Sanjay Patel 2c5adb18ba [InstCombine] fix wrong undef handling when converting select to shuffle
As discussed in:
https://bugs.llvm.org/show_bug.cgi?id=32486
...the canonicalization of vector select to shufflevector does not hold up
when undef elements are present in the condition vector. 

Try to make the undef handling clear in the code and the LangRef.

Differential Revision: https://reviews.llvm.org/D31980



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@300092 91177308-0d34-0410-b5e6-96231b3b80d8
2017-04-12 18:39:53 +00:00
..
2017-03-13 20:00:25 +00:00