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
This commit is contained in:
Chad Rosier 2011-07-15 18:25:04 +00:00
parent 167eb1f903
commit 71400b6afa

View File

@ -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<ScalarEvolution>();
if (!SE->hasLoopInvariantBackedgeTakenCount(L))