#include "llvm/DerivedTypes.h"
#include "llvm/Instructions.h"
#include "llvm/IntrinsicInst.h"
+#include "llvm/LLVMContext.h"
#include "llvm/Module.h"
#include "llvm/Pass.h"
#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/MallocFreeHelper.h"
#include "llvm/Target/TargetData.h"
#include "llvm/Support/CallSite.h"
-#include "llvm/Support/Compiler.h"
#include "llvm/Support/Debug.h"
+#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/GetElementPtrTypeIterator.h"
#include "llvm/Support/MathExtras.h"
+#include "llvm/Support/raw_ostream.h"
+#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/Statistic.h"
-#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/STLExtras.h"
#include <algorithm>
-#include <map>
-#include <set>
using namespace llvm;
STATISTIC(NumMarked , "Number of globals marked constant");
STATISTIC(NumFastCallFns , "Number of functions converted to fastcc");
STATISTIC(NumCtorsEvaluated, "Number of static ctors evaluated");
STATISTIC(NumNestRemoved , "Number of nest attributes removed");
+STATISTIC(NumAliasesResolved, "Number of global aliases resolved");
+STATISTIC(NumAliasesRemoved, "Number of global aliases eliminated");
namespace {
- struct VISIBILITY_HIDDEN GlobalOpt : public ModulePass {
+ struct GlobalOpt : public ModulePass {
virtual void getAnalysisUsage(AnalysisUsage &AU) const {
- AU.addRequired<TargetData>();
}
static char ID; // Pass identification, replacement for typeid
GlobalOpt() : ModulePass(&ID) {}
GlobalVariable *FindGlobalCtors(Module &M);
bool OptimizeFunctions(Module &M);
bool OptimizeGlobalVars(Module &M);
- bool ResolveAliases(Module &M);
+ bool OptimizeGlobalAliases(Module &M);
bool OptimizeGlobalCtorsList(GlobalVariable *&GCL);
bool ProcessInternalGlobal(GlobalVariable *GV,Module::global_iterator &GVI);
};
/// GlobalStatus - As we analyze each global, keep track of some information
/// about it. If we find out that the address of the global is taken, none of
/// this info will be accurate.
-struct VISIBILITY_HIDDEN GlobalStatus {
+struct GlobalStatus {
/// isLoaded - True if the global is ever loaded. If the global isn't ever
/// loaded it can be deleted.
bool isLoaded;
}
-/// ConstantIsDead - Return true if the specified constant is (transitively)
-/// dead. The constant may be used by other constants (e.g. constant arrays and
-/// constant exprs) as long as they are dead, but it cannot be used by anything
-/// else.
-static bool ConstantIsDead(Constant *C) {
+// SafeToDestroyConstant - It is safe to destroy a constant iff it is only used
+// by constants itself. Note that constants cannot be cyclic, so this test is
+// pretty easy to implement recursively.
+//
+static bool SafeToDestroyConstant(Constant *C) {
if (isa<GlobalValue>(C)) return false;
for (Value::use_iterator UI = C->use_begin(), E = C->use_end(); UI != E; ++UI)
if (Constant *CU = dyn_cast<Constant>(*UI)) {
- if (!ConstantIsDead(CU)) return false;
+ if (!SafeToDestroyConstant(CU)) return false;
} else
return false;
return true;
/// can't do anything with it.
///
static bool AnalyzeGlobal(Value *V, GlobalStatus &GS,
- std::set<PHINode*> &PHIUsers) {
+ SmallPtrSet<PHINode*, 16> &PHIUsers) {
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ++UI)
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(*UI)) {
GS.HasNonInstructionUser = true;
} else if (PHINode *PN = dyn_cast<PHINode>(I)) {
// PHI nodes we can check just like select or GEP instructions, but we
// have to be careful about infinite recursion.
- if (PHIUsers.insert(PN).second) // Not already visited.
+ if (PHIUsers.insert(PN)) // Not already visited.
if (AnalyzeGlobal(I, GS, PHIUsers)) return true;
GS.HasPHIUser = true;
} else if (isa<CmpInst>(I)) {
- } else if (isa<MemCpyInst>(I) || isa<MemMoveInst>(I)) {
+ } else if (isa<MemTransferInst>(I)) {
if (I->getOperand(1) == V)
GS.StoredType = GlobalStatus::isStored;
if (I->getOperand(2) == V)
} else if (Constant *C = dyn_cast<Constant>(*UI)) {
GS.HasNonInstructionUser = true;
// We might have a dead and dangling constant hanging off of here.
- if (!ConstantIsDead(C))
+ if (!SafeToDestroyConstant(C))
return true;
} else {
GS.HasNonInstructionUser = true;
return false;
}
-static Constant *getAggregateConstantElement(Constant *Agg, Constant *Idx) {
+static Constant *getAggregateConstantElement(Constant *Agg, Constant *Idx,
+ LLVMContext &Context) {
ConstantInt *CI = dyn_cast<ConstantInt>(Idx);
if (!CI) return 0;
unsigned IdxV = CI->getZExtValue();
/// users of the global, cleaning up the obvious ones. This is largely just a
/// quick scan over the use list to clean up the easy and obvious cruft. This
/// returns true if it made a change.
-static bool CleanupConstantGlobalUsers(Value *V, Constant *Init) {
+static bool CleanupConstantGlobalUsers(Value *V, Constant *Init,
+ LLVMContext &Context) {
bool Changed = false;
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;) {
User *U = *UI++;
Constant *SubInit = 0;
if (Init)
SubInit = ConstantFoldLoadThroughGEPConstantExpr(Init, CE);
- Changed |= CleanupConstantGlobalUsers(CE, SubInit);
+ Changed |= CleanupConstantGlobalUsers(CE, SubInit, Context);
} else if (CE->getOpcode() == Instruction::BitCast &&
isa<PointerType>(CE->getType())) {
// Pointer cast, delete any stores and memsets to the global.
- Changed |= CleanupConstantGlobalUsers(CE, 0);
+ Changed |= CleanupConstantGlobalUsers(CE, 0, Context);
}
if (CE->use_empty()) {
Constant *SubInit = 0;
if (!isa<ConstantExpr>(GEP->getOperand(0))) {
ConstantExpr *CE =
- dyn_cast_or_null<ConstantExpr>(ConstantFoldInstruction(GEP));
+ dyn_cast_or_null<ConstantExpr>(ConstantFoldInstruction(GEP, Context));
if (Init && CE && CE->getOpcode() == Instruction::GetElementPtr)
SubInit = ConstantFoldLoadThroughGEPConstantExpr(Init, CE);
}
- Changed |= CleanupConstantGlobalUsers(GEP, SubInit);
+ Changed |= CleanupConstantGlobalUsers(GEP, SubInit, Context);
if (GEP->use_empty()) {
GEP->eraseFromParent();
} else if (Constant *C = dyn_cast<Constant>(U)) {
// If we have a chain of dead constantexprs or other things dangling from
// us, and if they are all dead, nuke them without remorse.
- if (ConstantIsDead(C)) {
+ if (SafeToDestroyConstant(C)) {
C->destroyConstant();
// This could have invalidated UI, start over from scratch.
- CleanupConstantGlobalUsers(V, Init);
+ CleanupConstantGlobalUsers(V, Init, Context);
return true;
}
}
static bool isSafeSROAElementUse(Value *V) {
// We might have a dead and dangling constant hanging off of here.
if (Constant *C = dyn_cast<Constant>(V))
- return ConstantIsDead(C);
+ return SafeToDestroyConstant(C);
Instruction *I = dyn_cast<Instruction>(V);
if (!I) return false;
// Scalar replacing *just* the outer index of the array is probably not
// going to be a win anyway, so just give up.
for (++GEPI; // Skip array index.
- GEPI != E && (isa<ArrayType>(*GEPI) || isa<VectorType>(*GEPI));
+ GEPI != E;
++GEPI) {
uint64_t NumElements;
if (const ArrayType *SubArrayTy = dyn_cast<ArrayType>(*GEPI))
NumElements = SubArrayTy->getNumElements();
- else
- NumElements = cast<VectorType>(*GEPI)->getNumElements();
+ else if (const VectorType *SubVectorTy = dyn_cast<VectorType>(*GEPI))
+ NumElements = SubVectorTy->getNumElements();
+ else {
+ assert(isa<StructType>(*GEPI) &&
+ "Indexed GEP type is not array, vector, or struct!");
+ continue;
+ }
ConstantInt *IdxVal = dyn_cast<ConstantInt>(GEPI.getOperand());
if (!IdxVal || IdxVal->getZExtValue() >= NumElements)
/// behavior of the program in a more fine-grained way. We have determined that
/// this transformation is safe already. We return the first global variable we
/// insert so that the caller can reprocess it.
-static GlobalVariable *SRAGlobal(GlobalVariable *GV, const TargetData &TD) {
+static GlobalVariable *SRAGlobal(GlobalVariable *GV, const TargetData &TD,
+ LLVMContext &Context) {
// Make sure this global only has simple uses that we can SRA.
if (!GlobalUsersSafeToSRA(GV))
return 0;
- assert(GV->hasInternalLinkage() && !GV->isConstant());
+ assert(GV->hasLocalLinkage() && !GV->isConstant());
Constant *Init = GV->getInitializer();
const Type *Ty = Init->getType();
const StructLayout &Layout = *TD.getStructLayout(STy);
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i) {
Constant *In = getAggregateConstantElement(Init,
- ConstantInt::get(Type::Int32Ty, i));
+ ConstantInt::get(Type::getInt32Ty(Context), i),
+ Context);
assert(In && "Couldn't get element of initializer?");
- GlobalVariable *NGV = new GlobalVariable(STy->getElementType(i), false,
+ GlobalVariable *NGV = new GlobalVariable(Context,
+ STy->getElementType(i), false,
GlobalVariable::InternalLinkage,
- In, GV->getName()+"."+utostr(i),
- (Module *)NULL,
+ In, GV->getName()+"."+Twine(i),
GV->isThreadLocal(),
- GV->getType()->getAddressSpace());
+ GV->getType()->getAddressSpace());
Globals.insert(GV, NGV);
NewGlobals.push_back(NGV);
return 0; // It's not worth it.
NewGlobals.reserve(NumElements);
- uint64_t EltSize = TD.getABITypeSize(STy->getElementType());
+ uint64_t EltSize = TD.getTypeAllocSize(STy->getElementType());
unsigned EltAlign = TD.getABITypeAlignment(STy->getElementType());
for (unsigned i = 0, e = NumElements; i != e; ++i) {
Constant *In = getAggregateConstantElement(Init,
- ConstantInt::get(Type::Int32Ty, i));
+ ConstantInt::get(Type::getInt32Ty(Context), i),
+ Context);
assert(In && "Couldn't get element of initializer?");
- GlobalVariable *NGV = new GlobalVariable(STy->getElementType(), false,
+ GlobalVariable *NGV = new GlobalVariable(Context,
+ STy->getElementType(), false,
GlobalVariable::InternalLinkage,
- In, GV->getName()+"."+utostr(i),
- (Module *)NULL,
+ In, GV->getName()+"."+Twine(i),
GV->isThreadLocal(),
- GV->getType()->getAddressSpace());
+ GV->getType()->getAddressSpace());
Globals.insert(GV, NGV);
NewGlobals.push_back(NGV);
if (NewGlobals.empty())
return 0;
- DOUT << "PERFORMING GLOBAL SRA ON: " << *GV;
+ DEBUG(errs() << "PERFORMING GLOBAL SRA ON: " << *GV);
- Constant *NullInt = Constant::getNullValue(Type::Int32Ty);
+ Constant *NullInt = Constant::getNullValue(Type::getInt32Ty(Context));
// Loop over all of the uses of the global, replacing the constantexpr geps,
// with smaller constantexpr geps or direct references.
for (unsigned i = 3, e = GEPI->getNumOperands(); i != e; ++i)
Idxs.push_back(GEPI->getOperand(i));
NewPtr = GetElementPtrInst::Create(NewPtr, Idxs.begin(), Idxs.end(),
- GEPI->getName()+"."+utostr(Val), GEPI);
+ GEPI->getName()+"."+Twine(Val),GEPI);
}
}
GEP->replaceAllUsesWith(NewPtr);
return true;
}
-static bool OptimizeAwayTrappingUsesOfValue(Value *V, Constant *NewV) {
+static bool OptimizeAwayTrappingUsesOfValue(Value *V, Constant *NewV,
+ LLVMContext &Context) {
bool Changed = false;
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ) {
Instruction *I = cast<Instruction>(*UI++);
} else if (CastInst *CI = dyn_cast<CastInst>(I)) {
Changed |= OptimizeAwayTrappingUsesOfValue(CI,
ConstantExpr::getCast(CI->getOpcode(),
- NewV, CI->getType()));
+ NewV, CI->getType()), Context);
if (CI->use_empty()) {
Changed = true;
CI->eraseFromParent();
break;
if (Idxs.size() == GEPI->getNumOperands()-1)
Changed |= OptimizeAwayTrappingUsesOfValue(GEPI,
- ConstantExpr::getGetElementPtr(NewV, &Idxs[0],
- Idxs.size()));
+ ConstantExpr::getGetElementPtr(NewV, &Idxs[0],
+ Idxs.size()), Context);
if (GEPI->use_empty()) {
Changed = true;
GEPI->eraseFromParent();
/// value stored into it. If there are uses of the loaded value that would trap
/// if the loaded value is dynamically null, then we know that they cannot be
/// reachable with a null optimize away the load.
-static bool OptimizeAwayTrappingUsesOfLoads(GlobalVariable *GV, Constant *LV) {
- std::vector<LoadInst*> Loads;
+static bool OptimizeAwayTrappingUsesOfLoads(GlobalVariable *GV, Constant *LV,
+ LLVMContext &Context) {
bool Changed = false;
+ // Keep track of whether we are able to remove all the uses of the global
+ // other than the store that defines it.
+ bool AllNonStoreUsesGone = true;
+
// Replace all uses of loads with uses of uses of the stored value.
- for (Value::use_iterator GUI = GV->use_begin(), E = GV->use_end();
- GUI != E; ++GUI)
- if (LoadInst *LI = dyn_cast<LoadInst>(*GUI)) {
- Loads.push_back(LI);
- Changed |= OptimizeAwayTrappingUsesOfValue(LI, LV);
+ for (Value::use_iterator GUI = GV->use_begin(), E = GV->use_end(); GUI != E;){
+ User *GlobalUser = *GUI++;
+ if (LoadInst *LI = dyn_cast<LoadInst>(GlobalUser)) {
+ Changed |= OptimizeAwayTrappingUsesOfValue(LI, LV, Context);
+ // If we were able to delete all uses of the loads
+ if (LI->use_empty()) {
+ LI->eraseFromParent();
+ Changed = true;
+ } else {
+ AllNonStoreUsesGone = false;
+ }
+ } else if (isa<StoreInst>(GlobalUser)) {
+ // Ignore the store that stores "LV" to the global.
+ assert(GlobalUser->getOperand(1) == GV &&
+ "Must be storing *to* the global");
} else {
- // If we get here we could have stores, selects, or phi nodes whose values
- // are loaded.
- assert((isa<StoreInst>(*GUI) || isa<PHINode>(*GUI) ||
- isa<SelectInst>(*GUI) || isa<ConstantExpr>(*GUI)) &&
- "Only expect load and stores!");
+ AllNonStoreUsesGone = false;
+
+ // If we get here we could have other crazy uses that are transitively
+ // loaded.
+ assert((isa<PHINode>(GlobalUser) || isa<SelectInst>(GlobalUser) ||
+ isa<ConstantExpr>(GlobalUser)) && "Only expect load and stores!");
}
+ }
if (Changed) {
- DOUT << "OPTIMIZED LOADS FROM STORED ONCE POINTER: " << *GV;
+ DEBUG(errs() << "OPTIMIZED LOADS FROM STORED ONCE POINTER: " << *GV);
++NumGlobUses;
}
- // Delete all of the loads we can, keeping track of whether we nuked them all!
- bool AllLoadsGone = true;
- while (!Loads.empty()) {
- LoadInst *L = Loads.back();
- if (L->use_empty()) {
- L->eraseFromParent();
- Changed = true;
- } else {
- AllLoadsGone = false;
- }
- Loads.pop_back();
- }
-
// If we nuked all of the loads, then none of the stores are needed either,
// nor is the global.
- if (AllLoadsGone) {
- DOUT << " *** GLOBAL NOW DEAD!\n";
- CleanupConstantGlobalUsers(GV, 0);
+ if (AllNonStoreUsesGone) {
+ DEBUG(errs() << " *** GLOBAL NOW DEAD!\n");
+ CleanupConstantGlobalUsers(GV, 0, Context);
if (GV->use_empty()) {
GV->eraseFromParent();
++NumDeleted;
/// ConstantPropUsersOf - Walk the use list of V, constant folding all of the
/// instructions that are foldable.
-static void ConstantPropUsersOf(Value *V) {
+static void ConstantPropUsersOf(Value *V, LLVMContext &Context) {
for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; )
if (Instruction *I = dyn_cast<Instruction>(*UI++))
- if (Constant *NewC = ConstantFoldInstruction(I)) {
+ if (Constant *NewC = ConstantFoldInstruction(I, Context)) {
I->replaceAllUsesWith(NewC);
// Advance UI to the next non-I use to avoid invalidating it!
/// malloc, there is no reason to actually DO the malloc. Instead, turn the
/// malloc into a global, and any loads of GV as uses of the new global.
static GlobalVariable *OptimizeGlobalAddressOfMalloc(GlobalVariable *GV,
- MallocInst *MI) {
- DOUT << "PROMOTING MALLOC GLOBAL: " << *GV << " MALLOC = " << *MI;
- ConstantInt *NElements = cast<ConstantInt>(MI->getArraySize());
-
+ CallInst *CI,
+ BitCastInst *BCI,
+ LLVMContext &Context,
+ TargetData* TD) {
+ DEBUG(errs() << "PROMOTING MALLOC GLOBAL: " << *GV
+ << " CALL = " << *CI << " BCI = " << *BCI << '\n');
+
+ const Type *IntPtrTy = TD->getIntPtrType(Context);
+
+ Value* ArraySize = getMallocArraySize(CI, Context, TD);
+ assert(ArraySize && "not a malloc whose array size can be determined");
+ ConstantInt *NElements = cast<ConstantInt>(ArraySize);
if (NElements->getZExtValue() != 1) {
// If we have an array allocation, transform it to a single element
// allocation to make the code below simpler.
- Type *NewTy = ArrayType::get(MI->getAllocatedType(),
+ Type *NewTy = ArrayType::get(getMallocAllocatedType(CI),
NElements->getZExtValue());
- MallocInst *NewMI =
- new MallocInst(NewTy, Constant::getNullValue(Type::Int32Ty),
- MI->getAlignment(), MI->getName(), MI);
+ Value* NewM = CallInst::CreateMalloc(CI, IntPtrTy, NewTy);
+ Instruction* NewMI = cast<Instruction>(NewM);
Value* Indices[2];
- Indices[0] = Indices[1] = Constant::getNullValue(Type::Int32Ty);
+ Indices[0] = Indices[1] = Constant::getNullValue(IntPtrTy);
Value *NewGEP = GetElementPtrInst::Create(NewMI, Indices, Indices + 2,
- NewMI->getName()+".el0", MI);
- MI->replaceAllUsesWith(NewGEP);
- MI->eraseFromParent();
- MI = NewMI;
+ NewMI->getName()+".el0", CI);
+ BCI->replaceAllUsesWith(NewGEP);
+ BCI->eraseFromParent();
+ CI->eraseFromParent();
+ BCI = cast<BitCastInst>(NewMI);
+ CI = extractMallocCallFromBitCast(NewMI);
}
// Create the new global variable. The contents of the malloc'd memory is
// undefined, so initialize with an undef value.
- Constant *Init = UndefValue::get(MI->getAllocatedType());
- GlobalVariable *NewGV = new GlobalVariable(MI->getAllocatedType(), false,
+ const Type *MAT = getMallocAllocatedType(CI);
+ Constant *Init = UndefValue::get(MAT);
+ GlobalVariable *NewGV = new GlobalVariable(*GV->getParent(),
+ MAT, false,
GlobalValue::InternalLinkage, Init,
GV->getName()+".body",
- (Module *)NULL,
+ GV,
GV->isThreadLocal());
- // FIXME: This new global should have the alignment returned by malloc. Code
- // could depend on malloc returning large alignment (on the mac, 16 bytes) but
- // this would only guarantee some lower alignment.
- GV->getParent()->getGlobalList().insert(GV, NewGV);
-
+
// Anything that used the malloc now uses the global directly.
- MI->replaceAllUsesWith(NewGV);
+ BCI->replaceAllUsesWith(NewGV);
Constant *RepValue = NewGV;
if (NewGV->getType() != GV->getType()->getElementType())
// If there is a comparison against null, we will insert a global bool to
// keep track of whether the global was initialized yet or not.
GlobalVariable *InitBool =
- new GlobalVariable(Type::Int1Ty, false, GlobalValue::InternalLinkage,
- ConstantInt::getFalse(), GV->getName()+".init",
- (Module *)NULL, GV->isThreadLocal());
+ new GlobalVariable(Context, Type::getInt1Ty(Context), false,
+ GlobalValue::InternalLinkage,
+ ConstantInt::getFalse(Context), GV->getName()+".init",
+ GV->isThreadLocal());
bool InitBoolUsed = false;
// Loop over all uses of GV, processing them in turn.
if (!isa<ICmpInst>(LoadUse.getUser()))
LoadUse = RepValue;
else {
- ICmpInst *CI = cast<ICmpInst>(LoadUse.getUser());
+ ICmpInst *ICI = cast<ICmpInst>(LoadUse.getUser());
// Replace the cmp X, 0 with a use of the bool value.
- Value *LV = new LoadInst(InitBool, InitBool->getName()+".val", CI);
+ Value *LV = new LoadInst(InitBool, InitBool->getName()+".val", ICI);
InitBoolUsed = true;
- switch (CI->getPredicate()) {
- default: assert(0 && "Unknown ICmp Predicate!");
+ switch (ICI->getPredicate()) {
+ default: llvm_unreachable("Unknown ICmp Predicate!");
case ICmpInst::ICMP_ULT:
case ICmpInst::ICMP_SLT:
- LV = ConstantInt::getFalse(); // X < null -> always false
+ LV = ConstantInt::getFalse(Context); // X < null -> always false
break;
case ICmpInst::ICMP_ULE:
case ICmpInst::ICMP_SLE:
case ICmpInst::ICMP_EQ:
- LV = BinaryOperator::CreateNot(LV, "notinit", CI);
+ LV = BinaryOperator::CreateNot(LV, "notinit", ICI);
break;
case ICmpInst::ICMP_NE:
case ICmpInst::ICMP_UGE:
case ICmpInst::ICMP_SGT:
break; // no change.
}
- CI->replaceAllUsesWith(LV);
- CI->eraseFromParent();
+ ICI->replaceAllUsesWith(LV);
+ ICI->eraseFromParent();
}
}
LI->eraseFromParent();
} else {
StoreInst *SI = cast<StoreInst>(GV->use_back());
// The global is initialized when the store to it occurs.
- new StoreInst(ConstantInt::getTrue(), InitBool, SI);
+ new StoreInst(ConstantInt::getTrue(Context), InitBool, SI);
SI->eraseFromParent();
}
// Now the GV is dead, nuke it and the malloc.
GV->eraseFromParent();
- MI->eraseFromParent();
+ BCI->eraseFromParent();
+ CI->eraseFromParent();
// To further other optimizations, loop over all users of NewGV and try to
// constant prop them. This will promote GEP instructions with constant
// indices into GEP constant-exprs, which will allow global-opt to hack on it.
- ConstantPropUsersOf(NewGV);
+ ConstantPropUsersOf(NewGV, Context);
if (RepValue != NewGV)
- ConstantPropUsersOf(RepValue);
+ ConstantPropUsersOf(RepValue, Context);
return NewGV;
}
static bool ValueIsOnlyUsedLocallyOrStoredToOneGlobal(Instruction *V,
GlobalVariable *GV,
SmallPtrSet<PHINode*, 8> &PHIs) {
- for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E; ++UI)
- if (isa<LoadInst>(*UI) || isa<CmpInst>(*UI)) {
- // Fine, ignore.
- } else if (StoreInst *SI = dyn_cast<StoreInst>(*UI)) {
+ for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){
+ Instruction *Inst = cast<Instruction>(*UI);
+
+ if (isa<LoadInst>(Inst) || isa<CmpInst>(Inst)) {
+ continue; // Fine, ignore.
+ }
+
+ if (StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
if (SI->getOperand(0) == V && SI->getOperand(1) != GV)
return false; // Storing the pointer itself... bad.
- // Otherwise, storing through it, or storing into GV... fine.
- } else if (isa<GetElementPtrInst>(*UI)) {
- if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(cast<Instruction>(*UI),
- GV, PHIs))
+ continue; // Otherwise, storing through it, or storing into GV... fine.
+ }
+
+ if (isa<GetElementPtrInst>(Inst)) {
+ if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(Inst, GV, PHIs))
return false;
- } else if (PHINode *PN = dyn_cast<PHINode>(*UI)) {
+ continue;
+ }
+
+ if (PHINode *PN = dyn_cast<PHINode>(Inst)) {
// PHIs are ok if all uses are ok. Don't infinitely recurse through PHI
// cycles.
if (PHIs.insert(PN))
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(PN, GV, PHIs))
return false;
- } else {
- return false;
+ continue;
+ }
+
+ if (BitCastInst *BCI = dyn_cast<BitCastInst>(Inst)) {
+ if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(BCI, GV, PHIs))
+ return false;
+ continue;
}
+
+ return false;
+ }
return true;
}
} else if (PHINode *PN = dyn_cast<PHINode>(U)) {
// Insert the load in the corresponding predecessor, not right before the
// PHI.
- unsigned PredNo = Alloc->use_begin().getOperandNo()/2;
- InsertPt = PN->getIncomingBlock(PredNo)->getTerminator();
+ InsertPt = PN->getIncomingBlock(Alloc->use_begin())->getTerminator();
+ } else if (isa<BitCastInst>(U)) {
+ // Must be bitcast between the malloc and store to initialize the global.
+ ReplaceUsesOfMallocWithGlobal(U, GV);
+ U->eraseFromParent();
+ continue;
+ } else if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(U)) {
+ // If this is a "GEP bitcast" and the user is a store to the global, then
+ // just process it as a bitcast.
+ if (GEPI->hasAllZeroIndices() && GEPI->hasOneUse())
+ if (StoreInst *SI = dyn_cast<StoreInst>(GEPI->use_back()))
+ if (SI->getOperand(1) == GV) {
+ // Must be bitcast GEP between the malloc and store to initialize
+ // the global.
+ ReplaceUsesOfMallocWithGlobal(GEPI, GV);
+ GEPI->eraseFromParent();
+ continue;
+ }
}
-
+
// Insert a load from the global, and use it instead of the malloc.
Value *NL = new LoadInst(GV, GV->getName()+".val", InsertPt);
U->replaceUsesOfWith(Alloc, NL);
}
}
-/// GlobalLoadUsesSimpleEnoughForHeapSRA - If all users of values loaded from
+/// LoadUsesSimpleEnoughForHeapSRA - Verify that all uses of V (a load, or a phi
+/// 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(Value *V,
+ SmallPtrSet<PHINode*, 32> &LoadUsingPHIs,
+ SmallPtrSet<PHINode*, 32> &LoadUsingPHIsPerLoad) {
+ // We permit two users of the load: setcc comparing against the null
+ // pointer, and a getelementptr of a specific form.
+ for (Value::use_iterator UI = V->use_begin(), E = V->use_end(); UI != E;++UI){
+ Instruction *User = cast<Instruction>(*UI);
+
+ // Comparison against null is ok.
+ if (ICmpInst *ICI = dyn_cast<ICmpInst>(User)) {
+ if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
+ return false;
+ continue;
+ }
+
+ // getelementptr is also ok, but only a simple form.
+ if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(User)) {
+ // Must index into the array and into the struct.
+ if (GEPI->getNumOperands() < 3)
+ return false;
+
+ // Otherwise the GEP is ok.
+ continue;
+ }
+
+ if (PHINode *PN = dyn_cast<PHINode>(User)) {
+ if (!LoadUsingPHIsPerLoad.insert(PN))
+ // This means some phi nodes are dependent on each other.
+ // Avoid infinite looping!
+ return false;
+ if (!LoadUsingPHIs.insert(PN))
+ // If we have already analyzed this PHI, then it is safe.
+ continue;
+
+ // Make sure all uses of the PHI are simple enough to transform.
+ if (!LoadUsesSimpleEnoughForHeapSRA(PN,
+ LoadUsingPHIs, LoadUsingPHIsPerLoad))
+ return false;
+
+ continue;
+ }
+
+ // Otherwise we don't know what this is, not ok.
+ return false;
+ }
+
+ return true;
+}
+
+
+/// AllGlobalLoadUsesSimpleEnoughForHeapSRA - If all users of values loaded from
/// GV are simple enough to perform HeapSRA, return true.
-static bool GlobalLoadUsesSimpleEnoughForHeapSRA(GlobalVariable *GV,
- MallocInst *MI) {
+static bool AllGlobalLoadUsesSimpleEnoughForHeapSRA(GlobalVariable *GV,
+ Instruction *StoredVal) {
+ SmallPtrSet<PHINode*, 32> LoadUsingPHIs;
+ SmallPtrSet<PHINode*, 32> LoadUsingPHIsPerLoad;
for (Value::use_iterator UI = GV->use_begin(), E = GV->use_end(); UI != E;
++UI)
if (LoadInst *LI = dyn_cast<LoadInst>(*UI)) {
- // We permit two users of the load: setcc comparing against the null
- // pointer, and a getelementptr of a specific form.
- for (Value::use_iterator UI = LI->use_begin(), E = LI->use_end();
- UI != E; ++UI) {
- // Comparison against null is ok.
- if (ICmpInst *ICI = dyn_cast<ICmpInst>(*UI)) {
- if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
- return false;
- continue;
- }
-
- // getelementptr is also ok, but only a simple form.
- if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(*UI)) {
- // Must index into the array and into the struct.
- if (GEPI->getNumOperands() < 3)
- return false;
-
- // Otherwise the GEP is ok.
+ if (!LoadUsesSimpleEnoughForHeapSRA(LI, LoadUsingPHIs,
+ LoadUsingPHIsPerLoad))
+ return false;
+ LoadUsingPHIsPerLoad.clear();
+ }
+
+ // If we reach here, we know that all uses of the loads and transitive uses
+ // (through PHI nodes) are simple enough to transform. However, we don't know
+ // 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<PHINode*, 32>::iterator I = LoadUsingPHIs.begin(),
+ E = LoadUsingPHIs.end(); I != E; ++I) {
+ PHINode *PN = *I;
+ for (unsigned op = 0, e = PN->getNumIncomingValues(); op != e; ++op) {
+ Value *InVal = PN->getIncomingValue(op);
+
+ // PHI of the stored value itself is ok.
+ if (InVal == StoredVal) continue;
+
+ if (PHINode *InPN = dyn_cast<PHINode>(InVal)) {
+ // One of the PHIs in our set is (optimistically) ok.
+ if (LoadUsingPHIs.count(InPN))
continue;
- }
-
- if (PHINode *PN = dyn_cast<PHINode>(*UI)) {
- // We have a phi of a load from the global. We can only handle this
- // if the other PHI'd values are actually the same. In this case,
- // the rewriter will just drop the phi entirely.
- for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
- Value *IV = PN->getIncomingValue(i);
- if (IV == LI) continue; // Trivial the same.
-
- // If the phi'd value is from the malloc that initializes the value,
- // we can xform it.
- if (IV == MI) continue;
-
- // Otherwise, we don't know what it is.
- return false;
- }
- return true;
- }
-
- // Otherwise we don't know what this is, not ok.
return false;
}
+
+ // Load from GV is ok.
+ if (LoadInst *LI = dyn_cast<LoadInst>(InVal))
+ if (LI->getOperand(0) == GV)
+ continue;
+
+ // UNDEF? NULL?
+
+ // Anything else is rejected.
+ return false;
}
+ }
+
return true;
}
-/// GetHeapSROALoad - Return the load for the specified field of the HeapSROA'd
-/// value, lazily creating it on demand.
-static Value *GetHeapSROALoad(Instruction *Load, unsigned FieldNo,
- const std::vector<GlobalVariable*> &FieldGlobals,
- std::vector<Value *> &InsertedLoadsForPtr) {
- if (InsertedLoadsForPtr.size() <= FieldNo)
- InsertedLoadsForPtr.resize(FieldNo+1);
- if (InsertedLoadsForPtr[FieldNo] == 0)
- InsertedLoadsForPtr[FieldNo] = new LoadInst(FieldGlobals[FieldNo],
- Load->getName()+".f" +
- utostr(FieldNo), Load);
- return InsertedLoadsForPtr[FieldNo];
+static Value *GetHeapSROAValue(Value *V, unsigned FieldNo,
+ DenseMap<Value*, std::vector<Value*> > &InsertedScalarizedValues,
+ std::vector<std::pair<PHINode*, unsigned> > &PHIsToRewrite,
+ LLVMContext &Context) {
+ std::vector<Value*> &FieldVals = InsertedScalarizedValues[V];
+
+ if (FieldNo >= FieldVals.size())
+ FieldVals.resize(FieldNo+1);
+
+ // If we already have this value, just reuse the previously scalarized
+ // version.
+ if (Value *FieldVal = FieldVals[FieldNo])
+ return FieldVal;
+
+ // Depending on what instruction this is, we have several cases.
+ Value *Result;
+ if (LoadInst *LI = dyn_cast<LoadInst>(V)) {
+ // This is a scalarized version of the load from the global. Just create
+ // a new Load of the scalarized global.
+ Result = new LoadInst(GetHeapSROAValue(LI->getOperand(0), FieldNo,
+ InsertedScalarizedValues,
+ PHIsToRewrite, Context),
+ LI->getName()+".f"+Twine(FieldNo), LI);
+ } else if (PHINode *PN = dyn_cast<PHINode>(V)) {
+ // PN's type is pointer to struct. Make a new PHI of pointer to struct
+ // field.
+ const StructType *ST =
+ cast<StructType>(cast<PointerType>(PN->getType())->getElementType());
+
+ Result =
+ PHINode::Create(PointerType::getUnqual(ST->getElementType(FieldNo)),
+ PN->getName()+".f"+Twine(FieldNo), PN);
+ PHIsToRewrite.push_back(std::make_pair(PN, FieldNo));
+ } else {
+ llvm_unreachable("Unknown usable value");
+ Result = 0;
+ }
+
+ return FieldVals[FieldNo] = Result;
}
/// RewriteHeapSROALoadUser - Given a load instruction and a value derived from
/// the load, rewrite the derived value to use the HeapSRoA'd load.
-static void RewriteHeapSROALoadUser(LoadInst *Load, Instruction *LoadUser,
- const std::vector<GlobalVariable*> &FieldGlobals,
- std::vector<Value *> &InsertedLoadsForPtr) {
+static void RewriteHeapSROALoadUser(Instruction *LoadUser,
+ DenseMap<Value*, std::vector<Value*> > &InsertedScalarizedValues,
+ std::vector<std::pair<PHINode*, unsigned> > &PHIsToRewrite,
+ LLVMContext &Context) {
// If this is a comparison against null, handle it.
if (ICmpInst *SCI = dyn_cast<ICmpInst>(LoadUser)) {
assert(isa<ConstantPointerNull>(SCI->getOperand(1)));
// If we have a setcc of the loaded pointer, we can use a setcc of any
// field.
- Value *NPtr;
- if (InsertedLoadsForPtr.empty()) {
- NPtr = GetHeapSROALoad(Load, 0, FieldGlobals, InsertedLoadsForPtr);
- } else {
- NPtr = InsertedLoadsForPtr.back();
- }
+ Value *NPtr = GetHeapSROAValue(SCI->getOperand(0), 0,
+ InsertedScalarizedValues, PHIsToRewrite,
+ Context);
- Value *New = new ICmpInst(SCI->getPredicate(), NPtr,
- Constant::getNullValue(NPtr->getType()),
- SCI->getName(), SCI);
+ Value *New = new ICmpInst(SCI, SCI->getPredicate(), NPtr,
+ Constant::getNullValue(NPtr->getType()),
+ SCI->getName());
SCI->replaceAllUsesWith(New);
SCI->eraseFromParent();
return;
}
- // Handle 'getelementptr Ptr, Idx, uint FieldNo ...'
+ // Handle 'getelementptr Ptr, Idx, i32 FieldNo ...'
if (GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(LoadUser)) {
assert(GEPI->getNumOperands() >= 3 && isa<ConstantInt>(GEPI->getOperand(2))
&& "Unexpected GEPI!");
// Load the pointer for this field.
unsigned FieldNo = cast<ConstantInt>(GEPI->getOperand(2))->getZExtValue();
- Value *NewPtr = GetHeapSROALoad(Load, FieldNo,
- FieldGlobals, InsertedLoadsForPtr);
+ Value *NewPtr = GetHeapSROAValue(GEPI->getOperand(0), FieldNo,
+ InsertedScalarizedValues, PHIsToRewrite,
+ Context);
// Create the new GEP idx vector.
SmallVector<Value*, 8> GEPIdx;
GEPI->eraseFromParent();
return;
}
-
- // Handle PHI nodes. PHI nodes must be merging in the same values, plus
- // potentially the original malloc. Insert phi nodes for each field, then
- // process uses of the PHI.
+
+ // Recursively transform the users of PHI nodes. This will lazily create the
+ // PHIs that are needed for individual elements. Keep track of what PHIs we
+ // see in InsertedScalarizedValues so that we don't get infinite loops (very
+ // antisocial). If the PHI is already in InsertedScalarizedValues, it has
+ // already been seen first by another load, so its uses have already been
+ // processed.
PHINode *PN = cast<PHINode>(LoadUser);
- std::vector<Value *> PHIsForField;
- PHIsForField.resize(FieldGlobals.size());
- for (unsigned i = 0, e = FieldGlobals.size(); i != e; ++i) {
- Value *LoadV = GetHeapSROALoad(Load, i, FieldGlobals, InsertedLoadsForPtr);
-
- PHINode *FieldPN = PHINode::Create(LoadV->getType(),
- PN->getName()+"."+utostr(i), PN);
- // Fill in the predecessor values.
- for (unsigned pred = 0, e = PN->getNumIncomingValues(); pred != e; ++pred) {
- // Each predecessor either uses the load or the original malloc.
- Value *InVal = PN->getIncomingValue(pred);
- BasicBlock *BB = PN->getIncomingBlock(pred);
- Value *NewVal;
- if (isa<MallocInst>(InVal)) {
- // Insert a reload from the global in the predecessor.
- NewVal = GetHeapSROALoad(BB->getTerminator(), i, FieldGlobals,
- PHIsForField);
- } else {
- NewVal = InsertedLoadsForPtr[i];
- }
- FieldPN->addIncoming(NewVal, BB);
- }
- PHIsForField[i] = FieldPN;
- }
+ bool Inserted;
+ DenseMap<Value*, std::vector<Value*> >::iterator InsertPos;
+ tie(InsertPos, Inserted) =
+ InsertedScalarizedValues.insert(std::make_pair(PN, std::vector<Value*>()));
+ if (!Inserted) return;
- // Since PHIsForField specifies a phi for every input value, the lazy inserter
- // will never insert a load.
- while (!PN->use_empty())
- RewriteHeapSROALoadUser(Load, PN->use_back(), FieldGlobals, PHIsForField);
- PN->eraseFromParent();
+ // If this is the first time we've seen this PHI, recursively process all
+ // users.
+ for (Value::use_iterator UI = PN->use_begin(), E = PN->use_end(); UI != E; ) {
+ Instruction *User = cast<Instruction>(*UI++);
+ RewriteHeapSROALoadUser(User, InsertedScalarizedValues, PHIsToRewrite,
+ Context);
+ }
}
/// RewriteUsesOfLoadForHeapSRoA - We are performing Heap SRoA on a global. Ptr
/// is a value loaded from the global. Eliminate all uses of Ptr, making them
/// use FieldGlobals instead. All uses of loaded values satisfy
-/// GlobalLoadUsesSimpleEnoughForHeapSRA.
+/// AllGlobalLoadUsesSimpleEnoughForHeapSRA.
static void RewriteUsesOfLoadForHeapSRoA(LoadInst *Load,
- const std::vector<GlobalVariable*> &FieldGlobals) {
- std::vector<Value *> InsertedLoadsForPtr;
- //InsertedLoadsForPtr.resize(FieldGlobals.size());
- while (!Load->use_empty())
- RewriteHeapSROALoadUser(Load, Load->use_back(),
- FieldGlobals, InsertedLoadsForPtr);
+ DenseMap<Value*, std::vector<Value*> > &InsertedScalarizedValues,
+ std::vector<std::pair<PHINode*, unsigned> > &PHIsToRewrite,
+ LLVMContext &Context) {
+ for (Value::use_iterator UI = Load->use_begin(), E = Load->use_end();
+ UI != E; ) {
+ Instruction *User = cast<Instruction>(*UI++);
+ RewriteHeapSROALoadUser(User, InsertedScalarizedValues, PHIsToRewrite,
+ Context);
+ }
+
+ if (Load->use_empty()) {
+ Load->eraseFromParent();
+ InsertedScalarizedValues.erase(Load);
+ }
}
-/// PerformHeapAllocSRoA - MI is an allocation of an array of structures. Break
+/// PerformHeapAllocSRoA - CI is an allocation of an array of structures. Break
/// it up into multiple allocations of arrays of the fields.
-static GlobalVariable *PerformHeapAllocSRoA(GlobalVariable *GV, MallocInst *MI){
- DOUT << "SROA HEAP ALLOC: " << *GV << " MALLOC = " << *MI;
- const StructType *STy = cast<StructType>(MI->getAllocatedType());
+static GlobalVariable *PerformHeapAllocSRoA(GlobalVariable *GV,
+ CallInst *CI, BitCastInst* BCI,
+ LLVMContext &Context,
+ TargetData *TD){
+ DEBUG(errs() << "SROA HEAP ALLOC: " << *GV << " MALLOC CALL = " << *CI
+ << " BITCAST = " << *BCI << '\n');
+ const Type* MAT = getMallocAllocatedType(CI);
+ const StructType *STy = cast<StructType>(MAT);
+ Value* ArraySize = getMallocArraySize(CI, Context, TD);
+ assert(ArraySize && "not a malloc whose array size can be determined");
// There is guaranteed to be at least one use of the malloc (storing
// it into GV). If there are other uses, change them to be uses of
// the global to simplify later code. This also deletes the store
// into GV.
- ReplaceUsesOfMallocWithGlobal(MI, GV);
+ ReplaceUsesOfMallocWithGlobal(BCI, GV);
// Okay, at this point, there are no users of the malloc. Insert N
- // new mallocs at the same place as MI, and N globals.
- std::vector<GlobalVariable*> FieldGlobals;
- std::vector<MallocInst*> FieldMallocs;
+ // new mallocs at the same place as CI, and N globals.
+ std::vector<Value*> FieldGlobals;
+ std::vector<Value*> FieldMallocs;
for (unsigned FieldNo = 0, e = STy->getNumElements(); FieldNo != e;++FieldNo){
const Type *FieldTy = STy->getElementType(FieldNo);
- const Type *PFieldTy = PointerType::getUnqual(FieldTy);
+ const PointerType *PFieldTy = PointerType::getUnqual(FieldTy);
GlobalVariable *NGV =
- new GlobalVariable(PFieldTy, false, GlobalValue::InternalLinkage,
+ new GlobalVariable(*GV->getParent(),
+ PFieldTy, false, GlobalValue::InternalLinkage,
Constant::getNullValue(PFieldTy),
- GV->getName() + ".f" + utostr(FieldNo), GV,
+ GV->getName() + ".f" + Twine(FieldNo), GV,
GV->isThreadLocal());
FieldGlobals.push_back(NGV);
- MallocInst *NMI = new MallocInst(FieldTy, MI->getArraySize(),
- MI->getName() + ".f" + utostr(FieldNo),MI);
+ Value *NMI = CallInst::CreateMalloc(CI, TD->getIntPtrType(Context),
+ FieldTy, ArraySize,
+ BCI->getName() + ".f" + Twine(FieldNo));
FieldMallocs.push_back(NMI);
- new StoreInst(NMI, NGV, MI);
+ new StoreInst(NMI, NGV, BCI);
}
// The tricky aspect of this transformation is handling the case when malloc
// }
Value *RunningOr = 0;
for (unsigned i = 0, e = FieldMallocs.size(); i != e; ++i) {
- Value *Cond = new ICmpInst(ICmpInst::ICMP_EQ, FieldMallocs[i],
- Constant::getNullValue(FieldMallocs[i]->getType()),
- "isnull", MI);
+ Value *Cond = new ICmpInst(BCI, ICmpInst::ICMP_EQ, FieldMallocs[i],
+ Constant::getNullValue(FieldMallocs[i]->getType()),
+ "isnull");
if (!RunningOr)
RunningOr = Cond; // First seteq
else
- RunningOr = BinaryOperator::CreateOr(RunningOr, Cond, "tmp", MI);
+ RunningOr = BinaryOperator::CreateOr(RunningOr, Cond, "tmp", BCI);
}
// Split the basic block at the old malloc.
- BasicBlock *OrigBB = MI->getParent();
- BasicBlock *ContBB = OrigBB->splitBasicBlock(MI, "malloc_cont");
+ BasicBlock *OrigBB = BCI->getParent();
+ BasicBlock *ContBB = OrigBB->splitBasicBlock(BCI, "malloc_cont");
// Create the block to check the first condition. Put all these blocks at the
// end of the function as they are unlikely to be executed.
- BasicBlock *NullPtrBlock = BasicBlock::Create("malloc_ret_null",
+ BasicBlock *NullPtrBlock = BasicBlock::Create(Context, "malloc_ret_null",
OrigBB->getParent());
// Remove the uncond branch from OrigBB to ContBB, turning it into a cond
// pointer, because some may be null while others are not.
for (unsigned i = 0, e = FieldGlobals.size(); i != e; ++i) {
Value *GVVal = new LoadInst(FieldGlobals[i], "tmp", NullPtrBlock);
- Value *Cmp = new ICmpInst(ICmpInst::ICMP_NE, GVVal,
+ Value *Cmp = new ICmpInst(*NullPtrBlock, ICmpInst::ICMP_NE, GVVal,
Constant::getNullValue(GVVal->getType()),
- "tmp", NullPtrBlock);
- BasicBlock *FreeBlock = BasicBlock::Create("free_it", OrigBB->getParent());
- BasicBlock *NextBlock = BasicBlock::Create("next", OrigBB->getParent());
- BranchInst::Create(FreeBlock, NextBlock, Cmp, NullPtrBlock);
+ "tmp");
+ BasicBlock *FreeBlock = BasicBlock::Create(Context, "free_it",
+ OrigBB->getParent());
+ BasicBlock *NextBlock = BasicBlock::Create(Context, "next",
+ OrigBB->getParent());
+ Instruction *BI = BranchInst::Create(FreeBlock, NextBlock,
+ Cmp, NullPtrBlock);
// Fill in FreeBlock.
- new FreeInst(GVVal, FreeBlock);
+ CallInst::CreateFree(GVVal, BI);
new StoreInst(Constant::getNullValue(GVVal->getType()), FieldGlobals[i],
FreeBlock);
BranchInst::Create(NextBlock, FreeBlock);
BranchInst::Create(ContBB, NullPtrBlock);
- // MI is no longer needed, remove it.
- MI->eraseFromParent();
-
+ // CI and BCI are no longer needed, remove them.
+ BCI->eraseFromParent();
+ CI->eraseFromParent();
+
+ /// InsertedScalarizedLoads - As we process loads, if we can't immediately
+ /// update all uses of the load, keep track of what scalarized loads are
+ /// inserted for a given load.
+ DenseMap<Value*, std::vector<Value*> > InsertedScalarizedValues;
+ InsertedScalarizedValues[GV] = FieldGlobals;
+
+ std::vector<std::pair<PHINode*, unsigned> > PHIsToRewrite;
// Okay, the malloc site is completely handled. All of the uses of GV are now
// loads, and all uses of those loads are simple. Rewrite them to use loads
// of the per-field globals instead.
- while (!GV->use_empty()) {
- if (LoadInst *LI = dyn_cast<LoadInst>(GV->use_back())) {
- RewriteUsesOfLoadForHeapSRoA(LI, FieldGlobals);
- LI->eraseFromParent();
- } else {
- // Must be a store of null.
- StoreInst *SI = cast<StoreInst>(GV->use_back());
- assert(isa<Constant>(SI->getOperand(0)) &&
- cast<Constant>(SI->getOperand(0))->isNullValue() &&
- "Unexpected heap-sra user!");
-
- // Insert a store of null into each global.
- for (unsigned i = 0, e = FieldGlobals.size(); i != e; ++i) {
- Constant *Null =
- Constant::getNullValue(FieldGlobals[i]->getType()->getElementType());
- new StoreInst(Null, FieldGlobals[i], SI);
- }
- // Erase the original store.
- SI->eraseFromParent();
+ for (Value::use_iterator UI = GV->use_begin(), E = GV->use_end(); UI != E;) {
+ Instruction *User = cast<Instruction>(*UI++);
+
+ if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
+ RewriteUsesOfLoadForHeapSRoA(LI, InsertedScalarizedValues, PHIsToRewrite,
+ Context);
+ continue;
}
+
+ // Must be a store of null.
+ StoreInst *SI = cast<StoreInst>(User);
+ assert(isa<ConstantPointerNull>(SI->getOperand(0)) &&
+ "Unexpected heap-sra user!");
+
+ // Insert a store of null into each global.
+ for (unsigned i = 0, e = FieldGlobals.size(); i != e; ++i) {
+ const PointerType *PT = cast<PointerType>(FieldGlobals[i]->getType());
+ Constant *Null = Constant::getNullValue(PT->getElementType());
+ new StoreInst(Null, FieldGlobals[i], SI);
+ }
+ // Erase the original store.
+ SI->eraseFromParent();
}
+ // While we have PHIs that are interesting to rewrite, do it.
+ while (!PHIsToRewrite.empty()) {
+ PHINode *PN = PHIsToRewrite.back().first;
+ unsigned FieldNo = PHIsToRewrite.back().second;
+ PHIsToRewrite.pop_back();
+ PHINode *FieldPN = cast<PHINode>(InsertedScalarizedValues[PN][FieldNo]);
+ assert(FieldPN->getNumIncomingValues() == 0 &&"Already processed this phi");
+
+ // Add all the incoming values. This can materialize more phis.
+ for (unsigned i = 0, e = PN->getNumIncomingValues(); i != e; ++i) {
+ Value *InVal = PN->getIncomingValue(i);
+ InVal = GetHeapSROAValue(InVal, FieldNo, InsertedScalarizedValues,
+ PHIsToRewrite, Context);
+ FieldPN->addIncoming(InVal, PN->getIncomingBlock(i));
+ }
+ }
+
+ // Drop all inter-phi links and any loads that made it this far.
+ for (DenseMap<Value*, std::vector<Value*> >::iterator
+ I = InsertedScalarizedValues.begin(), E = InsertedScalarizedValues.end();
+ I != E; ++I) {
+ if (PHINode *PN = dyn_cast<PHINode>(I->first))
+ PN->dropAllReferences();
+ else if (LoadInst *LI = dyn_cast<LoadInst>(I->first))
+ LI->dropAllReferences();
+ }
+
+ // Delete all the phis and loads now that inter-references are dead.
+ for (DenseMap<Value*, std::vector<Value*> >::iterator
+ I = InsertedScalarizedValues.begin(), E = InsertedScalarizedValues.end();
+ I != E; ++I) {
+ if (PHINode *PN = dyn_cast<PHINode>(I->first))
+ PN->eraseFromParent();
+ else if (LoadInst *LI = dyn_cast<LoadInst>(I->first))
+ LI->eraseFromParent();
+ }
+
// The old global is now dead, remove it.
GV->eraseFromParent();
++NumHeapSRA;
- return FieldGlobals[0];
+ return cast<GlobalVariable>(FieldGlobals[0]);
}
+/// TryToOptimizeStoreOfMallocToGlobal - This function is called when we see a
+/// pointer global variable with a single value stored it that is a malloc or
+/// cast of malloc.
+static bool TryToOptimizeStoreOfMallocToGlobal(GlobalVariable *GV,
+ CallInst *CI,
+ BitCastInst *BCI,
+ Module::global_iterator &GVI,
+ TargetData *TD,
+ LLVMContext &Context) {
+ // If we can't figure out the type being malloced, then we can't optimize.
+ const Type *AllocTy = getMallocAllocatedType(CI);
+ assert(AllocTy);
+
+ // If this is a malloc of an abstract type, don't touch it.
+ if (!AllocTy->isSized())
+ return false;
+
+ // We can't optimize this global unless all uses of it are *known* to be
+ // of the malloc value, not of the null initializer value (consider a use
+ // that compares the global's value against zero to see if the malloc has
+ // been reached). To do this, we check to see if all uses of the global
+ // would trap if the global were null: this proves that they must all
+ // happen after the malloc.
+ if (!AllUsesOfLoadedValueWillTrapIfNull(GV))
+ return false;
+
+ // We can't optimize this if the malloc itself is used in a complex way,
+ // for example, being stored into multiple globals. This allows the
+ // malloc to be stored into the specified global, loaded setcc'd, and
+ // GEP'd. These are all things we could transform to using the global
+ // for.
+ {
+ SmallPtrSet<PHINode*, 8> PHIs;
+ if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(BCI, GV, PHIs))
+ return false;
+ }
+
+ // If we have a global that is only initialized with a fixed size malloc,
+ // transform the program to use global memory instead of malloc'd memory.
+ // This eliminates dynamic allocation, avoids an indirection accessing the
+ // data, and exposes the resultant global to further GlobalOpt.
+ Value *NElems = getMallocArraySize(CI, Context, TD);
+ // We cannot optimize the malloc if we cannot determine malloc array size.
+ if (NElems) {
+ if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
+ // Restrict this transformation to only working on small allocations
+ // (2048 bytes currently), as we don't want to introduce a 16M global or
+ // something.
+ if (TD &&
+ NElements->getZExtValue() * TD->getTypeAllocSize(AllocTy) < 2048) {
+ GVI = OptimizeGlobalAddressOfMalloc(GV, CI, BCI, Context, TD);
+ return true;
+ }
+
+ // If the allocation is an array of structures, consider transforming this
+ // into multiple malloc'd arrays, one for each field. This is basically
+ // SRoA for malloc'd memory.
+
+ // If this is an allocation of a fixed size array of structs, analyze as a
+ // variable size array. malloc [100 x struct],1 -> malloc struct, 100
+ if (!isArrayMalloc(CI, Context, TD))
+ if (const ArrayType *AT = dyn_cast<ArrayType>(AllocTy))
+ AllocTy = AT->getElementType();
+
+ if (const StructType *AllocSTy = dyn_cast<StructType>(AllocTy)) {
+ // This the structure has an unreasonable number of fields, leave it
+ // alone.
+ if (AllocSTy->getNumElements() <= 16 && AllocSTy->getNumElements() != 0 &&
+ AllGlobalLoadUsesSimpleEnoughForHeapSRA(GV, BCI)) {
+
+ // If this is a fixed size array, transform the Malloc to be an alloc of
+ // structs. malloc [100 x struct],1 -> malloc struct, 100
+ if (const ArrayType *AT =
+ dyn_cast<ArrayType>(getMallocAllocatedType(CI))) {
+ Value* NumElements = ConstantInt::get(Type::getInt32Ty(Context),
+ AT->getNumElements());
+ Value* NewMI = CallInst::CreateMalloc(CI, TD->getIntPtrType(Context),
+ AllocSTy, NumElements,
+ BCI->getName());
+ Value *Cast = new BitCastInst(NewMI, getMallocType(CI), "tmp", CI);
+ BCI->replaceAllUsesWith(Cast);
+ BCI->eraseFromParent();
+ CI->eraseFromParent();
+ BCI = cast<BitCastInst>(NewMI);
+ CI = extractMallocCallFromBitCast(NewMI);
+ }
+
+ GVI = PerformHeapAllocSRoA(GV, CI, BCI, Context, TD);
+ return true;
+ }
+ }
+ }
+
+ return false;
+}
// OptimizeOnceStoredGlobal - Try to optimize globals based on the knowledge
// that only one value (besides its initializer) is ever stored to the global.
static bool OptimizeOnceStoredGlobal(GlobalVariable *GV, Value *StoredOnceVal,
Module::global_iterator &GVI,
- TargetData &TD) {
- if (CastInst *CI = dyn_cast<CastInst>(StoredOnceVal))
- StoredOnceVal = CI->getOperand(0);
- else if (GetElementPtrInst *GEPI =dyn_cast<GetElementPtrInst>(StoredOnceVal)){
- // "getelementptr Ptr, 0, 0, 0" is really just a cast.
- bool IsJustACast = true;
- for (User::op_iterator i = GEPI->op_begin() + 1, e = GEPI->op_end();
- i != e; ++i)
- if (!isa<Constant>(*i) ||
- !cast<Constant>(*i)->isNullValue()) {
- IsJustACast = false;
- break;
- }
- if (IsJustACast)
- StoredOnceVal = GEPI->getOperand(0);
- }
+ TargetData *TD, LLVMContext &Context) {
+ // Ignore no-op GEPs and bitcasts.
+ StoredOnceVal = StoredOnceVal->stripPointerCasts();
// If we are dealing with a pointer global that is initialized to null and
// only has one (non-null) value stored into it, then we can optimize any
GV->getInitializer()->isNullValue()) {
if (Constant *SOVC = dyn_cast<Constant>(StoredOnceVal)) {
if (GV->getInitializer()->getType() != SOVC->getType())
- SOVC = ConstantExpr::getBitCast(SOVC, GV->getInitializer()->getType());
+ SOVC =
+ ConstantExpr::getBitCast(SOVC, GV->getInitializer()->getType());
// Optimize away any trapping uses of the loaded value.
- if (OptimizeAwayTrappingUsesOfLoads(GV, SOVC))
+ if (OptimizeAwayTrappingUsesOfLoads(GV, SOVC, Context))
return true;
- } else if (MallocInst *MI = dyn_cast<MallocInst>(StoredOnceVal)) {
- // If this is a malloc of an abstract type, don't touch it.
- if (!MI->getAllocatedType()->isSized())
- return false;
-
- // We can't optimize this global unless all uses of it are *known* to be
- // of the malloc value, not of the null initializer value (consider a use
- // that compares the global's value against zero to see if the malloc has
- // been reached). To do this, we check to see if all uses of the global
- // would trap if the global were null: this proves that they must all
- // happen after the malloc.
- if (!AllUsesOfLoadedValueWillTrapIfNull(GV))
- return false;
-
- // We can't optimize this if the malloc itself is used in a complex way,
- // for example, being stored into multiple globals. This allows the
- // malloc to be stored into the specified global, loaded setcc'd, and
- // GEP'd. These are all things we could transform to using the global
- // for.
- {
- SmallPtrSet<PHINode*, 8> PHIs;
- if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(MI, GV, PHIs))
- return false;
- }
-
-
- // If we have a global that is only initialized with a fixed size malloc,
- // transform the program to use global memory instead of malloc'd memory.
- // This eliminates dynamic allocation, avoids an indirection accessing the
- // data, and exposes the resultant global to further GlobalOpt.
- if (ConstantInt *NElements = dyn_cast<ConstantInt>(MI->getArraySize())) {
- // Restrict this transformation to only working on small allocations
- // (2048 bytes currently), as we don't want to introduce a 16M global or
- // something.
- if (NElements->getZExtValue()*
- TD.getABITypeSize(MI->getAllocatedType()) < 2048) {
- GVI = OptimizeGlobalAddressOfMalloc(GV, MI);
- return true;
- }
- }
-
- // If the allocation is an array of structures, consider transforming this
- // into multiple malloc'd arrays, one for each field. This is basically
- // SRoA for malloc'd memory.
- if (const StructType *AllocTy =
- dyn_cast<StructType>(MI->getAllocatedType())) {
- // This the structure has an unreasonable number of fields, leave it
- // alone.
- if (AllocTy->getNumElements() <= 16 && AllocTy->getNumElements() > 0 &&
- GlobalLoadUsesSimpleEnoughForHeapSRA(GV, MI)) {
- GVI = PerformHeapAllocSRoA(GV, MI);
+ } else if (CallInst *CI = extractMallocCall(StoredOnceVal)) {
+ if (getMallocAllocatedType(CI)) {
+ BitCastInst* BCI = NULL;
+ for (Value::use_iterator UI = CI->use_begin(), E = CI->use_end();
+ UI != E; )
+ BCI = dyn_cast<BitCastInst>(cast<Instruction>(*UI++));
+ if (BCI &&
+ TryToOptimizeStoreOfMallocToGlobal(GV, CI, BCI, GVI, TD, Context))
return true;
- }
}
}
}
/// two values ever stored into GV are its initializer and OtherVal. See if we
/// can shrink the global into a boolean and select between the two values
/// whenever it is used. This exposes the values to other scalar optimizations.
-static bool TryToShrinkGlobalToBoolean(GlobalVariable *GV, Constant *OtherVal) {
+static bool TryToShrinkGlobalToBoolean(GlobalVariable *GV, Constant *OtherVal,
+ LLVMContext &Context) {
const Type *GVElType = GV->getType()->getElementType();
// If GVElType is already i1, it is already shrunk. If the type of the GV is
- // an FP value or vector, don't do this optimization because a select between
- // them is very expensive and unlikely to lead to later simplification.
- if (GVElType == Type::Int1Ty || GVElType->isFloatingPoint() ||
- isa<VectorType>(GVElType))
+ // an FP value, pointer or vector, don't do this optimization because a select
+ // between them is very expensive and unlikely to lead to later
+ // simplification. In these cases, we typically end up with "cond ? v1 : v2"
+ // where v1 and v2 both require constant pool loads, a big loss.
+ if (GVElType == Type::getInt1Ty(Context) || GVElType->isFloatingPoint() ||
+ isa<PointerType>(GVElType) || isa<VectorType>(GVElType))
return false;
// Walk the use list of the global seeing if all the uses are load or store.
if (!isa<LoadInst>(I) && !isa<StoreInst>(I))
return false;
- DOUT << " *** SHRINKING TO BOOL: " << *GV;
+ DEBUG(errs() << " *** SHRINKING TO BOOL: " << *GV);
// Create the new global, initializing it to false.
- GlobalVariable *NewGV = new GlobalVariable(Type::Int1Ty, false,
- GlobalValue::InternalLinkage, ConstantInt::getFalse(),
+ GlobalVariable *NewGV = new GlobalVariable(Context,
+ Type::getInt1Ty(Context), false,
+ GlobalValue::InternalLinkage, ConstantInt::getFalse(Context),
GV->getName()+".b",
- (Module *)NULL,
GV->isThreadLocal());
GV->getParent()->getGlobalList().insert(GV, NewGV);
Constant *InitVal = GV->getInitializer();
- assert(InitVal->getType() != Type::Int1Ty && "No reason to shrink to bool!");
+ assert(InitVal->getType() != Type::getInt1Ty(Context) &&
+ "No reason to shrink to bool!");
// If initialized to zero and storing one into the global, we can use a cast
// instead of a select to synthesize the desired value.
// Only do this if we weren't storing a loaded value.
Value *StoreVal;
if (StoringOther || SI->getOperand(0) == InitVal)
- StoreVal = ConstantInt::get(Type::Int1Ty, StoringOther);
+ StoreVal = ConstantInt::get(Type::getInt1Ty(Context), StoringOther);
else {
// Otherwise, we are storing a previously loaded copy. To do this,
// change the copy from copying the original value to just copying the
/// it if possible. If we make a change, return true.
bool GlobalOpt::ProcessInternalGlobal(GlobalVariable *GV,
Module::global_iterator &GVI) {
- std::set<PHINode*> PHIUsers;
+ SmallPtrSet<PHINode*, 16> PHIUsers;
GlobalStatus GS;
GV->removeDeadConstantUsers();
if (GV->use_empty()) {
- DOUT << "GLOBAL DEAD: " << *GV;
+ DEBUG(errs() << "GLOBAL DEAD: " << *GV);
GV->eraseFromParent();
++NumDeleted;
return true;
//
// NOTE: It doesn't make sense to promote non single-value types since we
// are just replacing static memory to stack memory.
+ //
+ // If the global is in different address space, don't bring it to stack.
if (!GS.HasMultipleAccessingFunctions &&
GS.AccessingFunction && !GS.HasNonInstructionUser &&
GV->getType()->getElementType()->isSingleValueType() &&
GS.AccessingFunction->getName() == "main" &&
- GS.AccessingFunction->hasExternalLinkage()) {
- DOUT << "LOCALIZING GLOBAL: " << *GV;
+ GS.AccessingFunction->hasExternalLinkage() &&
+ GV->getType()->getAddressSpace() == 0) {
+ DEBUG(errs() << "LOCALIZING GLOBAL: " << *GV);
Instruction* FirstI = GS.AccessingFunction->getEntryBlock().begin();
const Type* ElemTy = GV->getType()->getElementType();
// FIXME: Pass Global's alignment when globals have alignment
// If the global is never loaded (but may be stored to), it is dead.
// Delete it now.
if (!GS.isLoaded) {
- DOUT << "GLOBAL NEVER LOADED: " << *GV;
+ DEBUG(errs() << "GLOBAL NEVER LOADED: " << *GV);
// Delete any stores we can find to the global. We may not be able to
// make it completely dead though.
- bool Changed = CleanupConstantGlobalUsers(GV, GV->getInitializer());
+ bool Changed = CleanupConstantGlobalUsers(GV, GV->getInitializer(),
+ GV->getContext());
// If the global is dead now, delete it.
if (GV->use_empty()) {
return Changed;
} else if (GS.StoredType <= GlobalStatus::isInitializerStored) {
- DOUT << "MARKING CONSTANT: " << *GV;
+ DEBUG(errs() << "MARKING CONSTANT: " << *GV);
GV->setConstant(true);
// Clean up any obviously simplifiable users now.
- CleanupConstantGlobalUsers(GV, GV->getInitializer());
+ CleanupConstantGlobalUsers(GV, GV->getInitializer(), GV->getContext());
// If the global is dead now, just nuke it.
if (GV->use_empty()) {
- DOUT << " *** Marking constant allowed us to simplify "
- << "all users and delete global!\n";
+ DEBUG(errs() << " *** Marking constant allowed us to simplify "
+ << "all users and delete global!\n");
GV->eraseFromParent();
++NumDeleted;
}
++NumMarked;
return true;
} else if (!GV->getInitializer()->getType()->isSingleValueType()) {
- if (GlobalVariable *FirstNewGV = SRAGlobal(GV,
- getAnalysis<TargetData>())) {
- GVI = FirstNewGV; // Don't skip the newly produced globals!
- return true;
- }
+ if (TargetData *TD = getAnalysisIfAvailable<TargetData>())
+ if (GlobalVariable *FirstNewGV = SRAGlobal(GV, *TD,
+ GV->getContext())) {
+ GVI = FirstNewGV; // Don't skip the newly produced globals!
+ return true;
+ }
} else if (GS.StoredType == GlobalStatus::isStoredOnce) {
// If the initial value for the global was an undef value, and if only
// one other value was stored into it, we can just change the
- // initializer to be an undef value, then delete all stores to the
+ // initializer to be the stored value, then delete all stores to the
// global. This allows us to mark it constant.
if (Constant *SOVConstant = dyn_cast<Constant>(GS.StoredOnceValue))
if (isa<UndefValue>(GV->getInitializer())) {
GV->setInitializer(SOVConstant);
// Clean up any obviously simplifiable users now.
- CleanupConstantGlobalUsers(GV, GV->getInitializer());
+ CleanupConstantGlobalUsers(GV, GV->getInitializer(),
+ GV->getContext());
if (GV->use_empty()) {
- DOUT << " *** Substituting initializer allowed us to "
- << "simplify all users and delete global!\n";
+ DEBUG(errs() << " *** Substituting initializer allowed us to "
+ << "simplify all users and delete global!\n");
GV->eraseFromParent();
++NumDeleted;
} else {
// Try to optimize globals based on the knowledge that only one value
// (besides its initializer) is ever stored to the global.
if (OptimizeOnceStoredGlobal(GV, GS.StoredOnceValue, GVI,
- getAnalysis<TargetData>()))
+ getAnalysisIfAvailable<TargetData>(),
+ GV->getContext()))
return true;
// Otherwise, if the global was not a boolean, we can shrink it to be a
// boolean.
if (Constant *SOVConstant = dyn_cast<Constant>(GS.StoredOnceValue))
- if (TryToShrinkGlobalToBoolean(GV, SOVConstant)) {
+ if (TryToShrinkGlobalToBoolean(GV, SOVConstant, GV->getContext())) {
++NumShrunkToBool;
return true;
}
return false;
}
-/// OnlyCalledDirectly - Return true if the specified function is only called
-/// directly. In other words, its address is never taken.
-static bool OnlyCalledDirectly(Function *F) {
- for (Value::use_iterator UI = F->use_begin(), E = F->use_end(); UI != E;++UI){
- Instruction *User = dyn_cast<Instruction>(*UI);
- if (!User) return false;
- if (!isa<CallInst>(User) && !isa<InvokeInst>(User)) return false;
-
- // See if the function address is passed as an argument.
- for (User::op_iterator i = User->op_begin() + 1, e = User->op_end();
- i != e; ++i)
- if (*i == F) return false;
- }
- return true;
-}
-
/// ChangeCalleesToFastCall - Walk all of the direct calls of the specified
/// function, changing them to FastCC.
static void ChangeCalleesToFastCall(Function *F) {
// Optimize functions.
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())
+ F->setLinkage(GlobalValue::InternalLinkage);
F->removeDeadConstantUsers();
- if (F->use_empty() && (F->hasInternalLinkage() ||
+ if (F->use_empty() && (F->hasLocalLinkage() ||
F->hasLinkOnceLinkage())) {
M.getFunctionList().erase(F);
Changed = true;
++NumFnDeleted;
- } else if (F->hasInternalLinkage()) {
+ } else if (F->hasLocalLinkage()) {
if (F->getCallingConv() == CallingConv::C && !F->isVarArg() &&
- OnlyCalledDirectly(F)) {
+ !F->hasAddressTaken()) {
// If this function has C calling conventions, is not a varargs
// function, and is only called directly, promote it to use the Fast
// calling convention.
}
if (F->getAttributes().hasAttrSomewhere(Attribute::Nest) &&
- OnlyCalledDirectly(F)) {
+ !F->hasAddressTaken()) {
// The function is not used by a trampoline intrinsic, so it is safe
// to remove the 'nest' attribute.
RemoveNestAttribute(F);
for (Module::global_iterator GVI = M.global_begin(), E = M.global_end();
GVI != E; ) {
GlobalVariable *GV = GVI++;
- if (!GV->isConstant() && GV->hasInternalLinkage() &&
+ // Global variables without names cannot be referenced outside this module.
+ if (!GV->hasName() && !GV->isDeclaration())
+ GV->setLinkage(GlobalValue::InternalLinkage);
+ if (!GV->isConstant() && GV->hasLocalLinkage() &&
GV->hasInitializer())
Changed |= ProcessInternalGlobal(GV, GVI);
}
if (!ATy) return 0;
const StructType *STy = dyn_cast<StructType>(ATy->getElementType());
if (!STy || STy->getNumElements() != 2 ||
- STy->getElementType(0) != Type::Int32Ty) return 0;
+ STy->getElementType(0) != Type::getInt32Ty(M.getContext())) return 0;
const PointerType *PFTy = dyn_cast<PointerType>(STy->getElementType(1));
if (!PFTy) return 0;
const FunctionType *FTy = dyn_cast<FunctionType>(PFTy->getElementType());
- if (!FTy || FTy->getReturnType() != Type::VoidTy || FTy->isVarArg() ||
- FTy->getNumParams() != 0)
+ if (!FTy || FTy->getReturnType() != Type::getVoidTy(M.getContext()) ||
+ FTy->isVarArg() || FTy->getNumParams() != 0)
return 0;
// Verify that the initializer is simple enough for us to handle.
- if (!I->hasInitializer()) return 0;
+ if (!I->hasDefinitiveInitializer()) return 0;
ConstantArray *CA = dyn_cast<ConstantArray>(I->getInitializer());
if (!CA) return 0;
for (User::op_iterator i = CA->op_begin(), e = CA->op_end(); i != e; ++i)
/// InstallGlobalCtors - Given a specified llvm.global_ctors list, install the
/// specified array, returning the new global to use.
static GlobalVariable *InstallGlobalCtors(GlobalVariable *GCL,
- const std::vector<Function*> &Ctors) {
+ const std::vector<Function*> &Ctors,
+ LLVMContext &Context) {
// If we made a change, reassemble the initializer list.
std::vector<Constant*> CSVals;
- CSVals.push_back(ConstantInt::get(Type::Int32Ty, 65535));
+ CSVals.push_back(ConstantInt::get(Type::getInt32Ty(Context), 65535));
CSVals.push_back(0);
// Create the new init list.
if (Ctors[i]) {
CSVals[1] = Ctors[i];
} else {
- const Type *FTy = FunctionType::get(Type::VoidTy,
- std::vector<const Type*>(), false);
+ const Type *FTy = FunctionType::get(Type::getVoidTy(Context), false);
const PointerType *PFTy = PointerType::getUnqual(FTy);
CSVals[1] = Constant::getNullValue(PFTy);
- CSVals[0] = ConstantInt::get(Type::Int32Ty, 2147483647);
+ CSVals[0] = ConstantInt::get(Type::getInt32Ty(Context), 2147483647);
}
- CAList.push_back(ConstantStruct::get(CSVals));
+ CAList.push_back(ConstantStruct::get(Context, CSVals, false));
}
// Create the array initializer.
const Type *StructTy =
- cast<ArrayType>(GCL->getType()->getElementType())->getElementType();
- Constant *CA = ConstantArray::get(ArrayType::get(StructTy, CAList.size()),
- CAList);
+
cast<ArrayType>(GCL->getType()->getElementType())->getElementType();
+ Constant *CA = ConstantArray::get(ArrayType::get(StructTy,
+ CAList.size()), CAList);
// If we didn't change the number of elements, don't create a new GV.
if (CA->getType() == GCL->getInitializer()->getType()) {
}
// Create the new global and insert it next to the existing list.
- GlobalVariable *NGV = new GlobalVariable(CA->getType(), GCL->isConstant(),
+ GlobalVariable *NGV = new GlobalVariable(Context, CA->getType(),
+ GCL->isConstant(),
GCL->getLinkage(), CA, "",
- (Module *)NULL,
GCL->isThreadLocal());
GCL->getParent()->getGlobalList().insert(GCL, NGV);
NGV->takeName(GCL);
}
-static Constant *getVal(std::map<Value*, Constant*> &ComputedValues,
+static Constant *getVal(DenseMap<Value*, Constant*> &ComputedValues,
Value *V) {
if (Constant *CV = dyn_cast<Constant>(V)) return CV;
Constant *R = ComputedValues[V];
/// enough for us to understand. In particular, if it is a cast of something,
/// we punt. We basically just support direct accesses to globals and GEP's of
/// globals. This should be kept up to date with CommitValueTo.
-static bool isSimpleEnoughPointerToCommit(Constant *C) {
- if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C)) {
- if (!GV->hasExternalLinkage() && !GV->hasInternalLinkage())
- return false; // do not allow weak/linkonce/dllimport/dllexport linkage.
- return !GV->isDeclaration(); // reject external globals.
- }
+static bool isSimpleEnoughPointerToCommit(Constant *C, LLVMContext &Context) {
+ // Conservatively, avoid aggregate types. This is because we don't
+ // want to worry about them partially overlapping other stores.
+ if (!cast<PointerType>(C->getType())->getElementType()->isSingleValueType())
+ return false;
+
+ if (GlobalVariable *GV = dyn_cast<GlobalVariable>(C))
+ // Do not allow weak/linkonce/dllimport/dllexport linkage or
+ // external globals.
+ return GV->hasDefinitiveInitializer();
+
if (ConstantExpr *CE = dyn_cast<ConstantExpr>(C))
// Handle a constantexpr gep.
if (CE->getOpcode() == Instruction::GetElementPtr &&
- isa<GlobalVariable>(CE->getOperand(0))) {
+ isa<GlobalVariable>(CE->getOperand(0)) &&
+ cast<GEPOperator>(CE)->isInBounds()) {
GlobalVariable *GV = cast<GlobalVariable>(CE->getOperand(0));
- if (!GV->hasExternalLinkage() && !GV->hasInternalLinkage())
- return false; // do not allow weak/linkonce/dllimport/dllexport linkage.
- return GV->hasInitializer() &&
- ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE);
+ // Do not allow weak/linkonce/dllimport/dllexport linkage or
+ // external globals.
+ if (!GV->hasDefinitiveInitializer())
+ return false;
+
+ // The first index must be zero.
+ ConstantInt *CI = dyn_cast<ConstantInt>(*next(CE->op_begin()));
+ if (!CI || !CI->isZero()) return false;
+
+ // The remaining indices must be compile-time known integers within the
+ // notional bounds of the corresponding static array types.
+ if (!CE->isGEPWithNoNotionalOverIndexing())
+ return false;
+
+ return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE);
}
return false;
}
/// initializer. This returns 'Init' modified to reflect 'Val' stored into it.
/// At this point, the GEP operands of Addr [0, OpNo) have been stepped into.
static Constant *EvaluateStoreInto(Constant *Init, Constant *Val,
- ConstantExpr *Addr, unsigned OpNo) {
+ ConstantExpr *Addr, unsigned OpNo,
+ LLVMContext &Context) {
// Base case of the recursion.
if (OpNo == Addr->getNumOperands()) {
assert(Val->getType() == Init->getType() && "Type mismatch!");
for (unsigned i = 0, e = STy->getNumElements(); i != e; ++i)
Elts.push_back(UndefValue::get(STy->getElementType(i)));
} else {
- assert(0 && "This code is out of sync with "
+ llvm_unreachable("This code is out of sync with "
" ConstantFoldLoadThroughGEPConstantExpr");
}
ConstantInt *CU = cast<ConstantInt>(Addr->getOperand(OpNo));
unsigned Idx = CU->getZExtValue();
assert(Idx < STy->getNumElements() && "Struct index out of range!");
- Elts[Idx] = EvaluateStoreInto(Elts[Idx], Val, Addr, OpNo+1);
+ Elts[Idx] = EvaluateStoreInto(Elts[Idx], Val, Addr, OpNo+1, Context);
// Return the modified struct.
- return ConstantStruct::get(&Elts[0], Elts.size(), STy->isPacked());
+ return ConstantStruct::get(Context, &Elts[0], Elts.size(), STy->isPacked());
} else {
ConstantInt *CI = cast<ConstantInt>(Addr->getOperand(OpNo));
const ArrayType *ATy = cast<ArrayType>(Init->getType());
Constant *Elt = UndefValue::get(ATy->getElementType());
Elts.assign(ATy->getNumElements(), Elt);
} else {
- assert(0 && "This code is out of sync with "
+ llvm_unreachable("This code is out of sync with "
" ConstantFoldLoadThroughGEPConstantExpr");
}
assert(CI->getZExtValue() < ATy->getNumElements());
Elts[CI->getZExtValue()] =
- EvaluateStoreInto(Elts[CI->getZExtValue()], Val, Addr, OpNo+1);
+ EvaluateStoreInto(Elts[CI->getZExtValue()], Val, Addr, OpNo+1, Context);
return ConstantArray::get(ATy, Elts);
}
}
/// CommitValueTo - We have decided that Addr (which satisfies the predicate
/// isSimpleEnoughPointerToCommit) should get Val as its value. Make it happen.
-static void CommitValueTo(Constant *Val, Constant *Addr) {
+static void CommitValueTo(Constant *Val, Constant *Addr,
+ LLVMContext &Context) {
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(Addr)) {
assert(GV->hasInitializer());
GV->setInitializer(Val);
GlobalVariable *GV = cast<GlobalVariable>(CE->getOperand(0));
Constant *Init = GV->getInitializer();
- Init = EvaluateStoreInto(Init, Val, CE, 2);
+ Init = EvaluateStoreInto(Init, Val, CE, 2, Context);
GV->setInitializer(Init);
}
/// P after the stores reflected by 'memory' have been performed. If we can't
/// decide, return null.
static Constant *ComputeLoadResult(Constant *P,
- const std::map<Constant*, Constant*> &Memory) {
+ const DenseMap<Constant*, Constant*> &Memory,
+ LLVMContext &Context) {
// If this memory location has been recently stored, use the stored value: it
// is the most up-to-date.
- std::map<Constant*, Constant*>::const_iterator I = Memory.find(P);
+ DenseMap<Constant*, Constant*>::const_iterator I = Memory.find(P);
if (I != Memory.end()) return I->second;
// Access it.
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(P)) {
- if (GV->hasInitializer())
+ if (GV->hasDefinitiveInitializer())
return GV->getInitializer();
return 0;
}
if (CE->getOpcode() == Instruction::GetElementPtr &&
isa<GlobalVariable>(CE->getOperand(0))) {
GlobalVariable *GV = cast<GlobalVariable>(CE->getOperand(0));
- if (GV->hasInitializer())
+ if (GV->hasDefinitiveInitializer())
return ConstantFoldLoadThroughGEPConstantExpr(GV->getInitializer(), CE);
}
/// successful, false if we can't evaluate it. ActualArgs contains the formal
/// arguments for the function.
static bool EvaluateFunction(Function *F, Constant *&RetVal,
- const std::vector<Constant*> &ActualArgs,
+ const SmallVectorImpl<Constant*> &ActualArgs,
std::vector<Function*> &CallStack,
- std::map<Constant*, Constant*> &MutatedMemory,
+ DenseMap<Constant*, Constant*> &MutatedMemory,
std::vector<GlobalVariable*> &AllocaTmps) {
// Check to see if this function is already executing (recursion). If so,
// bail out. TODO: we might want to accept limited recursion.
if (std::find(CallStack.begin(), CallStack.end(), F) != CallStack.end())
return false;
+ LLVMContext &Context = F->getContext();
+
CallStack.push_back(F);
/// Values - As we compute SSA register values, we store their contents here.
- std::map<Value*, Constant*> Values;
+ DenseMap<Value*, Constant*> Values;
// Initialize arguments to the incoming values specified.
unsigned ArgNo = 0;
/// ExecutedBlocks - We only handle non-looping, non-recursive code. As such,
/// we can only evaluate any one basic block at most once. This set keeps
/// track of what we have executed so we can detect recursive cases etc.
- std::set<BasicBlock*> ExecutedBlocks;
+ SmallPtrSet<BasicBlock*, 32> ExecutedBlocks;
// CurInst - The current instruction we're evaluating.
BasicBlock::iterator CurInst = F->begin()->begin();
if (StoreInst *SI = dyn_cast<StoreInst>(CurInst)) {
if (SI->isVolatile()) return false; // no volatile accesses.
Constant *Ptr = getVal(Values, SI->getOperand(1));
- if (!isSimpleEnoughPointerToCommit(Ptr))
+ if (!isSimpleEnoughPointerToCommit(Ptr, Context))
// If this is too complex for us to commit, reject it.
return false;
Constant *Val = getVal(Values, SI->getOperand(0));
getVal(Values, CI->getOperand(0)),
CI->getType());
} else if (SelectInst *SI = dyn_cast<SelectInst>(CurInst)) {
- InstResult = ConstantExpr::getSelect(getVal(Values, SI->getOperand(0)),
+ InstResult =
+ ConstantExpr::getSelect(getVal(Values, SI->getOperand(0)),
getVal(Values, SI->getOperand(1)),
getVal(Values, SI->getOperand(2)));
} else if (GetElementPtrInst *GEP = dyn_cast<GetElementPtrInst>(CurInst)) {
for (User::op_iterator i = GEP->op_begin() + 1, e = GEP->op_end();
i != e; ++i)
GEPOps.push_back(getVal(Values, *i));
- InstResult = ConstantExpr::getGetElementPtr(P, &GEPOps[0], GEPOps.size());
+ InstResult = cast<GEPOperator>(GEP)->isInBounds() ?
+ ConstantExpr::getInBoundsGetElementPtr(P, &GEPOps[0], GEPOps.size()) :
+ ConstantExpr::getGetElementPtr(P, &GEPOps[0], GEPOps.size());
} else if (LoadInst *LI = dyn_cast<LoadInst>(CurInst)) {
if (LI->isVolatile()) return false; // no volatile accesses.
InstResult = ComputeLoadResult(getVal(Values, LI->getOperand(0)),
- MutatedMemory);
+ MutatedMemory, Context);
if (InstResult == 0) return false; // Could not evaluate load.
} else if (AllocaInst *AI = dyn_cast<AllocaInst>(CurInst)) {
if (AI->isArrayAllocation()) return false; // Cannot handle array allocs.
const Type *Ty = AI->getType()->getElementType();
- AllocaTmps.push_back(new GlobalVariable(Ty, false,
+ AllocaTmps.push_back(new GlobalVariable(Context, Ty, false,
GlobalValue::InternalLinkage,
UndefValue::get(Ty),
AI->getName()));
InstResult = AllocaTmps.back();
} else if (CallInst *CI = dyn_cast<CallInst>(CurInst)) {
+
+ // Debug info can safely be ignored here.
+ if (isa<DbgInfoIntrinsic>(CI)) {
+ ++CurInst;
+ continue;
+ }
+
// Cannot handle inline asm.
if (isa<InlineAsm>(CI->getOperand(0))) return false;
Function *Callee = dyn_cast<Function>(getVal(Values, CI->getOperand(0)));
if (!Callee) return false; // Cannot resolve.
- std::vector<Constant*> Formals;
+ SmallVector<Constant*, 8> Formals;
for (User::op_iterator i = CI->op_begin() + 1, e = CI->op_end();
i != e; ++i)
Formals.push_back(getVal(Values, *i));
-
+
if (Callee->isDeclaration()) {
// If this is a function we can constant fold, do it.
- if (Constant *C = ConstantFoldCall(Callee, &Formals[0],
+ if (Constant *C = ConstantFoldCall(Callee, Formals.data(),
Formals.size())) {
InstResult = C;
} else {
return false;
Constant *RetVal;
-
// Execute the call, if successful, use the return value.
if (!EvaluateFunction(Callee, RetVal, Formals, CallStack,
MutatedMemory, AllocaTmps))
// Okay, we succeeded in evaluating this control flow. See if we have
// executed the new block before. If so, we have a looping function,
// which we cannot evaluate in reasonable time.
- if (!ExecutedBlocks.insert(NewBB).second)
+ if (!ExecutedBlocks.insert(NewBB))
return false; // looped!
// Okay, we have never been in this block before. Check to see if there
/// MutatedMemory - For each store we execute, we update this map. Loads
/// check this to get the most up-to-date value. If evaluation is successful,
/// this state is committed to the process.
- std::map<Constant*, Constant*> MutatedMemory;
+ DenseMap<Constant*, Constant*> MutatedMemory;
/// AllocaTmps - To 'execute' an alloca, we create a temporary global variable
/// to represent its body. This vector is needed so we can delete the
// Call the function.
Constant *RetValDummy;
- bool EvalSuccess = EvaluateFunction(F, RetValDummy, std::vector<Constant*>(),
- CallStack, MutatedMemory, AllocaTmps);
+ bool EvalSuccess = EvaluateFunction(F, RetValDummy,
+ SmallVector<Constant*, 0>(), CallStack,
+ MutatedMemory, AllocaTmps);
if (EvalSuccess) {
// We succeeded at evaluation: commit the result.
- DOUT << "FULLY EVALUATED GLOBAL CTOR FUNCTION '"
- << F->getName() << "' to " << MutatedMemory.size()
- << " stores.\n";
- for (std::map<Constant*, Constant*>::iterator I = MutatedMemory.begin(),
+ DEBUG(errs() << "FULLY EVALUATED GLOBAL CTOR FUNCTION '"
+ << F->getName() << "' to " << MutatedMemory.size()
+ << " stores.\n");
+ for (DenseMap<Constant*, Constant*>::iterator I = MutatedMemory.begin(),
E = MutatedMemory.end(); I != E; ++I)
- CommitValueTo(I->second, I->first);
+ CommitValueTo(I->second, I->first, F->getContext());
}
// At this point, we are done interpreting. If we created any 'alloca'
if (!MadeChange) return false;
- GCL = InstallGlobalCtors(GCL, Ctors);
+ GCL = InstallGlobalCtors(GCL, Ctors, GCL->getContext());
return true;
}
-bool GlobalOpt::ResolveAliases(Module &M) {
+bool GlobalOpt::OptimizeGlobalAliases(Module &M) {
bool Changed = false;
- for (Module::alias_iterator I = M.alias_begin(),
- E = M.alias_end(); I != E; ++I) {
- if (I->use_empty())
+ 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())
+ J->setLinkage(GlobalValue::InternalLinkage);
+ // If the aliasee may change at link time, nothing can be done - bail out.
+ if (J->mayBeOverridden())
continue;
- if (const GlobalValue *GV = I->resolveAliasedGlobal())
- if (GV != I) {
- I->replaceAllUsesWith(const_cast<GlobalValue*>(GV));
- Changed = true;
- }
+ Constant *Aliasee = J->getAliasee();
+ GlobalValue *Target = cast<GlobalValue>(Aliasee->stripPointerCasts());
+ Target->removeDeadConstantUsers();
+ bool hasOneUse = Target->hasOneUse() && Aliasee->hasOneUse();
+
+ // Make all users of the alias use the aliasee instead.
+ if (!J->use_empty()) {
+ J->replaceAllUsesWith(Aliasee);
+ ++NumAliasesResolved;
+ Changed = true;
+ }
+
+ // If the aliasee has internal linkage, give it the name and linkage
+ // of the alias, and delete the alias. This turns:
+ // define internal ... @f(...)
+ // @a = alias ... @f
+ // into:
+ // define ... @a(...)
+ if (!Target->hasLocalLinkage())
+ continue;
+
+ // The transform is only useful if the alias does not have internal linkage.
+ if (J->hasLocalLinkage())
+ continue;
+
+ // Do not perform the transform if multiple aliases potentially target the
+ // aliasee. This check also ensures that it is safe to replace the section
+ // and other attributes of the aliasee with those of the alias.
+ if (!hasOneUse)
+ continue;
+
+ // Give the aliasee the name, linkage and other attributes of the alias.
+ Target->takeName(J);
+ Target->setLinkage(J->getLinkage());
+ Target->GlobalValue::copyAttributesFrom(J);
+
+ // Delete the alias.
+ M.getAliasList().erase(J);
+ ++NumAliasesRemoved;
+ Changed = true;
}
return Changed;
LocalChange |= OptimizeGlobalVars(M);
// Resolve aliases, when possible.
- LocalChange |= ResolveAliases(M);
+ LocalChange |= OptimizeGlobalAliases(M);
Changed |= LocalChange;
}
projects / oota-llvm.git / blobdiff