Hi,
On Tue, Jul 11, 2017 at 10:47:27AM +0200, Georg-Johann Lay wrote:
> This small addition improves costs of PARALLELs in
> rtlanal.c:seq_cost(). Up to now, these costs are
> assumed to be 1 which gives gross inexact costs for,
> e.g. divmod which is represented as PARALLEL.
insn_rtx_cost returns 0 ("unknown") for such a PARALLEL, so your
current patch does not change this at all?
> --- rtlanal.c (revision 248745)
> +++ rtlanal.c (working copy)
> @@ -5300,6 +5300,9 @@ seq_cost (const rtx_insn *seq, bool spee
> set = single_set (seq);
> if (set)
> cost += set_rtx_cost (set, speed);
So, why does this not use insn_rtx_cost as well?
> + else if (INSN_P (seq)
> + && PARALLEL == GET_CODE (PATTERN (seq)))
Yoda conditions have we should not.
> + cost += 1 + insn_rtx_cost (PATTERN (seq), speed);
> else
> cost++;
> }
This whole thing could be something like
if (INSN_P (seq))
{
int t = insn_rtx_cost (PATTERN (seq), speed);
cost += t ? t : COST_N_INSNS (1);
}
else
cost++;
But set_rtx_cost does *not* return the same answer as insn_rtx_cost.
(Why do you need a check for INSN_P here? Why does it increment the
cost for non-insns? So many questions).
Segher
