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fold-const.c (fold_binary): Guard (X-X) -> 0 transformation with !HONOR_NANS and !HONOR_INFINITIES.

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* fold-const.c (fold_binary): Guard (X-X) -> 0 transformation
	with !HONOR_NANS and !HONOR_INFINITIES.
	* simplify-rtx.c (simplify_binary_operation_1): Likewise.

From-SVN: r125652
This commit is contained in:
Kaveh R. Ghazi 2007-06-12 16:28:01 +00:00 committed by Kaveh Ghazi
parent 1c2abe5e5c
commit 52a39a4c5d
3 changed files with 16 additions and 3 deletions
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6
gcc/ChangeLog
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@ -1,3 +1,9 @@
2007-06-12 Kaveh R. Ghazi <ghazi@caip.rutgers.edu>
* fold-const.c (fold_binary): Guard (X-X) -> 0 transformation
with !HONOR_NANS and !HONOR_INFINITIES.
* simplify-rtx.c (simplify_binary_operation_1): Likewise.
2007-06-12 Tristan Gingold <gingold@adacore.com>
* gcov.c: Comments updated.

5
gcc/fold-const.c
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@ -9585,7 +9585,10 @@ fold_binary (enum tree_code code, tree type, tree op0, tree op1)
Also note that operand_equal_p is always false if an operand
is volatile. */
if ((! FLOAT_TYPE_P (type) || flag_unsafe_math_optimizations)
if ((! FLOAT_TYPE_P (type)
|| (flag_unsafe_math_optimizations
&& !HONOR_NANS (TYPE_MODE (type))
&& !HONOR_INFINITIES (TYPE_MODE (type))))
&& operand_equal_p (arg0, arg1, 0))
return fold_convert (type, integer_zero_node);

8
gcc/simplify-rtx.c
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@ -1772,10 +1772,14 @@ simplify_binary_operation_1 (enum rtx_code code, enum machine_mode mode,
case MINUS:
/* We can't assume x-x is 0 even with non-IEEE floating point,
but since it is zero except in very strange circumstances, we
will treat it as zero with -funsafe-math-optimizations. */
will treat it as zero with -funsafe-math-optimizations and
-ffinite-math-only. */
if (rtx_equal_p (trueop0, trueop1)
&& ! side_effects_p (op0)
&& (! FLOAT_MODE_P (mode) || flag_unsafe_math_optimizations))
&& (! FLOAT_MODE_P (mode)
|| (flag_unsafe_math_optimizations
&& !HONOR_NANS (mode)
&& !HONOR_INFINITIES (mode))))
return CONST0_RTX (mode);
/* Change subtraction from zero into negation. (0 - x) is the