On Wed, Oct 22, 2025 at 2:15 AM Andrew Pinski
<[email protected]> wrote:
>
> This is the last patch that is needed to support to remove minmax_replacement.
> This fixes pr101024-1.c which is failing when minmax_replacement is removed.
>
> This next patch will remove it.
>
> gcc/ChangeLog:
>
> PR tree-optimization/101024
> * match.pd (`((signed)a </>= 0) ? min/max (a, c) : b`): New pattern.
> ---
> gcc/match.pd | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/gcc/match.pd b/gcc/match.pd
> index a4248a521cf..c6e7850a46e 100644
> --- a/gcc/match.pd
> +++ b/gcc/match.pd
> @@ -6911,6 +6911,27 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
> && integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, @3,
> @4)))
> (max @2 @4))))))
>
> +/* Optimize (((signed)a CMP 0) ? max<a,CST2> : a */
> +(for cmp (lt ge)
> + minmax (min max)
> + (simplify
> + (cond (cmp:c (nop_convert @0) integer_zerop@1) (minmax:c@2 @0 @3) @4)
why is @4 not @0 as in the comment above? Why do we need :c on the minmax
when @3 is a constant? (and why's that not checked for?)
> + (if (!TYPE_UNSIGNED (TREE_TYPE (@1)))
> + (with
> + {
> + tree c1 = fold_convert (TREE_TYPE (@0), TYPE_MIN_VALUE (TREE_TYPE
> (@1)));
I'd prefer a wide_int_to_tree of the appropriate value rather than
relying on TYPE_MIN_VALUE
here (but then ideally minmax_from_comparison wouldn't require a tree
in the first place...).
> + tree_code ncmp = cmp == GE_EXPR ? LT_EXPR : GE_EXPR;
> + tree_code code = minmax_from_comparison (ncmp, @0, c1, @0, @4);
> + }
> + (if (ncmp == LT_EXPR
> + && code == MIN_EXPR
> + && integer_nonzerop (fold_build2 (LE_EXPR, boolean_type_node, @3,
> @4)))
Err, can we please avoid building & folding trees here? Or at least
it warrants some comment
as to why this is necessary (esp. why not && (tem = fold_binary (...))
&& integer_nonzerop (tem)).
> + (min @2 @4)
> + (if (ncmp == GE_EXPR
> + && code == MAX_EXPR
> + && integer_nonzerop (fold_build2 (GE_EXPR, boolean_type_node, @3,
> @4)))
> + (max @2 @4)))))))
> +
> #if GIMPLE
> /* These patterns should be after min/max detection as simplifications
> of `(type)(zero_one ==/!= 0)` to `(type)(zero_one)`
> --
> 2.43.0
>
