[coreboot] Patch set updated for coreboot: d147cdd x86 memcpy: Copy 4 bytes at once
Stefan Reinauer (stefan.reinauer@coreboot.org)
gerrit at coreboot.org
Wed Nov 7 19:59:23 CET 2012
Stefan Reinauer (stefan.reinauer at coreboot.org) just uploaded a new patch set to gerrit, which you can find at http://review.coreboot.org/1742
-gerrit
commit d147cdd620bde2f132a34d898fc6bb3f537ca081
Author: Stefan Reinauer <reinauer at google.com>
Date: Wed Aug 22 17:01:08 2012 -0700
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 at google.com>
---
src/arch/x86/lib/memcpy.c | 10 ++++++----
1 file changed, 6 insertions(+), 4 deletions(-)
diff --git a/src/arch/x86/lib/memcpy.c b/src/arch/x86/lib/memcpy.c
index f8607cf..7f079ce 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;
}
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