<html><head><meta http-equiv="Content-Type" content="text/html; charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;" class="">Hi,<br class=""><div><br class=""><blockquote type="cite" class=""><div class="">On 21 Jul 2021, at 10:11, Zhang via llvm-dev <<a href="mailto:llvm-dev@lists.llvm.org" class="">llvm-dev@lists.llvm.org</a>> wrote:</div><br class="Apple-interchange-newline"><div class=""><div class=""><font class="">Hi:</font></div><div class=""><font class="">Here in our downstream project we use a ModulePass to schedule our TransformPasses through creating and executing Module/FunctionPassManagers internally.</font></div><div class=""><font class="">This "wrapper" pass is registered at ExtensionPoint EP_ModuleOptimizerEarly.</font></div><div class=""><font class=""><br class=""></font></div><div class=""><font class="">However, when certain passes in our Pipeline are disabled, LLVM optimization process crashes later in the pipeline with:</font></div><div class=""><font class=""><br class=""></font></div><div class=""><font class="">```</font></div><div class=""><div class="">Assertion failed: (L->getLoopPreheader() && "Can't expand add recurrences without a loop preheader!"), function getAddRecExprPHILiterally, file LLVM/llvm/lib/Transforms/Utils/ScalarEvolutionExpander.cpp, line 1275</div><div class="">1.<span class="Apple-tab-span" style="white-space:pre"> </span><eof> parser at end of file</div><div class="">2.<span class="Apple-tab-span" style="white-space:pre"> </span>Per-module optimization passes</div><div class="">3.<span class="Apple-tab-span" style="white-space:pre"> </span>Running pass 'CallGraph Pass Manager' on module 'src.cpp'.</div><div class="">4.<span class="Apple-tab-span" style="white-space:pre"> </span>Running pass 'Loop Pass Manager' on function '@_ZNK8XXXX'</div><div class="">5.<span class="Apple-tab-span" style="white-space:pre"> </span>Running pass 'Induction Variable Simplification' on basic block '%for.body110'</div><div class="">0 clang++ 0x0000000103df5535 llvm::sys::PrintStackTrace(llvm::raw_ostream&) + 37</div><div class="">1 clang++ 0x0000000103df4765 llvm::sys::RunSignalHandlers() + 85</div><div class="">2 clang++ 0x0000000103df4cc0 llvm::sys::CleanupOnSignal(unsigned long) + 208</div><div class="">3 clang++ 0x0000000103d45f2a (anonymous namespace)::CrashRecoveryContextImpl::HandleCrash(int, unsigned long) + 106</div><div class="">4 clang++ 0x0000000103d460b7 CrashRecoverySignalHandler(int) + 135</div><div class="">5 libsystem_platform.dylib 0x00007fff2055ed7d _sigtramp + 29</div><div class="">6 libdyld.dylib 0x00007fff20534473 dyldGlobalLockRelease() + 0</div><div class="">7 libsystem_c.dylib 0x00007fff2046d720 abort + 120</div><div class="">8 libsystem_c.dylib 0x00007fff2046c9d6 err + 0</div><div class="">9 clang++ 0x0000000106c11a83 llvm::SCEVExpander::getAddRecExprPHILiterally(llvm::SCEVAddRecExpr const*, llvm::Loop const*, llvm::Type*, llvm::Type*, llvm::Type*&, bool&) (.cold.1) + 35</div><div class="">10 clang++ 0x0000000103eb9643 llvm::SCEVExpander::getAddRecExprPHILiterally(llvm::SCEVAddRecExpr const*, llvm::Loop const*, llvm::Type*, llvm::Type*, llvm::Type*&, bool&) + 4259</div><div class="">11 clang++ 0x0000000103eb9bda llvm::SCEVExpander::expandAddRecExprLiterally(llvm::SCEVAddRecExpr const*) + 1066</div><div class="">12 clang++ 0x0000000103eb5f23 llvm::SCEVExpander::expand(llvm::SCEV const*) + 1027</div><div class="">13 clang++ 0x0000000103eb5aac llvm::SCEVExpander::expandCodeFor(llvm::SCEV const*, llvm::Type*) + 28</div><div class="">14 clang++ 0x0000000103ebbc31 llvm::SCEVVisitor<llvm::SCEVExpander, llvm::Value*>::visit(llvm::SCEV const*) + 193</div><div class="">15 clang++ 0x0000000103eb5f23 llvm::SCEVExpander::expand(llvm::SCEV const*) + 1027</div><div class="">16 clang++ 0x0000000103eb5aac llvm::SCEVExpander::expandCodeFor(llvm::SCEV const*, llvm::Type*) + 28</div><div class="">17 clang++ 0x0000000103eb8c49 llvm::SCEVExpander::getAddRecExprPHILiterally(llvm::SCEVAddRecExpr const*, llvm::Loop const*, llvm::Type*, llvm::Type*, llvm::Type*&, bool&) + 1705</div><div class="">18 clang++ 0x0000000103eb9bda llvm::SCEVExpander::expandAddRecExprLiterally(llvm::SCEVAddRecExpr const*) + 1066</div><div class="">19 clang++ 0x0000000103eb5f23 llvm::SCEVExpander::expand(llvm::SCEV const*) + 1027</div><div class="">20 clang++ 0x0000000103eb5aac llvm::SCEVExpander::expandCodeFor(llvm::SCEV const*, llvm::Type*) + 28</div><div class="">21 clang++ 0x0000000103eb9794 llvm::SCEVExpander::expandCodeFor(llvm::SCEV const*, llvm::Type*, llvm::Instruction*) + 148</div><div class="">22 clang++ 0x0000000103b3969a (anonymous namespace)::IndVarSimplify::run(llvm::Loop*) + 8522</div><div class="">23 clang++ 0x0000000103b463c7 (anonymous namespace)::IndVarSimplifyLegacyPass::runOnLoop(llvm::Loop*, llvm::LPPassManager&) + 951</div><div class="">24 clang++ 0x00000001030ee209 llvm::LPPassManager::runOnFunction(llvm::Function&) + 1513</div><div class="">25 clang++ 0x00000001036afe41 llvm::FPPassManager::runOnFunction(llvm::Function&) + 1073</div><div class="">26 clang++ 0x0000000102ff4534 (anonymous namespace)::CGPassManager::runOnModule(llvm::Module&) + 1540</div><div class="">27 clang++ 0x00000001036b049f llvm::legacy::PassManagerImpl::run(llvm::Module&) + 1103</div><div class="">28 clang++ 0x000000010407b653 clang::EmitBackendOutput(clang::DiagnosticsEngine&, clang::HeaderSearchOptions const&, clang::CodeGenOptions const&, clang::TargetOptions const&, clang::LangOptions const&, llvm::DataLayout const&, llvm::Module*, clang::BackendAction, std::__1::unique_ptr<llvm::raw_pwrite_stream, std::__1::default_delete<llvm::raw_pwrite_stream> >) + 15075</div><div class="">29 clang++ 0x00000001043456fb clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) + 1131</div><div class="">30 clang++ 0x0000000105438483 clang::ParseAST(clang::Sema&, bool, bool) + 643</div><div class="">31 clang++ 0x0000000104612d04 clang::FrontendAction::Execute() + 84</div><div class="">32 clang++ 0x00000001045b9f13 clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) + 2179</div><div class="">33 clang++ 0x00000001046878fb clang::ExecuteCompilerInvocation(clang::CompilerInstance*) + 1435</div><div class="">34 clang++ 0x00000001025db371 cc1_main(llvm::ArrayRef<char const*>, char const*, void*) + 2081</div><div class=""><br class=""></div></div><div class=""><font class="">```</font></div><div class=""><font class=""><br class=""></font></div><div class=""><font class="">I added createVerifierPass() at the end of our "WrapperPass" and the transformed IR passed the verification. I also didn't overload getAnalysisUsage, which, if my understanding is correct, invalidates all previous analysis including Loops Identified.</font></div></div></blockquote><br class=""></div><div>If IndVarSimplify crashes on valid IR, this is likely a bug. To confirm this, you can extract the IR before IndVarSimplify and check if running IndVarSimplify via opt on the extracted IR also crashes. </div><div><br class=""></div><div>If that’s the case, please file a bug report online <a href="https://bugs.llvm.org" class="">https://bugs.llvm.org</a> including the IR that causes IndVarSimplify to crash.</div><div><br class=""></div><div>Cheers,</div><div>Florian</div><br class=""></body></html>