Stewart Smith wrote:
> 2) Is this perf difference going to be true on different platforms?
Yes definitely. E.g. SSE4.2 supports an asm command for string
comparison. asm commands for mem cpms are on the way for future platforms.
Cheers,
Peter
--
Peter Benjamin Volk
Project Lead
DDEngine.org
On Sat, May 09, 2009 at 12:25:31AM -0700, Eric Day wrote:
> My linux vs sparc testing, completely unequal buffers. One thing
> I find really strange is that gcc -O3 memcmp was slower than gcc
> without a -O option.
Try -fno-builtin so that you're really running memcmp and not the gcc builtin.
--
My linux vs sparc testing, completely unequal buffers. One thing
I find really strange is that gcc -O3 memcmp was slower than gcc
without a -O option.
linux= 2.4ghz core2duo, gcc 4.3.2 64bit
linux> gcc -g -Wall -o a a.c
linux> ./a 1 8
1 repetitions
Testing memcmp . done,
So i broke out mtaylor's patch that we were bumming around with at the UC
to replace ptr_compare with a simple memcmp call.
At the UC I benched that this patch actually caused a measurable performance
regresssion.
So what's the difference?
(same benchmark and machine as in previous mail)
MAX_FIE
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