Improve __csum_partial by interleaving loads and adds.
On a 8xx, it brings neither improvement nor degradation.
On a 83xx, it brings a 25% improvement.
Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
---
arch/powerpc/lib/checksum_32.S | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/arch/powerpc/lib/checksum_32.S b/arch/powerpc/lib/checksum_32.S
index d2238ea82209..aa224069f93a 100644
--- a/arch/powerpc/lib/checksum_32.S
+++ b/arch/powerpc/lib/checksum_32.S
@@ -47,16 +47,25 @@ _GLOBAL(__csum_partial)
bdnz 2b
21: srwi. r6,r4,4 /* # blocks of 4 words to do */
beq 3f
+ lwz r0,4(r3)
mtctr r6
-22: lwz r0,4(r3)
lwz r6,8(r3)
+ adde r5,r5,r0
lwz r7,12(r3)
+ adde r5,r5,r6
lwzu r8,16(r3)
+ adde r5,r5,r7
+ bdz 23f
+22: lwz r0,4(r3)
+ adde r5,r5,r8
+ lwz r6,8(r3)
adde r5,r5,r0
+ lwz r7,12(r3)
adde r5,r5,r6
+ lwzu r8,16(r3)
adde r5,r5,r7
- adde r5,r5,r8
bdnz 22b
+23: adde r5,r5,r8
3: andi. r0,r4,2
beq+ 4f
lhz r0,4(r3)
--
2.13.3
