> Am 03.01.2026 um 02:12 schrieb Jakub Jelinek <[email protected]>:
>
> Hi!
>
> The following testcase ICEs since r15-1671, because the match.pd pattern
> now allows a cast and the function checks whether the ifn is supported
> on a wrong type. .SAT_{ADD,SUB,MUL} are binary ifns, so they care about
> the type of their first operand:
> #define binary_direct { 0, 0, true }
> where
> /* optabs can be parameterized by one or two modes. These fields describe
> how to select those modes from the types of the return value and
> arguments. A value of -1 says that the mode is determined by the
> return type while a value N >= 0 says that the mode is determined by
> the type of argument N. A value of -2 says that this internal
> function isn't directly mapped to an optab. */
> but in this function (unlike the function right below it for the
> same ifns) checks the type of the lhs which since that change can be
> actually a different type (expansion performs the operation on the
> argument types and then casts the result to the lhs type).
> So, e.g. on x86_64 -m32, it checks wether ussubsi3 insn can be used
> (which it can), but then actually uses it on DImode arguments and
> ussubdi3 is TARGET_64BIT only. Similarly for -m64 it checks ussubsi3 too
> instead of ussubti3 (which doesn't exist).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk
> and after a while for 15.3?
Ok
Richard
> 2026-01-03 Jakub Jelinek <[email protected]>
>
> PR tree-optimization/123372
> * tree-ssa-math-opts.cc
> (build_saturation_binary_arith_call_and_replace): Pass type of op_0
> rather than type of lhs as second argument to
> direct_internal_fn_supported_p.
>
> * gcc.dg/tree-ssa/pr123372.c: New test.
>
> --- gcc/tree-ssa-math-opts.cc.jj 2026-01-02 09:56:10.390332748 +0100
> +++ gcc/tree-ssa-math-opts.cc 2026-01-02 18:45:57.087546705 +0100
> @@ -4083,7 +4083,7 @@ build_saturation_binary_arith_call_and_r
> internal_fn fn, tree lhs,
> tree op_0, tree op_1)
> {
> - if (direct_internal_fn_supported_p (fn, TREE_TYPE (lhs),
> OPTIMIZE_FOR_BOTH))
> + if (direct_internal_fn_supported_p (fn, TREE_TYPE (op_0),
> OPTIMIZE_FOR_BOTH))
> {
> gcall *call = gimple_build_call_internal (fn, 2, op_0, op_1);
> gimple_call_set_lhs (call, lhs);
> --- gcc/testsuite/gcc.dg/tree-ssa/pr123372.c.jj 2026-01-02
> 18:49:45.419717435 +0100
> +++ gcc/testsuite/gcc.dg/tree-ssa/pr123372.c 2026-01-02 18:51:22.256093427
> +0100
> @@ -0,0 +1,25 @@
> +/* PR tree-optimization/123372 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -fgimple" } */
> +
> +#ifdef __SIZEOF_INT128__
> +#define T unsigned __int128
> +#else
> +#define T unsigned long long
> +#endif
> +
> +unsigned int __GIMPLE (ssa,startwith("phiopt4"))
> +foo (T a, T b)
> +{
> + T _4;
> + unsigned int _1;
> + bool _5;
> + unsigned int _6;
> +
> + __BB(2):
> + _5 = a_2(D) >= b_3(D);
> + _4 = a_2(D) - b_3(D);
> + _6 = (unsigned int) _4;
> + _1 = _5 ? _6 : 0U;
> + return _1;
> +}
>
> Jakub
>
