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| author | Stefan Reinauer <reinauer@google.com> | 2012-08-22 17:01:08 -0700 |
|---|---|---|
| committer | Stefan Reinauer <stefan.reinauer@coreboot.org> | 2012-11-08 19:40:26 +0100 |
| commit | 31409617a46c5ac6ef1a893d3c478f76ce4d7d3d (patch) | |
| tree | 28ab73ff80d809a7f4de38788cd07eecc2d55345 | |
| parent | 4b1610d766aa1ea0c825b39600fe8a3eb6d2a6be (diff) | |
x86 memcpy: Copy 4 bytes at once
This is a slight improvement over the rep movsb loop
Change-Id: Id71d9bfe5330b154a5c62fac85ce3955ae89b057
Signed-off-by: Stefan Reinauer <reinauer@google.com>
Reviewed-on: http://review.coreboot.org/1742
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
| -rw-r--r-- | src/arch/x86/lib/memcpy.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/src/arch/x86/lib/memcpy.c b/src/arch/x86/lib/memcpy.c index f8607cfc50..7f079ce9d6 100644 --- a/src/arch/x86/lib/memcpy.c +++ b/src/arch/x86/lib/memcpy.c @@ -5,11 +5,13 @@ void *memcpy(void *dest, const void *src, size_t n) unsigned long d0, d1, d2; asm volatile( - "rep movsb" - : "=S"(d0), "=D"(d1), "=c"(d2) - : "0"(src), "1"(dest), "2"(n) + "rep ; movsl\n\t" + "movl %4,%%ecx\n\t" + "rep ; movsb\n\t" + : "=&c" (d0), "=&D" (d1), "=&S" (d2) + : "0" (n >> 2), "g" (n & 3), "1" (dest), "2" (src) : "memory" - ); + ); return dest; } |