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800eb0148 perf bench: Also allow measuring alternative memcpy implementations ... Browse Code »

Intended to be able to support the current selection of the preferred
memcpy() implementation, this patch adds the ability to also measure the
two alternative implementations, again by way of using some
pre-processsor replacement.

While on my Westmere system this proves that the movsb based variant is
worse than the movsq based one (since the ERMS feature isn't there), it
also shows that here for the default as well as small sizes the unrolled
variant outperforms the movsq one.

Cc: Ingo Molnar
Cc: Paul Mackerras
Cc: Peter Zijlstra
Link: http://lkml.kernel.org/r/4F16D728020000780006D732@nat28.tlf.novell.com
Signed-off-by: Jan Beulich
Signed-off-by: Arnaldo Carvalho de Melo

Jan Beulich
2012-01-25 05:51:01 +0800

mem-memcpy-x86-64-asm-def.h 275 Bytes

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MEMCPY_FN(__memcpy,
	"x86-64-unrolled",
	"unrolled memcpy() in arch/x86/lib/memcpy_64.S")

MEMCPY_FN(memcpy_c,
	"x86-64-movsq",
	"movsq-based memcpy() in arch/x86/lib/memcpy_64.S")

MEMCPY_FN(memcpy_c_e,
	"x86-64-movsb",
	"movsb-based memcpy() in arch/x86/lib/memcpy_64.S")