[PATCH] D71177: [ValueTracking] Use the assumption that if the pointer was loaded/stored, then it is nonnull.

[Danila Kutenin via Phabricator via llvm-commits]

danlark created this revision.
Herald added subscribers: llvm-commits, steven.zhang, jsji, jfb, hiraditya, nemanjai.
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If the pointer was loaded/stored before the null check, the check is redundant and can be removed. For now the optimizers do not remove the nullptr check, see https://gcc.godbolt.org/z/-gBeJm. The patch allows to use more nonnull constraints on the pointers. Also, it found one more optimization in some PowerPC test. This is my first llvm review, I am free to any comments.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D71177

Files:
  llvm/lib/Analysis/ValueTracking.cpp
  llvm/test/Analysis/ValueTracking/known-nonnull-at.ll
  llvm/test/CodeGen/PowerPC/pr39815.ll
  llvm/test/Transforms/Coroutines/coro-swifterror.ll
  llvm/test/Transforms/InstCombine/element-atomic-memintrins.ll
  llvm/test/Transforms/InstCombine/memcpy-addrspace.ll
  llvm/test/Transforms/InstCombine/phi-equal-incoming-pointers.ll
  llvm/test/Transforms/InstCombine/sink-alloca.ll

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