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Re: Linux doesn't follow x86/x86-64 ABI wrt direction flag
On Thu, 6 Mar 2008, Andi Kleen wrote:
> To be realistic it is very unlikely anybody will measure a difference
> from a few more or a few less clds in a program.
Only an assumption, and in fact wrong. See upthread for a benchmark.
IIRC Uros also made measurements to justify the removal of cld (on P4 I
think), where it helps tremendously on small memcpy loops.