[PATCH] D140939: [X86] Transform AtomicRMW logic operations to BT{R|C|S} if only changing/testing a single bit.

[Alexander Kornienko via Phabricator via llvm-commits]

alexfh added a comment.

In D140939#4072473 <https://reviews.llvm.org/D140939#4072473>, @alexfh wrote:

> Unfortunately, there's another problem, which doesn't get fixed by https://reviews.llvm.org/D142166 / 2e25204779e5b972d668bf66a0014c1325813b35 <https://reviews.llvm.org/rG2e25204779e5b972d668bf66a0014c1325813b35>:
>
>   assert.h assertion failed at llvm/lib/Target/X86/X86ISelLowering.cpp:31466 in std::pair<Value *, BitTestKind> FindSingleBitChange(Value *): I != nullptr
>       @     0x56257abc9524  __assert_fail
>       @     0x562578c7fd1c  FindSingleBitChange()
>       @     0x562578c7f6dd  llvm::X86TargetLowering::shouldExpandLogicAtomicRMWInIR()
>       @     0x562578c8098b  llvm::X86TargetLowering::shouldExpandAtomicRMWInIR()
>       @     0x5625790a6099  (anonymous namespace)::AtomicExpand::tryExpandAtomicRMW()
>       @     0x5625790a59dd  (anonymous namespace)::AtomicExpand::runOnFunction()
>       @     0x56257a86e87d  llvm::FPPassManager::runOnFunction()
>       @     0x56257a876104  llvm::FPPassManager::runOnModule()
>       @     0x56257a86ef7c  llvm::legacy::PassManagerImpl::run()
>       @     0x562575bad581  clang::EmitBackendOutput()
>       @     0x562575baabe9  clang::BackendConsumer::HandleTranslationUnit()
>       @     0x562576a85e5c  clang::ParseAST()
>       @     0x5625767cbf23  clang::FrontendAction::Execute()
>       @     0x562576741cad  clang::CompilerInstance::ExecuteAction()
>       @     0x5625757871e8  clang::ExecuteCompilerInvocation()
>       @     0x56257577ae41  cc1_main()
>       @     0x562575776ec8  ExecuteCC1Tool()
>       @     0x5625768ed317  llvm::function_ref<>::callback_fn<>()
>       @     0x56257aa23d20  llvm::CrashRecoveryContext::RunSafely()
>       @     0x5625768ecb63  clang::driver::CC1Command::Execute()
>       @     0x5625768ab2e6  clang::driver::Compilation::ExecuteCommand()
>       @     0x5625768ab60f  clang::driver::Compilation::ExecuteJobs()
>       @     0x5625768caf70  clang::driver::Driver::ExecuteCompilation()
>       @     0x562575776027  clang_main()
>       @     0x7f8f04be3633  __libc_start_main
>       @     0x562575772bea  _start

I'd suggest to revert while investigating. I'm working on an isolated test case.


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D140939/new/

https://reviews.llvm.org/D140939