LowerTypeTests: Fix quadratic complexity.
Currently we have quadratic complexity in LowerTypeTests because
ScopedSaveAliaseesAndUsed loops over all aliases for each disjoint
set, and the number of aliases and number of disjoint sets is
roughly proportional to the program size. Fix that by moving
ScopedSaveAliaseesAndUsed to LowerTypeTestsModule::lower() so that
we do this only once.
Reviewers: fmayer, vitalybuka
Reviewed By: vitalybuka
Pull Request: https://github.com/llvm/llvm-project/pull/135875
diff --git a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
index 7cf7d74..8e9f24d 100644
--- a/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
+++ b/llvm/lib/Transforms/IPO/LowerTypeTests.cpp
@@ -1669,61 +1669,55 @@
lowerTypeTestCalls(TypeIds, JumpTable, GlobalLayout);
- {
- ScopedSaveAliaseesAndUsed S(M);
+ // Build aliases pointing to offsets into the jump table, and replace
+ // references to the original functions with references to the aliases.
+ for (unsigned I = 0; I != Functions.size(); ++I) {
+ Function *F = cast<Function>(Functions[I]->getGlobal());
+ bool IsJumpTableCanonical = Functions[I]->isJumpTableCanonical();
- // Build aliases pointing to offsets into the jump table, and replace
- // references to the original functions with references to the aliases.
- for (unsigned I = 0; I != Functions.size(); ++I) {
- Function *F = cast<Function>(Functions[I]->getGlobal());
- bool IsJumpTableCanonical = Functions[I]->isJumpTableCanonical();
+ Constant *CombinedGlobalElemPtr = ConstantExpr::getInBoundsGetElementPtr(
+ JumpTableType, JumpTable,
+ ArrayRef<Constant *>{ConstantInt::get(IntPtrTy, 0),
+ ConstantInt::get(IntPtrTy, I)});
- Constant *CombinedGlobalElemPtr = ConstantExpr::getInBoundsGetElementPtr(
- JumpTableType, JumpTable,
- ArrayRef<Constant *>{ConstantInt::get(IntPtrTy, 0),
- ConstantInt::get(IntPtrTy, I)});
+ const bool IsExported = Functions[I]->isExported();
+ if (!IsJumpTableCanonical) {
+ GlobalValue::LinkageTypes LT = IsExported ? GlobalValue::ExternalLinkage
+ : GlobalValue::InternalLinkage;
+ GlobalAlias *JtAlias = GlobalAlias::create(F->getValueType(), 0, LT,
+ F->getName() + ".cfi_jt",
+ CombinedGlobalElemPtr, &M);
+ if (IsExported)
+ JtAlias->setVisibility(GlobalValue::HiddenVisibility);
+ else
+ appendToUsed(M, {JtAlias});
+ }
- const bool IsExported = Functions[I]->isExported();
- if (!IsJumpTableCanonical) {
- GlobalValue::LinkageTypes LT = IsExported
- ? GlobalValue::ExternalLinkage
- : GlobalValue::InternalLinkage;
- GlobalAlias *JtAlias = GlobalAlias::create(F->getValueType(), 0, LT,
- F->getName() + ".cfi_jt",
- CombinedGlobalElemPtr, &M);
- if (IsExported)
- JtAlias->setVisibility(GlobalValue::HiddenVisibility);
- else
- appendToUsed(M, {JtAlias});
- }
+ if (IsExported) {
+ if (IsJumpTableCanonical)
+ ExportSummary->cfiFunctionDefs().emplace(F->getName());
+ else
+ ExportSummary->cfiFunctionDecls().emplace(F->getName());
+ }
- if (IsExported) {
- if (IsJumpTableCanonical)
- ExportSummary->cfiFunctionDefs().emplace(F->getName());
- else
- ExportSummary->cfiFunctionDecls().emplace(F->getName());
- }
+ if (!IsJumpTableCanonical) {
+ if (F->hasExternalWeakLinkage())
+ replaceWeakDeclarationWithJumpTablePtr(F, CombinedGlobalElemPtr,
+ IsJumpTableCanonical);
+ else
+ replaceCfiUses(F, CombinedGlobalElemPtr, IsJumpTableCanonical);
+ } else {
+ assert(F->getType()->getAddressSpace() == 0);
- if (!IsJumpTableCanonical) {
- if (F->hasExternalWeakLinkage())
- replaceWeakDeclarationWithJumpTablePtr(F, CombinedGlobalElemPtr,
- IsJumpTableCanonical);
- else
- replaceCfiUses(F, CombinedGlobalElemPtr, IsJumpTableCanonical);
- } else {
- assert(F->getType()->getAddressSpace() == 0);
-
- GlobalAlias *FAlias =
- GlobalAlias::create(F->getValueType(), 0, F->getLinkage(), "",
- CombinedGlobalElemPtr, &M);
- FAlias->setVisibility(F->getVisibility());
- FAlias->takeName(F);
- if (FAlias->hasName())
- F->setName(FAlias->getName() + ".cfi");
- replaceCfiUses(F, FAlias, IsJumpTableCanonical);
- if (!F->hasLocalLinkage())
- F->setVisibility(GlobalVariable::HiddenVisibility);
- }
+ GlobalAlias *FAlias = GlobalAlias::create(
+ F->getValueType(), 0, F->getLinkage(), "", CombinedGlobalElemPtr, &M);
+ FAlias->setVisibility(F->getVisibility());
+ FAlias->takeName(F);
+ if (FAlias->hasName())
+ F->setName(FAlias->getName() + ".cfi");
+ replaceCfiUses(F, FAlias, IsJumpTableCanonical);
+ if (!F->hasLocalLinkage())
+ F->setVisibility(GlobalVariable::HiddenVisibility);
}
}
@@ -2339,39 +2333,43 @@
if (GlobalClasses.empty())
return false;
- // For each disjoint set we found...
- for (const auto &C : GlobalClasses) {
- if (!C->isLeader())
- continue;
+ {
+ ScopedSaveAliaseesAndUsed S(M);
+ // For each disjoint set we found...
+ for (const auto &C : GlobalClasses) {
+ if (!C->isLeader())
+ continue;
- ++NumTypeIdDisjointSets;
- // Build the list of type identifiers in this disjoint set.
- std::vector<Metadata *> TypeIds;
- std::vector<GlobalTypeMember *> Globals;
- std::vector<ICallBranchFunnel *> ICallBranchFunnels;
- for (auto M : GlobalClasses.members(*C)) {
- if (isa<Metadata *>(M))
- TypeIds.push_back(cast<Metadata *>(M));
- else if (isa<GlobalTypeMember *>(M))
- Globals.push_back(cast<GlobalTypeMember *>(M));
- else
- ICallBranchFunnels.push_back(cast<ICallBranchFunnel *>(M));
+ ++NumTypeIdDisjointSets;
+ // Build the list of type identifiers in this disjoint set.
+ std::vector<Metadata *> TypeIds;
+ std::vector<GlobalTypeMember *> Globals;
+ std::vector<ICallBranchFunnel *> ICallBranchFunnels;
+ for (auto M : GlobalClasses.members(*C)) {
+ if (isa<Metadata *>(M))
+ TypeIds.push_back(cast<Metadata *>(M));
+ else if (isa<GlobalTypeMember *>(M))
+ Globals.push_back(cast<GlobalTypeMember *>(M));
+ else
+ ICallBranchFunnels.push_back(cast<ICallBranchFunnel *>(M));
+ }
+
+ // Order type identifiers by unique ID for determinism. This ordering is
+ // stable as there is a one-to-one mapping between metadata and unique
+ // IDs.
+ llvm::sort(TypeIds, [&](Metadata *M1, Metadata *M2) {
+ return TypeIdInfo[M1].UniqueId < TypeIdInfo[M2].UniqueId;
+ });
+
+ // Same for the branch funnels.
+ llvm::sort(ICallBranchFunnels,
+ [&](ICallBranchFunnel *F1, ICallBranchFunnel *F2) {
+ return F1->UniqueId < F2->UniqueId;
+ });
+
+ // Build bitsets for this disjoint set.
+ buildBitSetsFromDisjointSet(TypeIds, Globals, ICallBranchFunnels);
}
-
- // Order type identifiers by unique ID for determinism. This ordering is
- // stable as there is a one-to-one mapping between metadata and unique IDs.
- llvm::sort(TypeIds, [&](Metadata *M1, Metadata *M2) {
- return TypeIdInfo[M1].UniqueId < TypeIdInfo[M2].UniqueId;
- });
-
- // Same for the branch funnels.
- llvm::sort(ICallBranchFunnels,
- [&](ICallBranchFunnel *F1, ICallBranchFunnel *F2) {
- return F1->UniqueId < F2->UniqueId;
- });
-
- // Build bitsets for this disjoint set.
- buildBitSetsFromDisjointSet(TypeIds, Globals, ICallBranchFunnels);
}
allocateByteArrays();
