#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/ConstantFolding.h"
const DataLayout *DL;
TargetLibraryInfo *TLI;
+ SmallSet<const Comdat *, 8> NotDiscardableComdats;
};
}
/// value will trap if the value is dynamically null. PHIs keeps track of any
/// phi nodes we've seen to avoid reprocessing them.
static bool AllUsesOfValueWillTrapIfNull(const Value *V,
- SmallPtrSet<const PHINode*, 8> &PHIs) {
+ SmallPtrSetImpl<const PHINode*> &PHIs) {
for (const User *U : V->users())
if (isa<LoadInst>(U)) {
// Will trap.
/// it is to the specified global.
static bool ValueIsOnlyUsedLocallyOrStoredToOneGlobal(const Instruction *V,
const GlobalVariable *GV,
- SmallPtrSet<const PHINode*, 8> &PHIs) {
+ SmallPtrSetImpl<const PHINode*> &PHIs) {
for (const User *U : V->users()) {
const Instruction *Inst = cast<Instruction>(U);
/// of a load) are simple enough to perform heap SRA on. This permits GEP's
/// that index through the array and struct field, icmps of null, and PHIs.
static bool LoadUsesSimpleEnoughForHeapSRA(const Value *V,
- SmallPtrSet<const PHINode*, 32> &LoadUsingPHIs,
- SmallPtrSet<const PHINode*, 32> &LoadUsingPHIsPerLoad) {
+ SmallPtrSetImpl<const PHINode*> &LoadUsingPHIs,
+ SmallPtrSetImpl<const PHINode*> &LoadUsingPHIsPerLoad) {
// We permit two users of the load: setcc comparing against the null
// pointer, and a getelementptr of a specific form.
for (const User *U : V->users()) {
// that all inputs the to the PHI nodes are in the same equivalence sets.
// Check to verify that all operands of the PHIs are either PHIS that can be
// transformed, loads from GV, or MI itself.
- for (SmallPtrSet<const PHINode*, 32>::const_iterator I = LoadUsingPHIs.begin()
- , E = LoadUsingPHIs.end(); I != E; ++I) {
- const PHINode *PN = *I;
+ for (const PHINode *PN : LoadUsingPHIs) {
for (unsigned op = 0, e = PN->getNumIncomingValues(); op != e; ++op) {
Value *InVal = PN->getIncomingValue(op);
/// possible. If we make a change, return true.
bool GlobalOpt::ProcessGlobal(GlobalVariable *GV,
Module::global_iterator &GVI) {
- if (!GV->isDiscardableIfUnused())
- return false;
-
// Do more involved optimizations if the global is internal.
GV->removeDeadConstantUsers();
for (Module::iterator FI = M.begin(), E = M.end(); FI != E; ) {
Function *F = FI++;
// Functions without names cannot be referenced outside this module.
- if (!F->hasName() && !F->isDeclaration())
+ if (!F->hasName() && !F->isDeclaration() && !F->hasLocalLinkage())
F->setLinkage(GlobalValue::InternalLinkage);
+
+ const Comdat *C = F->getComdat();
+ bool inComdat = C && NotDiscardableComdats.count(C);
F->removeDeadConstantUsers();
- if (F->isDefTriviallyDead()) {
+ if ((!inComdat || F->hasLocalLinkage()) && F->isDefTriviallyDead()) {
F->eraseFromParent();
Changed = true;
++NumFnDeleted;
bool GlobalOpt::OptimizeGlobalVars(Module &M) {
bool Changed = false;
+
for (Module::global_iterator GVI = M.global_begin(), E = M.global_end();
GVI != E; ) {
GlobalVariable *GV = GVI++;
// Global variables without names cannot be referenced outside this module.
- if (!GV->hasName() && !GV->isDeclaration())
+ if (!GV->hasName() && !GV->isDeclaration() && !GV->hasLocalLinkage())
GV->setLinkage(GlobalValue::InternalLinkage);
// Simplify the initializer.
if (GV->hasInitializer())
GV->setInitializer(New);
}
- Changed |= ProcessGlobal(GV, GVI);
+ if (GV->isDiscardableIfUnused()) {
+ if (const Comdat *C = GV->getComdat())
+ if (NotDiscardableComdats.count(C) && !GV->hasLocalLinkage())
+ continue;
+ Changed |= ProcessGlobal(GV, GVI);
+ }
}
return Changed;
}
static inline bool
isSimpleEnoughValueToCommit(Constant *C,
- SmallPtrSet<Constant*, 8> &SimpleConstants,
+ SmallPtrSetImpl<Constant*> &SimpleConstants,
const DataLayout *DL);
/// in SimpleConstants to avoid having to rescan the same constants all the
/// time.
static bool isSimpleEnoughValueToCommitHelper(Constant *C,
- SmallPtrSet<Constant*, 8> &SimpleConstants,
+ SmallPtrSetImpl<Constant*> &SimpleConstants,
const DataLayout *DL) {
- // Simple integer, undef, constant aggregate zero, global addresses, etc are
- // all supported.
- if (C->getNumOperands() == 0 || isa<BlockAddress>(C) ||
- isa<GlobalValue>(C))
+ // Simple global addresses are supported, do not allow dllimport or
+ // thread-local globals.
+ if (auto *GV = dyn_cast<GlobalValue>(C))
+ return !GV->hasDLLImportStorageClass() && !GV->isThreadLocal();
+
+ // Simple integer, undef, constant aggregate zero, etc are all supported.
+ if (C->getNumOperands() == 0 || isa<BlockAddress>(C))
return true;
// Aggregate values are safe if all their elements are.
static inline bool
isSimpleEnoughValueToCommit(Constant *C,
- SmallPtrSet<Constant*, 8> &SimpleConstants,
+ SmallPtrSetImpl<Constant*> &SimpleConstants,
const DataLayout *DL) {
// If we already checked this constant, we win.
if (!SimpleConstants.insert(C)) return true;
return false;
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
- // Do not allow weak/*_odr/linkonce/dllimport/dllexport linkage or
- // external globals.
+ // Do not allow weak/*_odr/linkonce linkage or external globals.
return GV->hasUniqueInitializer();
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C)) {
return MutatedMemory;
}
- const SmallPtrSet<GlobalVariable*, 8> &getInvariants() const {
+ const SmallPtrSetImpl<GlobalVariable*> &getInvariants() const {
return Invariants;
}
getVal(SI->getOperand(2)));
DEBUG(dbgs() << "Found a Select! Simplifying: " << *InstResult
<< "\n");
+ } else if (auto *EVI = dyn_cast<ExtractValueInst>(CurInst)) {
+ InstResult = ConstantExpr::getExtractValue(
+ getVal(EVI->getAggregateOperand()), EVI->getIndices());
+ DEBUG(dbgs() << "Found an ExtractValueInst! Simplifying: " << *InstResult
+ << "\n");
+ } else if (auto *IVI = dyn_cast<InsertValueInst>(CurInst)) {
+ InstResult = ConstantExpr::getInsertValue(
+ getVal(IVI->getAggregateOperand()),
+ getVal(IVI->getInsertedValueOperand()), IVI->getIndices());
+ DEBUG(dbgs() << "Found an InsertValueInst! Simplifying: " << *InstResult
+ << "\n");
} else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(CurInst)) {
Constant *P = getVal(GEP->getOperand(0));
SmallVector<Constant*, 8> GEPOps;
Eval.getMutatedMemory().begin(), E = Eval.getMutatedMemory().end();
I != E; ++I)
CommitValueTo(I->second, I->first);
- for (SmallPtrSet<GlobalVariable*, 8>::const_iterator I =
- Eval.getInvariants().begin(), E = Eval.getInvariants().end();
- I != E; ++I)
- (*I)->setConstant(true);
+ for (GlobalVariable *GV : Eval.getInvariants())
+ GV->setConstant(true);
}
return EvalSuccess;
}
static void setUsedInitializer(GlobalVariable &V,
- SmallPtrSet<GlobalValue *, 8> Init) {
+ const SmallPtrSet<GlobalValue *, 8> &Init) {
if (Init.empty()) {
V.eraseFromParent();
return;
PointerType *Int8PtrTy = Type::getInt8PtrTy(V.getContext(), 0);
SmallVector<llvm::Constant *, 8> UsedArray;
- for (SmallPtrSet<GlobalValue *, 8>::iterator I = Init.begin(), E = Init.end();
- I != E; ++I) {
+ for (GlobalValue *GV : Init) {
Constant *Cast
- = ConstantExpr::getPointerBitCastOrAddrSpaceCast(*I, Int8PtrTy);
+ = ConstantExpr::getPointerBitCastOrAddrSpaceCast(GV, Int8PtrTy);
UsedArray.push_back(Cast);
}
// Sort to get deterministic order.
CompilerUsedV = collectUsedGlobalVariables(M, CompilerUsed, true);
}
typedef SmallPtrSet<GlobalValue *, 8>::iterator iterator;
+ typedef iterator_range<iterator> used_iterator_range;
iterator usedBegin() { return Used.begin(); }
iterator usedEnd() { return Used.end(); }
+ used_iterator_range used() {
+ return used_iterator_range(usedBegin(), usedEnd());
+ }
iterator compilerUsedBegin() { return CompilerUsed.begin(); }
iterator compilerUsedEnd() { return CompilerUsed.end(); }
+ used_iterator_range compilerUsed() {
+ return used_iterator_range(compilerUsedBegin(), compilerUsedEnd());
+ }
bool usedCount(GlobalValue *GV) const { return Used.count(GV); }
bool compilerUsedCount(GlobalValue *GV) const {
return CompilerUsed.count(GV);
return U.usedCount(&GA) || U.compilerUsedCount(&GA);
}
-static bool hasUsesToReplace(GlobalAlias &GA, LLVMUsed &U, bool &RenameTarget) {
+static bool hasUsesToReplace(GlobalAlias &GA, const LLVMUsed &U,
+ bool &RenameTarget) {
RenameTarget = false;
bool Ret = false;
if (hasUseOtherThanLLVMUsed(GA, U))
bool Changed = false;
LLVMUsed Used(M);
- for (SmallPtrSet<GlobalValue *, 8>::iterator I = Used.usedBegin(),
- E = Used.usedEnd();
- I != E; ++I)
- Used.compilerUsedErase(*I);
+ for (GlobalValue *GV : Used.used())
+ Used.compilerUsedErase(GV);
for (Module::alias_iterator I = M.alias_begin(), E = M.alias_end();
I != E;) {
Module::alias_iterator J = I++;
// Aliases without names cannot be referenced outside this module.
- if (!J->hasName() && !J->isDeclaration())
+ if (!J->hasName() && !J->isDeclaration() && !J->hasLocalLinkage())
J->setLinkage(GlobalValue::InternalLinkage);
// If the aliasee may change at link time, nothing can be done - bail out.
if (J->mayBeOverridden())
continue;
Constant *Aliasee = J->getAliasee();
- GlobalValue *Target = cast<GlobalValue>(Aliasee->stripPointerCasts());
+ GlobalValue *Target = dyn_cast<GlobalValue>(Aliasee->stripPointerCasts());
+ // We can't trivially replace the alias with the aliasee if the aliasee is
+ // non-trivial in some way.
+ // TODO: Try to handle non-zero GEPs of local aliasees.
+ if (!Target)
+ continue;
Target->removeDeadConstantUsers();
// Make all users of the alias use the aliasee instead.
if (!hasUsesToReplace(*J, Used, RenameTarget))
continue;
- J->replaceAllUsesWith(Aliasee);
+ J->replaceAllUsesWith(ConstantExpr::getBitCast(Aliasee, J->getType()));
++NumAliasesResolved;
Changed = true;
while (LocalChange) {
LocalChange = false;
+ NotDiscardableComdats.clear();
+ for (const GlobalVariable &GV : M.globals())
+ if (const Comdat *C = GV.getComdat())
+ if (!GV.isDiscardableIfUnused() || !GV.use_empty())
+ NotDiscardableComdats.insert(C);
+ for (Function &F : M)
+ if (const Comdat *C = F.getComdat())
+ if (!F.isDefTriviallyDead())
+ NotDiscardableComdats.insert(C);
+ for (GlobalAlias &GA : M.aliases())
+ if (const Comdat *C = GA.getComdat())
+ if (!GA.isDiscardableIfUnused() || !GA.use_empty())
+ NotDiscardableComdats.insert(C);
+
// Delete functions that are trivially dead, ccc -> fastcc
LocalChange |= OptimizeFunctions(M);
// Optimize global_ctors list.
- LocalChange |= optimizeGlobalCtorsList(M, [](void *C, Function *F) -> bool {
- GlobalOpt *self = static_cast<GlobalOpt *>(C);
- return EvaluateStaticConstructor(F, self->DL, self->TLI);
- }, this);
+ LocalChange |= optimizeGlobalCtorsList(M, [&](Function *F) {
+ return EvaluateStaticConstructor(F, DL, TLI);
+ });
// Optimize non-address-taken globals.
LocalChange |= OptimizeGlobalVars(M);