Summary:
When an LCSSA phi survives through instruction selection, the pass
ends up removing that phi entirely because it is dominated by the
logic that does the lanemask merging.
This then used to trigger an assertion when processing a dependent
phi instruction.
Change-Id: Id4949719f8298062fe476a25718acccc109113b6
Reviewers: llvm-commits
Subscribers: kzhuravl, jvesely, wdng, yaxunl, t-tye, tpr, dstuttard, rtaylor, arsenm
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60999
llvm-svn: 358983
Nicolai Haehnle