[PATCH] D137588: [ScalarEvolution] Skip values from unreachable bbs for phi ranges.

[Florian Hahn via Phabricator via llvm-commits]

fhahn created this revision.
fhahn added reviewers: nikic, efriedma, reames.
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Skip incoming value from unreachable blocks when computing ranges for
phis. Constructing SCEVs for values from unreachable blocks may lead to
violating assumptions based on dominance.

One example is the added LV test case. Here an assertion in GroupByComplexity
is triggered when constructing a SCEV for the incoming value from the unreachable
block because there's no dominance relation between 2 AddRecs.

It removes pr49856.ll because it is already part of
shift-recurrences.ll and needs updating.

Fixes #58811.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D137588

Files:
  llvm/lib/Analysis/ScalarEvolution.cpp
  llvm/test/Analysis/ScalarEvolution/pr49856.ll
  llvm/test/Analysis/ScalarEvolution/shift-recurrences.ll
  llvm/test/Transforms/LoopIdiom/X86/memset-size-compute.ll
  llvm/test/Transforms/LoopVectorize/scev-expansion-unreachable.ll

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