[PATCH] D104648: [Mem2Reg] Use poison instead of undef for read of uninitialized memory

[Nikita Popov via Phabricator via llvm-commits]

nikic created this revision.
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During mem2reg, make loads from uninitialized memory return a poison value rather than an undef value. Also clarify the alloca documentation in this regard.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D104648

Files:
  llvm/docs/LangRef.rst
  llvm/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
  llvm/test/CodeGen/AMDGPU/vector-alloca-bitcast.ll
  llvm/test/Transforms/Mem2Reg/debug-alloca-vla-1.ll
  llvm/test/Transforms/Mem2Reg/debug-alloca-vla-2.ll
  llvm/test/Transforms/Mem2Reg/pr24179.ll
  llvm/test/Transforms/Mem2Reg/undef-order.ll
  llvm/test/Transforms/PhaseOrdering/X86/nancvt.ll
  llvm/test/Transforms/SROA/addrspacecast.ll
  llvm/test/Transforms/SROA/basictest.ll
  llvm/test/Transforms/SROA/phi-and-select.ll
  llvm/test/Transforms/SROA/phi-gep.ll
  llvm/test/Transforms/SROA/phi-with-duplicate-pred.ll
  llvm/test/Transforms/SROA/pr37267.ll
  llvm/test/Transforms/SROA/scalable-vectors.ll
  llvm/test/Transforms/SROA/slice-width.ll
  llvm/test/Transforms/SROA/vector-promotion.ll

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