Hi!
This PR complains that seq_cost counts all non-single_set insns as 1
unconditionally, which is indeed bad. For some like compare + arithmetics
we even have now code in pattern_cost that handles those reasonably by
default, for others targets have the option through a hook to return
whatever they want.
On the other side, IMNSHO we don't want to count CODE_LABELs, NOTEs,
BARRIERs, DEBUG_INSNs...
Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
2017-11-29 Jakub Jelinek <ja...@redhat.com>
PR middle-end/80929
* rtlanal.c (seq_cost): For non-single_set insns try to use insn_cost.
--- gcc/rtlanal.c.jj 2017-10-27 14:16:39.000000000 +0200
+++ gcc/rtlanal.c 2017-11-27 13:35:46.321509933 +0100
@@ -5342,7 +5342,13 @@ seq_cost (const rtx_insn *seq, bool spee
if (set)
cost += set_rtx_cost (set, speed);
- else
- cost++;
+ else if (NONDEBUG_INSN_P (seq))
+ {
+ int this_cost = insn_cost (CONST_CAST_RTX_INSN (seq), speed);
+ if (this_cost > 0)
+ cost += this_cost;
+ else
+ cost++;
+ }
}
return cost;
Jakub
