Fix PR 23499 - Avoid multiple profile counters for functions in comdat sections.

Counter symbols created for linkonce functions are not discarded by ELF
linkers unless the symbols are placed in the same comdat section as its
associated function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@238335 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Diego Novillo 2015-05-27 16:44:47 +00:00
parent dbab00a2d4
commit df65fd3205

View File

@ -203,6 +203,7 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
uint64_t NumCounters = Inc->getNumCounters()->getZExtValue();
LLVMContext &Ctx = M->getContext();
ArrayType *CounterTy = ArrayType::get(Type::getInt64Ty(Ctx), NumCounters);
Function *Fn = Inc->getParent()->getParent();
// Create the counters variable.
auto *Counters = new GlobalVariable(*M, CounterTy, false, Name->getLinkage(),
@ -211,6 +212,10 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
Counters->setVisibility(Name->getVisibility());
Counters->setSection(getCountersSection());
Counters->setAlignment(8);
// Place the counters in the same comdat section as its parent function.
// Otherwise, we may get multiple counters for the same function in certain
// cases.
Counters->setComdat(Fn->getComdat());
RegionCounters[Inc->getName()] = Counters;
@ -235,6 +240,7 @@ InstrProfiling::getOrCreateRegionCounters(InstrProfIncrementInst *Inc) {
Data->setVisibility(Name->getVisibility());
Data->setSection(getDataSection());
Data->setAlignment(8);
Data->setComdat(Fn->getComdat());
// Mark the data variable as used so that it isn't stripped out.
UsedVars.push_back(Data);