https://gcc.gnu.org/g:e14c673ea9ab2eca5de4db91b478f0b5297ef321
commit r15-696-ge14c673ea9ab2eca5de4db91b478f0b5297ef321
Author: Wilco Dijkstra <wilco.dijks...@arm.com>
Date: Wed Apr 17 17:18:23 2024 +0100
AArch64: Improve costing of ctz
Improve costing of ctz - both TARGET_CSSC and vector cases were not handled
yet.
gcc:
* config/aarch64/aarch64.cc (aarch64_rtx_costs): Improve CTZ
costing.
Diff:
---
gcc/config/aarch64/aarch64.cc | 22 ++++++++++++++++++----
1 file changed, 18 insertions(+), 4 deletions(-)
diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
index 662ff5a9b0c7..ee12d8897a88 100644
--- a/gcc/config/aarch64/aarch64.cc
+++ b/gcc/config/aarch64/aarch64.cc
@@ -14349,10 +14349,24 @@ aarch64_rtx_costs (rtx x, machine_mode mode, int
outer ATTRIBUTE_UNUSED,
return false;
case CTZ:
- *cost = COSTS_N_INSNS (2);
-
- if (speed)
- *cost += extra_cost->alu.clz + extra_cost->alu.rev;
+ if (VECTOR_MODE_P (mode))
+ {
+ *cost = COSTS_N_INSNS (3);
+ if (speed)
+ *cost += extra_cost->vect.alu * 3;
+ }
+ else if (TARGET_CSSC)
+ {
+ *cost = COSTS_N_INSNS (1);
+ if (speed)
+ *cost += extra_cost->alu.clz;
+ }
+ else
+ {
+ *cost = COSTS_N_INSNS (2);
+ if (speed)
+ *cost += extra_cost->alu.clz + extra_cost->alu.rev;
+ }
return false;
case COMPARE:
