[PATCH] D116150: [SCEV] Use lshr in implications

[Max Kazantsev via Phabricator via llvm-commits]

mkazantsev created this revision.
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This patch adds support for implication inference logic for the
following pattern:

  lhs < (y >> z) <= y, y <= rhs --> lhs < rhs

We should be able to use the fact that value shifted to right is
not greater than the original value (provided it is non-negative).


https://reviews.llvm.org/D116150

Files:
  llvm/include/llvm/Analysis/ScalarEvolution.h
  llvm/lib/Analysis/ScalarEvolution.cpp
  llvm/test/Transforms/IndVarSimplify/shift-range-checks.ll

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