https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121104

--- Comment #5 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <[email protected]>:

https://gcc.gnu.org/g:49c7fc2d534cb7e16f0e95fd89f47eb0b0d34762

commit r16-7239-g49c7fc2d534cb7e16f0e95fd89f47eb0b0d34762
Author: Jakub Jelinek <[email protected]>
Date:   Mon Feb 2 10:07:15 2026 +0100

    widening_mul: Fix UADDC/USUBC pattern matching [PR121104]

    As the following testcase shows, I've missed a check that element type
    of lhs type of ovf1/ovf2 (.ADD_OVERFLOW/.SUB_OVERFLOW) matches type (there
    are some casts accepted on the way for the case of values in [0-1] range),
    so the following testcase got also matched as .SUBC and we get an ICE on
    type mismatch in there.  The other .{ADD,SUB}_OVERFLOW cases already check
    even the result type, both
                        if (gimple_call_internal_p (ovf, code == PLUS_EXPR
                                                         ? IFN_ADD_OVERFLOW
                                                         : IFN_SUB_OVERFLOW))
    ...
                            ovf_lhs = gimple_call_lhs (ovf);
                            tree ovf_lhs_type = TREE_TYPE (TREE_TYPE
(ovf_lhs));
                            ovf_arg1 = gimple_call_arg (ovf, 0);
                            ovf_arg2 = gimple_call_arg (ovf, 1);
                            /* In that case we need to punt if the types don't
                               mismatch.  */
                            if (!types_compatible_p (type, ovf_lhs_type)
                                || !types_compatible_p (type, TREE_TYPE
(ovf_arg1))
                                || !types_compatible_p (type,
                                                        TREE_TYPE (ovf_arg2)))
                              ovf_lhs = NULL_TREE;
    and
              gimple *ovf3
                = SSA_NAME_DEF_STMT (TREE_OPERAND (gimple_assign_rhs1 (im3),
0));
              if (gimple_call_internal_p (ovf3, ifn))
                {
                  lhs = gimple_call_lhs (ovf3);
                  arg1 = gimple_call_arg (ovf3, 0);
                  arg2 = gimple_call_arg (ovf3, 1);
                  if (types_compatible_p (type, TREE_TYPE (TREE_TYPE (lhs)))
                      && types_compatible_p (type, TREE_TYPE (arg1))
                      && types_compatible_p (type, TREE_TYPE (arg2)))

    2026-02-02  Jakub Jelinek  <[email protected]>

            PR tree-optimization/121104
            * tree-ssa-math-opts.cc (match_uaddc_usubc): Punt if
            lhs of ovf1 or ovf2 doesn't have element type compatible with type.

            * gcc.dg/pr121104.c: New test.

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