[PATCH] D38671: [X86][AVX512] lowering shuffle i/f intrinsic - llvm part

[Craig Topper via Phabricator via llvm-commits]

craig.topper added a comment.

I believe the X86ISelLowering.cpp changes are no longer necessary after r317403 and r317410. I've taught lowering to prefer the EVEX encoded SHUF instructions by default and then EVEX->VEX will turn them back into VPERM2F128 if they don't end up being masked, using broadcast loads, or using XMM16-31.

I think there's still a lost load folding opportunity since the SHUF instructions aren't commutable like the VPERM instructions. We can probably recover that with some isel patterns if we want.


https://reviews.llvm.org/D38671