[PATCH 2/2] armv8/cache.S: Triple with single instruction
Pierre-Clément Tosi
ptosi at google.com
Fri Aug 27 18:04:10 CEST 2021
Replace the current 2-instruction 2-step tripling code by a
corresponding single instruction leveraging ARMv8-A's "flexible second
operand as a register with optional shift". This has the added benefit
(albeit arguably negligible) of reducing the final code size.
Fix the comment as the tripled cache level is placed in x12, not x0.
Signed-off-by: Pierre-Clément Tosi <ptosi at google.com>
---
arch/arm/cpu/armv8/cache.S | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/arch/arm/cpu/armv8/cache.S b/arch/arm/cpu/armv8/cache.S
index aabb3dff61..5051597f6f 100644
--- a/arch/arm/cpu/armv8/cache.S
+++ b/arch/arm/cpu/armv8/cache.S
@@ -80,8 +80,7 @@ ENTRY(__asm_dcache_all)
/* x15 <- return address */
loop_level:
- lsl x12, x0, #1
- add x12, x12, x0 /* x0 <- tripled cache level */
+ add x12, x0, x0, lsl #1 /* x12 <- tripled cache level */
lsr x12, x10, x12
and x12, x12, #7 /* x12 <- cache type */
cmp x12, #2
--
2.33.0.259.gc128427fd7-goog
--
Pierre
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