This patch is a first step towards a more extendible method of matching combined target shuffle masks.
Initially this just pulls out the existing basic mask matches and adds support for some 256/512 bit equivalents. Future patterns will require a number of features to be added but I wanted to keep this patch simple.
I hope we can avoid duplication between shuffle lowering and combining and share more complex pattern match functions in future commits.
Differential Revision: http://reviews.llvm.org/D19198
llvm-svn: 270230
Patch to add support for target shuffle combining of X86ISD::VPERMV3 nodes, including support for detecting unary shuffles.
This uncovered several issues with the X86ISD::VPERMV3 shuffle mask decoding of non-64 bit shuffle mask elements - the bit masking wasn't being correctly computed.
Removed non-constant pool mask decode path as we have no way of testing it right now.
Differential Revision: http://reviews.llvm.org/D17916
llvm-svn: 262809
Simon Pilgrim