From a27014b85169692442ed857312473afad701c1f7 Mon Sep 17 00:00:00 2001 From: Aditya Kumar Date: Wed, 3 Oct 2018 06:21:05 +0000 Subject: Improve static analysis of cold basic blocks Differential Revision: https://reviews.llvm.org/D52704 Reviewers: sebpop, tejohnson, brzycki, SirishP Reviewed By: sebpop llvm-svn: 343663 --- llvm/lib/Transforms/IPO/HotColdSplitting.cpp | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) (limited to 'llvm/lib/Transforms/IPO/HotColdSplitting.cpp') diff --git a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp index 820d08316d6..810fdf418a2 100644 --- a/llvm/lib/Transforms/IPO/HotColdSplitting.cpp +++ b/llvm/lib/Transforms/IPO/HotColdSplitting.cpp @@ -111,6 +111,18 @@ bool blockEndsInUnreachable(const BasicBlock &BB) { return succ_empty(&BB); } +static bool exceptionHandlingFunctions(const CallInst *CI) { + auto F = CI->getCalledFunction(); + if (!F) + return false; + auto FName = F->getName(); + return FName == "__cxa_begin_catch" || + FName == "__cxa_free_exception" || + FName == "__cxa_allocate_exception" || + FName == "__cxa_begin_catch" || + FName == "__cxa_end_catch"; +} + static bool unlikelyExecuted(const BasicBlock &BB) { if (blockEndsInUnreachable(BB)) @@ -122,7 +134,8 @@ bool unlikelyExecuted(const BasicBlock &BB) { if (const CallInst *CI = dyn_cast(&I)) { // The block is cold if it calls functions tagged as cold or noreturn. if (CI->hasFnAttr(Attribute::Cold) || - CI->hasFnAttr(Attribute::NoReturn)) + CI->hasFnAttr(Attribute::NoReturn) || + exceptionHandlingFunctions(CI)) return true; // Assume that inline assembly is hot code. -- cgit v1.2.3