diff --git a/src/aotcompile.cpp b/src/aotcompile.cpp index 55d02edf7e3dd4..d288586916560b 100644 --- a/src/aotcompile.cpp +++ b/src/aotcompile.cpp @@ -650,6 +650,7 @@ static FunctionInfo getFunctionWeight(const Function &F) } struct ModuleInfo { + Triple triple; size_t globals; size_t funcs; size_t bbs; @@ -660,6 +661,7 @@ struct ModuleInfo { ModuleInfo compute_module_info(Module &M) { ModuleInfo info; + info.triple = Triple(M.getTargetTriple()); info.globals = 0; info.funcs = 0; info.bbs = 0; @@ -1406,6 +1408,13 @@ static unsigned compute_image_thread_count(const ModuleInfo &info) { LLVM_DEBUG(dbgs() << "32-bit systems are restricted to a single thread\n"); return 1; #endif + // COFF has limits on external symbols (even hidden) up to 65536. We reserve the last few + // for any of our other symbols that we insert during compilation. + if (info.triple.isOSBinFormatCOFF() && info.globals > 64000) { + LLVM_DEBUG(dbgs() << "COFF is restricted to a single thread for large images\n"); + return 1; + } + // This is not overridable because empty modules do occasionally appear, but they'll be very small and thus exit early to // known easy behavior. Plus they really don't warrant multiple threads if (info.weight < 1000) {