[PATCH] D20598: [X86] Detect SAD patterns and emit psadbw instructions on X86 redux

[Wei Mi via llvm-commits]

wmi added a comment.

LGTM. But I find that the code generated for sad_16i8/sad_32i8 are not very good because of INSERT_SUBVECTOR. Legalization of INSERT_SUBVECTOR introduces many useless stack saves/restores. We may need to fix them in a separate patch before recommit r267649 and this patch.


http://reviews.llvm.org/D20598