tree 3934c289ec597017f5f0b4bc6c23aff9f2b21816
parent 50f05d394ac2b6e392dc2847f496d8d7c3c710ee
author Krzysztof Parzyszek <kparzysz@codeaurora.org> 1528490587 +0000
committer Krzysztof Parzyszek <kparzysz@codeaurora.org> 1528490587 +0000

[SCEV] Look through zero-extends in howFarToZero

An expression like
  (zext i2 {(trunc i32 (1 + %B) to i2),+,1}<%while.body> to i32)
will become zero exactly when the nested value becomes zero in its type.
Strip injective operations from the input value in howFarToZero to make
the value simpler.

Differential Revision: https://reviews.llvm.org/D47951


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@334318 91177308-0d34-0410-b5e6-96231b3b80d8