[ThinLTO] Record calls to aliases
Summary:
When there is a call to an alias in the same module, we were not
adding a call edge. So we could incorrectly think that the alias
was dead if it was inlined in that function, despite having a
reference imported elsewhere. This resulted in unsats at link time.
Add a call edge when the call is to an alias.
Reviewers: davide, mehdi_amini
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D25384
llvm-svn: 283664
diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
index 5a9d9a6..c107deb 100644
--- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
+++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
@@ -101,15 +101,26 @@
auto CS = ImmutableCallSite(&I);
if (!CS)
continue;
+ auto *CalledValue = CS.getCalledValue();
auto *CalledFunction = CS.getCalledFunction();
+ // Check if this is an alias to a function. If so, get the
+ // called aliasee for the checks below.
+ if (auto *GA = dyn_cast<GlobalAlias>(CalledValue)) {
+ assert(!CalledFunction && "Expected null called function in callsite for alias");
+ CalledFunction = dyn_cast<Function>(GA->getBaseObject());
+ }
// Check if this is a direct call to a known function.
if (CalledFunction) {
// Skip nameless and intrinsics.
if (!CalledFunction->hasName() || CalledFunction->isIntrinsic())
continue;
auto ScaledCount = BFI ? BFI->getBlockProfileCount(&BB) : None;
+ // Use the original CalledValue, in case it was an alias. We want
+ // to record the call edge to the alias in that case. Eventually
+ // an alias summary will be created to associate the alias and
+ // aliasee.
auto *CalleeId =
- M.getValueSymbolTable().lookup(CalledFunction->getName());
+ M.getValueSymbolTable().lookup(CalledValue->getName());
auto Hotness = ScaledCount ? getHotness(ScaledCount.getValue(), PSI)
: CalleeInfo::HotnessType::Unknown;