https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107647
--- Comment #16 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Alexander Monakov from comment #15)
> I'm confused about the first hunk in the attached patch:
>
> --- a/gcc/tree-vect-slp-patterns.cc
> +++ b/gcc/tree-vect-slp-patterns.cc
> @@ -1035,8 +1035,10 @@ complex_mul_pattern::matches (complex_operation_t op,
> auto_vec<slp_tree> left_op, right_op;
> slp_tree add0 = NULL;
>
> - /* Check if we may be a multiply add. */
> + /* Check if we may be a multiply add. It's only valid to form FMAs
> + with -ffp-contract=fast. */
> if (!mul0
> + && flag_fp_contract_mode != FP_CONTRACT_FAST
> && vect_match_expression_p (l0node[0], PLUS_EXPR))
> {
> auto vals = SLP_TREE_CHILDREN (l0node[0]);
>
>
> Shouldn't it be ' == FP_CONTRACT_FAST' rather than '!='? It seems we are
> checking that a match is found and contracting across statement boundaries
> is allowed.
whoops yes, I'll fix and add a check for the type.
