The following patch avoids folding NaN < 0 to false if -ftrapping-math
is in effect.
Bootstrap & regtest pending on x86_64-unknown-linux-gnu.
Richard.
2015-07-30 Richard Biener <rguent...@suse.de>
PR middle-end/67052
* fold-const.c (fold_binary_loc): Do not fold NaN < 0 to false
if FP math can trap.
Index: gcc/fold-const.c
===================================================================
--- gcc/fold-const.c (revision 226387)
+++ gcc/fold-const.c (working copy)
@@ -11634,7 +11455,9 @@ fold_binary_loc (location_t loc,
/* Convert ABS_EXPR<x> < 0 to false. */
strict_overflow_p = false;
if (code == LT_EXPR
- && (integer_zerop (arg1) || real_zerop (arg1))
+ && (integer_zerop (arg1)
+ || ((! HONOR_NANS (arg0) || !flag_trapping_math)
+ && real_zerop (arg1)))
&& tree_expr_nonnegative_warnv_p (arg0, &strict_overflow_p))
{
if (strict_overflow_p)
