OpenE2K/gcc
2
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

ifcvt.c (noce_get_alt_condition): Use prev_nonnote_insn.

Browse Source 
* ifcvt.c (noce_get_alt_condition): Use prev_nonnote_insn.
	(noce_try_abs): Negate if the comparison is reversed.
	Look only one instruction backwards for a REG_EQUAL note.

From-SVN: r106706
This commit is contained in:
Eric Botcazou 2005-11-09 21:34:31 +00:00 committed by Eric Botcazou
parent 7ef67393c7
commit c8e90f4053
4 changed files with 53 additions and 15 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
gcc/ChangeLog
View File

@ -1,3 +1,9 @@
2005-11-09 Eric Botcazou <ebotcazou@adacore.com>
* ifcvt.c (noce_get_alt_condition): Use prev_nonnote_insn.
(noce_try_abs): Negate if the comparison is reversed.
Look only one instruction backwards for a REG_EQUAL note.
2005-11-09 Alexandre Oliva <aoliva@redhat.com>
PR other/4372

37
gcc/ifcvt.c
View File

@ -1485,7 +1485,7 @@ noce_get_alt_condition (struct noce_if_info *if_info, rtx target,
rtx prev_insn;
/* First, look to see if we put a constant in a register. */
prev_insn = PREV_INSN (if_info->cond_earliest);
prev_insn = prev_nonnote_insn (if_info->cond_earliest);
if (prev_insn
&& INSN_P (prev_insn)
&& GET_CODE (PATTERN (prev_insn)) == SET)
@ -1697,7 +1697,9 @@ noce_try_abs (struct noce_if_info *if_info)
if (no_new_pseudos)
return FALSE;
/* Recognize A and B as constituting an ABS or NABS. */
/* Recognize A and B as constituting an ABS or NABS. The canonical
form is a branch around the negation, taken when the object is the
first operand of a comparison against 0 that evaluates to true. */
a = if_info->a;
b = if_info->b;
if (GET_CODE (a) == NEG && rtx_equal_p (XEXP (a, 0), b))
@ -1718,25 +1720,30 @@ noce_try_abs (struct noce_if_info *if_info)
if (rtx_equal_p (XEXP (cond, 0), b))
c = XEXP (cond, 1);
else if (rtx_equal_p (XEXP (cond, 1), b))
c = XEXP (cond, 0);
{
c = XEXP (cond, 0);
negate = !negate;
}
else
return FALSE;
/* Verify that C is zero. Search backward through the block for
a REG_EQUAL note if necessary. */
/* Verify that C is zero. Search one step backward for a
REG_EQUAL note or a simple source if necessary. */
if (REG_P (c))
{
rtx insn, note = NULL;
for (insn = earliest;
insn != BB_HEAD (if_info->test_bb);
insn = PREV_INSN (insn))
if (INSN_P (insn)
&& ((note = find_reg_note (insn, REG_EQUAL, c))
|| (note = find_reg_note (insn, REG_EQUIV, c))))
break;
if (! note)
rtx set, insn = prev_nonnote_insn (earliest);
if (insn
&& (set = single_set (insn))
&& rtx_equal_p (SET_DEST (set), c))
{
rtx note = find_reg_equal_equiv_note (insn);
if (note)
c = XEXP (note, 0);
else
c = SET_SRC (set);
}
else
return FALSE;
c = XEXP (note, 0);
}
if (MEM_P (c)
&& GET_CODE (XEXP (c, 0)) == SYMBOL_REF

4
gcc/testsuite/ChangeLog
View File

@ -1,3 +1,7 @@
2005-11-09 Eric Botcazou <ebotcazou@adacore.com>
* gcc.dg/ifcvt-fabs-1.c: New test.
2005-11-09 Alexandre Oliva <aoliva@redhat.com>
PR other/4372

21
gcc/testsuite/gcc.dg/ifcvt-fabs-1.c Normal file
View File

@ -0,0 +1,21 @@
/* { dg-do run } */
/* { dg-options "-O" } */
/* { dg-options "-O -march=i686" { target i686-*-* } } */
extern void abort(void);
float foo(float f)
{
if (f < 0.0f)
f = -f;
return f;
}
int main(void)
{
if (foo (-1.0f) != 1.0f)
abort ();
return 0;
}