[Bug middle-end/108237] [13 Regression] ICE: in gimple_expand_vec_cond_expr, at gimple-isel.cc:281 at -O since r13-1085-g90467f0ad649d081

cvs-commit at gcc dot gnu.org gcc-bugzilla@gcc.gnu.org
Wed Jan 4 09:55:36 GMT 2023


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108237

--- Comment #6 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:345dffd0d4ebff7e705dfff1a8a72017a167120a

commit r13-4989-g345dffd0d4ebff7e705dfff1a8a72017a167120a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Wed Jan 4 10:54:38 2023 +0100

    generic-match-head: Don't assume GENERIC folding is done only early
[PR108237]

    We ICE on the following testcase, because a valid V2DImode
    != comparison is folded into an unsupported V2DImode > comparison.
    The match.pd pattern which does this looks like:
    /* Transform comparisons of the form (X & Y) CMP 0 to X CMP2 Z
       where ~Y + 1 == pow2 and Z = ~Y.  */
    (for cst (VECTOR_CST INTEGER_CST)
     (for cmp (eq ne)
          icmp (le gt)
      (simplify
       (cmp (bit_and:c@2 @0 cst@1) integer_zerop)
        (with { tree csts = bitmask_inv_cst_vector_p (@1); }
         (if (csts && (VECTOR_TYPE_P (TREE_TYPE (@1)) || single_use (@2)))
          (with { auto optab = VECTOR_TYPE_P (TREE_TYPE (@1))
                             ? optab_vector : optab_default;
                  tree utype = unsigned_type_for (TREE_TYPE (@1)); }
           (if (target_supports_op_p (utype, icmp, optab)
                || (optimize_vectors_before_lowering_p ()
                    && (!target_supports_op_p (type, cmp, optab)
                        || !target_supports_op_p (type, BIT_AND_EXPR, optab))))
            (if (TYPE_UNSIGNED (TREE_TYPE (@1)))
             (icmp @0 { csts; })
             (icmp (view_convert:utype @0) { csts; })))))))))
    and that optimize_vectors_before_lowering_p () guarded stuff there
    already deals with this problem, not trying to fold a supported comparison
    into a non-supported one.  The reason it doesn't work in this case is that
    it isn't GIMPLE folding which does this, but GENERIC folding done during
    forwprop4 - forward_propagate_into_comparison ->
forward_propagate_into_comparison_1
    -> combine_cond_expr_cond -> fold_binary_loc -> generic_simplify
    and we simply assumed that GENERIC folding happens only before
    gimplification.

    The following patch fixes that by checking cfun properties instead of
    always returning true in those cases.

    2023-01-04  Jakub Jelinek  <jakub@redhat.com>

            PR middle-end/108237
            * generic-match-head.cc: Include tree-pass.h.
            (canonicalize_math_p, optimize_vectors_before_lowering_p): Define
            to false if cfun and cfun->curr_properties has PROP_gimple_opt_math
            resp. PROP_gimple_lvec property set.

            * gcc.c-torture/compile/pr108237.c: New test.


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