On Wed, Sep 13, 2023 at 12:11 AM Andrew Pinski via Gcc-patches
<gcc-patches@gcc.gnu.org> wrote:
>
> This merges the two patterns to catch
> `(X % Y) < Y` and `Y > (X % Y)` into one by
> using :c on the comparison operator.
> It does not change any code generation nor
> anything else. It is more to allow for better
> maintainability of this pattern.
>
> OK? Bootstrapped and tested on x86_64-linux-gnu.
OK.
> gcc/ChangeLog:
>
> * match.pd (`Y > (X % Y)`): Merge
> into ...
> (`(X % Y) < Y`): Pattern by adding `:c`
> on the comparison.
> ---
> gcc/match.pd | 7 +------
> 1 file changed, 1 insertion(+), 6 deletions(-)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index 39c7ea1088f..24fd29863fb 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -1483,14 +1483,9 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> /* X % Y is smaller than Y. */
> (for cmp (lt ge)
> (simplify
> - (cmp (trunc_mod @0 @1) @1)
> + (cmp:c (trunc_mod @0 @1) @1)
> (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
> { constant_boolean_node (cmp == LT_EXPR, type); })))
> -(for cmp (gt le)
> - (simplify
> - (cmp @1 (trunc_mod @0 @1))
> - (if (TYPE_UNSIGNED (TREE_TYPE (@0)))
> - { constant_boolean_node (cmp == GT_EXPR, type); })))
>
> /* x | ~0 -> ~0 */
> (simplify
> --
> 2.31.1
>
