[Polly] Check for ISL errors after schedule optimization

[Meinersbur]

When ISL encounters an internal error, it sets the error flag, but it is not isl_error_quota that was already checked. Check for general errors and abort the schedule optimization if that happens, instead of continuing on the "good" path.

The error occured when compiling llvm-test-suite's MultiSource/Applications/JM/lencod/leaky_bucket.c with Polly enabled. Not adding a test case because it depends on ISL internals. We do not want to a test case to depend on which version of ISL is used.

[Meinersbur]

The full crash message was:

Assertion "!is_error()" failed at ../../src/llvm/feature/_src/polly/lib/External/isl/include/isl/isl-noexceptions.h:78 IMPLEMENTATION ERROR: Unhandled error state PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: /home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang -DNDEBUG -mllvm -polly -O3 -DNDEBUG -w -Werror=date-time -fcommon -D__USE_LARGEFILE64 -D_FILE_OFFSET_BITS=64 -MD -MT MultiSource/Applications/JM/lencod/CMakeFiles/lencod.dir/leaky_bucket.c.o -MF MultiSource/Applications/JM/lencod/CMakeFiles/lencod.dir/leaky_bucket.c.o.d -o MultiSource/Applications/JM/lencod/CMakeFiles/lencod.dir/leaky_bucket.c.o -c /home/meinersbur/llvm-testbbmaster/testsuite.src/MultiSource/Applications/JM/lencod/leaky_bucket.c 1. <eof> parser at end of file 2. Optimizer 3. Running pass "function<eager-inv>(drop-unnecessary-assumes,float2int,lower-constant-intrinsics,chr,polly::CodePreparationPass,polly::FunctionToScopPassAdaptor<PassManager<polly::Scop, AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&> >,sroa<modify-cfg>,early-cse<memssa>,speculative-execution<only-if-divergent-target>,jump-threading,correlated-propagation,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-arithmetic;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,aggressive-instcombine,libcalls-shrinkwrap,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-arithmetic;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,reassociate,constraint-elimination,loop-mssa(loop-instsimplify,loop-simplifycfg,licm<no-allowspeculation>,loop-rotate<header-duplication;no-prepare-for-lto>,licm<allowspeculation>,simple-loop-unswitch<nontrivial;trivial>),simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;no-switch-to-arithmetic;no-switch-to-lookup;keep-loops;no-hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,loop(loop-idiom,indvars,extra-simple-loop-unswitch-passes,loop-deletion,loop-unroll-full),sroa<modify-cfg>,vector-combine,mldst-motion<no-split-footer-bb>,gvn<>,sccp,bdce,instcombine<max-iterations=1;no-verify-fixpoint>,dfa-jump-threading,jump-threading,correlated-propagation,adce,memcpyopt,dse,move-auto-init,loop-mssa(licm<allowspeculation>),coro-elide,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;switch-to-arithmetic;no-switch-to-lookup;keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,instcombine<max-iterations=1;no-verify-fixpoint>,{anonymous}::Bye,loop(loop-rotate<header-duplication;no-prepare-for-lto>,loop-deletion),loop-distribute,inject-tli-mappings,loop-vectorize<no-interleave-forced-only;no-vectorize-forced-only;>,infer-alignment,loop-load-elim,instcombine<max-iterations=1;no-verify-fixpoint>,simplifycfg<bonus-inst-threshold=1;forward-switch-cond;switch-range-to-icmp;switch-to-arithmetic;switch-to-lookup;no-keep-loops;hoist-common-insts;no-hoist-loads-stores-with-cond-faulting;sink-common-insts;speculate-blocks;simplify-cond-branch;no-speculate-unpredictables>,slp-vectorizer,vector-combine,instcombine<max-iterations=1;no-verify-fixpoint>,loop-unroll<O3>,transform-warning,sroa<preserve-cfg>,infer-alignment,instcombine<max-iterations=1;no-verify-fixpoint>,loop-mssa(licm<allowspeculation>),alignment-from-assumptions,loop-sink,instsimplify,div-rem-pairs,tailcallelim,simplifycfg<bonus-inst-threshold=1;no-forward-switch-cond;switch-range-to-icmp;switch-to-arithmetic;no-switch-to-lookup;keep-loops;no-hoist-common-insts;hoist-loads-stores-with-cond-faulting;no-sink-common-insts;speculate-blocks;simplify-cond-branch;speculate-unpredictables>)" on module "/home/meinersbur/llvm-testbbmaster/testsuite.src/MultiSource/Applications/JM/lencod/leaky_bucket.c" 4. Running pass "polly::FunctionToScopPassAdaptor<PassManager<polly::Scop, AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&> >" on function "Sort" #0 0x00007ffb7bce5532 llvm::sys::PrintStackTrace(llvm::raw_ostream&, int) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x4477532) #1 0x00007ffb7bce222f llvm::sys::RunSignalHandlers() (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x447422f) #2 0x00007ffb7bc14808 CrashRecoverySignalHandler(int) CrashRecoveryContext.cpp:0:0 #3 0x00007ffb77285330 (/lib/x86_64-linux-gnu/libc.so.6+0x45330) #4 0x00007ffb772deb2c __pthread_kill_implementation ./nptl/pthread_kill.c:44:76 #5 0x00007ffb772deb2c __pthread_kill_internal ./nptl/pthread_kill.c:78:10 #6 0x00007ffb772deb2c pthread_kill ./nptl/pthread_kill.c:89:10 #7 0x00007ffb7728527e raise ./signal/../sysdeps/posix/raise.c:27:6 #8 0x00007ffb772688ff abort ./stdlib/abort.c:81:7 #9 0x00007ffb7cda22a6 (anonymous namespace)::runIslScheduleOptimizer(polly::Scop&, llvm::function_ref<polly::Dependences const& (polly::Dependences::AnalysisLevel)>, llvm::TargetTransformInfo*, llvm::OptimizationRemarkEmitter*, isl::schedule&, bool&) (.constprop.0) ScheduleOptimizer.cpp:0:0 #10 0x00007ffb7cda60c8 runIslScheduleOptimizerUsingNPM(polly::Scop&, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>&, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&, llvm::raw_ostream*) (.isra.0) ScheduleOptimizer.cpp:0:0 #11 0x00007ffb7cda66ed polly::IslScheduleOptimizerPass::run(polly::Scop&, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>&, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x55386ed) #12 0x00007ffb7cd7eb95 llvm::detail::PassModel<polly::Scop, polly::IslScheduleOptimizerPass, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&>::run(polly::Scop&, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>&, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x5510b95) #13 0x00007ffb7ce76cd4 llvm::PassManager<polly::Scop, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&>::run(polly::Scop&, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>&, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x5608cd4) #14 0x00007ffb7cd92587 polly::FunctionToScopPassAdaptor<llvm::PassManager<polly::Scop, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x5524587) #15 0x00007ffb7cd928b5 llvm::detail::PassModel<llvm::Function, polly::FunctionToScopPassAdaptor<llvm::PassManager<polly::Scop, llvm::AnalysisManager<polly::Scop, polly::ScopStandardAnalysisResults&>, polly::ScopStandardAnalysisResults&, polly::SPMUpdater&>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x55248b5) #16 0x00007ffb7b5f9de5 llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x3d8bde5) #17 0x00007ffb78ca4335 llvm::detail::PassModel<llvm::Function, llvm::PassManager<llvm::Function, llvm::AnalysisManager<llvm::Function>>, llvm::AnalysisManager<llvm::Function>>::run(llvm::Function&, llvm::AnalysisManager<llvm::Function>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x1436335) #18 0x00007ffb7b5f84e1 llvm::ModuleToFunctionPassAdaptor::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x3d8a4e1) #19 0x00007ffb78ca4a75 llvm::detail::PassModel<llvm::Module, llvm::ModuleToFunctionPassAdaptor, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x1436a75) #20 0x00007ffb7b5f8ccd llvm::PassManager<llvm::Module, llvm::AnalysisManager<llvm::Module>>::run(llvm::Module&, llvm::AnalysisManager<llvm::Module>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x3d8accd) #21 0x00007ffb7bfa05d6 (anonymous namespace)::EmitAssemblyHelper::RunOptimizationPipeline(clang::BackendAction, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>&, std::unique_ptr<llvm::ToolOutputFile, std::default_delete<llvm::ToolOutputFile>>&, clang::BackendConsumer*) BackendUtil.cpp:0:0 #22 0x00007ffb7bfa45dd clang::emitBackendOutput(clang::CompilerInstance&, clang::CodeGenOptions&, llvm::StringRef, llvm::Module*, clang::BackendAction, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>, std::unique_ptr<llvm::raw_pwrite_stream, std::default_delete<llvm::raw_pwrite_stream>>, clang::BackendConsumer*) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x47365dd) #23 0x00007ffb7c62c1e0 clang::BackendConsumer::HandleTranslationUnit(clang::ASTContext&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x4dbe1e0) #24 0x00007ffb7e4b84dc clang::ParseAST(clang::Sema&, bool, bool) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x6c4a4dc) #25 0x00007ffb7c957737 clang::FrontendAction::Execute() (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x50e9737) #26 0x00007ffb7c8dcf2e clang::CompilerInstance::ExecuteAction(clang::FrontendAction&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x506ef2e) #27 0x00007ffb7ca50b7e clang::ExecuteCompilerInvocation(clang::CompilerInstance*) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x51e2b7e) #28 0x00007ffb78816ceb cc1_main(llvm::ArrayRef<char const*>, char const*, void*) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0xfa8ceb) #29 0x00007ffb7880c287 ExecuteCC1Tool(llvm::SmallVectorImpl<char const*>&, llvm::ToolContext const&, llvm::IntrusiveRefCntPtr<llvm::vfs::FileSystem>) driver.cpp:0:0 #30 0x00007ffb7880c465 int llvm::function_ref<int (llvm::SmallVectorImpl<char const*>&)>::callback_fn<clang_main(int, char**, llvm::ToolContext const&)::'lambda'(llvm::SmallVectorImpl<char const*>&)>(long, llvm::SmallVectorImpl<char const*>&) driver.cpp:0:0 #31 0x00007ffb7c69a9bd void llvm::function_ref<void ()>::callback_fn<clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const::'lambda'()>(long) Job.cpp:0:0 #32 0x00007ffb7bc14cce llvm::CrashRecoveryContext::RunSafely(llvm::function_ref<void ()>) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x43a6cce) #33 0x00007ffb7c69bac8 clang::driver::CC1Command::Execute(llvm::ArrayRef<std::optional<llvm::StringRef>>, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char>>*, bool*) const (.part.0) Job.cpp:0:0 #34 0x00007ffb7c658657 clang::driver::Compilation::ExecuteCommand(clang::driver::Command const&, clang::driver::Command const*&, bool) const (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x4dea657) #35 0x00007ffb7c659752 clang::driver::Compilation::ExecuteJobs(clang::driver::JobList const&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&, bool) const (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x4deb752) #36 0x00007ffb7c6662c4 clang::driver::Driver::ExecuteCompilation(clang::driver::Compilation&, llvm::SmallVectorImpl<std::pair<int, clang::driver::Command const*>>&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0x4df82c4) #37 0x00007ffb78811bdc clang_main(int, char**, llvm::ToolContext const&) (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0xfa3bdc) #38 0x00007ffb78697b2a main (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0xe29b2a) #39 0x00007ffb7726a1ca __libc_start_call_main ./csu/../sysdeps/nptl/libc_start_call_main.h:74:3 #40 0x00007ffb7726a28b call_init ./csu/../csu/libc-start.c:128:20 #41 0x00007ffb7726a28b __libc_start_main ./csu/../csu/libc-start.c:347:5 #42 0x00007ffb7880b7f5 _start (/home/meinersbur/llvm-testbbmaster/install-llvm/bin/clang+0xf9d7f5) clang: error: clang frontend command failed with exit code 134 (use -v to see invocation) clang version 22.0.0git (/home/meinersbur/src/llvm/feature/_src/clang e8c4b09d9de0ad2bb6e905d4b602f8f993fb545b) Target: x86_64-unknown-linux-gnu Thread model: posix InstalledDir: /home/meinersbur/llvm-testbbmaster/install-llvm/bin Build config: +assertions clang: note: diagnostic msg: ******************** PLEASE ATTACH THE FOLLOWING FILES TO THE BUG REPORT: Preprocessed source(s) and associated run script(s) are located at: clang: note: diagnostic msg: /tmp/meinersbur/leaky_bucket-937a7b.c clang: note: diagnostic msg: /tmp/meinersbur/leaky_bucket-937a7b.sh clang: note: diagnostic msg: 

The ISL error state was set by
https://github.com/llvm/llvm-project/blob/main/polly/lib/External/isl/isl_scheduler.c#L5188-L5189