[PATCH] D25691: [DAGCombiner] Add vector demanded elements support to computeKnownBits

[Simon Pilgrim via llvm-commits]

RKSimon updated this revision to Diff 74961.
RKSimon added a comment.

Added the asserts suggested by Eli.

Improved VECTOR_SHUFFLE demanded elts handling - as long as the shuffle mask element isn't UNDEF then we can use the input demanded elts. This might be too pessimistic and we should be able to ignore UNDEFs as long as we don't need the element.

I'll investigate the InstCombine version - I don't know as much about the value tracking code so it might take a little longer.


Repository:
  rL LLVM

https://reviews.llvm.org/D25691

Files:
  include/llvm/CodeGen/SelectionDAG.h
  lib/CodeGen/SelectionDAG/SelectionDAG.cpp
  test/CodeGen/X86/avx-vperm2x128.ll
  test/CodeGen/X86/known-bits-vector.ll

-------------- next part --------------
A non-text attachment was scrubbed...
Name: D25691.74961.patch
Type: text/x-patch
Size: 15752 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20161018/4deb1314/attachment.bin>