From 71400b6afa3a650cac0ace1beb24a35518555f56 Mon Sep 17 00:00:00 2001 From: Chad Rosier Date: Fri, 15 Jul 2011 18:25:04 +0000 Subject: [PATCH] Disable loop idiom recognition of memset/memcpy if the function being compiled is named after a common idiom (i.e., memset/memcpy). Otherwise, we can run into infinite recursion. Ideally, the user should use the correct -fno-builtin flag, but in case they don't we should play nicely. rdar://9763412 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135286 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/Transforms/Scalar/LoopIdiomRecognize.cpp | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp index a7bc0e0b437..a0e41d9a977 100644 --- a/lib/Transforms/Scalar/LoopIdiomRecognize.cpp +++ b/lib/Transforms/Scalar/LoopIdiomRecognize.cpp @@ -173,6 +173,11 @@ static void deleteIfDeadInstruction(Value *V, ScalarEvolution &SE) { bool LoopIdiomRecognize::runOnLoop(Loop *L, LPPassManager &LPM) { CurLoop = L; + // Disable loop idiom recognition if the function's name is a common idiom. + StringRef Name = L->getHeader()->getParent()->getName(); + if (Name == "memset" || Name == "memcpy") + return false; + // The trip count of the loop must be analyzable. SE = &getAnalysis(); if (!SE->hasLoopInvariantBackedgeTakenCount(L))