linux/mem-memcpy-x86-64-asm.S at 9ea811973d49a1df0be04ff6e4df449e4fca4fb5 - linux - MSD Gitea: Git with a cup of tea

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Jan Beulich 9ea811973d perf bench: Make "default" memcpy() selection actually use glibc's implementation

Since arch/x86/lib/memcpy_64.S implements not only __memcpy, but also
memcpy, without further precautions this function will get chose by the
static linker for resolving all references, and hence the "default"
measurement didn't really measure anything else than the
"x86-64-unrolled" one.

Fix this by renaming (through the pre-processor) the conflicting symbol.

On my Westmere system, the glibc variant turns out to require about 4%
less instructions, but 15% more cycles for the default 1Mb block size
measured.

Cc: Ingo Molnar <mingo@elte.hu>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/4F16D6FD020000780006D72F@nat28.tlf.novell.com
Signed-off-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

2012-01-24 19:50:19 -02:00

3 lines

101 B

ArmAsm

Raw Blame History

	`#define memcpy MEMCPY /* don't hide glibc's memcpy() */`
	`#include "../../../arch/x86/lib/memcpy_64.S"`