Summary:
xxspltib/vspltisb are 3 cycle PM instructions,
xxleqv is 2 cycle ALU instruction.
We should use xxleqv to set all one vectors.
Reviewers: hfinkel, nemanjai, steven.zhang
Subscribers: hiraditya, kbarton, MaskRay, shchenz, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65529
llvm-svn: 369006