WIDE_INT otr_tok
+ = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (fn));
+ tree instance;
+ ipa_polymorphic_call_context context (current_function_decl,
+ fn, stmt, &instance);
+ context.get_dynamic_type (instance, OBJ_TYPE_REF_OBJECT (fn),
+ otr_type, stmt, NULL);
+ bool final;
+ vec <cgraph_node *> targets
+ = possible_polymorphic_call_targets (obj_type_ref_class (fn),
+ otr_tok, context, &final);
+ if (dump_file)
+ dump_possible_polymorphic_call_targets (dump_file,
+ obj_type_ref_class (fn),
+ otr_tok, context);
+ if (final && targets.length () <= 1 && dbg_cnt (devirt))
+ {
+ tree fn;
+ if (targets.length () == 1)
+ fn = targets[0]->decl;
+ else
+ fn = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
+ if (dump_enabled_p ())
+ {
+ dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, stmt,
+ "converting indirect call to "
+ "function %s\n",
+ lang_hooks.decl_printable_name (fn, 2));
+ }
+ gimple_call_set_fndecl (call_stmt, fn);
+ /* If changing the call to __builtin_unreachable
+ or similar noreturn function, adjust gimple_call_fntype
+ too. */
+ if (gimple_call_noreturn_p (call_stmt)
+ && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fn)))
+ && TYPE_ARG_TYPES (TREE_TYPE (fn))
+ && (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fn)))
+ == void_type_node))
+ gimple_call_set_fntype (call_stmt, TREE_TYPE (fn));
+ maybe_remove_unused_call_args (cfun, call_stmt);
+ modified = true;
+ }
+ }
+ }
-/* Set *ID according to RESULT. */
+ if (modified)
+ {
+ /* When changing a call into a noreturn call, cfg cleanup
+ is needed to fix up the noreturn call. */
+ if (!was_noreturn
+ && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt))
+ to_fixup.safe_push (stmt);
+ /* When changing a condition or switch into one we know what
+ edge will be executed, schedule a cfg cleanup. */
+ if ((gimple_code (stmt) == GIMPLE_COND
+ && (gimple_cond_true_p (as_a <gcond *> (stmt))
+ || gimple_cond_false_p (as_a <gcond *> (stmt))))
+ || (gimple_code (stmt) == GIMPLE_SWITCH
+ && TREE_CODE (gimple_switch_index
+ (as_a <gswitch *> (stmt))) == INTEGER_CST))
+ el_todo |= TODO_cleanup_cfg;
+ /* If we removed EH side-effects from the statement, clean
+ its EH information. */
+ if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
+ {
+ bitmap_set_bit (need_eh_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed EH side-effects.\n");
+ }
+ /* Likewise for AB side-effects. */
+ if (can_make_abnormal_goto
+ && !stmt_can_make_abnormal_goto (stmt))
+ {
+ bitmap_set_bit (need_ab_cleanup,
+ gimple_bb (stmt)->index);
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, " Removed AB side-effects.\n");
+ }
+ update_stmt (stmt);
+ /* In case the VDEF on the original stmt was released, value-number
+ it to the VUSE. This is to make vuse_ssa_val able to skip
+ released virtual operands. */
+ if (vdef && SSA_NAME_IN_FREE_LIST (vdef))
+ VN_INFO (vdef)->valnum = vuse;
+ }
-static void
-set_value_id_for_result (tree result, unsigned int *id)
-{
- if (result && TREE_CODE (result) == SSA_NAME)
- *id = VN_INFO (result)->value_id;
- else if (result && is_gimple_min_invariant (result))
- *id = get_or_alloc_constant_value_id (result);
- else
- *id = get_next_value_id ();
+ /* Make new values available - for fully redundant LHS we
+ continue with the next stmt above and skip this. */
+ def_operand_p defp;
+ FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_DEF)
+ eliminate_push_avail (b, DEF_FROM_PTR (defp));
}
-/* Set the value ids in the valid hash tables. */
+/* Perform elimination for the basic-block B during the domwalk. */
-static void
-set_hashtable_value_ids (void)
+edge
+eliminate_dom_walker::before_dom_children (basic_block b)
{
- vn_nary_op_iterator_type hin;
- vn_phi_iterator_type hip;
- vn_reference_iterator_type hir;
- vn_nary_op_t vno;
- vn_reference_t vr;
- vn_phi_t vp;
+ /* Mark new bb. */
+ avail_stack.safe_push (NULL_TREE);
- /* Now set the value ids of the things we had put in the hash
- table. */
+ /* Skip unreachable blocks marked unreachable during the SCCVN domwalk. */
+ if (!(b->flags & BB_EXECUTABLE))
+ return NULL;
- FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->nary, vno, vn_nary_op_t, hin)
- set_value_id_for_result (vno->result, &vno->value_id);
+ vn_context_bb = b;
- FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->phis, vp, vn_phi_t, hip)
- set_value_id_for_result (vp->result, &vp->value_id);
+ for (gphi_iterator gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
+ {
+ gphi *phi = gsi.phi ();
+ tree res = PHI_RESULT (phi);
- FOR_EACH_HASH_TABLE_ELEMENT (*valid_info->references, vr, vn_reference_t,
- hir)
- set_value_id_for_result (vr->result, &vr->value_id);
-}
+ if (virtual_operand_p (res))
+ {
+ gsi_next (&gsi);
+ continue;
+ }
-class sccvn_dom_walker : public dom_walker
-{
-public:
- sccvn_dom_walker ()
- : dom_walker (CDI_DOMINATORS, REACHABLE_BLOCKS), cond_stack (0) {}
+ tree sprime = eliminate_avail (b, res);
+ if (sprime
+ && sprime != res)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced redundant PHI node defining ");
+ print_generic_expr (dump_file, res);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, sprime);
+ fprintf (dump_file, "\n");
+ }
- virtual edge before_dom_children (basic_block);
- virtual void after_dom_children (basic_block);
+ /* If we inserted this PHI node ourself, it's not an elimination. */
+ if (! inserted_exprs
+ || ! bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
+ eliminations++;
- void record_cond (basic_block,
- enum tree_code code, tree lhs, tree rhs, bool value);
- void record_conds (basic_block,
- enum tree_code code, tree lhs, tree rhs, bool value);
+ /* If we will propagate into all uses don't bother to do
+ anything. */
+ if (may_propagate_copy (res, sprime))
+ {
+ /* Mark the PHI for removal. */
+ to_remove.safe_push (phi);
+ gsi_next (&gsi);
+ continue;
+ }
- auto_vec<std::pair <basic_block, std::pair <vn_nary_op_t, vn_nary_op_t> > >
- cond_stack;
-};
+ remove_phi_node (&gsi, false);
-/* Record a temporary condition for the BB and its dominated blocks. */
+ if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
+ sprime = fold_convert (TREE_TYPE (res), sprime);
+ gimple *stmt = gimple_build_assign (res, sprime);
+ gimple_stmt_iterator gsi2 = gsi_after_labels (b);
+ gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
+ continue;
+ }
-void
-sccvn_dom_walker::record_cond (basic_block bb,
- enum tree_code code, tree lhs, tree rhs,
- bool value)
-{
- tree ops[2] = { lhs, rhs };
- vn_nary_op_t old = NULL;
- if (vn_nary_op_lookup_pieces (2, code, boolean_type_node, ops, &old))
- current_info->nary->remove_elt_with_hash (old, old->hashcode);
- vn_nary_op_t cond
- = vn_nary_op_insert_pieces (2, code, boolean_type_node, ops,
- value
- ? boolean_true_node
- : boolean_false_node, 0);
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Recording temporarily ");
- print_generic_expr (dump_file, ops[0], TDF_SLIM);
- fprintf (dump_file, " %s ", get_tree_code_name (code));
- print_generic_expr (dump_file, ops[1], TDF_SLIM);
- fprintf (dump_file, " == %s%s\n",
- value ? "true" : "false",
- old ? " (old entry saved)" : "");
+ eliminate_push_avail (b, res);
+ gsi_next (&gsi);
}
- cond_stack.safe_push (std::make_pair (bb, std::make_pair (cond, old)));
-}
-
-/* Record temporary conditions for the BB and its dominated blocks
- according to LHS CODE RHS == VALUE and its dominated conditions. */
-
-void
-sccvn_dom_walker::record_conds (basic_block bb,
- enum tree_code code, tree lhs, tree rhs,
- bool value)
-{
- /* Record the original condition. */
- record_cond (bb, code, lhs, rhs, value);
- if (!value)
- return;
+ for (gimple_stmt_iterator gsi = gsi_start_bb (b);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ eliminate_stmt (b, &gsi);
- /* Record dominated conditions if the condition is true. Note that
- the inversion is already recorded. */
- switch (code)
- {
- case LT_EXPR:
- case GT_EXPR:
- record_cond (bb, code == LT_EXPR ? LE_EXPR : GE_EXPR, lhs, rhs, true);
- record_cond (bb, NE_EXPR, lhs, rhs, true);
- record_cond (bb, EQ_EXPR, lhs, rhs, false);
- break;
+ /* Replace destination PHI arguments. */
+ edge_iterator ei;
+ edge e;
+ FOR_EACH_EDGE (e, ei, b->succs)
+ if (e->flags & EDGE_EXECUTABLE)
+ for (gphi_iterator gsi = gsi_start_phis (e->dest);
+ !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gphi *phi = gsi.phi ();
+ use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e);
+ tree arg = USE_FROM_PTR (use_p);
+ if (TREE_CODE (arg) != SSA_NAME
+ || virtual_operand_p (arg))
+ continue;
+ tree sprime = eliminate_avail (b, arg);
+ if (sprime && may_propagate_copy (arg, sprime))
+ propagate_value (use_p, sprime);
+ }
- case EQ_EXPR:
- record_cond (bb, LE_EXPR, lhs, rhs, true);
- record_cond (bb, GE_EXPR, lhs, rhs, true);
- record_cond (bb, LT_EXPR, lhs, rhs, false);
- record_cond (bb, GT_EXPR, lhs, rhs, false);
- break;
+ vn_context_bb = NULL;
- default:
- break;
- }
+ return NULL;
}
-
-/* Restore expressions and values derived from conditionals. */
+
+/* Make no longer available leaders no longer available. */
void
-sccvn_dom_walker::after_dom_children (basic_block bb)
+eliminate_dom_walker::after_dom_children (basic_block)
{
- while (!cond_stack.is_empty ()
- && cond_stack.last ().first == bb)
+ tree entry;
+ while ((entry = avail_stack.pop ()) != NULL_TREE)
{
- vn_nary_op_t cond = cond_stack.last ().second.first;
- vn_nary_op_t old = cond_stack.last ().second.second;
- current_info->nary->remove_elt_with_hash (cond, cond->hashcode);
- if (old)
- vn_nary_op_insert_into (old, current_info->nary, false);
- cond_stack.pop ();
+ tree valnum = VN_INFO (entry)->valnum;
+ tree old = avail[SSA_NAME_VERSION (valnum)];
+ if (old == entry)
+ avail[SSA_NAME_VERSION (valnum)] = NULL_TREE;
+ else
+ avail[SSA_NAME_VERSION (valnum)] = entry;
}
}
-/* Value number all statements in BB. */
+/* Remove queued stmts and perform delayed cleanups. */
-edge
-sccvn_dom_walker::before_dom_children (basic_block bb)
+unsigned
+eliminate_dom_walker::eliminate_cleanup (bool region_p)
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Visiting BB %d\n", bb->index);
+ statistics_counter_event (cfun, "Eliminated", eliminations);
+ statistics_counter_event (cfun, "Insertions", insertions);
- /* If we have a single predecessor record the equivalence from a
- possible condition on the predecessor edge. */
- edge pred_e = single_pred_edge_ignoring_loop_edges (bb, false);
- if (pred_e)
+ /* We cannot remove stmts during BB walk, especially not release SSA
+ names there as this confuses the VN machinery. The stmts ending
+ up in to_remove are either stores or simple copies.
+ Remove stmts in reverse order to make debug stmt creation possible. */
+ while (!to_remove.is_empty ())
{
- /* Check if there are multiple executable successor edges in
- the source block. Otherwise there is no additional info
- to be recorded. */
- edge_iterator ei;
- edge e2;
- FOR_EACH_EDGE (e2, ei, pred_e->src->succs)
- if (e2 != pred_e
- && e2->flags & EDGE_EXECUTABLE)
- break;
- if (e2 && (e2->flags & EDGE_EXECUTABLE))
+ bool do_release_defs = true;
+ gimple *stmt = to_remove.pop ();
+
+ /* When we are value-numbering a region we do not require exit PHIs to
+ be present so we have to make sure to deal with uses outside of the
+ region of stmts that we thought are eliminated.
+ ??? Note we may be confused by uses in dead regions we didn't run
+ elimination on. Rather than checking individual uses we accept
+ dead copies to be generated here (gcc.c-torture/execute/20060905-1.c
+ contains such example). */
+ if (region_p)
{
- gimple *stmt = last_stmt (pred_e->src);
- if (stmt
- && gimple_code (stmt) == GIMPLE_COND)
+ if (gphi *phi = dyn_cast <gphi *> (stmt))
{
- enum tree_code code = gimple_cond_code (stmt);
- tree lhs = gimple_cond_lhs (stmt);
- tree rhs = gimple_cond_rhs (stmt);
- record_conds (bb, code, lhs, rhs,
- (pred_e->flags & EDGE_TRUE_VALUE) != 0);
- code = invert_tree_comparison (code, HONOR_NANS (lhs));
- if (code != ERROR_MARK)
- record_conds (bb, code, lhs, rhs,
- (pred_e->flags & EDGE_TRUE_VALUE) == 0);
+ tree lhs = gimple_phi_result (phi);
+ if (!has_zero_uses (lhs))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Keeping eliminated stmt live "
+ "as copy because of out-of-region uses\n");
+ tree sprime = eliminate_avail (gimple_bb (stmt), lhs);
+ gimple *copy = gimple_build_assign (lhs, sprime);
+ gimple_stmt_iterator gsi
+ = gsi_after_labels (gimple_bb (stmt));
+ gsi_insert_before (&gsi, copy, GSI_SAME_STMT);
+ do_release_defs = false;
+ }
}
+ else if (tree lhs = gimple_get_lhs (stmt))
+ if (TREE_CODE (lhs) == SSA_NAME
+ && !has_zero_uses (lhs))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Keeping eliminated stmt live "
+ "as copy because of out-of-region uses\n");
+ tree sprime = eliminate_avail (gimple_bb (stmt), lhs);
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ if (is_gimple_assign (stmt))
+ {
+ gimple_assign_set_rhs_from_tree (&gsi, sprime);
+ stmt = gsi_stmt (gsi);
+ update_stmt (stmt);
+ if (maybe_clean_or_replace_eh_stmt (stmt, stmt))
+ bitmap_set_bit (need_eh_cleanup, gimple_bb (stmt)->index);
+ continue;
+ }
+ else
+ {
+ gimple *copy = gimple_build_assign (lhs, sprime);
+ gsi_insert_before (&gsi, copy, GSI_SAME_STMT);
+ do_release_defs = false;
+ }
+ }
}
- }
-
- /* Value-number all defs in the basic-block. */
- for (gphi_iterator gsi = gsi_start_phis (bb);
- !gsi_end_p (gsi); gsi_next (&gsi))
- {
- gphi *phi = gsi.phi ();
- tree res = PHI_RESULT (phi);
- if (!VN_INFO (res)->visited)
- DFS (res);
- }
- for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
- !gsi_end_p (gsi); gsi_next (&gsi))
- {
- ssa_op_iter i;
- tree op;
- FOR_EACH_SSA_TREE_OPERAND (op, gsi_stmt (gsi), i, SSA_OP_ALL_DEFS)
- if (!VN_INFO (op)->visited)
- DFS (op);
- }
- /* Finally look at the last stmt. */
- gimple *stmt = last_stmt (bb);
- if (!stmt)
- return NULL;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Removing dead stmt ");
+ print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ }
- enum gimple_code code = gimple_code (stmt);
- if (code != GIMPLE_COND
- && code != GIMPLE_SWITCH
- && code != GIMPLE_GOTO)
- return NULL;
+ gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
+ if (gimple_code (stmt) == GIMPLE_PHI)
+ remove_phi_node (&gsi, do_release_defs);
+ else
+ {
+ basic_block bb = gimple_bb (stmt);
+ unlink_stmt_vdef (stmt);
+ if (gsi_remove (&gsi, true))
+ bitmap_set_bit (need_eh_cleanup, bb->index);
+ if (is_gimple_call (stmt) && stmt_can_make_abnormal_goto (stmt))
+ bitmap_set_bit (need_ab_cleanup, bb->index);
+ if (do_release_defs)
+ release_defs (stmt);
+ }
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Visiting control stmt ending BB %d: ", bb->index);
- print_gimple_stmt (dump_file, stmt, 0);
+ /* Removing a stmt may expose a forwarder block. */
+ el_todo |= TODO_cleanup_cfg;
}
- /* ??? We can even handle stmts with outgoing EH or ABNORMAL edges
- if value-numbering can prove they are not reachable. Handling
- computed gotos is also possible. */
- tree val;
- switch (code)
+ /* Fixup stmts that became noreturn calls. This may require splitting
+ blocks and thus isn't possible during the dominator walk. Do this
+ in reverse order so we don't inadvertedly remove a stmt we want to
+ fixup by visiting a dominating now noreturn call first. */
+ while (!to_fixup.is_empty ())
{
- case GIMPLE_COND:
- {
- tree lhs = vn_valueize (gimple_cond_lhs (stmt));
- tree rhs = vn_valueize (gimple_cond_rhs (stmt));
- val = gimple_simplify (gimple_cond_code (stmt),
- boolean_type_node, lhs, rhs,
- NULL, vn_valueize);
- /* If that didn't simplify to a constant see if we have recorded
- temporary expressions from taken edges. */
- if (!val || TREE_CODE (val) != INTEGER_CST)
- {
- tree ops[2];
- ops[0] = lhs;
- ops[1] = rhs;
- val = vn_nary_op_lookup_pieces (2, gimple_cond_code (stmt),
- boolean_type_node, ops, NULL);
- }
- break;
- }
- case GIMPLE_SWITCH:
- val = gimple_switch_index (as_a <gswitch *> (stmt));
- break;
- case GIMPLE_GOTO:
- val = gimple_goto_dest (stmt);
- break;
- default:
- gcc_unreachable ();
+ gimple *stmt = to_fixup.pop ();
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Fixing up noreturn call ");
+ print_gimple_stmt (dump_file, stmt, 0);
+ }
+
+ if (fixup_noreturn_call (stmt))
+ el_todo |= TODO_cleanup_cfg;
}
- if (!val)
- return NULL;
- edge taken = find_taken_edge (bb, vn_valueize (val));
- if (!taken)
- return NULL;
+ bool do_eh_cleanup = !bitmap_empty_p (need_eh_cleanup);
+ bool do_ab_cleanup = !bitmap_empty_p (need_ab_cleanup);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, "Marking all edges out of BB %d but (%d -> %d) as "
- "not executable\n", bb->index, bb->index, taken->dest->index);
+ if (do_eh_cleanup)
+ gimple_purge_all_dead_eh_edges (need_eh_cleanup);
+
+ if (do_ab_cleanup)
+ gimple_purge_all_dead_abnormal_call_edges (need_ab_cleanup);
- return taken;
+ if (do_eh_cleanup || do_ab_cleanup)
+ el_todo |= TODO_cleanup_cfg;
+
+ return el_todo;
}
-/* Do SCCVN. Returns true if it finished, false if we bailed out
- due to resource constraints. DEFAULT_VN_WALK_KIND_ specifies
- how we use the alias oracle walking during the VN process. */
+/* Eliminate fully redundant computations. */
-void
-run_scc_vn (vn_lookup_kind default_vn_walk_kind_)
+unsigned
+eliminate_with_rpo_vn (bitmap inserted_exprs)
{
- size_t i;
+ eliminate_dom_walker walker (CDI_DOMINATORS, inserted_exprs);
- default_vn_walk_kind = default_vn_walk_kind_;
+ walker.walk (cfun->cfg->x_entry_block_ptr);
+ return walker.eliminate_cleanup ();
+}
- init_scc_vn ();
+static unsigned
+do_rpo_vn (function *fn, edge entry, bitmap exit_bbs,
+ bool iterate, bool eliminate);
- /* Collect pointers we know point to readonly memory. */
- const_parms = BITMAP_ALLOC (NULL);
- tree fnspec = lookup_attribute ("fn spec",
- TYPE_ATTRIBUTES (TREE_TYPE (cfun->decl)));
- if (fnspec)
- {
- fnspec = TREE_VALUE (TREE_VALUE (fnspec));
- i = 1;
- for (tree arg = DECL_ARGUMENTS (cfun->decl);
- arg; arg = DECL_CHAIN (arg), ++i)
- {
- if (i >= (unsigned) TREE_STRING_LENGTH (fnspec))
- break;
- if (TREE_STRING_POINTER (fnspec)[i] == 'R'
- || TREE_STRING_POINTER (fnspec)[i] == 'r')
- {
- tree name = ssa_default_def (cfun, arg);
- if (name)
- bitmap_set_bit (const_parms, SSA_NAME_VERSION (name));
- }
- }
- }
+void
+run_rpo_vn (vn_lookup_kind kind)
+{
+ default_vn_walk_kind = kind;
+ do_rpo_vn (cfun, NULL, NULL, true, false);
- /* Walk all blocks in dominator order, value-numbering stmts
- SSA defs and decide whether outgoing edges are not executable. */
- sccvn_dom_walker walker;
- walker.walk (ENTRY_BLOCK_PTR_FOR_FN (cfun));
+ /* ??? Prune requirement of these. */
+ constant_to_value_id = new hash_table<vn_constant_hasher> (23);
+ constant_value_ids = BITMAP_ALLOC (NULL);
/* Initialize the value ids and prune out remaining VN_TOPs
from dead code. */
tree name;
+ unsigned i;
FOR_EACH_SSA_NAME (i, name, cfun)
{
vn_ssa_aux_t info = VN_INFO (name);
print_generic_expr (dump_file, name);
fprintf (dump_file, " = ");
print_generic_expr (dump_file, SSA_VAL (name));
- fprintf (dump_file, "\n");
+ fprintf (dump_file, " (%04d)\n", VN_INFO (name)->value_id);
}
}
}
}
-/* Return the maximum value id we have ever seen. */
-
-unsigned int
-get_max_value_id (void)
-{
- return next_value_id;
-}
-
-/* Return the next unique value id. */
-
-unsigned int
-get_next_value_id (void)
-{
- return next_value_id++;
-}
-
-
-/* Compare two expressions E1 and E2 and return true if they are equal. */
-
-bool
-expressions_equal_p (tree e1, tree e2)
-{
- /* The obvious case. */
- if (e1 == e2)
- return true;
-
- /* If either one is VN_TOP consider them equal. */
- if (e1 == VN_TOP || e2 == VN_TOP)
- return true;
-
- /* If only one of them is null, they cannot be equal. */
- if (!e1 || !e2)
- return false;
-
- /* Now perform the actual comparison. */
- if (TREE_CODE (e1) == TREE_CODE (e2)
- && operand_equal_p (e1, e2, OEP_PURE_SAME))
- return true;
-
- return false;
-}
-
+/* Free VN associated data structures. */
-/* Return true if the nary operation NARY may trap. This is a copy
- of stmt_could_throw_1_p adjusted to the SCCVN IL. */
-
-bool
-vn_nary_may_trap (vn_nary_op_t nary)
+void
+free_rpo_vn (void)
{
- tree type;
- tree rhs2 = NULL_TREE;
- bool honor_nans = false;
- bool honor_snans = false;
- bool fp_operation = false;
- bool honor_trapv = false;
- bool handled, ret;
- unsigned i;
-
- if (TREE_CODE_CLASS (nary->opcode) == tcc_comparison
- || TREE_CODE_CLASS (nary->opcode) == tcc_unary
- || TREE_CODE_CLASS (nary->opcode) == tcc_binary)
- {
- type = nary->type;
- fp_operation = FLOAT_TYPE_P (type);
- if (fp_operation)
- {
- honor_nans = flag_trapping_math && !flag_finite_math_only;
- honor_snans = flag_signaling_nans != 0;
- }
- else if (INTEGRAL_TYPE_P (type)
- && TYPE_OVERFLOW_TRAPS (type))
- honor_trapv = true;
- }
- if (nary->length >= 2)
- rhs2 = nary->op[1];
- ret = operation_could_trap_helper_p (nary->opcode, fp_operation,
- honor_trapv,
- honor_nans, honor_snans, rhs2,
- &handled);
- if (handled
- && ret)
- return true;
-
- for (i = 0; i < nary->length; ++i)
- if (tree_could_trap_p (nary->op[i]))
- return true;
+ free_vn_table (valid_info);
+ XDELETE (valid_info);
+ obstack_free (&vn_tables_obstack, NULL);
+ obstack_free (&vn_tables_insert_obstack, NULL);
+
+ vn_ssa_aux_iterator_type it;
+ vn_ssa_aux_t info;
+ FOR_EACH_HASH_TABLE_ELEMENT (*vn_ssa_aux_hash, info, vn_ssa_aux_t, it)
+ if (info->needs_insertion)
+ release_ssa_name (info->name);
+ obstack_free (&vn_ssa_aux_obstack, NULL);
+ delete vn_ssa_aux_hash;
- return false;
+ delete constant_to_value_id;
+ constant_to_value_id = NULL;
+ BITMAP_FREE (constant_value_ids);
}
+/* Hook for maybe_push_res_to_seq, lookup the expression in the VN tables. */
-class eliminate_dom_walker : public dom_walker
-{
-public:
- eliminate_dom_walker (cdi_direction, bitmap);
- ~eliminate_dom_walker ();
-
- virtual edge before_dom_children (basic_block);
- virtual void after_dom_children (basic_block);
-
- tree eliminate_avail (tree op);
- void eliminate_push_avail (tree op);
- tree eliminate_insert (gimple_stmt_iterator *gsi, tree val);
-
- bool do_pre;
- unsigned int el_todo;
- unsigned int eliminations;
- unsigned int insertions;
-
- /* SSA names that had their defs inserted by PRE if do_pre. */
- bitmap inserted_exprs;
-
- /* Blocks with statements that have had their EH properties changed. */
- bitmap need_eh_cleanup;
-
- /* Blocks with statements that have had their AB properties changed. */
- bitmap need_ab_cleanup;
-
- auto_vec<gimple *> to_remove;
- auto_vec<gimple *> to_fixup;
- auto_vec<tree> avail;
- auto_vec<tree> avail_stack;
-};
-
-eliminate_dom_walker::eliminate_dom_walker (cdi_direction direction,
- bitmap inserted_exprs_)
- : dom_walker (direction), do_pre (inserted_exprs_ != NULL),
- el_todo (0), eliminations (0), insertions (0),
- inserted_exprs (inserted_exprs_)
-{
- need_eh_cleanup = BITMAP_ALLOC (NULL);
- need_ab_cleanup = BITMAP_ALLOC (NULL);
-}
-
-eliminate_dom_walker::~eliminate_dom_walker ()
+static tree
+vn_lookup_simplify_result (gimple_match_op *res_op)
{
- BITMAP_FREE (need_eh_cleanup);
- BITMAP_FREE (need_ab_cleanup);
+ if (!res_op->code.is_tree_code ())
+ return NULL_TREE;
+ tree *ops = res_op->ops;
+ unsigned int length = res_op->num_ops;
+ if (res_op->code == CONSTRUCTOR
+ /* ??? We're arriving here with SCCVNs view, decomposed CONSTRUCTOR
+ and GIMPLEs / match-and-simplifies, CONSTRUCTOR as GENERIC tree. */
+ && TREE_CODE (res_op->ops[0]) == CONSTRUCTOR)
+ {
+ length = CONSTRUCTOR_NELTS (res_op->ops[0]);
+ ops = XALLOCAVEC (tree, length);
+ for (unsigned i = 0; i < length; ++i)
+ ops[i] = CONSTRUCTOR_ELT (res_op->ops[0], i)->value;
+ }
+ vn_nary_op_t vnresult = NULL;
+ tree res = vn_nary_op_lookup_pieces (length, (tree_code) res_op->code,
+ res_op->type, ops, &vnresult);
+ /* If this is used from expression simplification make sure to
+ return an available expression. */
+ if (res && TREE_CODE (res) == SSA_NAME && mprts_hook && rpo_avail)
+ res = rpo_avail->eliminate_avail (vn_context_bb, res);
+ return res;
}
-/* Return a leader for OP that is available at the current point of the
- eliminate domwalk. */
+/* Return a leader for OPs value that is valid at BB. */
tree
-eliminate_dom_walker::eliminate_avail (tree op)
+rpo_elim::eliminate_avail (basic_block bb, tree op)
{
- tree valnum = VN_INFO (op)->valnum;
+ bool visited;
+ tree valnum = SSA_VAL (op, &visited);
+ /* If we didn't visit OP then it must be defined outside of the
+ region we process and also dominate it. So it is available. */
+ if (!visited)
+ return op;
if (TREE_CODE (valnum) == SSA_NAME)
{
if (SSA_NAME_IS_DEFAULT_DEF (valnum))
return valnum;
- if (avail.length () > SSA_NAME_VERSION (valnum))
- return avail[SSA_NAME_VERSION (valnum)];
+ vn_avail *av = VN_INFO (valnum)->avail;
+ if (!av)
+ return NULL_TREE;
+ if (av->location == bb->index)
+ /* On tramp3d 90% of the cases are here. */
+ return ssa_name (av->leader);
+ do
+ {
+ basic_block abb = BASIC_BLOCK_FOR_FN (cfun, av->location);
+ /* ??? During elimination we have to use availability at the
+ definition site of a use we try to replace. This
+ is required to not run into inconsistencies because
+ of dominated_by_p_w_unex behavior and removing a definition
+ while not replacing all uses.
+ ??? We could try to consistently walk dominators
+ ignoring non-executable regions. The nearest common
+ dominator of bb and abb is where we can stop walking. We
+ may also be able to "pre-compute" (bits of) the next immediate
+ (non-)dominator during the RPO walk when marking edges as
+ executable. */
+ if (dominated_by_p_w_unex (bb, abb))
+ {
+ tree leader = ssa_name (av->leader);
+ /* Prevent eliminations that break loop-closed SSA. */
+ if (loops_state_satisfies_p (LOOP_CLOSED_SSA)
+ && ! SSA_NAME_IS_DEFAULT_DEF (leader)
+ && ! flow_bb_inside_loop_p (gimple_bb (SSA_NAME_DEF_STMT
+ (leader))->loop_father,
+ bb))
+ return NULL_TREE;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ print_generic_expr (dump_file, leader);
+ fprintf (dump_file, " is available for ");
+ print_generic_expr (dump_file, valnum);
+ fprintf (dump_file, "\n");
+ }
+ /* On tramp3d 99% of the _remaining_ cases succeed at
+ the first enty. */
+ return leader;
+ }
+ /* ??? Can we somehow skip to the immediate dominator
+ RPO index (bb_to_rpo)? Again, maybe not worth, on
+ tramp3d the worst number of elements in the vector is 9. */
+ av = av->next;
+ }
+ while (av);
}
- else if (is_gimple_min_invariant (valnum))
+ else if (valnum != VN_TOP)
+ /* valnum is is_gimple_min_invariant. */
return valnum;
return NULL_TREE;
}
-/* At the current point of the eliminate domwalk make OP available. */
+/* Make LEADER a leader for its value at BB. */
void
-eliminate_dom_walker::eliminate_push_avail (tree op)
+rpo_elim::eliminate_push_avail (basic_block bb, tree leader)
{
- tree valnum = VN_INFO (op)->valnum;
- if (TREE_CODE (valnum) == SSA_NAME)
+ tree valnum = VN_INFO (leader)->valnum;
+ if (valnum == VN_TOP
+ || is_gimple_min_invariant (valnum))
+ return;
+ if (dump_file && (dump_flags & TDF_DETAILS))
{
- if (avail.length () <= SSA_NAME_VERSION (valnum))
- avail.safe_grow_cleared (SSA_NAME_VERSION (valnum) + 1);
- tree pushop = op;
- if (avail[SSA_NAME_VERSION (valnum)])
- pushop = avail[SSA_NAME_VERSION (valnum)];
- avail_stack.safe_push (pushop);
- avail[SSA_NAME_VERSION (valnum)] = op;
+ fprintf (dump_file, "Making available beyond BB%d ", bb->index);
+ print_generic_expr (dump_file, leader);
+ fprintf (dump_file, " for value ");
+ print_generic_expr (dump_file, valnum);
+ fprintf (dump_file, "\n");
+ }
+ vn_ssa_aux_t value = VN_INFO (valnum);
+ vn_avail *av;
+ if (m_avail_freelist)
+ {
+ av = m_avail_freelist;
+ m_avail_freelist = m_avail_freelist->next;
}
+ else
+ av = XOBNEW (&vn_ssa_aux_obstack, vn_avail);
+ av->location = bb->index;
+ av->leader = SSA_NAME_VERSION (leader);
+ av->next = value->avail;
+ value->avail = av;
}
-/* Insert the expression recorded by SCCVN for VAL at *GSI. Returns
- the leader for the expression if insertion was successful. */
+/* Valueization hook for RPO VN plus required state. */
tree
-eliminate_dom_walker::eliminate_insert (gimple_stmt_iterator *gsi, tree val)
+rpo_vn_valueize (tree name)
{
- /* We can insert a sequence with a single assignment only. */
- gimple_seq stmts = VN_INFO (val)->expr;
- if (!gimple_seq_singleton_p (stmts))
- return NULL_TREE;
- gassign *stmt = dyn_cast <gassign *> (gimple_seq_first_stmt (stmts));
- if (!stmt
- || (!CONVERT_EXPR_CODE_P (gimple_assign_rhs_code (stmt))
- && gimple_assign_rhs_code (stmt) != VIEW_CONVERT_EXPR
- && gimple_assign_rhs_code (stmt) != BIT_FIELD_REF
- && (gimple_assign_rhs_code (stmt) != BIT_AND_EXPR
- || TREE_CODE (gimple_assign_rhs2 (stmt)) != INTEGER_CST)))
- return NULL_TREE;
-
- tree op = gimple_assign_rhs1 (stmt);
- if (gimple_assign_rhs_code (stmt) == VIEW_CONVERT_EXPR
- || gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
- op = TREE_OPERAND (op, 0);
- tree leader = TREE_CODE (op) == SSA_NAME ? eliminate_avail (op) : op;
- if (!leader)
- return NULL_TREE;
-
- tree res;
- stmts = NULL;
- if (gimple_assign_rhs_code (stmt) == BIT_FIELD_REF)
- res = gimple_build (&stmts, BIT_FIELD_REF,
- TREE_TYPE (val), leader,
- TREE_OPERAND (gimple_assign_rhs1 (stmt), 1),
- TREE_OPERAND (gimple_assign_rhs1 (stmt), 2));
- else if (gimple_assign_rhs_code (stmt) == BIT_AND_EXPR)
- res = gimple_build (&stmts, BIT_AND_EXPR,
- TREE_TYPE (val), leader, gimple_assign_rhs2 (stmt));
- else
- res = gimple_build (&stmts, gimple_assign_rhs_code (stmt),
- TREE_TYPE (val), leader);
- if (TREE_CODE (res) != SSA_NAME
- || SSA_NAME_IS_DEFAULT_DEF (res)
- || gimple_bb (SSA_NAME_DEF_STMT (res)))
+ if (TREE_CODE (name) == SSA_NAME)
{
- gimple_seq_discard (stmts);
-
- /* During propagation we have to treat SSA info conservatively
- and thus we can end up simplifying the inserted expression
- at elimination time to sth not defined in stmts. */
- /* But then this is a redundancy we failed to detect. Which means
- res now has two values. That doesn't play well with how
- we track availability here, so give up. */
- if (dump_file && (dump_flags & TDF_DETAILS))
+ vn_ssa_aux_t val = VN_INFO (name);
+ if (val)
{
- if (TREE_CODE (res) == SSA_NAME)
- res = eliminate_avail (res);
- if (res)
+ tree tem = val->valnum;
+ if (tem != VN_TOP && tem != name)
{
- fprintf (dump_file, "Failed to insert expression for value ");
- print_generic_expr (dump_file, val);
- fprintf (dump_file, " which is really fully redundant to ");
- print_generic_expr (dump_file, res);
- fprintf (dump_file, "\n");
+ if (TREE_CODE (tem) != SSA_NAME)
+ return tem;
+ /* For all values we only valueize to an available leader
+ which means we can use SSA name info without restriction. */
+ tem = rpo_avail->eliminate_avail (vn_context_bb, tem);
+ if (tem)
+ return tem;
}
}
-
- return NULL_TREE;
- }
- else
- {
- gsi_insert_seq_before (gsi, stmts, GSI_SAME_STMT);
- VN_INFO_GET (res)->valnum = val;
}
+ return name;
+}
- insertions++;
- if (dump_file && (dump_flags & TDF_DETAILS))
+/* Insert on PRED_E predicates derived from CODE OPS being true besides the
+ inverted condition. */
+
+static void
+insert_related_predicates_on_edge (enum tree_code code, tree *ops, edge pred_e)
+{
+ switch (code)
{
- fprintf (dump_file, "Inserted ");
- print_gimple_stmt (dump_file, SSA_NAME_DEF_STMT (res), 0);
+ case LT_EXPR:
+ /* a < b -> a {!,<}= b */
+ vn_nary_op_insert_pieces_predicated (2, NE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, LE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ /* a < b -> ! a {>,=} b */
+ vn_nary_op_insert_pieces_predicated (2, GT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, EQ_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ break;
+ case GT_EXPR:
+ /* a > b -> a {!,>}= b */
+ vn_nary_op_insert_pieces_predicated (2, NE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, GE_EXPR, boolean_type_node,
+ ops, boolean_true_node, 0, pred_e);
+ /* a > b -> ! a {<,=} b */
+ vn_nary_op_insert_pieces_predicated (2, LT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, EQ_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ break;
+ case EQ_EXPR:
+ /* a == b -> ! a {<,>} b */
+ vn_nary_op_insert_pieces_predicated (2, LT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ vn_nary_op_insert_pieces_predicated (2, GT_EXPR, boolean_type_node,
+ ops, boolean_false_node, 0, pred_e);
+ break;
+ case LE_EXPR:
+ case GE_EXPR:
+ case NE_EXPR:
+ /* Nothing besides inverted condition. */
+ break;
+ default:;
}
-
- return res;
}
+/* Main stmt worker for RPO VN, process BB. */
-
-/* Perform elimination for the basic-block B during the domwalk. */
-
-edge
-eliminate_dom_walker::before_dom_children (basic_block b)
+static unsigned
+process_bb (rpo_elim &avail, basic_block bb,
+ bool bb_visited, bool iterate_phis, bool iterate, bool eliminate,
+ bool do_region, bitmap exit_bbs, bool skip_phis)
{
- /* Mark new bb. */
- avail_stack.safe_push (NULL_TREE);
-
- /* Skip unreachable blocks marked unreachable during the SCCVN domwalk. */
+ unsigned todo = 0;
edge_iterator ei;
edge e;
- FOR_EACH_EDGE (e, ei, b->preds)
- if (e->flags & EDGE_EXECUTABLE)
- break;
- if (! e)
- return NULL;
-
- for (gphi_iterator gsi = gsi_start_phis (b); !gsi_end_p (gsi);)
- {
- gphi *phi = gsi.phi ();
- tree res = PHI_RESULT (phi);
-
- if (virtual_operand_p (res))
- {
- gsi_next (&gsi);
- continue;
- }
- tree sprime = eliminate_avail (res);
- if (sprime
- && sprime != res)
+ vn_context_bb = bb;
+
+ /* If we are in loop-closed SSA preserve this state. This is
+ relevant when called on regions from outside of FRE/PRE. */
+ bool lc_phi_nodes = false;
+ if (!skip_phis
+ && loops_state_satisfies_p (LOOP_CLOSED_SSA))
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (e->src->loop_father != e->dest->loop_father
+ && flow_loop_nested_p (e->dest->loop_father,
+ e->src->loop_father))
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Replaced redundant PHI node defining ");
- print_generic_expr (dump_file, res);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, "\n");
- }
-
- /* If we inserted this PHI node ourself, it's not an elimination. */
- if (! inserted_exprs
- || ! bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (res)))
- eliminations++;
-
- /* If we will propagate into all uses don't bother to do
- anything. */
- if (may_propagate_copy (res, sprime))
- {
- /* Mark the PHI for removal. */
- to_remove.safe_push (phi);
- gsi_next (&gsi);
- continue;
- }
-
- remove_phi_node (&gsi, false);
-
- if (!useless_type_conversion_p (TREE_TYPE (res), TREE_TYPE (sprime)))
- sprime = fold_convert (TREE_TYPE (res), sprime);
- gimple *stmt = gimple_build_assign (res, sprime);
- gimple_stmt_iterator gsi2 = gsi_after_labels (b);
- gsi_insert_before (&gsi2, stmt, GSI_NEW_STMT);
- continue;
+ lc_phi_nodes = true;
+ break;
}
- eliminate_push_avail (res);
- gsi_next (&gsi);
- }
-
- for (gimple_stmt_iterator gsi = gsi_start_bb (b);
- !gsi_end_p (gsi);
- gsi_next (&gsi))
+ /* When we visit a loop header substitute into loop info. */
+ if (!iterate && eliminate && bb->loop_father->header == bb)
{
- tree sprime = NULL_TREE;
- gimple *stmt = gsi_stmt (gsi);
- tree lhs = gimple_get_lhs (stmt);
- if (lhs && TREE_CODE (lhs) == SSA_NAME
- && !gimple_has_volatile_ops (stmt)
- /* See PR43491. Do not replace a global register variable when
- it is a the RHS of an assignment. Do replace local register
- variables since gcc does not guarantee a local variable will
- be allocated in register.
- ??? The fix isn't effective here. This should instead
- be ensured by not value-numbering them the same but treating
- them like volatiles? */
- && !(gimple_assign_single_p (stmt)
- && (TREE_CODE (gimple_assign_rhs1 (stmt)) == VAR_DECL
- && DECL_HARD_REGISTER (gimple_assign_rhs1 (stmt))
- && is_global_var (gimple_assign_rhs1 (stmt)))))
- {
- sprime = eliminate_avail (lhs);
- if (!sprime)
- {
- /* If there is no existing usable leader but SCCVN thinks
- it has an expression it wants to use as replacement,
- insert that. */
- tree val = VN_INFO (lhs)->valnum;
- if (val != VN_TOP
- && TREE_CODE (val) == SSA_NAME
- && VN_INFO (val)->needs_insertion
- && VN_INFO (val)->expr != NULL
- && (sprime = eliminate_insert (&gsi, val)) != NULL_TREE)
- eliminate_push_avail (sprime);
- }
-
- /* If this now constitutes a copy duplicate points-to
- and range info appropriately. This is especially
- important for inserted code. See tree-ssa-copy.c
- for similar code. */
- if (sprime
- && TREE_CODE (sprime) == SSA_NAME)
- {
- basic_block sprime_b = gimple_bb (SSA_NAME_DEF_STMT (sprime));
- if (POINTER_TYPE_P (TREE_TYPE (lhs))
- && VN_INFO_PTR_INFO (lhs)
- && ! VN_INFO_PTR_INFO (sprime))
- {
- duplicate_ssa_name_ptr_info (sprime,
- VN_INFO_PTR_INFO (lhs));
- if (b != sprime_b)
- mark_ptr_info_alignment_unknown
- (SSA_NAME_PTR_INFO (sprime));
- }
- else if (INTEGRAL_TYPE_P (TREE_TYPE (lhs))
- && VN_INFO_RANGE_INFO (lhs)
- && ! VN_INFO_RANGE_INFO (sprime)
- && b == sprime_b)
- duplicate_ssa_name_range_info (sprime,
- VN_INFO_RANGE_TYPE (lhs),
- VN_INFO_RANGE_INFO (lhs));
- }
-
- /* Inhibit the use of an inserted PHI on a loop header when
- the address of the memory reference is a simple induction
- variable. In other cases the vectorizer won't do anything
- anyway (either it's loop invariant or a complicated
- expression). */
- if (sprime
- && TREE_CODE (sprime) == SSA_NAME
- && do_pre
- && (flag_tree_loop_vectorize || flag_tree_parallelize_loops > 1)
- && loop_outer (b->loop_father)
- && has_zero_uses (sprime)
- && bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))
- && gimple_assign_load_p (stmt))
- {
- gimple *def_stmt = SSA_NAME_DEF_STMT (sprime);
- basic_block def_bb = gimple_bb (def_stmt);
- if (gimple_code (def_stmt) == GIMPLE_PHI
- && def_bb->loop_father->header == def_bb)
- {
- loop_p loop = def_bb->loop_father;
- ssa_op_iter iter;
- tree op;
- bool found = false;
- FOR_EACH_SSA_TREE_OPERAND (op, stmt, iter, SSA_OP_USE)
- {
- affine_iv iv;
- def_bb = gimple_bb (SSA_NAME_DEF_STMT (op));
- if (def_bb
- && flow_bb_inside_loop_p (loop, def_bb)
- && simple_iv (loop, loop, op, &iv, true))
- {
- found = true;
- break;
- }
- }
- if (found)
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Not replacing ");
- print_gimple_expr (dump_file, stmt, 0);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, " which would add a loop"
- " carried dependence to loop %d\n",
- loop->num);
- }
- /* Don't keep sprime available. */
- sprime = NULL_TREE;
- }
- }
- }
-
- if (sprime)
- {
- /* If we can propagate the value computed for LHS into
- all uses don't bother doing anything with this stmt. */
- if (may_propagate_copy (lhs, sprime))
- {
- /* Mark it for removal. */
- to_remove.safe_push (stmt);
-
- /* ??? Don't count copy/constant propagations. */
- if (gimple_assign_single_p (stmt)
- && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
- || gimple_assign_rhs1 (stmt) == sprime))
- continue;
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Replaced ");
- print_gimple_expr (dump_file, stmt, 0);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, " in all uses of ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
-
- eliminations++;
- continue;
- }
-
- /* If this is an assignment from our leader (which
- happens in the case the value-number is a constant)
- then there is nothing to do. */
- if (gimple_assign_single_p (stmt)
- && sprime == gimple_assign_rhs1 (stmt))
- continue;
-
- /* Else replace its RHS. */
- bool can_make_abnormal_goto
- = is_gimple_call (stmt)
- && stmt_can_make_abnormal_goto (stmt);
-
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Replaced ");
- print_gimple_expr (dump_file, stmt, 0);
- fprintf (dump_file, " with ");
- print_generic_expr (dump_file, sprime);
- fprintf (dump_file, " in ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
+ /* Keep fields in sync with substitute_in_loop_info. */
+ if (bb->loop_father->nb_iterations)
+ bb->loop_father->nb_iterations
+ = simplify_replace_tree (bb->loop_father->nb_iterations,
+ NULL_TREE, NULL_TREE, vn_valueize);
+ }
- eliminations++;
- gimple *orig_stmt = stmt;
- if (!useless_type_conversion_p (TREE_TYPE (lhs),
- TREE_TYPE (sprime)))
- sprime = fold_convert (TREE_TYPE (lhs), sprime);
- tree vdef = gimple_vdef (stmt);
- tree vuse = gimple_vuse (stmt);
- propagate_tree_value_into_stmt (&gsi, sprime);
- stmt = gsi_stmt (gsi);
- update_stmt (stmt);
- if (vdef != gimple_vdef (stmt))
- VN_INFO (vdef)->valnum = vuse;
-
- /* If we removed EH side-effects from the statement, clean
- its EH information. */
- if (maybe_clean_or_replace_eh_stmt (orig_stmt, stmt))
- {
- bitmap_set_bit (need_eh_cleanup,
- gimple_bb (stmt)->index);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed EH side-effects.\n");
- }
+ /* Value-number all defs in the basic-block. */
+ if (!skip_phis)
+ for (gphi_iterator gsi = gsi_start_phis (bb); !gsi_end_p (gsi);
+ gsi_next (&gsi))
+ {
+ gphi *phi = gsi.phi ();
+ tree res = PHI_RESULT (phi);
+ vn_ssa_aux_t res_info = VN_INFO (res);
+ if (!bb_visited)
+ {
+ gcc_assert (!res_info->visited);
+ res_info->valnum = VN_TOP;
+ res_info->visited = true;
+ }
- /* Likewise for AB side-effects. */
- if (can_make_abnormal_goto
- && !stmt_can_make_abnormal_goto (stmt))
- {
- bitmap_set_bit (need_ab_cleanup,
- gimple_bb (stmt)->index);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed AB side-effects.\n");
- }
+ /* When not iterating force backedge values to varying. */
+ visit_stmt (phi, !iterate_phis);
+ if (virtual_operand_p (res))
+ continue;
- continue;
- }
- }
+ /* Eliminate */
+ /* The interesting case is gcc.dg/tree-ssa/pr22230.c for correctness
+ how we handle backedges and availability.
+ And gcc.dg/tree-ssa/ssa-sccvn-2.c for optimization. */
+ tree val = res_info->valnum;
+ if (res != val && !iterate && eliminate)
+ {
+ if (tree leader = avail.eliminate_avail (bb, res))
+ {
+ if (leader != res
+ /* Preserve loop-closed SSA form. */
+ && (! lc_phi_nodes
+ || is_gimple_min_invariant (leader)))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Replaced redundant PHI node "
+ "defining ");
+ print_generic_expr (dump_file, res);
+ fprintf (dump_file, " with ");
+ print_generic_expr (dump_file, leader);
+ fprintf (dump_file, "\n");
+ }
+ avail.eliminations++;
+
+ if (may_propagate_copy (res, leader))
+ {
+ /* Schedule for removal. */
+ avail.to_remove.safe_push (phi);
+ continue;
+ }
+ /* ??? Else generate a copy stmt. */
+ }
+ }
+ }
+ /* Only make defs available that not already are. But make
+ sure loop-closed SSA PHI node defs are picked up for
+ downstream uses. */
+ if (lc_phi_nodes
+ || res == val
+ || ! avail.eliminate_avail (bb, res))
+ avail.eliminate_push_avail (bb, res);
+ }
- /* If the statement is a scalar store, see if the expression
- has the same value number as its rhs. If so, the store is
- dead. */
- if (gimple_assign_single_p (stmt)
- && !gimple_has_volatile_ops (stmt)
- && !is_gimple_reg (gimple_assign_lhs (stmt))
- && (TREE_CODE (gimple_assign_rhs1 (stmt)) == SSA_NAME
- || is_gimple_min_invariant (gimple_assign_rhs1 (stmt))))
+ /* For empty BBs mark outgoing edges executable. For non-empty BBs
+ we do this when processing the last stmt as we have to do this
+ before elimination which otherwise forces GIMPLE_CONDs to
+ if (1 != 0) style when seeing non-executable edges. */
+ if (gsi_end_p (gsi_start_bb (bb)))
+ {
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
- tree val;
- tree rhs = gimple_assign_rhs1 (stmt);
- vn_reference_t vnresult;
- val = vn_reference_lookup (lhs, gimple_vuse (stmt), VN_WALKREWRITE,
- &vnresult, false);
- if (TREE_CODE (rhs) == SSA_NAME)
- rhs = VN_INFO (rhs)->valnum;
- if (val
- && operand_equal_p (val, rhs, 0))
+ if (!(e->flags & EDGE_EXECUTABLE))
{
- /* We can only remove the later store if the former aliases
- at least all accesses the later one does or if the store
- was to readonly memory storing the same value. */
- alias_set_type set = get_alias_set (lhs);
- if (! vnresult
- || vnresult->set == set
- || alias_set_subset_of (set, vnresult->set))
- {
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Deleted redundant store ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
-
- /* Queue stmt for removal. */
- to_remove.safe_push (stmt);
- continue;
- }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking outgoing edge %d -> %d executable\n",
+ e->src->index, e->dest->index);
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
}
- }
-
- /* If this is a control statement value numbering left edges
- unexecuted on force the condition in a way consistent with
- that. */
- if (gcond *cond = dyn_cast <gcond *> (stmt))
- {
- if ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE)
- ^ (EDGE_SUCC (b, 1)->flags & EDGE_EXECUTABLE))
+ else if (!(e->dest->flags & BB_EXECUTABLE))
{
- if (dump_file && (dump_flags & TDF_DETAILS))
- {
- fprintf (dump_file, "Removing unexecutable edge from ");
- print_gimple_stmt (dump_file, stmt, 0);
- }
- if (((EDGE_SUCC (b, 0)->flags & EDGE_TRUE_VALUE) != 0)
- == ((EDGE_SUCC (b, 0)->flags & EDGE_EXECUTABLE) != 0))
- gimple_cond_make_true (cond);
- else
- gimple_cond_make_false (cond);
- update_stmt (cond);
- el_todo |= TODO_cleanup_cfg;
- continue;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking destination block %d reachable\n",
+ e->dest->index);
+ e->dest->flags |= BB_EXECUTABLE;
}
}
-
- bool can_make_abnormal_goto = stmt_can_make_abnormal_goto (stmt);
- bool was_noreturn = (is_gimple_call (stmt)
- && gimple_call_noreturn_p (stmt));
- tree vdef = gimple_vdef (stmt);
- tree vuse = gimple_vuse (stmt);
-
- /* If we didn't replace the whole stmt (or propagate the result
- into all uses), replace all uses on this stmt with their
- leaders. */
- bool modified = false;
- use_operand_p use_p;
- ssa_op_iter iter;
- FOR_EACH_SSA_USE_OPERAND (use_p, stmt, iter, SSA_OP_USE)
+ }
+ for (gimple_stmt_iterator gsi = gsi_start_bb (bb);
+ !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ ssa_op_iter i;
+ tree op;
+ if (!bb_visited)
{
- tree use = USE_FROM_PTR (use_p);
- /* ??? The call code above leaves stmt operands un-updated. */
- if (TREE_CODE (use) != SSA_NAME)
- continue;
- tree sprime = eliminate_avail (use);
- if (sprime && sprime != use
- && may_propagate_copy (use, sprime)
- /* We substitute into debug stmts to avoid excessive
- debug temporaries created by removed stmts, but we need
- to avoid doing so for inserted sprimes as we never want
- to create debug temporaries for them. */
- && (!inserted_exprs
- || TREE_CODE (sprime) != SSA_NAME
- || !is_gimple_debug (stmt)
- || !bitmap_bit_p (inserted_exprs, SSA_NAME_VERSION (sprime))))
+ FOR_EACH_SSA_TREE_OPERAND (op, gsi_stmt (gsi), i, SSA_OP_ALL_DEFS)
{
- propagate_value (use_p, sprime);
- modified = true;
+ vn_ssa_aux_t op_info = VN_INFO (op);
+ gcc_assert (!op_info->visited);
+ op_info->valnum = VN_TOP;
+ op_info->visited = true;
}
+
+ /* We somehow have to deal with uses that are not defined
+ in the processed region. Forcing unvisited uses to
+ varying here doesn't play well with def-use following during
+ expression simplification, so we deal with this by checking
+ the visited flag in SSA_VAL. */
}
- /* Fold the stmt if modified, this canonicalizes MEM_REFs we propagated
- into which is a requirement for the IPA devirt machinery. */
- gimple *old_stmt = stmt;
- if (modified)
+ visit_stmt (gsi_stmt (gsi));
+
+ gimple *last = gsi_stmt (gsi);
+ e = NULL;
+ switch (gimple_code (last))
{
- /* If a formerly non-invariant ADDR_EXPR is turned into an
- invariant one it was on a separate stmt. */
- if (gimple_assign_single_p (stmt)
- && TREE_CODE (gimple_assign_rhs1 (stmt)) == ADDR_EXPR)
- recompute_tree_invariant_for_addr_expr (gimple_assign_rhs1 (stmt));
- gimple_stmt_iterator prev = gsi;
- gsi_prev (&prev);
- if (fold_stmt (&gsi))
- {
- /* fold_stmt may have created new stmts inbetween
- the previous stmt and the folded stmt. Mark
- all defs created there as varying to not confuse
- the SCCVN machinery as we're using that even during
- elimination. */
- if (gsi_end_p (prev))
- prev = gsi_start_bb (b);
- else
- gsi_next (&prev);
- if (gsi_stmt (prev) != gsi_stmt (gsi))
- do
+ case GIMPLE_SWITCH:
+ e = find_taken_edge (bb, vn_valueize (gimple_switch_index
+ (as_a <gswitch *> (last))));
+ break;
+ case GIMPLE_COND:
+ {
+ tree lhs = vn_valueize (gimple_cond_lhs (last));
+ tree rhs = vn_valueize (gimple_cond_rhs (last));
+ tree val = gimple_simplify (gimple_cond_code (last),
+ boolean_type_node, lhs, rhs,
+ NULL, vn_valueize);
+ /* If the condition didn't simplfy see if we have recorded
+ an expression from sofar taken edges. */
+ if (! val || TREE_CODE (val) != INTEGER_CST)
+ {
+ vn_nary_op_t vnresult;
+ tree ops[2];
+ ops[0] = lhs;
+ ops[1] = rhs;
+ val = vn_nary_op_lookup_pieces (2, gimple_cond_code (last),
+ boolean_type_node, ops,
+ &vnresult);
+ /* Did we get a predicated value? */
+ if (! val && vnresult && vnresult->predicated_values)
{
- tree def;
- ssa_op_iter dit;
- FOR_EACH_SSA_TREE_OPERAND (def, gsi_stmt (prev),
- dit, SSA_OP_ALL_DEFS)
- /* As existing DEFs may move between stmts
- we have to guard VN_INFO_GET. */
- if (! has_VN_INFO (def))
- VN_INFO_GET (def)->valnum = def;
- if (gsi_stmt (prev) == gsi_stmt (gsi))
- break;
- gsi_next (&prev);
+ val = vn_nary_op_get_predicated_value (vnresult, bb);
+ if (val && dump_file && (dump_flags & TDF_DETAILS))
+ {
+ fprintf (dump_file, "Got predicated value ");
+ print_generic_expr (dump_file, val, TDF_NONE);
+ fprintf (dump_file, " for ");
+ print_gimple_stmt (dump_file, last, TDF_SLIM);
+ }
}
- while (1);
- }
- stmt = gsi_stmt (gsi);
- /* In case we folded the stmt away schedule the NOP for removal. */
- if (gimple_nop_p (stmt))
- to_remove.safe_push (stmt);
+ }
+ if (val)
+ e = find_taken_edge (bb, val);
+ if (! e)
+ {
+ /* If we didn't manage to compute the taken edge then
+ push predicated expressions for the condition itself
+ and related conditions to the hashtables. This allows
+ simplification of redundant conditions which is
+ important as early cleanup. */
+ edge true_e, false_e;
+ extract_true_false_edges_from_block (bb, &true_e, &false_e);
+ enum tree_code code = gimple_cond_code (last);
+ enum tree_code icode
+ = invert_tree_comparison (code, HONOR_NANS (lhs));
+ tree ops[2];
+ ops[0] = lhs;
+ ops[1] = rhs;
+ if (do_region
+ && bitmap_bit_p (exit_bbs, true_e->dest->index))
+ true_e = NULL;
+ if (do_region
+ && bitmap_bit_p (exit_bbs, false_e->dest->index))
+ false_e = NULL;
+ if (true_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, code, boolean_type_node, ops,
+ boolean_true_node, 0, true_e);
+ if (false_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, code, boolean_type_node, ops,
+ boolean_false_node, 0, false_e);
+ if (icode != ERROR_MARK)
+ {
+ if (true_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, icode, boolean_type_node, ops,
+ boolean_false_node, 0, true_e);
+ if (false_e)
+ vn_nary_op_insert_pieces_predicated
+ (2, icode, boolean_type_node, ops,
+ boolean_true_node, 0, false_e);
+ }
+ /* Relax for non-integers, inverted condition handled
+ above. */
+ if (INTEGRAL_TYPE_P (TREE_TYPE (lhs)))
+ {
+ if (true_e)
+ insert_related_predicates_on_edge (code, ops, true_e);
+ if (false_e)
+ insert_related_predicates_on_edge (icode, ops, false_e);
+ }
+ }
+ break;
+ }
+ case GIMPLE_GOTO:
+ e = find_taken_edge (bb, vn_valueize (gimple_goto_dest (last)));
+ break;
+ default:
+ e = NULL;
}
-
- /* Visit indirect calls and turn them into direct calls if
- possible using the devirtualization machinery. Do this before
- checking for required EH/abnormal/noreturn cleanup as devird
- may expose more of those. */
- if (gcall *call_stmt = dyn_cast <gcall *> (stmt))
+ if (e)
{
- tree fn = gimple_call_fn (call_stmt);
- if (fn
- && flag_devirtualize
- && virtual_method_call_p (fn))
+ todo = TODO_cleanup_cfg;
+ if (!(e->flags & EDGE_EXECUTABLE))
{
- tree otr_type = obj_type_ref_class (fn);
- unsigned HOST_WIDE_INT otr_tok
- = tree_to_uhwi (OBJ_TYPE_REF_TOKEN (fn));
- tree instance;
- ipa_polymorphic_call_context context (current_function_decl,
- fn, stmt, &instance);
- context.get_dynamic_type (instance, OBJ_TYPE_REF_OBJECT (fn),
- otr_type, stmt);
- bool final;
- vec <cgraph_node *> targets
- = possible_polymorphic_call_targets (obj_type_ref_class (fn),
- otr_tok, context, &final);
- if (dump_file)
- dump_possible_polymorphic_call_targets (dump_file,
- obj_type_ref_class (fn),
- otr_tok, context);
- if (final && targets.length () <= 1 && dbg_cnt (devirt))
- {
- tree fn;
- if (targets.length () == 1)
- fn = targets[0]->decl;
- else
- fn = builtin_decl_implicit (BUILT_IN_UNREACHABLE);
- if (dump_enabled_p ())
- {
- dump_printf_loc (MSG_OPTIMIZED_LOCATIONS, stmt,
- "converting indirect call to "
- "function %s\n",
- lang_hooks.decl_printable_name (fn, 2));
- }
- gimple_call_set_fndecl (call_stmt, fn);
- /* If changing the call to __builtin_unreachable
- or similar noreturn function, adjust gimple_call_fntype
- too. */
- if (gimple_call_noreturn_p (call_stmt)
- && VOID_TYPE_P (TREE_TYPE (TREE_TYPE (fn)))
- && TYPE_ARG_TYPES (TREE_TYPE (fn))
- && (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (fn)))
- == void_type_node))
- gimple_call_set_fntype (call_stmt, TREE_TYPE (fn));
- maybe_remove_unused_call_args (cfun, call_stmt);
- modified = true;
- }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking known outgoing %sedge %d -> %d executable\n",
+ e->flags & EDGE_DFS_BACK ? "back-" : "",
+ e->src->index, e->dest->index);
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
}
- }
-
- if (modified)
- {
- /* When changing a call into a noreturn call, cfg cleanup
- is needed to fix up the noreturn call. */
- if (!was_noreturn
- && is_gimple_call (stmt) && gimple_call_noreturn_p (stmt))
- to_fixup.safe_push (stmt);
- /* When changing a condition or switch into one we know what
- edge will be executed, schedule a cfg cleanup. */
- if ((gimple_code (stmt) == GIMPLE_COND
- && (gimple_cond_true_p (as_a <gcond *> (stmt))
- || gimple_cond_false_p (as_a <gcond *> (stmt))))
- || (gimple_code (stmt) == GIMPLE_SWITCH
- && TREE_CODE (gimple_switch_index
- (as_a <gswitch *> (stmt))) == INTEGER_CST))
- el_todo |= TODO_cleanup_cfg;
- /* If we removed EH side-effects from the statement, clean
- its EH information. */
- if (maybe_clean_or_replace_eh_stmt (old_stmt, stmt))
+ else if (!(e->dest->flags & BB_EXECUTABLE))
{
- bitmap_set_bit (need_eh_cleanup,
- gimple_bb (stmt)->index);
if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed EH side-effects.\n");
+ fprintf (dump_file,
+ "marking destination block %d reachable\n",
+ e->dest->index);
+ e->dest->flags |= BB_EXECUTABLE;
}
- /* Likewise for AB side-effects. */
- if (can_make_abnormal_goto
- && !stmt_can_make_abnormal_goto (stmt))
+ }
+ else if (gsi_one_before_end_p (gsi))
+ {
+ FOR_EACH_EDGE (e, ei, bb->succs)
{
- bitmap_set_bit (need_ab_cleanup,
- gimple_bb (stmt)->index);
- if (dump_file && (dump_flags & TDF_DETAILS))
- fprintf (dump_file, " Removed AB side-effects.\n");
+ if (!(e->flags & EDGE_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking outgoing edge %d -> %d executable\n",
+ e->src->index, e->dest->index);
+ e->flags |= EDGE_EXECUTABLE;
+ e->dest->flags |= BB_EXECUTABLE;
+ }
+ else if (!(e->dest->flags & BB_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file,
+ "marking destination block %d reachable\n",
+ e->dest->index);
+ e->dest->flags |= BB_EXECUTABLE;
+ }
}
- update_stmt (stmt);
- if (vdef != gimple_vdef (stmt))
- VN_INFO (vdef)->valnum = vuse;
}
- /* Make new values available - for fully redundant LHS we
- continue with the next stmt above and skip this. */
- def_operand_p defp;
- FOR_EACH_SSA_DEF_OPERAND (defp, stmt, iter, SSA_OP_DEF)
- eliminate_push_avail (DEF_FROM_PTR (defp));
+ /* Eliminate. That also pushes to avail. */
+ if (eliminate && ! iterate)
+ avail.eliminate_stmt (bb, &gsi);
+ else
+ /* If not eliminating, make all not already available defs
+ available. */
+ FOR_EACH_SSA_TREE_OPERAND (op, gsi_stmt (gsi), i, SSA_OP_DEF)
+ if (! avail.eliminate_avail (bb, op))
+ avail.eliminate_push_avail (bb, op);
}
- /* Replace destination PHI arguments. */
- FOR_EACH_EDGE (e, ei, b->succs)
- if (e->flags & EDGE_EXECUTABLE)
+ /* Eliminate in destination PHI arguments. Always substitute in dest
+ PHIs, even for non-executable edges. This handles region
+ exits PHIs. */
+ if (!iterate && eliminate)
+ FOR_EACH_EDGE (e, ei, bb->succs)
for (gphi_iterator gsi = gsi_start_phis (e->dest);
- !gsi_end_p (gsi);
- gsi_next (&gsi))
+ !gsi_end_p (gsi); gsi_next (&gsi))
{
gphi *phi = gsi.phi ();
use_operand_p use_p = PHI_ARG_DEF_PTR_FROM_EDGE (phi, e);
if (TREE_CODE (arg) != SSA_NAME
|| virtual_operand_p (arg))
continue;
- tree sprime = eliminate_avail (arg);
- if (sprime && may_propagate_copy (arg, sprime))
+ tree sprime;
+ if (SSA_NAME_IS_DEFAULT_DEF (arg))
+ {
+ sprime = SSA_VAL (arg);
+ gcc_assert (TREE_CODE (sprime) != SSA_NAME
+ || SSA_NAME_IS_DEFAULT_DEF (sprime));
+ }
+ else
+ /* Look for sth available at the definition block of the argument.
+ This avoids inconsistencies between availability there which
+ decides if the stmt can be removed and availability at the
+ use site. The SSA property ensures that things available
+ at the definition are also available at uses. */
+ sprime = avail.eliminate_avail (gimple_bb (SSA_NAME_DEF_STMT (arg)),
+ arg);
+ if (sprime
+ && sprime != arg
+ && may_propagate_copy (arg, sprime))
propagate_value (use_p, sprime);
}
- return NULL;
+
+ vn_context_bb = NULL;
+ return todo;
}
-/* Make no longer available leaders no longer available. */
+/* Unwind state per basic-block. */
-void
-eliminate_dom_walker::after_dom_children (basic_block)
+struct unwind_state
{
- tree entry;
- while ((entry = avail_stack.pop ()) != NULL_TREE)
+ /* Times this block has been visited. */
+ unsigned visited;
+ /* Whether to handle this as iteration point or whether to treat
+ incoming backedge PHI values as varying. */
+ bool iterate;
+ /* Maximum RPO index this block is reachable from. */
+ int max_rpo;
+ /* Unwind state. */
+ void *ob_top;
+ vn_reference_t ref_top;
+ vn_phi_t phi_top;
+ vn_nary_op_t nary_top;
+};
+
+/* Unwind the RPO VN state for iteration. */
+
+static void
+do_unwind (unwind_state *to, int rpo_idx, rpo_elim &avail, int *bb_to_rpo)
+{
+ gcc_assert (to->iterate);
+ for (; last_inserted_nary != to->nary_top;
+ last_inserted_nary = last_inserted_nary->next)
{
- tree valnum = VN_INFO (entry)->valnum;
- tree old = avail[SSA_NAME_VERSION (valnum)];
- if (old == entry)
- avail[SSA_NAME_VERSION (valnum)] = NULL_TREE;
+ vn_nary_op_t *slot;
+ slot = valid_info->nary->find_slot_with_hash
+ (last_inserted_nary, last_inserted_nary->hashcode, NO_INSERT);
+ /* Predication causes the need to restore previous state. */
+ if ((*slot)->unwind_to)
+ *slot = (*slot)->unwind_to;
else
- avail[SSA_NAME_VERSION (valnum)] = entry;
+ valid_info->nary->clear_slot (slot);
+ }
+ for (; last_inserted_phi != to->phi_top;
+ last_inserted_phi = last_inserted_phi->next)
+ {
+ vn_phi_t *slot;
+ slot = valid_info->phis->find_slot_with_hash
+ (last_inserted_phi, last_inserted_phi->hashcode, NO_INSERT);
+ valid_info->phis->clear_slot (slot);
+ }
+ for (; last_inserted_ref != to->ref_top;
+ last_inserted_ref = last_inserted_ref->next)
+ {
+ vn_reference_t *slot;
+ slot = valid_info->references->find_slot_with_hash
+ (last_inserted_ref, last_inserted_ref->hashcode, NO_INSERT);
+ (*slot)->operands.release ();
+ valid_info->references->clear_slot (slot);
+ }
+ obstack_free (&vn_tables_obstack, to->ob_top);
+
+ /* Prune [rpo_idx, ] from avail. */
+ /* ??? This is O(number-of-values-in-region) which is
+ O(region-size) rather than O(iteration-piece). */
+ for (hash_table<vn_ssa_aux_hasher>::iterator i = vn_ssa_aux_hash->begin ();
+ i != vn_ssa_aux_hash->end (); ++i)
+ {
+ while ((*i)->avail)
+ {
+ if (bb_to_rpo[(*i)->avail->location] < rpo_idx)
+ break;
+ vn_avail *av = (*i)->avail;
+ (*i)->avail = (*i)->avail->next;
+ av->next = avail.m_avail_freelist;
+ avail.m_avail_freelist = av;
+ }
}
}
-/* Eliminate fully redundant computations. */
+/* Do VN on a SEME region specified by ENTRY and EXIT_BBS in FN.
+ If ITERATE is true then treat backedges optimistically as not
+ executed and iterate. If ELIMINATE is true then perform
+ elimination, otherwise leave that to the caller. */
-unsigned int
-vn_eliminate (bitmap inserted_exprs)
+static unsigned
+do_rpo_vn (function *fn, edge entry, bitmap exit_bbs,
+ bool iterate, bool eliminate)
{
- eliminate_dom_walker el (CDI_DOMINATORS, inserted_exprs);
- el.avail.reserve (num_ssa_names);
+ unsigned todo = 0;
- el.walk (cfun->cfg->x_entry_block_ptr);
+ /* We currently do not support region-based iteration when
+ elimination is requested. */
+ gcc_assert (!entry || !iterate || !eliminate);
+ /* When iterating we need loop info up-to-date. */
+ gcc_assert (!iterate || !loops_state_satisfies_p (LOOPS_NEED_FIXUP));
- /* We cannot remove stmts during BB walk, especially not release SSA
- names there as this confuses the VN machinery. The stmts ending
- up in to_remove are either stores or simple copies.
- Remove stmts in reverse order to make debug stmt creation possible. */
- while (!el.to_remove.is_empty ())
+ bool do_region = entry != NULL;
+ if (!do_region)
{
- gimple *stmt = el.to_remove.pop ();
+ entry = single_succ_edge (ENTRY_BLOCK_PTR_FOR_FN (fn));
+ exit_bbs = BITMAP_ALLOC (NULL);
+ bitmap_set_bit (exit_bbs, EXIT_BLOCK);
+ }
- if (dump_file && (dump_flags & TDF_DETAILS))
+ /* Clear EDGE_DFS_BACK on "all" entry edges, RPO order compute will
+ re-mark those that are contained in the region. */
+ edge_iterator ei;
+ edge e;
+ FOR_EACH_EDGE (e, ei, entry->dest->preds)
+ e->flags &= ~EDGE_DFS_BACK;
+
+ int *rpo = XNEWVEC (int, n_basic_blocks_for_fn (fn) - NUM_FIXED_BLOCKS);
+ int n = rev_post_order_and_mark_dfs_back_seme
+ (fn, entry, exit_bbs, !loops_state_satisfies_p (LOOPS_NEED_FIXUP), rpo);
+ /* rev_post_order_and_mark_dfs_back_seme fills RPO in reverse order. */
+ for (int i = 0; i < n / 2; ++i)
+ std::swap (rpo[i], rpo[n-i-1]);
+
+ if (!do_region)
+ BITMAP_FREE (exit_bbs);
+
+ /* If there are any non-DFS_BACK edges into entry->dest skip
+ processing PHI nodes for that block. This supports
+ value-numbering loop bodies w/o the actual loop. */
+ FOR_EACH_EDGE (e, ei, entry->dest->preds)
+ if (e != entry
+ && !(e->flags & EDGE_DFS_BACK))
+ break;
+ bool skip_entry_phis = e != NULL;
+ if (skip_entry_phis && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Region does not contain all edges into "
+ "the entry block, skipping its PHIs.\n");
+
+ int *bb_to_rpo = XNEWVEC (int, last_basic_block_for_fn (fn));
+ for (int i = 0; i < n; ++i)
+ bb_to_rpo[rpo[i]] = i;
+
+ unwind_state *rpo_state = XNEWVEC (unwind_state, n);
+
+ rpo_elim avail (entry->dest);
+ rpo_avail = &avail;
+
+ /* Verify we have no extra entries into the region. */
+ if (flag_checking && do_region)
+ {
+ auto_bb_flag bb_in_region (fn);
+ for (int i = 0; i < n; ++i)
{
- fprintf (dump_file, "Removing dead stmt ");
- print_gimple_stmt (dump_file, stmt, 0, TDF_NONE);
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ bb->flags |= bb_in_region;
}
-
- gimple_stmt_iterator gsi = gsi_for_stmt (stmt);
- if (gimple_code (stmt) == GIMPLE_PHI)
- remove_phi_node (&gsi, true);
- else
+ /* We can't merge the first two loops because we cannot rely
+ on EDGE_DFS_BACK for edges not within the region. But if
+ we decide to always have the bb_in_region flag we can
+ do the checking during the RPO walk itself (but then it's
+ also easy to handle MEME conservatively). */
+ for (int i = 0; i < n; ++i)
{
- basic_block bb = gimple_bb (stmt);
- unlink_stmt_vdef (stmt);
- if (gsi_remove (&gsi, true))
- bitmap_set_bit (el.need_eh_cleanup, bb->index);
- if (is_gimple_call (stmt) && stmt_can_make_abnormal_goto (stmt))
- bitmap_set_bit (el.need_ab_cleanup, bb->index);
- release_defs (stmt);
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ gcc_assert (e == entry
+ || (skip_entry_phis && bb == entry->dest)
+ || (e->src->flags & bb_in_region));
}
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ bb->flags &= ~bb_in_region;
+ }
+ }
- /* Removing a stmt may expose a forwarder block. */
- el.el_todo |= TODO_cleanup_cfg;
+ /* Create the VN state. For the initial size of the various hashtables
+ use a heuristic based on region size and number of SSA names. */
+ unsigned region_size = (((unsigned HOST_WIDE_INT)n * num_ssa_names)
+ / (n_basic_blocks_for_fn (fn) - NUM_FIXED_BLOCKS));
+ VN_TOP = create_tmp_var_raw (void_type_node, "vn_top");
+ next_value_id = 1;
+
+ vn_ssa_aux_hash = new hash_table <vn_ssa_aux_hasher> (region_size * 2);
+ gcc_obstack_init (&vn_ssa_aux_obstack);
+
+ gcc_obstack_init (&vn_tables_obstack);
+ gcc_obstack_init (&vn_tables_insert_obstack);
+ valid_info = XCNEW (struct vn_tables_s);
+ allocate_vn_table (valid_info, region_size);
+ last_inserted_ref = NULL;
+ last_inserted_phi = NULL;
+ last_inserted_nary = NULL;
+
+ vn_valueize = rpo_vn_valueize;
+
+ /* Initialize the unwind state and edge/BB executable state. */
+ bool need_max_rpo_iterate = false;
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ rpo_state[i].visited = 0;
+ rpo_state[i].max_rpo = i;
+ bb->flags &= ~BB_EXECUTABLE;
+ bool has_backedges = false;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ if (e->flags & EDGE_DFS_BACK)
+ has_backedges = true;
+ e->flags &= ~EDGE_EXECUTABLE;
+ if (iterate || e == entry || (skip_entry_phis && bb == entry->dest))
+ continue;
+ if (bb_to_rpo[e->src->index] > i)
+ {
+ rpo_state[i].max_rpo = MAX (rpo_state[i].max_rpo,
+ bb_to_rpo[e->src->index]);
+ need_max_rpo_iterate = true;
+ }
+ else
+ rpo_state[i].max_rpo
+ = MAX (rpo_state[i].max_rpo,
+ rpo_state[bb_to_rpo[e->src->index]].max_rpo);
+ }
+ rpo_state[i].iterate = iterate && has_backedges;
+ }
+ entry->flags |= EDGE_EXECUTABLE;
+ entry->dest->flags |= BB_EXECUTABLE;
+
+ /* When there are irreducible regions the simplistic max_rpo computation
+ above for the case of backedges doesn't work and we need to iterate
+ until there are no more changes. */
+ unsigned nit = 0;
+ while (need_max_rpo_iterate)
+ {
+ nit++;
+ need_max_rpo_iterate = false;
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ {
+ if (e == entry || (skip_entry_phis && bb == entry->dest))
+ continue;
+ int max_rpo = MAX (rpo_state[i].max_rpo,
+ rpo_state[bb_to_rpo[e->src->index]].max_rpo);
+ if (rpo_state[i].max_rpo != max_rpo)
+ {
+ rpo_state[i].max_rpo = max_rpo;
+ need_max_rpo_iterate = true;
+ }
+ }
+ }
}
+ statistics_histogram_event (cfun, "RPO max_rpo iterations", nit);
- /* Fixup stmts that became noreturn calls. This may require splitting
- blocks and thus isn't possible during the dominator walk. Do this
- in reverse order so we don't inadvertedly remove a stmt we want to
- fixup by visiting a dominating now noreturn call first. */
- while (!el.to_fixup.is_empty ())
+ /* As heuristic to improve compile-time we handle only the N innermost
+ loops and the outermost one optimistically. */
+ if (iterate)
{
- gimple *stmt = el.to_fixup.pop ();
+ loop_p loop;
+ unsigned max_depth = PARAM_VALUE (PARAM_RPO_VN_MAX_LOOP_DEPTH);
+ FOR_EACH_LOOP (loop, LI_ONLY_INNERMOST)
+ if (loop_depth (loop) > max_depth)
+ for (unsigned i = 2;
+ i < loop_depth (loop) - max_depth; ++i)
+ {
+ basic_block header = superloop_at_depth (loop, i)->header;
+ bool non_latch_backedge = false;
+ edge e;
+ edge_iterator ei;
+ FOR_EACH_EDGE (e, ei, header->preds)
+ if (e->flags & EDGE_DFS_BACK)
+ {
+ /* There can be a non-latch backedge into the header
+ which is part of an outer irreducible region. We
+ cannot avoid iterating this block then. */
+ if (!dominated_by_p (CDI_DOMINATORS,
+ e->src, e->dest))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "non-latch backedge %d -> %d "
+ "forces iteration of loop %d\n",
+ e->src->index, e->dest->index, loop->num);
+ non_latch_backedge = true;
+ }
+ else
+ e->flags |= EDGE_EXECUTABLE;
+ }
+ rpo_state[bb_to_rpo[header->index]].iterate = non_latch_backedge;
+ }
+ }
- if (dump_file && (dump_flags & TDF_DETAILS))
+ uint64_t nblk = 0;
+ int idx = 0;
+ if (iterate)
+ /* Go and process all blocks, iterating as necessary. */
+ do
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[idx]);
+
+ /* If the block has incoming backedges remember unwind state. This
+ is required even for non-executable blocks since in irreducible
+ regions we might reach them via the backedge and re-start iterating
+ from there.
+ Note we can individually mark blocks with incoming backedges to
+ not iterate where we then handle PHIs conservatively. We do that
+ heuristically to reduce compile-time for degenerate cases. */
+ if (rpo_state[idx].iterate)
+ {
+ rpo_state[idx].ob_top = obstack_alloc (&vn_tables_obstack, 0);
+ rpo_state[idx].ref_top = last_inserted_ref;
+ rpo_state[idx].phi_top = last_inserted_phi;
+ rpo_state[idx].nary_top = last_inserted_nary;
+ }
+
+ if (!(bb->flags & BB_EXECUTABLE))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Block %d: BB%d found not executable\n",
+ idx, bb->index);
+ idx++;
+ continue;
+ }
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Processing block %d: BB%d\n", idx, bb->index);
+ nblk++;
+ todo |= process_bb (avail, bb,
+ rpo_state[idx].visited != 0,
+ rpo_state[idx].iterate,
+ iterate, eliminate, do_region, exit_bbs, false);
+ rpo_state[idx].visited++;
+
+ /* Verify if changed values flow over executable outgoing backedges
+ and those change destination PHI values (that's the thing we
+ can easily verify). Reduce over all such edges to the farthest
+ away PHI. */
+ int iterate_to = -1;
+ edge_iterator ei;
+ edge e;
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if ((e->flags & (EDGE_DFS_BACK|EDGE_EXECUTABLE))
+ == (EDGE_DFS_BACK|EDGE_EXECUTABLE)
+ && rpo_state[bb_to_rpo[e->dest->index]].iterate)
+ {
+ int destidx = bb_to_rpo[e->dest->index];
+ if (!rpo_state[destidx].visited)
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Unvisited destination %d\n",
+ e->dest->index);
+ if (iterate_to == -1 || destidx < iterate_to)
+ iterate_to = destidx;
+ continue;
+ }
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Looking for changed values of backedge"
+ " %d->%d destination PHIs\n",
+ e->src->index, e->dest->index);
+ vn_context_bb = e->dest;
+ gphi_iterator gsi;
+ for (gsi = gsi_start_phis (e->dest);
+ !gsi_end_p (gsi); gsi_next (&gsi))
+ {
+ bool inserted = false;
+ /* While we'd ideally just iterate on value changes
+ we CSE PHIs and do that even across basic-block
+ boundaries. So even hashtable state changes can
+ be important (which is roughly equivalent to
+ PHI argument value changes). To not excessively
+ iterate because of that we track whether a PHI
+ was CSEd to with GF_PLF_1. */
+ bool phival_changed;
+ if ((phival_changed = visit_phi (gsi.phi (),
+ &inserted, false))
+ || (inserted && gimple_plf (gsi.phi (), GF_PLF_1)))
+ {
+ if (!phival_changed
+ && dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "PHI was CSEd and hashtable "
+ "state (changed)\n");
+ if (iterate_to == -1 || destidx < iterate_to)
+ iterate_to = destidx;
+ break;
+ }
+ }
+ vn_context_bb = NULL;
+ }
+ if (iterate_to != -1)
+ {
+ do_unwind (&rpo_state[iterate_to], iterate_to, avail, bb_to_rpo);
+ idx = iterate_to;
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Iterating to %d BB%d\n",
+ iterate_to, rpo[iterate_to]);
+ continue;
+ }
+
+ idx++;
+ }
+ while (idx < n);
+
+ else /* !iterate */
+ {
+ /* Process all blocks greedily with a worklist that enforces RPO
+ processing of reachable blocks. */
+ auto_bitmap worklist;
+ bitmap_set_bit (worklist, 0);
+ while (!bitmap_empty_p (worklist))
{
- fprintf (dump_file, "Fixing up noreturn call ");
- print_gimple_stmt (dump_file, stmt, 0);
+ int idx = bitmap_first_set_bit (worklist);
+ bitmap_clear_bit (worklist, idx);
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[idx]);
+ gcc_assert ((bb->flags & BB_EXECUTABLE)
+ && !rpo_state[idx].visited);
+
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Processing block %d: BB%d\n", idx, bb->index);
+
+ /* When we run into predecessor edges where we cannot trust its
+ executable state mark them executable so PHI processing will
+ be conservative.
+ ??? Do we need to force arguments flowing over that edge
+ to be varying or will they even always be? */
+ edge_iterator ei;
+ edge e;
+ FOR_EACH_EDGE (e, ei, bb->preds)
+ if (!(e->flags & EDGE_EXECUTABLE)
+ && (bb == entry->dest
+ || (!rpo_state[bb_to_rpo[e->src->index]].visited
+ && (rpo_state[bb_to_rpo[e->src->index]].max_rpo
+ >= (int)idx))))
+ {
+ if (dump_file && (dump_flags & TDF_DETAILS))
+ fprintf (dump_file, "Cannot trust state of predecessor "
+ "edge %d -> %d, marking executable\n",
+ e->src->index, e->dest->index);
+ e->flags |= EDGE_EXECUTABLE;
+ }
+
+ nblk++;
+ todo |= process_bb (avail, bb, false, false, false, eliminate,
+ do_region, exit_bbs,
+ skip_entry_phis && bb == entry->dest);
+ rpo_state[idx].visited++;
+
+ FOR_EACH_EDGE (e, ei, bb->succs)
+ if ((e->flags & EDGE_EXECUTABLE)
+ && e->dest->index != EXIT_BLOCK
+ && (!do_region || !bitmap_bit_p (exit_bbs, e->dest->index))
+ && !rpo_state[bb_to_rpo[e->dest->index]].visited)
+ bitmap_set_bit (worklist, bb_to_rpo[e->dest->index]);
}
+ }
- if (fixup_noreturn_call (stmt))
- el.el_todo |= TODO_cleanup_cfg;
+ /* If statistics or dump file active. */
+ int nex = 0;
+ unsigned max_visited = 1;
+ for (int i = 0; i < n; ++i)
+ {
+ basic_block bb = BASIC_BLOCK_FOR_FN (fn, rpo[i]);
+ if (bb->flags & BB_EXECUTABLE)
+ nex++;
+ statistics_histogram_event (cfun, "RPO block visited times",
+ rpo_state[i].visited);
+ if (rpo_state[i].visited > max_visited)
+ max_visited = rpo_state[i].visited;
+ }
+ unsigned nvalues = 0, navail = 0;
+ for (hash_table<vn_ssa_aux_hasher>::iterator i = vn_ssa_aux_hash->begin ();
+ i != vn_ssa_aux_hash->end (); ++i)
+ {
+ nvalues++;
+ vn_avail *av = (*i)->avail;
+ while (av)
+ {
+ navail++;
+ av = av->next;
+ }
+ }
+ statistics_counter_event (cfun, "RPO blocks", n);
+ statistics_counter_event (cfun, "RPO blocks visited", nblk);
+ statistics_counter_event (cfun, "RPO blocks executable", nex);
+ statistics_histogram_event (cfun, "RPO iterations", 10*nblk / nex);
+ statistics_histogram_event (cfun, "RPO num values", nvalues);
+ statistics_histogram_event (cfun, "RPO num avail", navail);
+ statistics_histogram_event (cfun, "RPO num lattice",
+ vn_ssa_aux_hash->elements ());
+ if (dump_file && (dump_flags & (TDF_DETAILS|TDF_STATS)))
+ {
+ fprintf (dump_file, "RPO iteration over %d blocks visited %" PRIu64
+ " blocks in total discovering %d executable blocks iterating "
+ "%d.%d times, a block was visited max. %u times\n",
+ n, nblk, nex,
+ (int)((10*nblk / nex)/10), (int)((10*nblk / nex)%10),
+ max_visited);
+ fprintf (dump_file, "RPO tracked %d values available at %d locations "
+ "and %" PRIu64 " lattice elements\n",
+ nvalues, navail, (uint64_t) vn_ssa_aux_hash->elements ());
}
- bool do_eh_cleanup = !bitmap_empty_p (el.need_eh_cleanup);
- bool do_ab_cleanup = !bitmap_empty_p (el.need_ab_cleanup);
+ if (eliminate)
+ {
+ /* When !iterate we already performed elimination during the RPO
+ walk. */
+ if (iterate)
+ {
+ /* Elimination for region-based VN needs to be done within the
+ RPO walk. */
+ gcc_assert (! do_region);
+ /* Note we can't use avail.walk here because that gets confused
+ by the existing availability and it will be less efficient
+ as well. */
+ todo |= eliminate_with_rpo_vn (NULL);
+ }
+ else
+ todo |= avail.eliminate_cleanup (do_region);
+ }
- if (do_eh_cleanup)
- gimple_purge_all_dead_eh_edges (el.need_eh_cleanup);
+ vn_valueize = NULL;
+ rpo_avail = NULL;
- if (do_ab_cleanup)
- gimple_purge_all_dead_abnormal_call_edges (el.need_ab_cleanup);
+ XDELETEVEC (bb_to_rpo);
+ XDELETEVEC (rpo);
+ XDELETEVEC (rpo_state);
- if (do_eh_cleanup || do_ab_cleanup)
- el.el_todo |= TODO_cleanup_cfg;
+ return todo;
+}
- statistics_counter_event (cfun, "Eliminated", el.eliminations);
- statistics_counter_event (cfun, "Insertions", el.insertions);
+/* Region-based entry for RPO VN. Performs value-numbering and elimination
+ on the SEME region specified by ENTRY and EXIT_BBS. If ENTRY is not
+ the only edge into the region at ENTRY->dest PHI nodes in ENTRY->dest
+ are not considered. */
- return el.el_todo;
+unsigned
+do_rpo_vn (function *fn, edge entry, bitmap exit_bbs)
+{
+ default_vn_walk_kind = VN_WALKREWRITE;
+ unsigned todo = do_rpo_vn (fn, entry, exit_bbs, false, true);
+ free_rpo_vn ();
+ return todo;
}
{
public:
pass_fre (gcc::context *ctxt)
- : gimple_opt_pass (pass_data_fre, ctxt)
+ : gimple_opt_pass (pass_data_fre, ctxt), may_iterate (true)
{}
/* opt_pass methods: */
opt_pass * clone () { return new pass_fre (m_ctxt); }
- virtual bool gate (function *) { return flag_tree_fre != 0; }
+ void set_pass_param (unsigned int n, bool param)
+ {
+ gcc_assert (n == 0);
+ may_iterate = param;
+ }
+ virtual bool gate (function *)
+ {
+ return flag_tree_fre != 0 && (may_iterate || optimize > 1);
+ }
virtual unsigned int execute (function *);
+private:
+ bool may_iterate;
}; // class pass_fre
unsigned int
-pass_fre::execute (function *)
+pass_fre::execute (function *fun)
{
- unsigned int todo = 0;
+ unsigned todo = 0;
+
+ /* At -O[1g] use the cheap non-iterating mode. */
+ bool iterate_p = may_iterate && (optimize > 1);
+ calculate_dominance_info (CDI_DOMINATORS);
+ if (iterate_p)
+ loop_optimizer_init (AVOID_CFG_MODIFICATIONS);
- run_scc_vn (VN_WALKREWRITE);
+ default_vn_walk_kind = VN_WALKREWRITE;
+ todo = do_rpo_vn (fun, NULL, NULL, iterate_p, true);
+ free_rpo_vn ();
- /* Remove all the redundant expressions. */
- todo |= vn_eliminate (NULL);
+ if (iterate_p)
+ loop_optimizer_finalize ();
- scc_vn_restore_ssa_info ();
- free_scc_vn ();
+ /* For late FRE after IVOPTs and unrolling, see if we can
+ remove some TREE_ADDRESSABLE and rewrite stuff into SSA. */
+ if (!may_iterate)
+ todo |= TODO_update_address_taken;
return todo;
}
{
return new pass_fre (ctxt);
}
+
+#undef BB_EXECUTABLE
projects / gcc.git / blobdiff