https://gcc.gnu.org/bugzilla/show_bug.cgi?id=126328
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |ASSIGNED
Ever confirmed|0 |1
Assignee|unassigned at gcc dot gnu.org |rguenth at gcc dot
gnu.org
Last reconfirmed| |2026-07-21
--- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> ---
(In reply to Richard Biener from comment #3)
[...]
> That works for the case at hand, but is still quite arbitrary cost,
> but it avoids regressing gcc.target/i386/pr54400.c when we SLP vectorize
> the horizontal reductions.
>
> @@ -23538,8 +23547,10 @@ ix86_rtx_costs (rtx x, machine_mode mode, int
> outer_code_i, int opno,
> /* ??? Assume all of these vector manipulation patterns are
> recognizable. In which case they all pretty much have the
> same cost.
> - ??? We should still recruse when computing cost. */
> + ??? We should still recurse when computing cost. */
> *total = cost->sse_op;
> + if (GET_CODE (XEXP (x, 0)) == PLUS || GET_CODE (XEXP (x, 0)) == MINUS)
> + return false;
> return true;
>
> case VEC_SELECT:
that said, I'll try to cook up a complete match for hadd matching in
the insn_cost hook.
