[InstCombine] Allow values with multiple users in SimplifyDemandedVectorElts
Summary:
Allow for ignoring the check for a single use in SimplifyDemandedVectorElts
to be able to simplify operands if DemandedElts is known to contain
the union of elements used by all users.
It is a responsibility of a caller of SimplifyDemandedVectorElts to
supply correct DemandedElts.
Simplify a series of extractelement instructions if only a subset of
elements is used.
Reviewers: reames, arsenm, majnemer, nhaehnle
Reviewed By: nhaehnle
Subscribers: wdng, jvesely, nhaehnle, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67345
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375395
91177308-0d34-0410-b5e6-
96231b3b80d8