[X86][SSE] Improve vector ZERO_EXTEND by combining to ZERO_EXTEND_VECTOR_INREG

Generalise the existing SIGN_EXTEND to SIGN_EXTEND_VECTOR_INREG combine to support zero extension as well and get rid of a lot of unnecessary ANY_EXTEND + mask patterns.

Differential Revision: http://reviews.llvm.org/D17691

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@262599 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed