Re: [PATCH 4/7] MIN/MAX should be treated similar as comparisons for trapping

[Richard Biener <richard.guenther@gmail.com>]

On Mon, Apr 24, 2023 at 11:31 PM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> While looking into moving optimizations from minmax_replacement
> in phiopt to match.pd, I Noticed that min/max were considered
> trapping even if -ffinite-math-only was being used. This changes
> those expressions to be similar as comparisons so that they are
> not considered trapping if -ffinite-math-only is on.
>
> OK? Bootstrapped and tested with no regressions on x86_64-linux-gnu.

OK.

> gcc/ChangeLog:
>
>         * rtlanal.cc (may_trap_p_1): Treat SMIN/SMAX similar as
>         COMPARISON.
>         * tree-eh.cc (operation_could_trap_helper_p): Treate
>         MIN_EXPR/MAX_EXPR similar as other comparisons.
> ---
>  gcc/rtlanal.cc | 3 +++
>  gcc/tree-eh.cc | 3 +++
>  2 files changed, 6 insertions(+)
>
> diff --git a/gcc/rtlanal.cc b/gcc/rtlanal.cc
> index c96a88cebf1..b7948ecfad1 100644
> --- a/gcc/rtlanal.cc
> +++ b/gcc/rtlanal.cc
> @@ -3204,6 +3204,9 @@ may_trap_p_1 (const_rtx x, unsigned flags)
>      case LT:
>      case LTGT:
>      case COMPARE:
> +    /* Treat min/max similar as comparisons.  */
> +    case SMIN:
> +    case SMAX:
>        /* Some floating point comparisons may trap.  */
>        if (!flag_trapping_math)
>         break;
> diff --git a/gcc/tree-eh.cc b/gcc/tree-eh.cc
> index 41cf57d2b30..dbaa27d95c5 100644
> --- a/gcc/tree-eh.cc
> +++ b/gcc/tree-eh.cc
> @@ -2490,6 +2490,9 @@ operation_could_trap_helper_p (enum tree_code op,
>      case GT_EXPR:
>      case GE_EXPR:
>      case LTGT_EXPR:
> +    /* MIN/MAX similar as LT/LE/GT/GE. */
> +    case MIN_EXPR:
> +    case MAX_EXPR:
>        /* Some floating point comparisons may trap.  */
>        return honor_nans;
>
> --
> 2.39.1
>