From: Andrew Pinski <apin...@marvell.com>
Like I mentioned in https://gcc.gnu.org/ml/gcc/2020-01/msg00157.html,
The shift by a register should be just COSTS_N_INSNS (1) rather than
COSTS_N_INSNS (2). This allows lshift_cheap_p to return true now
and converting switches to be using shift and other like
structures. I noticed this difference when I was working
through PR 93131 and understanding what reassoc could handle.
OK? Bootstrapped and tested on aarch64-linux-gnu with no regressions.
Thanks,
Andrew Pinski
ChangeLog:
* config/arm/aarch-cost-tables.h (cortexa57_extra_costs): Change
alu.shift_reg to 0.
---
gcc/config/arm/aarch-cost-tables.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/gcc/config/arm/aarch-cost-tables.h
b/gcc/config/arm/aarch-cost-tables.h
index 6a30d92cde9..cf818659901 100644
--- a/gcc/config/arm/aarch-cost-tables.h
+++ b/gcc/config/arm/aarch-cost-tables.h
@@ -235,7 +235,7 @@ const struct cpu_cost_table cortexa57_extra_costs =
0, /* arith. */
0, /* logical. */
0, /* shift. */
- COSTS_N_INSNS (1), /* shift_reg. */
+ 0, /* shift_reg. */
COSTS_N_INSNS (1), /* arith_shift. */
COSTS_N_INSNS (1), /* arith_shift_reg. */
COSTS_N_INSNS (1), /* log_shift. */
--
2.17.1
