[all-commits] [llvm/llvm-project] 355aee: Revert "[IR][LoopRotate] avoid leaving phi with no...

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  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 355aee3dcd441461a6da6e56c43dc1bd81c79f31
      https://github.com/llvm/llvm-project/commit/355aee3dcd441461a6da6e56c43dc1bd81c79f31
  Author: Sanjay Patel <spatel at rotateright.com>
  Date:   2020-11-30 (Mon, 30 Nov 2020)

  Changed paths:
    M llvm/include/llvm/IR/BasicBlock.h
    M llvm/lib/IR/BasicBlock.cpp
    R llvm/test/Transforms/LoopRotate/phi-empty.ll

  Log Message:
  -----------
  Revert "[IR][LoopRotate] avoid leaving phi with no operands (PR48296)"

This reverts commit bfd2c216ea8ef09f8fb1f755ca2b89f86f74acbb.
This appears to be causing stage2 msan failures on buildbots:
  FAIL: LLVM :: Transforms/SimplifyCFG/X86/bug-25299.ll (65872 of 71835)
  ******************** TEST 'LLVM :: Transforms/SimplifyCFG/X86/bug-25299.ll' FAILED ********************
  Script:
  --
  : 'RUN: at line 1';   /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/opt < /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/test/Transforms/SimplifyCFG/X86/bug-25299.ll -simplifycfg -S | /b/sanitizer-x86_64-linux-fast/build/llvm_build_msan/bin/FileCheck /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/test/Transforms/SimplifyCFG/X86/bug-25299.ll
  --
  Exit Code: 2
  Command Output (stderr):
  --
  ==87374==WARNING: MemorySanitizer: use-of-uninitialized-value
      #0 0x9de47b6 in getBasicBlockIndex /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/include/llvm/IR/Instructions.h:2749:5
      #1 0x9de47b6 in simplifyCommonResume /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:4112:23
      #2 0x9de47b6 in simplifyResume /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:4039:12
      #3 0x9de47b6 in (anonymous namespace)::SimplifyCFGOpt::simplifyOnce(llvm::BasicBlock*) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:6330:16
      #4 0x9dcca13 in run /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:6358:16
      #5 0x9dcca13 in llvm::simplifyCFG(llvm::BasicBlock*, llvm::TargetTransformInfo const&, llvm::SimplifyCFGOptions const&, llvm::SmallPtrSetImpl<llvm::BasicBlock*>*) /b/sanitizer-x86_64-linux-fast/build/llvm-project/llvm/lib/Transforms/Utils/SimplifyCFG.cpp:6369:8
      #6 0x974643d in iterativelySimplifyCFG(