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Subject[PATCH -mm] i386 usercopy.c opcode reordering (pipelining)
Hi all,

this one wrote to register %0 and immediately right-shifted it,
so let's andl register %3 first for better parallelism (rrright?).

Signed-off-by: Andreas Mohr <andi@lisas.de>


diff -urN linux-2.6.17-rc6-mm2.orig/arch/i386/lib/usercopy.c linux-2.6.17-rc6-mm2.my/arch/i386/lib/usercopy.c
--- linux-2.6.17-rc6-mm2.orig/arch/i386/lib/usercopy.c 2006-06-13 19:28:09.000000000 +0200
+++ linux-2.6.17-rc6-mm2.my/arch/i386/lib/usercopy.c 2006-06-13 19:38:11.000000000 +0200
@@ -646,8 +646,8 @@
" subl %0,%3\n" \
"4: rep; movsb\n" \
" movl %3,%0\n" \
- " shrl $2,%0\n" \
" andl $3,%3\n" \
+ " shrl $2,%0\n" \
" .align 2,0x90\n" \
"0: rep; movsl\n" \
" movl %3,%0\n" \
@@ -682,8 +682,8 @@
" subl %0,%3\n" \
"4: rep; movsb\n" \
" movl %3,%0\n" \
- " shrl $2,%0\n" \
" andl $3,%3\n" \
+ " shrl $2,%0\n" \
" .align 2,0x90\n" \
"0: rep; movsl\n" \
" movl %3,%0\n" \
-
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