[x86] use PMOVMSK for vector-sized equality comparisons
We could do better by splitting any oversized type into whatever vector size the target supports,
but I left that for future work if it ever comes up. The motivating case is memcmp() calls on 16-byte
structs, so I think we can wire that up with a TLI hook that feeds into this.
Differential Revision: https://reviews.llvm.org/D31156
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@298376 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed