bool DominatingValue<RValue>::saved_type::needsSaving(RValue rv) {
if (rv.isScalar())
return DominatingLLVMValue::needsSaving(rv.getScalarVal());
if (rv.isAggregate())
return DominatingLLVMValue::needsSaving(rv.getAggregateAddr());
return true;
}
DominatingValue<RValue>::saved_type
DominatingValue<RValue>::saved_type::save(CodeGenFunction &CGF, RValue rv) {
if (rv.isScalar()) {
llvm::Value *V = rv.getScalarVal();
// These automatically dominate and don't need to be saved.
if (!DominatingLLVMValue::needsSaving(V))
return saved_type(V, ScalarLiteral);
// Everything else needs an alloca.
llvm::Value *addr = CGF.CreateTempAlloca(V->getType(), "saved-rvalue");
CGF.Builder.CreateStore(V, addr);
return saved_type(addr, ScalarAddress);
}
if (rv.isComplex()) {
CodeGenFunction::ComplexPairTy V = rv.getComplexVal();
llvm::Type *ComplexTy =
llvm::StructType::get(V.first->getType(), V.second->getType(),
(void*) nullptr);
llvm::Value *addr = CGF.CreateTempAlloca(ComplexTy, "saved-complex");
CGF.Builder.CreateStore(V.first, CGF.Builder.CreateStructGEP(addr, 0));
CGF.Builder.CreateStore(V.second, CGF.Builder.CreateStructGEP(addr, 1));
return saved_type(addr, ComplexAddress);
}
assert(rv.isAggregate());
llvm::Value *V = rv.getAggregateAddr(); // TODO: volatile?
if (!DominatingLLVMValue::needsSaving(V))
return saved_type(V, AggregateLiteral);
llvm::Value *addr = CGF.CreateTempAlloca(V->getType(), "saved-rvalue");
CGF.Builder.CreateStore(V, addr);
return saved_type(addr, AggregateAddress);
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore) {
assert(Src.isAggregate() && "value must be aggregate value!");
// If the result is ignored, don't copy from the value.
if (DestPtr == 0) {
if (!Src.isVolatileQualified() || (IgnoreResult && Ignore))
return;
// If the source is volatile, we must read from it; to do that, we need
// some place to put it.
DestPtr = CGF.CreateMemTemp(E->getType(), "agg.tmp");
}
if (RequiresGCollection) {
CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
DestPtr, Src.getAggregateAddr(),
E->getType());
return;
}
// If the result of the assignment is used, copy the LHS there also.
// FIXME: Pass VolatileDest as well. I think we also need to merge volatile
// from the source as well, as we can't eliminate it if either operand
// is volatile, unless copy has volatile for both source and destination..
CGF.EmitAggregateCopy(DestPtr, Src.getAggregateAddr(), E->getType(),
VolatileDest|Src.isVolatileQualified());
}
/// Copy an r-value into memory as part of storing to an atomic type.
/// This needs to create a bit-pattern suitable for atomic operations.
void AtomicInfo::emitCopyIntoMemory(RValue rvalue, LValue dest) const {
// If we have an r-value, the rvalue should be of the atomic type,
// which means that the caller is responsible for having zeroed
// any padding. Just do an aggregate copy of that type.
if (rvalue.isAggregate()) {
CGF.EmitAggregateCopy(dest.getAddress(),
rvalue.getAggregateAddr(),
getAtomicType(),
(rvalue.isVolatileQualified()
|| dest.isVolatileQualified()),
dest.getAlignment());
return;
}
// Okay, otherwise we're copying stuff.
// Zero out the buffer if necessary.
emitMemSetZeroIfNecessary(dest);
// Drill past the padding if present.
dest = projectValue(dest);
// Okay, store the rvalue in.
if (rvalue.isScalar()) {
CGF.EmitStoreOfScalar(rvalue.getScalarVal(), dest, /*init*/ true);
} else {
CGF.EmitStoreOfComplex(rvalue.getComplexVal(), dest, /*init*/ true);
}
}
void
CodeGenFunction::ExpandTypeToArgs(QualType Ty, RValue RV,
llvm::SmallVector<llvm::Value*, 16> &Args) {
const RecordType *RT = Ty->getAsStructureType();
assert(RT && "Can only expand structure types.");
RecordDecl *RD = RT->getDecl();
assert(RV.isAggregate() && "Unexpected rvalue during struct expansion");
llvm::Value *Addr = RV.getAggregateAddr();
for (RecordDecl::field_iterator i = RD->field_begin(), e = RD->field_end();
i != e; ++i) {
FieldDecl *FD = *i;
QualType FT = FD->getType();
// FIXME: What are the right qualifiers here?
LValue LV = EmitLValueForField(Addr, FD, false, 0);
if (CodeGenFunction::hasAggregateLLVMType(FT)) {
ExpandTypeToArgs(FT, RValue::getAggregate(LV.getAddress()), Args);
} else {
RValue RV = EmitLoadOfLValue(LV, FT);
assert(RV.isScalar() &&
"Unexpected non-scalar rvalue during struct expansion.");
Args.push_back(RV.getScalarVal());
}
}
}
void CodeGenFunction::EmitReturnOfRValue(RValue RV, QualType Ty) {
if (RV.isScalar()) {
Builder.CreateStore(RV.getScalarVal(), ReturnValue);
} else if (RV.isAggregate()) {
EmitAggregateCopy(ReturnValue, RV.getAggregateAddr(), Ty);
} else {
StoreComplexToAddr(RV.getComplexVal(), ReturnValue, false);
}
EmitBranchThroughCleanup(ReturnBlock);
}
/// Emit a store to an l-value of atomic type.
///
/// Note that the r-value is expected to be an r-value *of the atomic
/// type*; this means that for aggregate r-values, it should include
/// storage for any padding that was necessary.
void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, bool isInit) {
// If this is an aggregate r-value, it should agree in type except
// maybe for address-space qualification.
assert(!rvalue.isAggregate() ||
rvalue.getAggregateAddr()->getType()->getPointerElementType()
== dest.getAddress()->getType()->getPointerElementType());
AtomicInfo atomics(*this, dest);
// If this is an initialization, just put the value there normally.
if (isInit) {
atomics.emitCopyIntoMemory(rvalue, dest);
return;
}
// Check whether we should use a library call.
if (atomics.shouldUseLibcall()) {
// Produce a source address.
llvm::Value *srcAddr = atomics.materializeRValue(rvalue);
// void __atomic_store(size_t size, void *mem, void *val, int order)
CallArgList args;
args.add(RValue::get(atomics.getAtomicSizeValue()),
getContext().getSizeType());
args.add(RValue::get(EmitCastToVoidPtr(dest.getAddress())),
getContext().VoidPtrTy);
args.add(RValue::get(EmitCastToVoidPtr(srcAddr)),
getContext().VoidPtrTy);
args.add(RValue::get(llvm::ConstantInt::get(
IntTy, AtomicExpr::AO_ABI_memory_order_seq_cst)),
getContext().IntTy);
emitAtomicLibcall(*this, "__atomic_store", getContext().VoidTy, args);
return;
}
// Okay, we're doing this natively.
llvm::Value *intValue = atomics.convertRValueToInt(rvalue);
// Do the atomic store.
llvm::Value *addr = atomics.emitCastToAtomicIntPointer(dest.getAddress());
llvm::StoreInst *store = Builder.CreateStore(intValue, addr);
// Initializations don't need to be atomic.
if (!isInit) store->setAtomic(llvm::SequentiallyConsistent);
// Other decoration.
store->setAlignment(dest.getAlignment().getQuantity());
if (dest.isVolatileQualified())
store->setVolatile(true);
if (dest.getTBAAInfo())
CGM.DecorateInstruction(store, dest.getTBAAInfo());
}
DominatingValue<RValue>::saved_type
DominatingValue<RValue>::saved_type::save(CodeGenFunction &CGF, RValue rv) {
if (rv.isScalar()) {
llvm::Value *V = rv.getScalarVal();
// These automatically dominate and don't need to be saved.
if (!DominatingLLVMValue::needsSaving(V))
return saved_type(V, ScalarLiteral);
// Everything else needs an alloca.
Address addr =
CGF.CreateDefaultAlignTempAlloca(V->getType(), "saved-rvalue");
CGF.Builder.CreateStore(V, addr);
return saved_type(addr.getPointer(), ScalarAddress);
}
if (rv.isComplex()) {
CodeGenFunction::ComplexPairTy V = rv.getComplexVal();
llvm::Type *ComplexTy =
llvm::StructType::get(V.first->getType(), V.second->getType(),
(void*) nullptr);
Address addr = CGF.CreateDefaultAlignTempAlloca(ComplexTy, "saved-complex");
CGF.Builder.CreateStore(V.first,
CGF.Builder.CreateStructGEP(addr, 0, CharUnits()));
CharUnits offset = CharUnits::fromQuantity(
CGF.CGM.getDataLayout().getTypeAllocSize(V.first->getType()));
CGF.Builder.CreateStore(V.second,
CGF.Builder.CreateStructGEP(addr, 1, offset));
return saved_type(addr.getPointer(), ComplexAddress);
}
assert(rv.isAggregate());
Address V = rv.getAggregateAddress(); // TODO: volatile?
if (!DominatingLLVMValue::needsSaving(V.getPointer()))
return saved_type(V.getPointer(), AggregateLiteral,
V.getAlignment().getQuantity());
Address addr =
CGF.CreateTempAlloca(V.getType(), CGF.getPointerAlign(), "saved-rvalue");
CGF.Builder.CreateStore(V.getPointer(), addr);
return saved_type(addr.getPointer(), AggregateAddress,
V.getAlignment().getQuantity());
}
/// EmitFinalDestCopy - Perform the final copy to DestPtr, if desired.
void AggExprEmitter::EmitFinalDestCopy(const Expr *E, RValue Src, bool Ignore,
unsigned Alignment) {
assert(Src.isAggregate() && "value must be aggregate value!");
// If Dest is ignored, then we're evaluating an aggregate expression
// in a context (like an expression statement) that doesn't care
// about the result. C says that an lvalue-to-rvalue conversion is
// performed in these cases; C++ says that it is not. In either
// case, we don't actually need to do anything unless the value is
// volatile.
if (Dest.isIgnored()) {
if (!Src.isVolatileQualified() ||
CGF.CGM.getLangOptions().CPlusPlus ||
(IgnoreResult && Ignore))
return;
// If the source is volatile, we must read from it; to do that, we need
// some place to put it.
Dest = CGF.CreateAggTemp(E->getType(), "agg.tmp");
}
if (Dest.requiresGCollection()) {
CharUnits size = CGF.getContext().getTypeSizeInChars(E->getType());
llvm::Type *SizeTy = CGF.ConvertType(CGF.getContext().getSizeType());
llvm::Value *SizeVal = llvm::ConstantInt::get(SizeTy, size.getQuantity());
CGF.CGM.getObjCRuntime().EmitGCMemmoveCollectable(CGF,
Dest.getAddr(),
Src.getAggregateAddr(),
SizeVal);
return;
}
// If the result of the assignment is used, copy the LHS there also.
// FIXME: Pass VolatileDest as well. I think we also need to merge volatile
// from the source as well, as we can't eliminate it if either operand
// is volatile, unless copy has volatile for both source and destination..
CGF.EmitAggregateCopy(Dest.getAddr(), Src.getAggregateAddr(), E->getType(),
Dest.isVolatile()|Src.isVolatileQualified(),
Alignment);
}
/// Emit a compare-and-exchange op for atomic type.
///
std::pair<RValue, RValue> CodeGenFunction::EmitAtomicCompareExchange(
LValue Obj, RValue Expected, RValue Desired, SourceLocation Loc,
llvm::AtomicOrdering Success, llvm::AtomicOrdering Failure, bool IsWeak,
AggValueSlot Slot) {
// If this is an aggregate r-value, it should agree in type except
// maybe for address-space qualification.
assert(!Expected.isAggregate() ||
Expected.getAggregateAddr()->getType()->getPointerElementType() ==
Obj.getAddress()->getType()->getPointerElementType());
assert(!Desired.isAggregate() ||
Desired.getAggregateAddr()->getType()->getPointerElementType() ==
Obj.getAddress()->getType()->getPointerElementType());
AtomicInfo Atomics(*this, Obj);
if (Failure >= Success)
// Don't assert on undefined behavior.
Failure = llvm::AtomicCmpXchgInst::getStrongestFailureOrdering(Success);
auto Alignment = Atomics.getValueAlignment();
// Check whether we should use a library call.
if (Atomics.shouldUseLibcall()) {
auto *ExpectedAddr = Atomics.materializeRValue(Expected);
// Produce a source address.
auto *DesiredAddr = Atomics.materializeRValue(Desired);
// bool __atomic_compare_exchange(size_t size, void *obj, void *expected,
// void *desired, int success, int failure);
CallArgList Args;
Args.add(RValue::get(Atomics.getAtomicSizeValue()),
getContext().getSizeType());
Args.add(RValue::get(EmitCastToVoidPtr(Obj.getAddress())),
getContext().VoidPtrTy);
Args.add(RValue::get(EmitCastToVoidPtr(ExpectedAddr)),
getContext().VoidPtrTy);
Args.add(RValue::get(EmitCastToVoidPtr(DesiredAddr)),
getContext().VoidPtrTy);
Args.add(RValue::get(llvm::ConstantInt::get(IntTy, Success)),
getContext().IntTy);
Args.add(RValue::get(llvm::ConstantInt::get(IntTy, Failure)),
getContext().IntTy);
auto SuccessFailureRVal = emitAtomicLibcall(
*this, "__atomic_compare_exchange", getContext().BoolTy, Args);
auto *PreviousVal =
Builder.CreateAlignedLoad(ExpectedAddr, Alignment.getQuantity());
return std::make_pair(RValue::get(PreviousVal), SuccessFailureRVal);
}
// If we've got a scalar value of the right size, try to avoid going
// through memory.
auto *ExpectedIntVal = Atomics.convertRValueToInt(Expected);
auto *DesiredIntVal = Atomics.convertRValueToInt(Desired);
// Do the atomic store.
auto *Addr = Atomics.emitCastToAtomicIntPointer(Obj.getAddress());
auto *Inst = Builder.CreateAtomicCmpXchg(Addr, ExpectedIntVal, DesiredIntVal,
Success, Failure);
// Other decoration.
Inst->setVolatile(Obj.isVolatileQualified());
Inst->setWeak(IsWeak);
// Okay, turn that back into the original value type.
auto *PreviousVal = Builder.CreateExtractValue(Inst, /*Idxs=*/0);
auto *SuccessFailureVal = Builder.CreateExtractValue(Inst, /*Idxs=*/1);
return std::make_pair(Atomics.convertIntToValue(PreviousVal, Slot, Loc),
RValue::get(SuccessFailureVal));
}
/// Emit a store to an l-value of atomic type.
///
/// Note that the r-value is expected to be an r-value *of the atomic
/// type*; this means that for aggregate r-values, it should include
/// storage for any padding that was necessary.
void CodeGenFunction::EmitAtomicStore(RValue rvalue, LValue dest, bool isInit) {
// If this is an aggregate r-value, it should agree in type except
// maybe for address-space qualification.
assert(!rvalue.isAggregate() ||
rvalue.getAggregateAddr()->getType()->getPointerElementType()
== dest.getAddress()->getType()->getPointerElementType());
AtomicInfo atomics(*this, dest);
// If this is an initialization, just put the value there normally.
if (isInit) {
atomics.emitCopyIntoMemory(rvalue, dest);
return;
}
// Check whether we should use a library call.
if (atomics.shouldUseLibcall()) {
// Produce a source address.
llvm::Value *srcAddr = atomics.materializeRValue(rvalue);
// void __atomic_store(size_t size, void *mem, void *val, int order)
CallArgList args;
args.add(RValue::get(atomics.getAtomicSizeValue()),
getContext().getSizeType());
args.add(RValue::get(EmitCastToVoidPtr(dest.getAddress())),
getContext().VoidPtrTy);
args.add(RValue::get(EmitCastToVoidPtr(srcAddr)),
getContext().VoidPtrTy);
args.add(RValue::get(llvm::ConstantInt::get(
IntTy, AtomicExpr::AO_ABI_memory_order_seq_cst)),
getContext().IntTy);
emitAtomicLibcall(*this, "__atomic_store", getContext().VoidTy, args);
return;
}
// Okay, we're doing this natively.
llvm::Value *intValue;
// If we've got a scalar value of the right size, try to avoid going
// through memory.
if (rvalue.isScalar() && !atomics.hasPadding()) {
llvm::Value *value = rvalue.getScalarVal();
if (isa<llvm::IntegerType>(value->getType())) {
intValue = value;
} else {
llvm::IntegerType *inputIntTy =
llvm::IntegerType::get(getLLVMContext(), atomics.getValueSizeInBits());
if (isa<llvm::PointerType>(value->getType())) {
intValue = Builder.CreatePtrToInt(value, inputIntTy);
} else {
intValue = Builder.CreateBitCast(value, inputIntTy);
}
}
// Otherwise, we need to go through memory.
} else {
// Put the r-value in memory.
llvm::Value *addr = atomics.materializeRValue(rvalue);
// Cast the temporary to the atomic int type and pull a value out.
addr = atomics.emitCastToAtomicIntPointer(addr);
intValue = Builder.CreateAlignedLoad(addr,
atomics.getAtomicAlignment().getQuantity());
}
// Do the atomic store.
llvm::Value *addr = atomics.emitCastToAtomicIntPointer(dest.getAddress());
llvm::StoreInst *store = Builder.CreateStore(intValue, addr);
// Initializations don't need to be atomic.
if (!isInit) store->setAtomic(llvm::SequentiallyConsistent);
// Other decoration.
store->setAlignment(dest.getAlignment().getQuantity());
if (dest.isVolatileQualified())
store->setVolatile(true);
if (dest.getTBAAInfo())
CGM.DecorateInstruction(store, dest.getTBAAInfo());
}
