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| author | Eric Dumazet <dada1@cosmosbay.com> | 2005-09-07 02:16:17 +0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@g5.osdl.org> | 2005-09-08 03:57:15 +0400 |
| commit | 19aaabb5841439988fc357f90d5c59d28fa84658 (patch) | |
| tree | 928d0b695a7c27a61ef7b93549a50014374bf4fe /include | |
| parent | c078d3266e58a3edd698b9f143f78fc585679031 (diff) | |
| download | linux-19aaabb5841439988fc357f90d5c59d28fa84658.tar.xz | |
[PATCH] x86_64: prefetchw() can fall back to prefetch() if !3DNOW
This is a multi-part message in MIME format. If the cpu lacks 3DNOW
feature, we can use a normal prefetcht0 instruction instead of NOP5.
"prefetchw (%rxx)" and "prefetcht0 (%rxx)" have the same length, ranging
from 3 to 5 bytes depending on the register. So this patch even helps
AMD64, shortening the length of the code.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Acked-by: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/asm-x86_64/processor.h | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/include/asm-x86_64/processor.h b/include/asm-x86_64/processor.h index 194160f6a43f..a8321999448f 100644 --- a/include/asm-x86_64/processor.h +++ b/include/asm-x86_64/processor.h @@ -398,7 +398,7 @@ static inline void prefetch(void *x) #define ARCH_HAS_PREFETCHW 1 static inline void prefetchw(void *x) { - alternative_input(ASM_NOP5, + alternative_input("prefetcht0 (%1)", "prefetchw (%1)", X86_FEATURE_3DNOW, "r" (x)); |