[AVX] VEXTRACTF128 support.  This commit includes patterns for
matching EXTRACT_SUBVECTOR to VEXTRACTF128 along with support routines
to examine and translate index values.  VINSERTF128 comes next.  With
these two in place we can begin supporting more AVX operations as
INSERT/EXTRACT can be used as a fallback when 256-bit support is not
available.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124797 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed