[SCEV] Simplify zext/trunc idiom that appears when handling bitmasks.
Summary:
Specifically, we transform
zext(2^K * (trunc X to iN)) to iM ->
2^K * (zext(trunc X to i{N-K}) to iM)<nuw>
This is helpful because pulling the 2^K out of the zext allows further
optimizations.
Reviewers: sanjoy
Subscribers: hiraditya, llvm-commits, timshen
Differential Revision: https://reviews.llvm.org/D48158
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334737 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed