On Thu, Nov 26, 2020 at 01:56:03PM -0000, Roger Sayle wrote:
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -3998,7 +3998,7 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> (cmp @0 { build_real (TREE_TYPE (@1), dconst0); }))
> /* x != NaN is always true, other ops are always false. */
> (if (REAL_VALUE_ISNAN (TREE_REAL_CST (@1))
> - && ! HONOR_SNANS (@1))
> + && ! flag_trapping_math)
Shouldn't this one stay as is for cmp == EQ_EXPR || cmp == NE_EXPR?
I mean, == or != only raise exceptions on sNaNs, while other simple
comparisons raise on both sNaNs and qNaNs.
> --- a/gcc/simplify-rtx.c
> +++ b/gcc/simplify-rtx.c
> @@ -5732,12 +5732,13 @@ simplify_const_relational_operation (enum rtx_code
> code,
> if (REAL_VALUE_ISNAN (*d0) || REAL_VALUE_ISNAN (*d1))
> switch (code)
> {
> + case NE:
> + return flag_trapping_math ? 0 : const_true_rtx;
And here too (for NE and would need moving EQ later too.
> case UNEQ:
> case UNLT:
> case UNGT:
> case UNLE:
> case UNGE:
> - case NE:
> case UNORDERED:
> return const_true_rtx;
> case EQ:
> @@ -5746,6 +5747,7 @@ simplify_const_relational_operation (enum rtx_code code,
> case LE:
> case GE:
> case LTGT:
> + return flag_trapping_math ? 0 : const0_rtx;
> case ORDERED:
> return const0_rtx;
> default:
Jakub
