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Re: [PATCH] faster string operations for buldozer.
> 2012-09-26 Ondrej Bilka <neleai@seznam.cz>
>
> * sysdeps/x86_64/multiarch/init_arch.c (__init_cpu_features):
> Set bit_Prefer_PMINUB_for_stringop for AMD processors.
> Set bit_Fast_Unaligned_Load for AMD processors with AVX
Use tabs for indentation, not 8 spaces.
Missing period on the second sentence.
> @@ -131,6 +131,9 @@ __init_cpu_features (void)
> __cpu_features.feature[index_Prefer_SSE_for_memop]
> |= bit_Prefer_SSE_for_memop;
>
> + /* Assuming unaligned loads are fast when avx is available.*/
"Assume", not "Assuming". AVX in caps. Two spaces after a sentence.
> + if ((ecx & bit_AVX) != 0)
> + __cpu_features.feature[index_Fast_Rep_String]
> + |= ( bit_Fast_Unaligned_Load);
Excess space and paren here. The indentation here is wrong.
The consequent should be two spaces right of the "if".
The |= should be two spaces right of that.
> + __cpu_features.feature[index_Fast_Rep_String]
> + |= bit_Prefer_PMINUB_for_stringop;
Same indentation problem here.
Once all these nits are fixed, for a performance change we need to see
benchmark data. I thought Carlos had made a wiki page about benchmark
requirements for supposed performance enhancements, but I'm not sure.
Thanks,
Roland