>It probably should go to the 4.6 branch as well. H.J. Lu's original patch that splits unaligned load and store was checked in gcc 4.7 trunk. We found that, splitting unaligned store is beneficial to bdver1, splitting unaligned load degrades cfp2006 by 1.3% in geomean on Bulldozer. As a result, we suggest putting unaligned store splitting (H.J. original patch + this one) back to 4.6 branch.
>Note that I find the >X86_TUNE_AVX256_SPLIT_UNALIGNED_LOAD_OPTIMAL odd, >why not call it simply X86_TUNE_AVX256_SPLIT_UNALIGNED_LOAD? AVX256_SPLIT_UNALIGNED_LOAD has already been used for the flag: -mavx256-split-unaligned-load, and we intend to keep that flag for performance tuning. As a result, we put _OPTIMAL (or _BENEFICAL) at the end for default setting. >I'll defer to x86 maintainers for approval. So, is it OK to commit this patch to trunk, and H.J's original patch + this to 4.6 branch? Thanks, Changpeng >Richard. > Thanks, > > Changpeng
