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.