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combine.c (try_combine): Handle the case that undobuf.other_insn has been turned into a return or...

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* combine.c (try_combine): Handle the case that undobuf.other_insn
	has been turned into a return or unconditional jump, by inserting
	a BARRIER if necessary.
	(simplify_set):  Test if a condition code setter has a constant
	comparison at compile time, if so convert this insn to a no-op move
	and update/simplify the condition code user (undobuf.other_insn).

From-SVN: r56955
This commit is contained in:
Roger Sayle 2002-09-08 18:07:54 +00:00 committed by Roger Sayle
parent e2f97e264e
commit f40f4c8ed1
2 changed files with 52 additions and 2 deletions
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9
gcc/ChangeLog
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@ -1,3 +1,12 @@
2002-09-08 Roger Sayle <roger@eyesopen.com>
* combine.c (try_combine): Handle the case that undobuf.other_insn
has been turned into a return or unconditional jump, by inserting
a BARRIER if necessary.
(simplify_set): Test if a condition code setter has a constant
comparison at compile time, if so convert this insn to a no-op move
and update/simplify the condition code user (undobuf.other_insn).
2002-09-08 Krister Walfridsson <cato@df.lth.se>
* config/arm/netbsd.h (INITIALIZE_TRAMPOLINE): Redefine.

45
gcc/combine.c
View File

@ -2823,7 +2823,7 @@ try_combine (i3, i2, i1, new_direct_jump_p)
BARRIER following it since it may have initially been a
conditional jump. It may also be the last nonnote insn. */
if (GET_CODE (newpat) == RETURN || any_uncondjump_p (i3))
if (returnjump_p (i3) || any_uncondjump_p (i3))
{
*new_direct_jump_p = 1;
@ -2831,6 +2831,18 @@ try_combine (i3, i2, i1, new_direct_jump_p)
|| GET_CODE (temp) != BARRIER)
emit_barrier_after (i3);
}
if (undobuf.other_insn != NULL_RTX
&& (returnjump_p (undobuf.other_insn)
|| any_uncondjump_p (undobuf.other_insn)))
{
*new_direct_jump_p = 1;
if ((temp = next_nonnote_insn (undobuf.other_insn)) == NULL_RTX
|| GET_CODE (temp) != BARRIER)
emit_barrier_after (undobuf.other_insn);
}
/* An NOOP jump does not need barrier, but it does need cleaning up
of CFG. */
if (GET_CODE (newpat) == SET
@ -5014,15 +5026,44 @@ simplify_set (x)
{
enum rtx_code old_code = GET_CODE (*cc_use);
enum rtx_code new_code;
rtx op0, op1;
rtx op0, op1, tmp;
int other_changed = 0;
enum machine_mode compare_mode = GET_MODE (dest);
enum machine_mode tmp_mode;
if (GET_CODE (src) == COMPARE)
op0 = XEXP (src, 0), op1 = XEXP (src, 1);
else
op0 = src, op1 = const0_rtx;
/* Check whether the comparison is known at compile time. */
if (GET_MODE (op0) != VOIDmode)
tmp_mode = GET_MODE (op0);
else if (GET_MODE (op1) != VOIDmode)
tmp_mode = GET_MODE (op1);
else
tmp_mode = compare_mode;
tmp = simplify_relational_operation (old_code, tmp_mode, op0, op1);
if (tmp != NULL_RTX)
{
rtx pat = PATTERN (other_insn);
undobuf.other_insn = other_insn;
SUBST (*cc_use, tmp);
/* Attempt to simplify CC user. */
if (GET_CODE (pat) == SET)
{
rtx new = simplify_rtx (SET_SRC (pat));
if (new != NULL_RTX)
SUBST (SET_SRC (pat), new);
}
/* Convert X into a no-op move. */
SUBST (SET_DEST (x), pc_rtx);
SUBST (SET_SRC (x), pc_rtx);
return x;
}
/* Simplify our comparison, if possible. */
new_code = simplify_comparison (old_code, &op0, &op1);