Diff 344509

llvm/lib/Transforms/IPO/GlobalOpt.cpp

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using namespace llvm;		using namespace llvm;

#define DEBUG_TYPE "globalopt"		#define DEBUG_TYPE "globalopt"

STATISTIC(NumMarked , "Number of globals marked constant");		STATISTIC(NumMarked , "Number of globals marked constant");
STATISTIC(NumUnnamed , "Number of globals marked unnamed_addr");		STATISTIC(NumUnnamed , "Number of globals marked unnamed_addr");
STATISTIC(NumSRA , "Number of aggregate globals broken into scalars");		STATISTIC(NumSRA , "Number of aggregate globals broken into scalars");
STATISTIC(NumHeapSRA , "Number of heap objects SRA'd");
STATISTIC(NumSubstitute,"Number of globals with initializers stored into them");		STATISTIC(NumSubstitute,"Number of globals with initializers stored into them");
STATISTIC(NumDeleted , "Number of globals deleted");		STATISTIC(NumDeleted , "Number of globals deleted");
STATISTIC(NumGlobUses , "Number of global uses devirtualized");		STATISTIC(NumGlobUses , "Number of global uses devirtualized");
STATISTIC(NumLocalized , "Number of globals localized");		STATISTIC(NumLocalized , "Number of globals localized");
STATISTIC(NumShrunkToBool , "Number of global vars shrunk to booleans");		STATISTIC(NumShrunkToBool , "Number of global vars shrunk to booleans");
STATISTIC(NumFastCallFns , "Number of functions converted to fastcc");		STATISTIC(NumFastCallFns , "Number of functions converted to fastcc");
STATISTIC(NumCtorsEvaluated, "Number of static ctors evaluated");		STATISTIC(NumCtorsEvaluated, "Number of static ctors evaluated");
STATISTIC(NumNestRemoved , "Number of nest attributes removed");		STATISTIC(NumNestRemoved , "Number of nest attributes removed");
▲ Show 20 Lines • Show All 901 Lines • ▼ Show 20 Lines	if (RepValue != NewGV)
ConstantPropUsersOf(RepValue, DL, TLI);		ConstantPropUsersOf(RepValue, DL, TLI);

return NewGV;		return NewGV;
}		}

/// Scan the use-list of V checking to make sure that there are no complex uses		/// Scan the use-list of V checking to make sure that there are no complex uses
/// of V. We permit simple things like dereferencing the pointer, but not		/// of V. We permit simple things like dereferencing the pointer, but not
/// storing through the address, unless it is to the specified global.		/// storing through the address, unless it is to the specified global.
static bool ValueIsOnlyUsedLocallyOrStoredToOneGlobal(const Instruction *V,		static bool
const GlobalVariable *GV,		valueIsOnlyUsedLocallyOrStoredToOneGlobal(const Instruction *V,
SmallPtrSetImpl<const PHINode*> &PHIs) {		const GlobalVariable *GV) {
for (const User *U : V->users()) {		for (const User *U : V->users()) {
const Instruction *Inst = cast<Instruction>(U);		const Instruction *Inst = cast<Instruction>(U);

if (isa<LoadInst>(Inst) \|\| isa<CmpInst>(Inst)) {		if (isa<LoadInst>(Inst) \|\| isa<CmpInst>(Inst)) {
continue; // Fine, ignore.		continue; // Fine, ignore.
}		}

if (const StoreInst *SI = dyn_cast<StoreInst>(Inst)) {		if (const StoreInst *SI = dyn_cast<StoreInst>(Inst)) {
if (SI->getOperand(0) == V && SI->getOperand(1) != GV)		if (SI->getOperand(0) == V && SI->getOperand(1) != GV)
return false; // Storing the pointer itself... bad.		return false; // Storing the pointer itself... bad.
continue; // Otherwise, storing through it, or storing into GV... fine.		continue; // Otherwise, storing through it, or storing into GV... fine.
}		}

// Must index into the array and into the struct.
if (isa<GetElementPtrInst>(Inst) && Inst->getNumOperands() >= 3) {
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(Inst, GV, PHIs))
return false;
continue;
}

if (const 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).second)
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(PN, GV, PHIs))
aeubanksUnsubmitted Not Done Reply Inline Actions these could still be used to get to `OptimizeGlobalAddressOfMalloc`, why are these being deleted? if you are deleting the Phi part, `PHIs` is no longer used aeubanks: these could still be used to get to `OptimizeGlobalAddressOfMalloc`, why are these being…
return false;
continue;
}

if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Inst)) {		if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Inst)) {
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(BCI, GV, PHIs))		if (!valueIsOnlyUsedLocallyOrStoredToOneGlobal(BCI, GV))
return false;
continue;
}

return false;
}
return true;
}

/// The Alloc pointer is stored into GV somewhere. Transform all uses of the
/// allocation into loads from the global and uses of the resultant pointer.
/// Further, delete the store into GV. This assumes that these value pass the
/// 'ValueIsOnlyUsedLocallyOrStoredToOneGlobal' predicate.
static void ReplaceUsesOfMallocWithGlobal(Instruction *Alloc,
GlobalVariable *GV) {
while (!Alloc->use_empty()) {
Instruction U = cast<Instruction>(Alloc->user_begin());
Instruction *InsertPt = U;
if (StoreInst *SI = dyn_cast<StoreInst>(U)) {
// If this is the store of the allocation into the global, remove it.
if (SI->getOperand(1) == GV) {
SI->eraseFromParent();
continue;
}
} else if (PHINode *PN = dyn_cast<PHINode>(U)) {
// Insert the load in the corresponding predecessor, not right before the
// PHI.
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->user_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->getValueType(), GV, GV->getName() + ".val", InsertPt);
U->replaceUsesOfWith(Alloc, NL);
}
}

/// 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(const Value *V,
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()) {
const Instruction *UI = cast<Instruction>(U);

// Comparison against null is ok.
if (const ICmpInst *ICI = dyn_cast<ICmpInst>(UI)) {
if (!isa<ConstantPointerNull>(ICI->getOperand(1)))
return false;		return false;
continue;		continue;
}		}

// getelementptr is also ok, but only a simple form.
if (const GetElementPtrInst *GEPI = dyn_cast<GetElementPtrInst>(UI)) {
// Must index into the array and into the struct.
if (GEPI->getNumOperands() < 3)
return false;		return false;

// Otherwise the GEP is ok.
continue;
}

if (const PHINode *PN = dyn_cast<PHINode>(UI)) {
if (!LoadUsingPHIsPerLoad.insert(PN).second)
// This means some phi nodes are dependent on each other.
// Avoid infinite looping!
return false;
if (!LoadUsingPHIs.insert(PN).second)
// 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;
}

/// If all users of values loaded from GV are simple enough to perform HeapSRA,
/// return true.
static bool AllGlobalLoadUsesSimpleEnoughForHeapSRA(const GlobalVariable *GV,
Instruction *StoredVal) {
SmallPtrSet<const PHINode*, 32> LoadUsingPHIs;
SmallPtrSet<const PHINode*, 32> LoadUsingPHIsPerLoad;
for (const User *U : GV->users())
if (const LoadInst *LI = dyn_cast<LoadInst>(U)) {
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 (const PHINode *PN : LoadUsingPHIs) {
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 (const PHINode *InPN = dyn_cast<PHINode>(InVal)) {
// One of the PHIs in our set is (optimistically) ok.
if (LoadUsingPHIs.count(InPN))
continue;
return false;
}

// Load from GV is ok.
if (const LoadInst *LI = dyn_cast<LoadInst>(InVal))
if (LI->getOperand(0) == GV)
continue;

// UNDEF? NULL?

// Anything else is rejected.
return false;
}
}		}

return true;		return true;
}		}

static Value GetHeapSROAValue(Value V, unsigned FieldNo,
DenseMap<Value , std::vector<Value >> &InsertedScalarizedValues,
std::vector<std::pair<PHINode *, unsigned>> &PHIsToRewrite) {
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.
Value *V = GetHeapSROAValue(LI->getOperand(0), FieldNo,
InsertedScalarizedValues, PHIsToRewrite);
Result = new LoadInst(V->getType()->getPointerElementType(), V,
LI->getName() + ".f" + Twine(FieldNo), LI);
} else {
PHINode *PN = cast<PHINode>(V);
// PN's type is pointer to struct. Make a new PHI of pointer to struct
// field.

PointerType *PTy = cast<PointerType>(PN->getType());
StructType *ST = cast<StructType>(PTy->getElementType());

unsigned AS = PTy->getAddressSpace();
PHINode *NewPN =
PHINode::Create(PointerType::get(ST->getElementType(FieldNo), AS),
PN->getNumIncomingValues(),
PN->getName()+".f"+Twine(FieldNo), PN);
Result = NewPN;
PHIsToRewrite.push_back(std::make_pair(PN, FieldNo));
}

return FieldVals[FieldNo] = Result;
}

/// Given a load instruction and a value derived from the load, rewrite the
/// derived value to use the HeapSRoA'd load.
static void RewriteHeapSROALoadUser(Instruction *LoadUser,
DenseMap<Value , std::vector<Value >> &InsertedScalarizedValues,
std::vector<std::pair<PHINode *, unsigned>> &PHIsToRewrite) {
// 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 = GetHeapSROAValue(SCI->getOperand(0), 0,
InsertedScalarizedValues, PHIsToRewrite);

Value *New = new ICmpInst(SCI, SCI->getPredicate(), NPtr,
Constant::getNullValue(NPtr->getType()),
SCI->getName());
SCI->replaceAllUsesWith(New);
SCI->eraseFromParent();
return;
}

// 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 = GetHeapSROAValue(GEPI->getOperand(0), FieldNo,
InsertedScalarizedValues, PHIsToRewrite);

// Create the new GEP idx vector.
SmallVector<Value*, 8> GEPIdx;
GEPIdx.push_back(GEPI->getOperand(1));
GEPIdx.append(GEPI->op_begin()+3, GEPI->op_end());

Value *NGEPI = GetElementPtrInst::Create(GEPI->getResultElementType(), NewPtr, GEPIdx,
GEPI->getName(), GEPI);
GEPI->replaceAllUsesWith(NGEPI);
GEPI->eraseFromParent();
return;
}

// 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);
if (!InsertedScalarizedValues.insert(std::make_pair(PN,
std::vector<Value *>())).second)
return;

// If this is the first time we've seen this PHI, recursively process all
// users.
for (auto UI = PN->user_begin(), E = PN->user_end(); UI != E;) {
Instruction User = cast<Instruction>(UI++);
RewriteHeapSROALoadUser(User, InsertedScalarizedValues, PHIsToRewrite);
}
}

/// 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 AllGlobalLoadUsesSimpleEnoughForHeapSRA.
static void RewriteUsesOfLoadForHeapSRoA(LoadInst *Load,
DenseMap<Value , std::vector<Value >> &InsertedScalarizedValues,
std::vector<std::pair<PHINode *, unsigned> > &PHIsToRewrite) {
for (auto UI = Load->user_begin(), E = Load->user_end(); UI != E;) {
Instruction User = cast<Instruction>(UI++);
RewriteHeapSROALoadUser(User, InsertedScalarizedValues, PHIsToRewrite);
}

if (Load->use_empty()) {
Load->eraseFromParent();
InsertedScalarizedValues.erase(Load);
}
}

/// 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, CallInst *CI,
Value *NElems, const DataLayout &DL,
const TargetLibraryInfo *TLI) {
LLVM_DEBUG(dbgs() << "SROA HEAP ALLOC: " << GV << " MALLOC = " << CI
<< '\n');
Type *MAT = getMallocAllocatedType(CI, TLI);
StructType *STy = cast<StructType>(MAT);

// 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(CI, GV);

// Okay, at this point, there are no users of the malloc. Insert N
// new mallocs at the same place as CI, and N globals.
std::vector<Value *> FieldGlobals;
std::vector<Value *> FieldMallocs;

SmallVector<OperandBundleDef, 1> OpBundles;
CI->getOperandBundlesAsDefs(OpBundles);

unsigned AS = GV->getType()->getPointerAddressSpace();
for (unsigned FieldNo = 0, e = STy->getNumElements(); FieldNo != e;++FieldNo){
Type *FieldTy = STy->getElementType(FieldNo);
PointerType *PFieldTy = PointerType::get(FieldTy, AS);

GlobalVariable *NGV = new GlobalVariable(
*GV->getParent(), PFieldTy, false, GlobalValue::InternalLinkage,
Constant::getNullValue(PFieldTy), GV->getName() + ".f" + Twine(FieldNo),
nullptr, GV->getThreadLocalMode());
NGV->copyAttributesFrom(GV);
FieldGlobals.push_back(NGV);

unsigned TypeSize = DL.getTypeAllocSize(FieldTy);
if (StructType *ST = dyn_cast<StructType>(FieldTy))
TypeSize = DL.getStructLayout(ST)->getSizeInBytes();
Type *IntPtrTy = DL.getIntPtrType(CI->getType());
Value *NMI = CallInst::CreateMalloc(CI, IntPtrTy, FieldTy,
ConstantInt::get(IntPtrTy, TypeSize),
NElems, OpBundles, nullptr,
CI->getName() + ".f" + Twine(FieldNo));
FieldMallocs.push_back(NMI);
new StoreInst(NMI, NGV, CI);
}

// The tricky aspect of this transformation is handling the case when malloc
// fails. In the original code, malloc failing would set the result pointer
// of malloc to null. In this case, some mallocs could succeed and others
// could fail. As such, we emit code that looks like this:
// F0 = malloc(field0)
// F1 = malloc(field1)
// F2 = malloc(field2)
// if (F0 == 0 \|\| F1 == 0 \|\| F2 == 0) {
// if (F0) { free(F0); F0 = 0; }
// if (F1) { free(F1); F1 = 0; }
// if (F2) { free(F2); F2 = 0; }
// }
// The malloc can also fail if its argument is too large.
Constant *ConstantZero = ConstantInt::get(CI->getArgOperand(0)->getType(), 0);
Value *RunningOr = new ICmpInst(CI, ICmpInst::ICMP_SLT, CI->getArgOperand(0),
ConstantZero, "isneg");
for (unsigned i = 0, e = FieldMallocs.size(); i != e; ++i) {
Value *Cond = new ICmpInst(CI, ICmpInst::ICMP_EQ, FieldMallocs[i],
Constant::getNullValue(FieldMallocs[i]->getType()),
"isnull");
RunningOr = BinaryOperator::CreateOr(RunningOr, Cond, "tmp", CI);
}

// Split the basic block at the old malloc.
BasicBlock *OrigBB = CI->getParent();
BasicBlock *ContBB =
OrigBB->splitBasicBlock(CI->getIterator(), "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(OrigBB->getContext(),
"malloc_ret_null",
OrigBB->getParent());

// Remove the uncond branch from OrigBB to ContBB, turning it into a cond
// branch on RunningOr.
OrigBB->getTerminator()->eraseFromParent();
BranchInst::Create(NullPtrBlock, ContBB, RunningOr, OrigBB);

// Within the NullPtrBlock, we need to emit a comparison and branch for each
// pointer, because some may be null while others are not.
for (unsigned i = 0, e = FieldGlobals.size(); i != e; ++i) {
Value *GVVal =
new LoadInst(cast<GlobalVariable>(FieldGlobals[i])->getValueType(),
FieldGlobals[i], "tmp", NullPtrBlock);
Value Cmp = new ICmpInst(NullPtrBlock, ICmpInst::ICMP_NE, GVVal,
Constant::getNullValue(GVVal->getType()));
BasicBlock *FreeBlock = BasicBlock::Create(Cmp->getContext(), "free_it",
OrigBB->getParent());
BasicBlock *NextBlock = BasicBlock::Create(Cmp->getContext(), "next",
OrigBB->getParent());
Instruction *BI = BranchInst::Create(FreeBlock, NextBlock,
Cmp, NullPtrBlock);

// Fill in FreeBlock.
CallInst::CreateFree(GVVal, OpBundles, BI);
new StoreInst(Constant::getNullValue(GVVal->getType()), FieldGlobals[i],
FreeBlock);
BranchInst::Create(NextBlock, FreeBlock);

NullPtrBlock = NextBlock;
}

BranchInst::Create(ContBB, NullPtrBlock);

// CI is no longer needed, remove it.
CI->eraseFromParent();

/// 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.
for (auto UI = GV->user_begin(), E = GV->user_end(); UI != E;) {
Instruction User = cast<Instruction>(UI++);

if (LoadInst *LI = dyn_cast<LoadInst>(User)) {
RewriteUsesOfLoadForHeapSRoA(LI, InsertedScalarizedValues, PHIsToRewrite);
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) {
Type *ValTy = cast<GlobalValue>(FieldGlobals[i])->getValueType();
Constant *Null = Constant::getNullValue(ValTy);
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);
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 cast<GlobalVariable>(FieldGlobals[0]);
}

/// This function is called when we see a pointer global variable with a single		/// 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.		/// value stored it that is a malloc or cast of malloc.
static bool tryToOptimizeStoreOfMallocToGlobal(GlobalVariable GV, CallInst CI,		static bool tryToOptimizeStoreOfMallocToGlobal(GlobalVariable GV, CallInst CI,
Type *AllocTy,		Type *AllocTy,
AtomicOrdering Ordering,		AtomicOrdering Ordering,
const DataLayout &DL,		const DataLayout &DL,
TargetLibraryInfo *TLI) {		TargetLibraryInfo *TLI) {
// If this is a malloc of an abstract type, don't touch it.		// If this is a malloc of an abstract type, don't touch it.
if (!AllocTy->isSized())		if (!AllocTy->isSized())
return false;		return false;

// We can't optimize this global unless all uses of it are known to be		// 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		// 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		// 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		// 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		// would trap if the global were null: this proves that they must all
// happen after the malloc.		// happen after the malloc.
if (!AllUsesOfLoadedValueWillTrapIfNull(GV))		if (!AllUsesOfLoadedValueWillTrapIfNull(GV))
return false;		return false;

// We can't optimize this if the malloc itself is used in a complex way,		// 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		// for example, being stored into multiple globals. This allows the
// malloc to be stored into the specified global, loaded icmp'd, and		// malloc to be stored into the specified global, loaded icmp'd.
// GEP'd. These are all things we could transform to using the global		// These are all things we could transform to using the global for.
// for.		if (!valueIsOnlyUsedLocallyOrStoredToOneGlobal(CI, GV))
SmallPtrSet<const PHINode*, 8> PHIs;
if (!ValueIsOnlyUsedLocallyOrStoredToOneGlobal(CI, GV, PHIs))
return false;		return false;

// If we have a global that is only initialized with a fixed size malloc,		// 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.		// transform the program to use global memory instead of malloc'd memory.
// This eliminates dynamic allocation, avoids an indirection accessing the		// This eliminates dynamic allocation, avoids an indirection accessing the
// data, and exposes the resultant global to further GlobalOpt.		// data, and exposes the resultant global to further GlobalOpt.
// We cannot optimize the malloc if we cannot determine malloc array size.		// We cannot optimize the malloc if we cannot determine malloc array size.
Value *NElems = getMallocArraySize(CI, DL, TLI, true);		Value *NElems = getMallocArraySize(CI, DL, TLI, true);
if (!NElems)		if (!NElems)
return false;		return false;

if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))		if (ConstantInt *NElements = dyn_cast<ConstantInt>(NElems))
// Restrict this transformation to only working on small allocations		// Restrict this transformation to only working on small allocations
// (2048 bytes currently), as we don't want to introduce a 16M global or		// (2048 bytes currently), as we don't want to introduce a 16M global or
// something.		// something.
if (NElements->getZExtValue() * DL.getTypeAllocSize(AllocTy) < 2048) {		if (NElements->getZExtValue() * DL.getTypeAllocSize(AllocTy) < 2048) {
OptimizeGlobalAddressOfMalloc(GV, CI, AllocTy, NElements, DL, TLI);		OptimizeGlobalAddressOfMalloc(GV, CI, AllocTy, NElements, DL, TLI);
return true;		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 (Ordering != AtomicOrdering::NotAtomic)
return false;

// 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 (NElems == ConstantInt::get(CI->getArgOperand(0)->getType(), 1))
if (ArrayType *AT = dyn_cast<ArrayType>(AllocTy))
AllocTy = AT->getElementType();

StructType *AllocSTy = dyn_cast<StructType>(AllocTy);
if (!AllocSTy)
return false;

// This the structure has an unreasonable number of fields, leave it
// alone.
if (AllocSTy->getNumElements() <= 16 && AllocSTy->getNumElements() != 0 &&
AllGlobalLoadUsesSimpleEnoughForHeapSRA(GV, CI)) {

// 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 (ArrayType *AT = dyn_cast<ArrayType>(getMallocAllocatedType(CI, TLI))) {
Type *IntPtrTy = DL.getIntPtrType(CI->getType());
unsigned TypeSize = DL.getStructLayout(AllocSTy)->getSizeInBytes();
Value *AllocSize = ConstantInt::get(IntPtrTy, TypeSize);
Value *NumElements = ConstantInt::get(IntPtrTy, AT->getNumElements());
SmallVector<OperandBundleDef, 1> OpBundles;
CI->getOperandBundlesAsDefs(OpBundles);
Instruction *Malloc =
CallInst::CreateMalloc(CI, IntPtrTy, AllocSTy, AllocSize, NumElements,
OpBundles, nullptr, CI->getName());
Instruction *Cast = new BitCastInst(Malloc, CI->getType(), "tmp", CI);
CI->replaceAllUsesWith(Cast);
CI->eraseFromParent();
if (BitCastInst *BCI = dyn_cast<BitCastInst>(Malloc))
CI = cast<CallInst>(BCI->getOperand(0));
else
CI = cast<CallInst>(Malloc);
}

PerformHeapAllocSRoA(GV, CI, getMallocArraySize(CI, DL, TLI, true), DL,
TLI);
return true;
}

return false;		return false;
}		}

// Try to optimize globals based on the knowledge that only one value (besides		// Try to optimize globals based on the knowledge that only one value (besides
// its initializer) is ever stored to the global.		// its initializer) is ever stored to the global.
static bool		static bool
optimizeOnceStoredGlobal(GlobalVariable GV, Value StoredOnceVal,		optimizeOnceStoredGlobal(GlobalVariable GV, Value StoredOnceVal,
AtomicOrdering Ordering, const DataLayout &DL,		AtomicOrdering Ordering, const DataLayout &DL,
▲ Show 20 Lines • Show All 1,612 Lines • Show Last 20 Lines

llvm/test/Transforms/GlobalOpt/MallocSROA-section.ll

	; RUN: opt -globalopt -S < %s \| FileCheck %s			; RUN: opt -globalopt -S < %s \| FileCheck %s
	; CHECK: @Y.f0			; CHECK: @Y = {{.*}} section ".foo"
	; CHECK: section ".foo"
	; CHECK: @Y.f1
	; CHECK: section ".foo"

	%struct.xyz = type { double, i32 }			%struct.xyz = type { double, i32 }

	@Y = internal global %struct.xyz* null ,section ".foo" ; <%struct.xyz**> [#uses=2]			@Y = internal global %struct.xyz* null ,section ".foo" ; <%struct.xyz**> [#uses=2]
	@numf2s = external global i32 ; <i32*> [#uses=1]			@numf2s = external global i32 ; <i32*> [#uses=1]

	define void @init_net() {			define void @init_net() {
	entry:			entry:
	Show All 15 Lines

llvm/test/Transforms/GlobalOpt/heap-sra-1.ll

	; RUN: opt < %s -globalopt -S \| FileCheck %s			; RUN: opt < %s -globalopt -S \| FileCheck %s
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"			target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

				;; Heap SROA has been removed. This tests we don't perform heap SROA.
				; CHECK: @X =
	%struct.foo = type { i32, i32 }			%struct.foo = type { i32, i32 }
	@X = internal global %struct.foo* null			@X = internal global %struct.foo* null
	; CHECK: @X.f0
	; CHECK: @X.f1

	define void @bar(i64 %Size) nounwind noinline {			define void @bar(i64 %Size) nounwind noinline {
	entry:			entry:
	%mallocsize = mul i64 %Size, 8 ; <i64> [#uses=1]			%mallocsize = mul i64 %Size, 8 ; <i64> [#uses=1]
	%malloccall = tail call i8* @malloc(i64 %mallocsize) ; <i8*> [#uses=1]			%malloccall = tail call i8* @malloc(i64 %mallocsize) ; <i8*> [#uses=1]
	%.sub = bitcast i8* %malloccall to %struct.foo* ; <%struct.foo*> [#uses=1]			%.sub = bitcast i8* %malloccall to %struct.foo* ; <%struct.foo*> [#uses=1]
	store %struct.foo* %.sub, %struct.foo** @X, align 4			store %struct.foo* %.sub, %struct.foo** @X, align 4
	ret void			ret void
	Show All 30 Lines

llvm/test/Transforms/GlobalOpt/heap-sra-2.ll

	; RUN: opt < %s -globalopt -S \| FileCheck %s			; RUN: opt < %s -globalopt -S \| FileCheck %s
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"			target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

				;; Heap SROA has been removed. This tests we don't perform heap SROA.
				; CHECK: @X =
	%struct.foo = type { i32, i32 }			%struct.foo = type { i32, i32 }
	@X = internal global %struct.foo* null ; <%struct.foo**> [#uses=2]			@X = internal global %struct.foo* null ; <%struct.foo**> [#uses=2]
	; CHECK: @X.f0
	; CHECK: @X.f1

	define void @bar(i32 %Size) nounwind noinline {			define void @bar(i32 %Size) nounwind noinline {
	entry:			entry:
	%malloccall = tail call i8* @malloc(i64 8000000) ; <i8*> [#uses=1]			%malloccall = tail call i8* @malloc(i64 8000000) ; <i8*> [#uses=1]
	%0 = bitcast i8* %malloccall to [1000000 x %struct.foo]* ; <[1000000 x %struct.foo]*> [#uses=1]			%0 = bitcast i8* %malloccall to [1000000 x %struct.foo]* ; <[1000000 x %struct.foo]*> [#uses=1]
	%.sub = getelementptr [1000000 x %struct.foo], [1000000 x %struct.foo]* %0, i32 0, i32 0 ; <%struct.foo*> [#uses=1]			%.sub = getelementptr [1000000 x %struct.foo], [1000000 x %struct.foo]* %0, i32 0, i32 0 ; <%struct.foo*> [#uses=1]
	store %struct.foo* %.sub, %struct.foo** @X, align 4			store %struct.foo* %.sub, %struct.foo** @X, align 4
	ret void			ret void
	Show All 30 Lines

llvm/test/Transforms/GlobalOpt/heap-sra-3-no-null-opt.ll

This file was deleted.

	; RUN: opt < %s -globalopt -S \| FileCheck %s
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

	%struct.foo = type { i32, i32 }
	@X = internal global %struct.foo* null
	; CHECK: @X
	; CHECK-NOT: @X.f0

	define void @bar(i64 %Size) nounwind noinline #0 {
	entry:
	%mallocsize = mul i64 8, %Size ; <i64> [#uses=1]
	; CHECK: mul i64 8, %Size
	%malloccall = tail call i8* @malloc(i64 %mallocsize) ; <i8*> [#uses=1]
	%.sub = bitcast i8* %malloccall to %struct.foo* ; <%struct.foo*> [#uses=1]
	store %struct.foo* %.sub, %struct.foo** @X, align 4
	ret void
	}

	declare noalias i8* @malloc(i64)

	define i32 @baz() nounwind readonly noinline #0 {
	bb1.thread:
	; CHECK: load %struct.foo, %struct.foo* @X, align 4
	%0 = load %struct.foo, %struct.foo* @X, align 4
	br label %bb1

	bb1: ; preds = %bb1, %bb1.thread
	%i.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %indvar.next, %bb1 ]
	%sum.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %3, %bb1 ]
	%1 = getelementptr %struct.foo, %struct.foo* %0, i32 %i.0.reg2mem.0, i32 0
	%2 = load i32, i32* %1, align 4
	%3 = add i32 %2, %sum.0.reg2mem.0
	%indvar.next = add i32 %i.0.reg2mem.0, 1
	%exitcond = icmp eq i32 %indvar.next, 1200
	br i1 %exitcond, label %bb2, label %bb1

	bb2: ; preds = %bb1
	ret i32 %3
	}

	attributes #0 = { null_pointer_is_valid }

llvm/test/Transforms/GlobalOpt/heap-sra-3.ll

This file was deleted.

	; RUN: opt < %s -globalopt -S \| FileCheck %s
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

	%struct.foo = type { i32, i32 }
	@X = internal global %struct.foo* null
	; CHECK: @X.f0
	; CHECK: @X.f1

	define void @bar(i64 %Size) nounwind noinline {
	entry:
	%mallocsize = mul i64 8, %Size ; <i64> [#uses=1]
	; CHECK: mul i64 %Size, 4
	%malloccall = tail call i8* @malloc(i64 %mallocsize) ; <i8*> [#uses=1]
	%.sub = bitcast i8* %malloccall to %struct.foo* ; <%struct.foo*> [#uses=1]
	store %struct.foo* %.sub, %struct.foo** @X, align 4
	ret void
	}

	declare noalias i8* @malloc(i64)

	define i32 @baz() nounwind readonly noinline {
	bb1.thread:
	%0 = load %struct.foo, %struct.foo* @X, align 4
	br label %bb1

	bb1: ; preds = %bb1, %bb1.thread
	%i.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %indvar.next, %bb1 ]
	%sum.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %3, %bb1 ]
	%1 = getelementptr %struct.foo, %struct.foo* %0, i32 %i.0.reg2mem.0, i32 0
	%2 = load i32, i32* %1, align 4
	%3 = add i32 %2, %sum.0.reg2mem.0
	%indvar.next = add i32 %i.0.reg2mem.0, 1
	%exitcond = icmp eq i32 %indvar.next, 1200
	br i1 %exitcond, label %bb2, label %bb1

	bb2: ; preds = %bb1
	ret i32 %3
	}

	define void @bam(i64 %Size) nounwind noinline #0 {
	entry:
	%0 = load %struct.foo, %struct.foo* @X, align 4
	ret void
	}

	attributes #0 = { null_pointer_is_valid }

llvm/test/Transforms/GlobalOpt/heap-sra-4-no-null-opt.ll

This file was deleted.

	; RUN: opt < %s -globalopt -S \| FileCheck %s
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

	%struct.foo = type { i32, i32 }

	@X = internal global %struct.foo* null
	; CHECK: @X
	; CHECK-NOT: @X.f0

	define void @bar(i64 %Size) nounwind noinline #0 {
	entry:
	%mallocsize = shl i64 %Size, 3 ; <i64> [#uses=1]
	%malloccall = tail call i8* @malloc(i64 %mallocsize) ; <i8*> [#uses=1]
	; CHECK: shl i64 %Size, 3
	%.sub = bitcast i8* %malloccall to %struct.foo* ; <%struct.foo*> [#uses=1]
	store %struct.foo* %.sub, %struct.foo** @X, align 4
	ret void
	}

	declare noalias i8* @malloc(i64)

	define i32 @baz() nounwind readonly noinline #0 {
	; CHECK-LABEL: @baz(
	bb1.thread:
	; CHECK: load %struct.foo, %struct.foo* @X, align 4
	%0 = load %struct.foo, %struct.foo* @X, align 4
	br label %bb1

	bb1: ; preds = %bb1, %bb1.thread
	%i.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %indvar.next, %bb1 ]
	%sum.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %3, %bb1 ]
	%1 = getelementptr %struct.foo, %struct.foo* %0, i32 %i.0.reg2mem.0, i32 0
	%2 = load i32, i32* %1, align 4
	; CHECK: load i32, i32* %1, align 4
	%3 = add i32 %2, %sum.0.reg2mem.0
	%indvar.next = add i32 %i.0.reg2mem.0, 1
	%exitcond = icmp eq i32 %indvar.next, 1200
	br i1 %exitcond, label %bb2, label %bb1

	bb2: ; preds = %bb1
	ret i32 %3
	}

	attributes #0 = { null_pointer_is_valid }

llvm/test/Transforms/GlobalOpt/heap-sra-4.ll

This file was deleted.

	; RUN: opt < %s -globalopt -S \| FileCheck %s
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

	%struct.foo = type { i32, i32 }
	@X = internal global %struct.foo* null
	; CHECK: @X.f0
	; CHECK: @X.f1

	define void @bar(i64 %Size) nounwind noinline {
	entry:
	%mallocsize = shl i64 %Size, 3 ; <i64> [#uses=1]
	%malloccall = tail call i8* @malloc(i64 %mallocsize) ; <i8*> [#uses=1]
	; CHECK: mul i64 %Size, 4
	%.sub = bitcast i8* %malloccall to %struct.foo* ; <%struct.foo*> [#uses=1]
	store %struct.foo* %.sub, %struct.foo** @X, align 4
	ret void
	}

	declare noalias i8* @malloc(i64)

	define i32 @baz() nounwind readonly noinline {
	bb1.thread:
	%0 = load %struct.foo, %struct.foo* @X, align 4
	br label %bb1

	bb1: ; preds = %bb1, %bb1.thread
	%i.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %indvar.next, %bb1 ]
	%sum.0.reg2mem.0 = phi i32 [ 0, %bb1.thread ], [ %3, %bb1 ]
	%1 = getelementptr %struct.foo, %struct.foo* %0, i32 %i.0.reg2mem.0, i32 0
	%2 = load i32, i32* %1, align 4
	%3 = add i32 %2, %sum.0.reg2mem.0
	%indvar.next = add i32 %i.0.reg2mem.0, 1
	%exitcond = icmp eq i32 %indvar.next, 1200
	br i1 %exitcond, label %bb2, label %bb1

	bb2: ; preds = %bb1
	ret i32 %3
	}

	define void @bam(i64 %Size) nounwind noinline #0 {
	entry:
	%0 = load %struct.foo, %struct.foo* @X, align 4
	ret void
	}

	attributes #0 = { null_pointer_is_valid }

llvm/test/Transforms/GlobalOpt/heap-sra-phi.ll

	; RUN: opt < %s -globalopt -S \| FileCheck %s			; RUN: opt < %s -globalopt -S \| FileCheck %s
	; CHECK: tmp.f1 = phi i32*
	; CHECK: tmp.f0 = phi i32*
	target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"			target datalayout = "E-p:64:64:64-a0:0:8-f32:32:32-f64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-v64:64:64-v128:128:128"

				;; Heap SROA has been removed. This tests we don't perform heap SROA.
				; CHECK: @X =
	%struct.foo = type { i32, i32 }			%struct.foo = type { i32, i32 }
	@X = internal global %struct.foo* null ; <%struct.foo**> [#uses=2]			@X = internal global %struct.foo* null ; <%struct.foo**> [#uses=2]

	define void @bar(i32 %Size) nounwind noinline {			define void @bar(i32 %Size) nounwind noinline {
	entry:			entry:
	%malloccall = tail call i8* @malloc(i64 8000000) ; <i8*> [#uses=1]			%malloccall = tail call i8* @malloc(i64 8000000) ; <i8*> [#uses=1]
	%tmp = bitcast i8* %malloccall to [1000000 x %struct.foo]* ; <[1000000 x %struct.foo]*> [#uses=1]			%tmp = bitcast i8* %malloccall to [1000000 x %struct.foo]* ; <[1000000 x %struct.foo]*> [#uses=1]
	%.sub = getelementptr [1000000 x %struct.foo], [1000000 x %struct.foo]* %tmp, i32 0, i32 0 ; <%struct.foo*> [#uses=1]			%.sub = getelementptr [1000000 x %struct.foo], [1000000 x %struct.foo]* %tmp, i32 0, i32 0 ; <%struct.foo*> [#uses=1]
	Show All 39 Lines

This is an archive of the discontinued LLVM Phabricator instance.

[GlobalOpt] Remove heap SROA
ClosedPublic

Details

Diff Detail

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Revision Contents

Diff 344509

llvm/lib/Transforms/IPO/GlobalOpt.cpp

llvm/test/Transforms/GlobalOpt/MallocSROA-section.ll

llvm/test/Transforms/GlobalOpt/heap-sra-1.ll

llvm/test/Transforms/GlobalOpt/heap-sra-2.ll

llvm/test/Transforms/GlobalOpt/heap-sra-3-no-null-opt.ll

llvm/test/Transforms/GlobalOpt/heap-sra-3.ll

llvm/test/Transforms/GlobalOpt/heap-sra-4-no-null-opt.ll

llvm/test/Transforms/GlobalOpt/heap-sra-4.ll

llvm/test/Transforms/GlobalOpt/heap-sra-phi.ll

This is an archive of the discontinued LLVM Phabricator instance.

[GlobalOpt] Remove heap SROAClosedPublic

Details

Diff Detail

Event Timeline

Revision Contents

Diff 344509

llvm/lib/Transforms/IPO/GlobalOpt.cpp

llvm/test/Transforms/GlobalOpt/MallocSROA-section.ll

llvm/test/Transforms/GlobalOpt/heap-sra-1.ll

llvm/test/Transforms/GlobalOpt/heap-sra-2.ll

llvm/test/Transforms/GlobalOpt/heap-sra-3-no-null-opt.ll

llvm/test/Transforms/GlobalOpt/heap-sra-3.ll

llvm/test/Transforms/GlobalOpt/heap-sra-4-no-null-opt.ll

llvm/test/Transforms/GlobalOpt/heap-sra-4.ll

llvm/test/Transforms/GlobalOpt/heap-sra-phi.ll

[GlobalOpt] Remove heap SROA
ClosedPublic