[ThinLTO] Don't import GV which contains blockaddress
Differential revision: https://reviews.llvm.org/D53139
llvm-svn: 344325
diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
index bca4004..3eb150b 100644
--- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
+++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
@@ -74,9 +74,17 @@
// Walk through the operands of a given User via worklist iteration and populate
// the set of GlobalValue references encountered. Invoked either on an
// Instruction or a GlobalVariable (which walks its initializer).
-static void findRefEdges(ModuleSummaryIndex &Index, const User *CurUser,
+// Return true if any of the operands contains blockaddress. This is important
+// to know when computing summary for global var, because if global variable
+// references basic block address we can't import it separately from function
+// containing that basic block. For simplicity we currently don't import such
+// global vars at all. When importing function we aren't interested if any
+// instruction in it takes an address of any basic block, because instruction
+// can only take an address of basic block located in the same function.
+static bool findRefEdges(ModuleSummaryIndex &Index, const User *CurUser,
SetVector<ValueInfo> &RefEdges,
SmallPtrSet<const User *, 8> &Visited) {
+ bool HasBlockAddress = false;
SmallVector<const User *, 32> Worklist;
Worklist.push_back(CurUser);
@@ -92,8 +100,10 @@
const User *Operand = dyn_cast<User>(OI);
if (!Operand)
continue;
- if (isa<BlockAddress>(Operand))
+ if (isa<BlockAddress>(Operand)) {
+ HasBlockAddress = true;
continue;
+ }
if (auto *GV = dyn_cast<GlobalValue>(Operand)) {
// We have a reference to a global value. This should be added to
// the reference set unless it is a callee. Callees are handled
@@ -105,6 +115,7 @@
Worklist.push_back(Operand);
}
}
+ return HasBlockAddress;
}
static CalleeInfo::HotnessType getHotness(uint64_t ProfileCount,
@@ -369,7 +380,7 @@
DenseSet<GlobalValue::GUID> &CantBePromoted) {
SetVector<ValueInfo> RefEdges;
SmallPtrSet<const User *, 8> Visited;
- findRefEdges(Index, &V, RefEdges, Visited);
+ bool HasBlockAddress = findRefEdges(Index, &V, RefEdges, Visited);
bool NonRenamableLocal = isNonRenamableLocal(V);
GlobalValueSummary::GVFlags Flags(V.getLinkage(), NonRenamableLocal,
/* Live = */ false, V.isDSOLocal());
@@ -377,6 +388,8 @@
llvm::make_unique<GlobalVarSummary>(Flags, RefEdges.takeVector());
if (NonRenamableLocal)
CantBePromoted.insert(V.getGUID());
+ if (HasBlockAddress)
+ GVarSummary->setNotEligibleToImport();
Index.addGlobalValueSummary(V, std::move(GVarSummary));
}