/* Common subexpression elimination for GNU compiler.
Copyright (C) 1987, 1988, 1989, 1992, 1993, 1994, 1995, 1996, 1997, 1998
- 1999, 2000, 2001 Free Software Foundation, Inc.
+ 1999, 2000, 2001, 2002 Free Software Foundation, Inc.
This file is part of GCC.
#include "toplev.h"
#include "output.h"
#include "ggc.h"
+#include "timevar.h"
/* The basic idea of common subexpression elimination is to go
through the code, keeping a record of expressions that would
/* Return an estimate of the cost of the registers used in an rtx.
This is mostly the number of different REG expressions in the rtx;
- however for some excecptions like fixed registers we use a cost of
+ however for some exceptions like fixed registers we use a cost of
0. If any other hard register reference occurs, return MAX_COST. */
static int
}
\f
/* Return cost of address expression X.
- Expect that X is propertly formed address reference. */
+ Expect that X is properly formed address reference. */
int
address_cost (x, mode)
{
next = p->next_same_hash;
if (GET_CODE (p->exp) != REG
- && refers_to_regno_p (regno, regno + 1, p->exp, (rtx*)0))
+ && refers_to_regno_p (regno, regno + 1, p->exp, (rtx*) 0))
remove_from_table (p, i);
}
}
|| (((SUBREG_BYTE (exp)
+ (GET_MODE_SIZE (GET_MODE (exp)) - 1)) >= offset)
&& SUBREG_BYTE (exp) <= end))
- && refers_to_regno_p (regno, regno + 1, p->exp, (rtx*)0))
+ && refers_to_regno_p (regno, regno + 1, p->exp, (rtx*) 0))
remove_from_table (p, i);
}
}
|| CLASS_LIKELY_SPILLED_P (REGNO_REG_CLASS (regno))
|| (SMALL_REGISTER_CLASSES
&& ! fixed_regs[regno]
- && regno != FRAME_POINTER_REGNUM
- && regno != HARD_FRAME_POINTER_REGNUM
- && regno != ARG_POINTER_REGNUM
- && regno != STACK_POINTER_REGNUM
+ && x != frame_pointer_rtx
+ && x != hard_frame_pointer_rtx
+ && x != arg_pointer_rtx
+ && x != stack_pointer_rtx
&& GET_MODE_CLASS (GET_MODE (x)) != MODE_CC)))
{
do_not_record = 1;
+ (unsigned) CONST_DOUBLE_HIGH (x));
return hash;
+ case CONST_VECTOR:
+ {
+ int units;
+ rtx elt;
+
+ units = CONST_VECTOR_NUNITS (x);
+
+ for (i = 0; i < units; ++i)
+ {
+ elt = CONST_VECTOR_ELT (x, i);
+ hash += canon_hash (elt, GET_MODE (elt));
+ }
+
+ return hash;
+ }
+
/* Assume there is only one rtx object for any given label. */
case LABEL_REF:
hash += ((unsigned) LABEL_REF << 7) + (unsigned long) XEXP (x, 0);
case CONST:
case CONST_INT:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case SYMBOL_REF:
case LABEL_REF:
case ADDR_VEC:
case CONST:
case CONST_INT:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case SYMBOL_REF:
case LABEL_REF:
case REG:
case SYMBOL_REF:
case LABEL_REF:
case CONST_DOUBLE:
+ case CONST_VECTOR:
const_arg = arg;
break;
& HASH_MASK), mode_arg0))
&& p0->first_same_value == p1->first_same_value))
{
- /* Sadly two equal NaNs are not equivalent. */
- if (TARGET_FLOAT_FORMAT != IEEE_FLOAT_FORMAT
- || ! FLOAT_MODE_P (mode_arg0)
- || flag_unsafe_math_optimizations)
- return ((code == EQ || code == LE || code == GE
- || code == LEU || code == GEU || code == UNEQ
- || code == UNLE || code == UNGE || code == ORDERED)
- ? true_rtx : false_rtx);
- /* Take care for the FP compares we can resolve. */
- if (code == UNEQ || code == UNLE || code == UNGE)
- return true_rtx;
- if (code == LTGT || code == LT || code == GT)
- return false_rtx;
+ /* Sadly two equal NaNs are not equivalent. */
+ if (!HONOR_NANS (mode_arg0))
+ return ((code == EQ || code == LE || code == GE
+ || code == LEU || code == GEU || code == UNEQ
+ || code == UNLE || code == UNGE
+ || code == ORDERED)
+ ? true_rtx : false_rtx);
+ /* Take care for the FP compares we can resolve. */
+ if (code == UNEQ || code == UNLE || code == UNGE)
+ return true_rtx;
+ if (code == LTGT || code == LT || code == GT)
+ return false_rtx;
}
/* If FOLDED_ARG0 is a register, see if the comparison we are
CONST_INT, see if we can find a register equivalent to the
positive constant. Make a MINUS if so. Don't do this for
a non-negative constant since we might then alternate between
- chosing positive and negative constants. Having the positive
+ choosing positive and negative constants. Having the positive
constant previously-used is the more common case. Be sure
the resulting constant is non-negative; if const_arg1 were
the smallest negative number this would overflow: depending
&& GET_CODE (XEXP (XEXP (src_const, 0), 0)) == LABEL_REF
&& GET_CODE (XEXP (XEXP (src_const, 0), 1)) == LABEL_REF))
{
- tem = find_reg_note (insn, REG_EQUAL, NULL_RTX);
-
/* Make sure that the rtx is not shared with any other insn. */
src_const = copy_rtx (src_const);
/* Record the actual constant value in a REG_EQUAL note, making
a new one if one does not already exist. */
- if (tem)
- XEXP (tem, 0) = src_const;
- else
- REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_EQUAL,
- src_const, REG_NOTES (insn));
+ set_unique_reg_note (insn, REG_EQUAL, src_const);
/* If storing a constant value in a register that
previously held the constant value 0,
be a conditional or computed branch. */
else if (dest == pc_rtx && GET_CODE (src) == LABEL_REF)
{
+ /* Now emit a BARRIER after the unconditional jump. */
+ if (NEXT_INSN (insn) == 0
+ || GET_CODE (NEXT_INSN (insn)) != BARRIER)
+ emit_barrier_after (insn);
+
/* We reemit the jump in as many cases as possible just in
case the form of an unconditional jump is significantly
different than a computed jump or conditional jump.
and hope for the best. */
if (n_sets == 1)
{
- rtx new = emit_jump_insn_before (gen_jump (XEXP (src, 0)), insn);
+ rtx new = emit_jump_insn_after (gen_jump (XEXP (src, 0)), insn);
+
JUMP_LABEL (new) = XEXP (src, 0);
LABEL_NUSES (XEXP (src, 0))++;
+ delete_insn (insn);
insn = new;
+
+ /* Now emit a BARRIER after the unconditional jump. */
+ if (NEXT_INSN (insn) == 0
+ || GET_CODE (NEXT_INSN (insn)) != BARRIER)
+ emit_barrier_after (insn);
}
else
INSN_CODE (insn) = -1;
- never_reached_warning (insn);
+ never_reached_warning (insn, NULL);
- /* Now emit a BARRIER after the unconditional jump. Do not bother
- deleting any unreachable code, let jump/flow do that. */
- if (NEXT_INSN (insn) != 0
- && GET_CODE (NEXT_INSN (insn)) != BARRIER)
- emit_barrier_after (insn);
+ /* Do not bother deleting any unreachable code,
+ let jump/flow do that. */
cse_jumps_altered = 1;
sets[i].rtl = 0;
/* Don't put a hard register source into the table if this is
the last insn of a libcall. In this case, we only need
to put src_eqv_elt in src_elt. */
- if (GET_CODE (src) != REG
- || REGNO (src) >= FIRST_PSEUDO_REGISTER
- || ! find_reg_note (insn, REG_RETVAL, NULL_RTX))
+ if (! find_reg_note (insn, REG_RETVAL, NULL_RTX))
{
struct table_elt *elt;
case SYMBOL_REF:
case LABEL_REF:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case PC:
case CC0:
case LO_SUM:
}
\f
/* Called via for_each_rtx to see if an insn is using a LABEL_REF for which
- there isn't a REG_DEAD note. Return one if so. DATA is the insn. */
+ there isn't a REG_LABEL note. Return one if so. DATA is the insn. */
static int
check_for_label_ref (rtl, data)
LABEL_REF for a CODE_LABEL that isn't in the insn chain, don't do this
since no REG_LABEL will be added. */
return (GET_CODE (*rtl) == LABEL_REF
+ && ! LABEL_REF_NONLOCAL_P (*rtl)
&& LABEL_P (XEXP (*rtl, 0))
&& INSN_UID (XEXP (*rtl, 0)) != 0
&& ! find_reg_note (insn, REG_LABEL, XEXP (*rtl, 0)));
case CONST:
case CONST_INT:
case CONST_DOUBLE:
+ case CONST_VECTOR:
case SYMBOL_REF:
case LABEL_REF:
return;
move dead invariants out of loops or make givs for dead quantities. The
remaining passes of the compilation are also sped up. */
-void
-delete_trivially_dead_insns (insns, nreg, preserve_basic_blocks)
+int
+delete_trivially_dead_insns (insns, nreg)
rtx insns;
int nreg;
- int preserve_basic_blocks;
{
int *counts;
rtx insn, prev;
- int i;
int in_libcall = 0, dead_libcall = 0;
- basic_block bb;
+ int ndead = 0, nlastdead, niterations = 0;
+ timevar_push (TV_DELETE_TRIVIALLY_DEAD);
/* First count the number of times each register is used. */
counts = (int *) xcalloc (nreg, sizeof (int));
for (insn = next_real_insn (insns); insn; insn = next_real_insn (insn))
count_reg_usage (insn, counts, NULL_RTX, 1);
- /* Go from the last insn to the first and delete insns that only set unused
- registers or copy a register to itself. As we delete an insn, remove
- usage counts for registers it uses.
-
- The first jump optimization pass may leave a real insn as the last
- insn in the function. We must not skip that insn or we may end
- up deleting code that is not really dead. */
- insn = get_last_insn ();
- if (! INSN_P (insn))
- insn = prev_real_insn (insn);
-
- if (!preserve_basic_blocks)
- for (; insn; insn = prev)
- {
- int live_insn = 0;
-
- prev = prev_real_insn (insn);
-
- /* Don't delete any insns that are part of a libcall block unless
- we can delete the whole libcall block.
-
- Flow or loop might get confused if we did that. Remember
- that we are scanning backwards. */
- if (find_reg_note (insn, REG_RETVAL, NULL_RTX))
- {
- in_libcall = 1;
- live_insn = 1;
- dead_libcall = dead_libcall_p (insn);
- }
- else if (in_libcall)
- live_insn = ! dead_libcall;
- else
- live_insn = insn_live_p (insn, counts);
-
- /* If this is a dead insn, delete it and show registers in it aren't
- being used. */
-
- if (! live_insn)
- {
- count_reg_usage (insn, counts, NULL_RTX, -1);
- delete_related_insns (insn);
- }
+ do
+ {
+ nlastdead = ndead;
+ niterations++;
+ /* Go from the last insn to the first and delete insns that only set unused
+ registers or copy a register to itself. As we delete an insn, remove
+ usage counts for registers it uses.
+
+ The first jump optimization pass may leave a real insn as the last
+ insn in the function. We must not skip that insn or we may end
+ up deleting code that is not really dead. */
+ insn = get_last_insn ();
+ if (! INSN_P (insn))
+ insn = prev_real_insn (insn);
- if (find_reg_note (insn, REG_LIBCALL, NULL_RTX))
- {
- in_libcall = 0;
- dead_libcall = 0;
- }
- }
- else
- for (i = 0; i < n_basic_blocks; i++)
- for (bb = BASIC_BLOCK (i), insn = bb->end; insn != bb->head; insn = prev)
+ for (; insn; insn = prev)
{
int live_insn = 0;
- prev = PREV_INSN (insn);
- if (!INSN_P (insn))
- continue;
+ prev = prev_real_insn (insn);
/* Don't delete any insns that are part of a libcall block unless
we can delete the whole libcall block.
if (! live_insn)
{
count_reg_usage (insn, counts, NULL_RTX, -1);
- delete_insn (insn);
+ delete_insn_and_edges (insn);
+ ndead++;
}
if (find_reg_note (insn, REG_LIBCALL, NULL_RTX))
dead_libcall = 0;
}
}
+ } while (ndead != nlastdead);
+ if (rtl_dump_file && ndead)
+ fprintf (rtl_dump_file, "Deleted %i trivially dead insns; %i iterations\n",
+ ndead, niterations);
/* Clean up. */
free (counts);
+ timevar_pop (TV_DELETE_TRIVIALLY_DEAD);
+ return ndead;
}
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