/* Register renaming for the GNU compiler.
- Copyright (C) 2000-2014 Free Software Foundation, Inc.
+ Copyright (C) 2000-2016 Free Software Foundation, Inc.
This file is part of GCC.
#include "config.h"
#include "system.h"
#include "coretypes.h"
-#include "tm.h"
-#include "rtl-error.h"
+#include "backend.h"
+#include "target.h"
+#include "rtl.h"
+#include "df.h"
#include "tm_p.h"
#include "insn-config.h"
#include "regs.h"
+#include "emit-rtl.h"
+#include "recog.h"
#include "addresses.h"
-#include "hard-reg-set.h"
-#include "predict.h"
-#include "vec.h"
-#include "hashtab.h"
-#include "hash-set.h"
-#include "machmode.h"
-#include "input.h"
-#include "function.h"
-#include "dominance.h"
-#include "cfg.h"
#include "cfganal.h"
-#include "basic-block.h"
-#include "reload.h"
-#include "output.h"
-#include "recog.h"
-#include "flags.h"
-#include "obstack.h"
#include "tree-pass.h"
-#include "df.h"
-#include "target.h"
-#include "emit-rtl.h"
#include "regrename.h"
/* This file implements the RTL register renaming pass of the compiler. It is
record_operand_use. */
static operand_rr_info *cur_operand;
+/* Set while scanning RTL if a register dies. Used to tie chains. */
+static struct du_head *terminated_this_insn;
+
/* Return the chain corresponding to id number ID. Take into account that
chains may have been merged. */
du_head_p
static void
record_operand_use (struct du_head *head, struct du_chain *this_du)
{
- if (cur_operand == NULL)
+ if (cur_operand == NULL || cur_operand->failed)
return;
+ if (head->cannot_rename)
+ {
+ cur_operand->failed = true;
+ return;
+ }
gcc_assert (cur_operand->n_chains < MAX_REGS_PER_ADDRESS);
cur_operand->heads[cur_operand->n_chains] = head;
cur_operand->chains[cur_operand->n_chains++] = this_du;
struct du_chain *this_du;
int nregs;
+ memset (head, 0, sizeof *head);
head->next_chain = open_chains;
head->regno = this_regno;
head->nregs = this_nregs;
- head->need_caller_save_reg = 0;
- head->cannot_rename = 0;
id_to_chain.safe_push (head);
head->id = current_id++;
|| (crtl->is_leaf
&& !LEAF_REGISTERS[new_reg + i])
#endif
-#ifdef HARD_REGNO_RENAME_OK
- || ! HARD_REGNO_RENAME_OK (reg + i, new_reg + i)
-#endif
- )
+ || ! HARD_REGNO_RENAME_OK (reg + i, new_reg + i))
return false;
/* See whether it accepts all modes that occur in
preferred_class
= (enum reg_class) targetm.preferred_rename_class (super_class);
+ /* Pick and check the register from the tied chain iff the tied chain
+ is not renamed. */
+ if (this_head->tied_chain && !this_head->tied_chain->renamed
+ && check_new_reg_p (old_reg, this_head->tied_chain->regno,
+ this_head, *unavailable))
+ return this_head->tied_chain->regno;
+
/* If PREFERRED_CLASS is not NO_REGS, we iterate in the first pass
over registers that belong to PREFERRED_CLASS and try to find the
best register within the class. If that failed, we iterate in
return best_new_reg;
}
+/* Iterate over elements in the chain HEAD in order to:
+ 1. Count number of uses, storing it in *PN_USES.
+ 2. Narrow the set of registers we can use for renaming, adding
+ unavailable registers to *PUNAVAILABLE, which must be
+ initialized by the caller.
+ 3. Compute the superunion of register classes in this chain
+ and return it. */
+reg_class
+regrename_find_superclass (du_head_p head, int *pn_uses,
+ HARD_REG_SET *punavailable)
+{
+ int n_uses = 0;
+ reg_class super_class = NO_REGS;
+ for (du_chain *tmp = head->first; tmp; tmp = tmp->next_use)
+ {
+ if (DEBUG_INSN_P (tmp->insn))
+ continue;
+ n_uses++;
+ IOR_COMPL_HARD_REG_SET (*punavailable,
+ reg_class_contents[tmp->cl]);
+ super_class
+ = reg_class_superunion[(int) super_class][(int) tmp->cl];
+ }
+ *pn_uses = n_uses;
+ return super_class;
+}
+
/* Perform register renaming on the current function. */
static void
rename_chains (void)
if (frame_pointer_needed)
{
add_to_hard_reg_set (&unavailable, Pmode, FRAME_POINTER_REGNUM);
-#if !HARD_FRAME_POINTER_IS_FRAME_POINTER
- add_to_hard_reg_set (&unavailable, Pmode, HARD_FRAME_POINTER_REGNUM);
-#endif
+ if (!HARD_FRAME_POINTER_IS_FRAME_POINTER)
+ add_to_hard_reg_set (&unavailable, Pmode, HARD_FRAME_POINTER_REGNUM);
}
FOR_EACH_VEC_ELT (id_to_chain, i, this_head)
{
int best_new_reg;
int n_uses;
- struct du_chain *tmp;
HARD_REG_SET this_unavailable;
int reg = this_head->regno;
- enum reg_class super_class = NO_REGS;
if (this_head->cannot_rename)
continue;
if (fixed_regs[reg] || global_regs[reg]
-#if !HARD_FRAME_POINTER_IS_FRAME_POINTER
- || (frame_pointer_needed && reg == HARD_FRAME_POINTER_REGNUM)
-#else
- || (frame_pointer_needed && reg == FRAME_POINTER_REGNUM)
-#endif
- )
+ || (!HARD_FRAME_POINTER_IS_FRAME_POINTER && frame_pointer_needed
+ && reg == HARD_FRAME_POINTER_REGNUM)
+ || (HARD_FRAME_POINTER_REGNUM && frame_pointer_needed
+ && reg == FRAME_POINTER_REGNUM))
continue;
COPY_HARD_REG_SET (this_unavailable, unavailable);
- /* Iterate over elements in the chain in order to:
- 1. Count number of uses, and narrow the set of registers we can
- use for renaming.
- 2. Compute the superunion of register classes in this chain. */
- n_uses = 0;
- super_class = NO_REGS;
- for (tmp = this_head->first; tmp; tmp = tmp->next_use)
- {
- if (DEBUG_INSN_P (tmp->insn))
- continue;
- n_uses++;
- IOR_COMPL_HARD_REG_SET (this_unavailable,
- reg_class_contents[tmp->cl]);
- super_class
- = reg_class_superunion[(int) super_class][(int) tmp->cl];
- }
-
+ reg_class super_class = regrename_find_superclass (this_head, &n_uses,
+ &this_unavailable);
if (n_uses < 2)
continue;
continue;
}
- if (dump_file)
- fprintf (dump_file, ", renamed as %s\n", reg_names[best_new_reg]);
-
- regrename_do_replace (this_head, best_new_reg);
- tick[best_new_reg] = ++this_tick;
- df_set_regs_ever_live (best_new_reg, true);
+ if (regrename_do_replace (this_head, best_new_reg))
+ {
+ if (dump_file)
+ fprintf (dump_file, ", renamed as %s\n", reg_names[best_new_reg]);
+ tick[best_new_reg] = ++this_tick;
+ df_set_regs_ever_live (best_new_reg, true);
+ }
+ else
+ {
+ if (dump_file)
+ fprintf (dump_file, ", renaming as %s failed\n",
+ reg_names[best_new_reg]);
+ tick[reg] = ++this_tick;
+ }
}
}
bb->aux = NULL;
}
-void
+/* Attempt to replace all uses of the register in the chain beginning with
+ HEAD with REG. Returns true on success and false if the replacement is
+ rejected because the insns would not validate. The latter can happen
+ e.g. if a match_parallel predicate enforces restrictions on register
+ numbering in its subpatterns. */
+
+bool
regrename_do_replace (struct du_head *head, int reg)
{
struct du_chain *chain;
int reg_ptr = REG_POINTER (*chain->loc);
if (DEBUG_INSN_P (chain->insn) && REGNO (*chain->loc) != base_regno)
- INSN_VAR_LOCATION_LOC (chain->insn) = gen_rtx_UNKNOWN_VAR_LOC ();
+ validate_change (chain->insn, &(INSN_VAR_LOCATION_LOC (chain->insn)),
+ gen_rtx_UNKNOWN_VAR_LOC (), true);
else
{
- *chain->loc = gen_raw_REG (GET_MODE (*chain->loc), reg);
+ validate_change (chain->insn, chain->loc,
+ gen_raw_REG (GET_MODE (*chain->loc), reg), true);
if (regno >= FIRST_PSEUDO_REGISTER)
ORIGINAL_REGNO (*chain->loc) = regno;
REG_ATTRS (*chain->loc) = attr;
REG_POINTER (*chain->loc) = reg_ptr;
}
-
- df_insn_rescan (chain->insn);
}
+ if (!apply_change_group ())
+ return false;
+
mode = GET_MODE (*head->first->loc);
+ head->renamed = 1;
head->regno = reg;
head->nregs = hard_regno_nregs[reg][mode];
+ return true;
}
return false;
regno = REGNO (op);
- nregs = hard_regno_nregs[regno][GET_MODE (op)];
+ nregs = REG_NREGS (op);
all_live = all_dead = true;
while (nregs-- > 0)
if (TEST_HARD_REG_BIT (*pset, regno + nregs))
{
struct du_head **p;
rtx x = *loc;
- machine_mode mode = GET_MODE (x);
unsigned this_regno = REGNO (x);
- int this_nregs = hard_regno_nregs[this_regno][mode];
+ int this_nregs = REG_NREGS (x);
if (action == mark_write)
{
if (type == OP_OUT)
- create_new_chain (this_regno, this_nregs, loc, insn, cl);
+ {
+ du_head_p c;
+ rtx pat = PATTERN (insn);
+
+ c = create_new_chain (this_regno, this_nregs, loc, insn, cl);
+
+ /* We try to tie chains in a move instruction for
+ a single output. */
+ if (recog_data.n_operands == 2
+ && GET_CODE (pat) == SET
+ && GET_CODE (SET_DEST (pat)) == REG
+ && GET_CODE (SET_SRC (pat)) == REG
+ && terminated_this_insn
+ && terminated_this_insn->nregs
+ == REG_NREGS (recog_data.operand[1]))
+ {
+ gcc_assert (terminated_this_insn->regno
+ == REGNO (recog_data.operand[1]));
+
+ c->tied_chain = terminated_this_insn;
+ terminated_this_insn->tied_chain = c;
+
+ if (dump_file)
+ fprintf (dump_file, "Tying chain %s (%d) with %s (%d)\n",
+ reg_names[c->regno], c->id,
+ reg_names[terminated_this_insn->regno],
+ terminated_this_insn->id);
+ }
+ }
+
return;
}
SET_HARD_REG_BIT (live_hard_regs, head->regno + nregs);
}
+ if (action == terminate_dead)
+ terminated_this_insn = *p;
*p = next;
if (dump_file)
fprintf (dump_file,
case PRE_INC:
case PRE_DEC:
case PRE_MODIFY:
-#ifndef AUTO_INC_DEC
/* If the target doesn't claim to handle autoinc, this must be
something special, like a stack push. Kill this chain. */
- action = mark_all_read;
-#endif
+ if (!AUTO_INC_DEC)
+ action = mark_all_read;
+
break;
case MEM:
cur_operand = insn_info->op_info + i;
prev_open = open_chains;
+ if (earlyclobber)
+ scan_rtx (insn, loc, cl, terminate_write, OP_OUT);
scan_rtx (insn, loc, cl, mark_write, OP_OUT);
/* ??? Many targets have output constraints on the SET_DEST
enum rtx_code set_code = SET;
enum rtx_code clobber_code = CLOBBER;
insn_rr_info *insn_info = NULL;
+ terminated_this_insn = NULL;
/* Process the insn, determining its effect on the def-use
chains and live hard registers. We perform the following
untracked_operands |= 1 << matches;
}
}
+#ifdef STACK_REGS
+ if (regstack_completed
+ && REG_P (op)
+ && IN_RANGE (REGNO (op), FIRST_STACK_REG, LAST_STACK_REG))
+ untracked_operands |= 1 << i;
+#endif
/* If there's an in-out operand with a register that is not
being tracked at all yet, open a chain. */
if (recog_data.operand_type[i] == OP_INOUT
&& !(untracked_operands & (1 << i))
&& REG_P (op)
&& !verify_reg_tracked (op))
- {
- machine_mode mode = GET_MODE (op);
- unsigned this_regno = REGNO (op);
- unsigned this_nregs = hard_regno_nregs[this_regno][mode];
- create_new_chain (this_regno, this_nregs, NULL, NULL,
- NO_REGS);
- }
+ create_new_chain (REGNO (op), REG_NREGS (op), NULL, NULL,
+ NO_REGS);
}
if (fail_current_block)
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