Revert "[ThinLTO] Add summary entries for index-based WPD"
Mistaken commit of something still under review!
This reverts commit r351453.
llvm-svn: 351455
diff --git a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
index af3d97a..87f76d4 100644
--- a/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
+++ b/llvm/lib/Analysis/ModuleSummaryAnalysis.cpp
@@ -406,98 +406,9 @@
Index.addGlobalValueSummary(F, std::move(FuncSummary));
}
-/// Find function pointers referenced within the given vtable initializer
-/// (or subset of an initializer) \p I. The starting offset of \p I within
-/// the vtable initializer is \p StartingOffset. Any discovered function
-/// pointers are added to \p VTableFuncs along with their cumulative offset
-/// within the initializer.
-static void findFuncPointers(const Constant *I, uint64_t StartingOffset,
- const Module &M, ModuleSummaryIndex &Index,
- VTableFuncList &VTableFuncs) {
- // First check if this is a function pointer.
- if (I->getType()->isPointerTy()) {
- auto Fn = dyn_cast<Function>(I->stripPointerCasts());
- // We can disregard __cxa_pure_virtual as a possible call target, as
- // calls to pure virtuals are UB.
- if (Fn && Fn->getName() != "__cxa_pure_virtual")
- VTableFuncs.push_back(
- std::make_pair(Index.getOrInsertValueInfo(Fn), StartingOffset));
- return;
- }
-
- // Walk through the elements in the constant struct or array and recursively
- // look for virtual function pointers.
- const DataLayout &DL = M.getDataLayout();
- if (auto *C = dyn_cast<ConstantStruct>(I)) {
- StructType *STy = dyn_cast<StructType>(C->getType());
- assert(STy);
- const StructLayout *SL = DL.getStructLayout(C->getType());
-
- for (StructType::element_iterator EB = STy->element_begin(), EI = EB,
- EE = STy->element_end();
- EI != EE; ++EI) {
- auto Offset = SL->getElementOffset(EI - EB);
- unsigned Op = SL->getElementContainingOffset(Offset);
- findFuncPointers(cast<Constant>(I->getOperand(Op)),
- StartingOffset + Offset, M, Index, VTableFuncs);
- }
- } else if (auto *C = dyn_cast<ConstantArray>(I)) {
- ArrayType *ATy = C->getType();
- Type *EltTy = ATy->getElementType();
- uint64_t EltSize = DL.getTypeAllocSize(EltTy);
- for (unsigned i = 0, e = ATy->getNumElements(); i != e; ++i) {
- findFuncPointers(cast<Constant>(I->getOperand(i)),
- StartingOffset + i * EltSize, M, Index, VTableFuncs);
- }
- }
-}
-
-// Identify the function pointers referenced by vtable definition \p V.
-static void computeVTableFuncs(ModuleSummaryIndex &Index,
- const GlobalVariable &V, const Module &M,
- VTableFuncList &VTableFuncs) {
- if (!V.isConstant())
- return;
-
- findFuncPointers(V.getInitializer(), /*StartingOffset=*/0, M, Index,
- VTableFuncs);
-
-#ifndef NDEBUG
- // Validate that the VTableFuncs list is ordered by offset.
- uint64_t PrevOffset = 0;
- for (auto &P : VTableFuncs) {
- // The findVFuncPointers traversal should have encountered the
- // functions in offset order. We need to use ">=" since PrevOffset
- // starts at 0.
- assert(P.second >= PrevOffset);
- PrevOffset = P.second;
- }
-#endif
-}
-
-/// Record vtable definition \p V for each type metadata it references.
-static void recordTypeIdMetadataReferences(ModuleSummaryIndex &Index,
- const GlobalVariable &V,
- SmallVectorImpl<MDNode *> &Types) {
- for (MDNode *Type : Types) {
- auto TypeID = Type->getOperand(1).get();
-
- uint64_t Offset =
- cast<ConstantInt>(
- cast<ConstantAsMetadata>(Type->getOperand(0))->getValue())
- ->getZExtValue();
-
- if (auto *TypeId = dyn_cast<MDString>(TypeID))
- Index.getOrInsertTypeIdMetadataSummary(TypeId->getString())
- .push_back({Offset, Index.getOrInsertValueInfo(&V)});
- }
-}
-
-static void computeVariableSummary(ModuleSummaryIndex &Index,
- const GlobalVariable &V,
- DenseSet<GlobalValue::GUID> &CantBePromoted,
- const Module &M,
- SmallVectorImpl<MDNode *> &Types) {
+static void
+computeVariableSummary(ModuleSummaryIndex &Index, const GlobalVariable &V,
+ DenseSet<GlobalValue::GUID> &CantBePromoted) {
SetVector<ValueInfo> RefEdges;
SmallPtrSet<const User *, 8> Visited;
bool HasBlockAddress = findRefEdges(Index, &V, RefEdges, Visited);
@@ -505,21 +416,6 @@
GlobalValueSummary::GVFlags Flags(V.getLinkage(), NonRenamableLocal,
/* Live = */ false, V.isDSOLocal());
- VTableFuncList VTableFuncs;
- // If splitting is not enabled, then we compute the summary information
- // necessary for index-based whole program devirtualization.
- if (!Index.enableSplitLTOUnit()) {
- Types.clear();
- V.getMetadata(LLVMContext::MD_type, Types);
- if (!Types.empty()) {
- // Identify the function pointers referenced by this vtable definition.
- computeVTableFuncs(Index, V, M, VTableFuncs);
-
- // Record this vtable definition for each type metadata it references.
- recordTypeIdMetadataReferences(Index, V, Types);
- }
- }
-
// Don't mark variables we won't be able to internalize as read-only.
GlobalVarSummary::GVarFlags VarFlags(
!V.hasComdat() && !V.hasAppendingLinkage() && !V.isInterposable() &&
@@ -530,8 +426,6 @@
CantBePromoted.insert(V.getGUID());
if (HasBlockAddress)
GVarSummary->setNotEligibleToImport();
- if (!VTableFuncs.empty())
- GVarSummary->setVTableFuncs(VTableFuncs);
Index.addGlobalValueSummary(V, std::move(GVarSummary));
}
@@ -674,11 +568,10 @@
// Compute summaries for all variables defined in module, and save in the
// index.
- SmallVector<MDNode *, 2> Types;
for (const GlobalVariable &G : M.globals()) {
if (G.isDeclaration())
continue;
- computeVariableSummary(Index, G, CantBePromoted, M, Types);
+ computeVariableSummary(Index, G, CantBePromoted);
}
// Compute summaries for all aliases defined in module, and save in the