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Some improvements to the handling of C11 atomic types: 

- Add atomic-to/from-nonatomic cast types
- Emit atomic operations for arithmetic on atomic types
- Emit non-atomic stores for initialisation of atomic types, but atomic stores and loads for every other store / load
- Add a __atomic_init() intrinsic which does a non-atomic store to an _Atomic() type.  This is needed for the corresponding C11 stdatomic.h function.
- Enables the relevant __has_feature() checks.  The feature isn't 100% complete yet, but it's done enough that we want people testing it.

Still to do:

- Make the arithmetic operations on atomic types (e.g. Atomic(int) foo = 1; foo++;) use the correct LLVM intrinsic if one exists, not a loop with a cmpxchg.
- Add a signal fence builtin
- Properly set the fenv state in atomic operations on floating point values
- Correctly handle things like _Atomic(_Complex double) which are too large for an atomic cmpxchg on some platforms (this requires working out what 'correctly' means in this context)
- Fix the many remaining corner cases

llvm-svn: 148242
This commit is contained in:
David Chisnall 2012-01-16 17:27:18 +00:00
parent 44a2895a03
commit fa35df628a
23 changed files with 269 additions and 26 deletions
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8
clang/include/clang/AST/Expr.h
View File

@ -4410,7 +4410,7 @@ public:
class AtomicExpr : public Expr {
public:
enum AtomicOp { Load, Store, CmpXchgStrong, CmpXchgWeak, Xchg,
Add, Sub, And, Or, Xor };
Add, Sub, And, Or, Xor, Init };
private:
enum { PTR, ORDER, VAL1, ORDER_FAIL, VAL2, END_EXPR };
Stmt* SubExprs[END_EXPR];
@ -4438,10 +4438,16 @@ public:
SubExprs[ORDER] = E;
}
Expr *getVal1() const {
if (Op == Init)
return cast<Expr>(SubExprs[ORDER]);
assert(NumSubExprs >= 3);
return cast<Expr>(SubExprs[VAL1]);
}
void setVal1(Expr *E) {
if (Op == Init) {
SubExprs[ORDER] = E;
return;
}
assert(NumSubExprs >= 3);
SubExprs[VAL1] = E;
}

7
clang/include/clang/AST/OperationKinds.h
View File

@ -267,7 +267,12 @@ enum CastKind {
/// in ARC cause blocks to be copied; this is for cases where that
/// would not otherwise be guaranteed, such as when casting to a
/// non-block pointer type.
CK_ARCExtendBlockObject
CK_ARCExtendBlockObject,
/// \brief Converts from _Atomic(T) to T.
CK_AtomicToNonAtomic,
/// \brief Converts from T to _Atomic(T).
CK_NonAtomicToAtomic
};
#define CK_Invalid ((CastKind) -1)

1
clang/include/clang/Basic/Builtins.def
View File

@ -599,6 +599,7 @@ BUILTIN(__atomic_fetch_or, "v.", "t")
BUILTIN(__atomic_fetch_xor, "v.", "t")
BUILTIN(__atomic_thread_fence, "vi", "n")
BUILTIN(__atomic_signal_fence, "vi", "n")
BUILTIN(__atomic_init, "v.", "t")
BUILTIN(__atomic_is_lock_free, "iz", "n")
// Non-overloaded atomic builtins.

18
clang/lib/AST/Expr.cpp
View File

@ -1092,6 +1092,8 @@ void CastExpr::CheckCastConsistency() const {
case CK_Dependent:
case CK_LValueToRValue:
case CK_NoOp:
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_PointerToBoolean:
case CK_IntegralToBoolean:
case CK_FloatingToBoolean:
@ -1204,6 +1206,10 @@ const char *CastExpr::getCastKindName() const {
return "ARCReclaimReturnedObject";
case CK_ARCExtendBlockObject:
return "ARCCExtendBlockObject";
case CK_AtomicToNonAtomic:
return "AtomicToNonAtomic";
case CK_NonAtomicToAtomic:
return "NonAtomicToAtomic";
}
llvm_unreachable("Unhandled cast kind!");
@ -2536,6 +2542,18 @@ bool Expr::isConstantInitializer(ASTContext &Ctx, bool IsForRef) const {
case CStyleCastExprClass: {
const CastExpr *CE = cast<CastExpr>(this);
// If we're promoting an integer to an _Atomic type then this is constant
// if the integer is constant. We also need to check the converse in case
// someone does something like:
//
// int a = (_Atomic(int))42;
//
// I doubt anyone would write code like this directly, but it's quite
// possible as the result of macro expansions.
if (CE->getCastKind() == CK_NonAtomicToAtomic ||
CE->getCastKind() == CK_AtomicToNonAtomic)
return CE->getSubExpr()->isConstantInitializer(Ctx, false);
// Handle bitcasts of vector constants.
if (getType()->isVectorType() && CE->getCastKind() == CK_BitCast)
return CE->getSubExpr()->isConstantInitializer(Ctx, false);

8
clang/lib/AST/ExprConstant.cpp
View File

@ -2277,6 +2277,8 @@ public:
default:
break;
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
return StmtVisitorTy::Visit(E->getSubExpr());
@ -4531,6 +4533,8 @@ bool IntExprEvaluator::VisitCastExpr(const CastExpr *E) {
return Error(E);
case CK_LValueToRValue:
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
return ExprEvaluatorBaseTy::VisitCastExpr(E);
@ -4997,6 +5001,8 @@ bool ComplexExprEvaluator::VisitCastExpr(const CastExpr *E) {
llvm_unreachable("invalid cast kind for complex value");
case CK_LValueToRValue:
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
return ExprEvaluatorBaseTy::VisitCastExpr(E);
@ -5855,6 +5861,8 @@ static ICEDiag CheckICE(const Expr* E, ASTContext &Ctx) {
}
switch (cast<CastExpr>(E)->getCastKind()) {
case CK_LValueToRValue:
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
case CK_IntegralToBoolean:
case CK_IntegralCast:

6
clang/lib/AST/StmtPrinter.cpp
View File

@ -1052,6 +1052,9 @@ void StmtPrinter::VisitPseudoObjectExpr(PseudoObjectExpr *Node) {
void StmtPrinter::VisitAtomicExpr(AtomicExpr *Node) {
const char *Name = 0;
switch (Node->getOp()) {
case AtomicExpr::Init:
Name = "__atomic_init(";
break;
case AtomicExpr::Load:
Name = "__atomic_load(";
break;
@ -1094,7 +1097,8 @@ void StmtPrinter::VisitAtomicExpr(AtomicExpr *Node) {
PrintExpr(Node->getVal2());
OS << ", ";
}
PrintExpr(Node->getOrder());
if (Node->getOp() != AtomicExpr::Init)
PrintExpr(Node->getOrder());
if (Node->isCmpXChg()) {
OS << ", ";
PrintExpr(Node->getOrderFail());

16
clang/lib/CodeGen/CGDecl.cpp
View File

@ -494,7 +494,7 @@ void CodeGenFunction::EmitScalarInit(const Expr *init,
llvm::Value *value = EmitScalarExpr(init);
if (capturedByInit)
drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
EmitStoreThroughLValue(RValue::get(value), lvalue);
EmitStoreThroughLValue(RValue::get(value), lvalue, true);
return;
}
@ -535,7 +535,7 @@ void CodeGenFunction::EmitScalarInit(const Expr *init,
// Otherwise just do a simple store.
else
EmitStoreOfScalar(zero, tempLV);
EmitStoreOfScalar(zero, tempLV, /* isInitialization */ true);
}
// Emit the initializer.
@ -581,19 +581,19 @@ void CodeGenFunction::EmitScalarInit(const Expr *init,
// both __weak and __strong, but __weak got filtered out above.
if (accessedByInit && lifetime == Qualifiers::OCL_Strong) {
llvm::Value *oldValue = EmitLoadOfScalar(lvalue);
EmitStoreOfScalar(value, lvalue);
EmitStoreOfScalar(value, lvalue, /* isInitialization */ true);
EmitARCRelease(oldValue, /*precise*/ false);
return;
}
EmitStoreOfScalar(value, lvalue);
EmitStoreOfScalar(value, lvalue, /* isInitialization */ true);
}
/// EmitScalarInit - Initialize the given lvalue with the given object.
void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) {
Qualifiers::ObjCLifetime lifetime = lvalue.getObjCLifetime();
if (!lifetime)
return EmitStoreThroughLValue(RValue::get(init), lvalue);
return EmitStoreThroughLValue(RValue::get(init), lvalue, true);
switch (lifetime) {
case Qualifiers::OCL_None:
@ -617,7 +617,7 @@ void CodeGenFunction::EmitScalarInit(llvm::Value *init, LValue lvalue) {
break;
}
EmitStoreOfScalar(init, lvalue);
EmitStoreOfScalar(init, lvalue, /* isInitialization */ true);
}
/// canEmitInitWithFewStoresAfterMemset - Decide whether we can emit the
@ -1045,7 +1045,7 @@ void CodeGenFunction::EmitExprAsInit(const Expr *init,
RValue rvalue = EmitReferenceBindingToExpr(init, D);
if (capturedByInit)
drillIntoBlockVariable(*this, lvalue, cast<VarDecl>(D));
EmitStoreThroughLValue(rvalue, lvalue);
EmitStoreThroughLValue(rvalue, lvalue, true);
} else if (!hasAggregateLLVMType(type)) {
EmitScalarInit(init, D, lvalue, capturedByInit);
} else if (type->isAnyComplexType()) {
@ -1505,7 +1505,7 @@ void CodeGenFunction::EmitParmDecl(const VarDecl &D, llvm::Value *Arg,
if (doStore) {
LValue lv = MakeAddrLValue(DeclPtr, Ty,
getContext().getDeclAlign(&D));
EmitStoreOfScalar(Arg, lv);
EmitStoreOfScalar(Arg, lv, /* isInitialization */ true);
}
}

37
clang/lib/CodeGen/CGExpr.cpp
View File

@ -764,6 +764,9 @@ llvm::Value *CodeGenFunction::EmitLoadOfScalar(llvm::Value *Addr, bool Volatile,
Load->setAlignment(Alignment);
if (TBAAInfo)
CGM.DecorateInstruction(Load, TBAAInfo);
// If this is an atomic type, all normal reads must be atomic
if (Ty->isAtomicType())
Load->setAtomic(llvm::SequentiallyConsistent);
return EmitFromMemory(Load, Ty);
}
@ -800,7 +803,8 @@ llvm::Value *CodeGenFunction::EmitFromMemory(llvm::Value *Value, QualType Ty) {
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
bool Volatile, unsigned Alignment,
QualType Ty,
llvm::MDNode *TBAAInfo) {
llvm::MDNode *TBAAInfo,
bool isInit) {
Value = EmitToMemory(Value, Ty);
llvm::StoreInst *Store = Builder.CreateStore(Value, Addr, Volatile);
@ -808,12 +812,15 @@ void CodeGenFunction::EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
Store->setAlignment(Alignment);
if (TBAAInfo)
CGM.DecorateInstruction(Store, TBAAInfo);
if (!isInit && Ty->isAtomicType())
Store->setAtomic(llvm::SequentiallyConsistent);
}
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue) {
void CodeGenFunction::EmitStoreOfScalar(llvm::Value *value, LValue lvalue,
bool isInit) {
EmitStoreOfScalar(value, lvalue.getAddress(), lvalue.isVolatile(),
lvalue.getAlignment().getQuantity(), lvalue.getType(),
lvalue.getTBAAInfo());
lvalue.getTBAAInfo(), isInit);
}
/// EmitLoadOfLValue - Given an expression that represents a value lvalue, this
@ -961,7 +968,7 @@ RValue CodeGenFunction::EmitLoadOfExtVectorElementLValue(LValue LV) {
/// EmitStoreThroughLValue - Store the specified rvalue into the specified
/// lvalue, where both are guaranteed to the have the same type, and that type
/// is 'Ty'.
void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst) {
void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit) {
if (!Dst.isSimple()) {
if (Dst.isVectorElt()) {
// Read/modify/write the vector, inserting the new element.
@ -1041,7 +1048,7 @@ void CodeGenFunction::EmitStoreThroughLValue(RValue Src, LValue Dst) {
}
assert(Src.isScalar() && "Can't emit an agg store with this method");
EmitStoreOfScalar(Src.getScalarVal(), Dst);
EmitStoreOfScalar(Src.getScalarVal(), Dst, isInit);
}
void CodeGenFunction::EmitStoreThroughBitfieldLValue(RValue Src, LValue Dst,
@ -2052,6 +2059,11 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
case CK_Dependent:
llvm_unreachable("dependent cast kind in IR gen!");
// These two casts are currently treated as no-ops, although they could
// potentially be real operations depending on the target's ABI.
case CK_NonAtomicToAtomic:
case CK_AtomicToNonAtomic:
case CK_NoOp:
case CK_LValueToRValue:
@ -2541,6 +2553,7 @@ EmitAtomicOp(CodeGenFunction &CGF, AtomicExpr *E, llvm::Value *Dest,
case AtomicExpr::CmpXchgWeak:
case AtomicExpr::CmpXchgStrong:
case AtomicExpr::Store:
case AtomicExpr::Init:
case AtomicExpr::Load: assert(0 && "Already handled!");
case AtomicExpr::Add: Op = llvm::AtomicRMWInst::Add; break;
case AtomicExpr::Sub: Op = llvm::AtomicRMWInst::Sub; break;
@ -2588,8 +2601,20 @@ RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E, llvm::Value *Dest) {
getContext().getTargetInfo().getMaxAtomicInlineWidth();
bool UseLibcall = (Size != Align || Size > MaxInlineWidth);
llvm::Value *Ptr, *Order, *OrderFail = 0, *Val1 = 0, *Val2 = 0;
Ptr = EmitScalarExpr(E->getPtr());
if (E->getOp() == AtomicExpr::Init) {
assert(!Dest && "Init does not return a value");
Val1 = EmitScalarExpr(E->getVal1());
llvm::StoreInst *Store = Builder.CreateStore(Val1, Ptr);
Store->setAlignment(Size);
Store->setVolatile(E->isVolatile());
return RValue::get(0);
}
Order = EmitScalarExpr(E->getOrder());
if (E->isCmpXChg()) {
Val1 = EmitScalarExpr(E->getVal1());
@ -2703,7 +2728,7 @@ RValue CodeGenFunction::EmitAtomicExpr(AtomicExpr *E, llvm::Value *Dest) {
// enforce that in general.
break;
}
if (E->getOp() == AtomicExpr::Store)
if (E->getOp() == AtomicExpr::Store || E->getOp() == AtomicExpr::Init)
return RValue::get(0);
return ConvertTempToRValue(*this, E->getType(), OrigDest);
}

2
clang/lib/CodeGen/CGExprAgg.cpp
View File

@ -337,6 +337,8 @@ void AggExprEmitter::VisitCastExpr(CastExpr *E) {
case CK_LValueToRValue: // hope for downstream optimization
case CK_NoOp:
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_UserDefinedConversion:
case CK_ConstructorConversion:
assert(CGF.getContext().hasSameUnqualifiedType(E->getSubExpr()->getType(),

4
clang/lib/CodeGen/CGExprComplex.cpp
View File

@ -358,6 +358,10 @@ ComplexPairTy ComplexExprEmitter::EmitCast(CastExpr::CastKind CK, Expr *Op,
switch (CK) {
case CK_Dependent: llvm_unreachable("dependent cast kind in IR gen!");
// Atomic to non-atomic casts may be more than a no-op for some platforms and
// for some types.
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
case CK_LValueToRValue:
case CK_UserDefinedConversion:

2
clang/lib/CodeGen/CGExprConstant.cpp
View File

@ -624,6 +624,8 @@ public:
return CGM.getCXXABI().EmitMemberPointerConversion(C, E);
case CK_LValueToRValue:
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
return C;

52
clang/lib/CodeGen/CGExprScalar.cpp
View File

@ -1064,6 +1064,8 @@ Value *ScalarExprEmitter::VisitCastExpr(CastExpr *CE) {
Value *Src = Visit(const_cast<Expr*>(E));
return Builder.CreateBitCast(Src, ConvertType(DestTy));
}
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
case CK_NoOp:
case CK_UserDefinedConversion:
return Visit(const_cast<Expr*>(E));
@ -1293,9 +1295,21 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
QualType type = E->getSubExpr()->getType();
llvm::Value *value = EmitLoadOfLValue(LV);
llvm::Value *input = value;
llvm::PHINode *atomicPHI = 0;
int amount = (isInc ? 1 : -1);
if (const AtomicType *atomicTy = type->getAs<AtomicType>()) {
llvm::BasicBlock *startBB = Builder.GetInsertBlock();
llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
Builder.CreateBr(opBB);
Builder.SetInsertPoint(opBB);
atomicPHI = Builder.CreatePHI(value->getType(), 2);
atomicPHI->addIncoming(value, startBB);
type = atomicTy->getValueType();
value = atomicPHI;
}
// Special case of integer increment that we have to check first: bool++.
// Due to promotion rules, we get:
// bool++ -> bool = bool + 1
@ -1415,6 +1429,18 @@ ScalarExprEmitter::EmitScalarPrePostIncDec(const UnaryOperator *E, LValue LV,
value = Builder.CreateInBoundsGEP(value, sizeValue, "incdec.objptr");
value = Builder.CreateBitCast(value, input->getType());
}
if (atomicPHI) {
llvm::BasicBlock *opBB = Builder.GetInsertBlock();
llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
llvm::Value *old = Builder.CreateAtomicCmpXchg(LV.getAddress(), atomicPHI,
value, llvm::SequentiallyConsistent);
atomicPHI->addIncoming(old, opBB);
llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI);
Builder.CreateCondBr(success, contBB, opBB);
Builder.SetInsertPoint(contBB);
return isPre ? value : input;
}
// Store the updated result through the lvalue.
if (LV.isBitField())
@ -1670,12 +1696,38 @@ LValue ScalarExprEmitter::EmitCompoundAssignLValue(
OpInfo.LHS = EmitLoadOfLValue(LHSLV);
OpInfo.LHS = EmitScalarConversion(OpInfo.LHS, LHSTy,
E->getComputationLHSType());
llvm::PHINode *atomicPHI = 0;
if (const AtomicType *atomicTy = OpInfo.Ty->getAs<AtomicType>()) {
// FIXME: For floating point types, we should be saving and restoring the
// floating point environment in the loop.
llvm::BasicBlock *startBB = Builder.GetInsertBlock();
llvm::BasicBlock *opBB = CGF.createBasicBlock("atomic_op", CGF.CurFn);
Builder.CreateBr(opBB);
Builder.SetInsertPoint(opBB);
atomicPHI = Builder.CreatePHI(OpInfo.LHS->getType(), 2);
atomicPHI->addIncoming(OpInfo.LHS, startBB);
OpInfo.Ty = atomicTy->getValueType();
OpInfo.LHS = atomicPHI;
}
// Expand the binary operator.
Result = (this->*Func)(OpInfo);
// Convert the result back to the LHS type.
Result = EmitScalarConversion(Result, E->getComputationResultType(), LHSTy);
if (atomicPHI) {
llvm::BasicBlock *opBB = Builder.GetInsertBlock();
llvm::BasicBlock *contBB = CGF.createBasicBlock("atomic_cont", CGF.CurFn);
llvm::Value *old = Builder.CreateAtomicCmpXchg(LHSLV.getAddress(), atomicPHI,
Result, llvm::SequentiallyConsistent);
atomicPHI->addIncoming(old, opBB);
llvm::Value *success = Builder.CreateICmpEQ(old, atomicPHI);
Builder.CreateCondBr(success, contBB, opBB);
Builder.SetInsertPoint(contBB);
return LHSLV;
}
// Store the result value into the LHS lvalue. Bit-fields are handled
// specially because the result is altered by the store, i.e., [C99 6.5.16p1]

9
clang/lib/CodeGen/CodeGenFunction.h
View File

@ -2029,13 +2029,14 @@ public:
/// the LLVM value representation.
void EmitStoreOfScalar(llvm::Value *Value, llvm::Value *Addr,
bool Volatile, unsigned Alignment, QualType Ty,
llvm::MDNode *TBAAInfo = 0);
llvm::MDNode *TBAAInfo = 0, bool isInit=false);
/// EmitStoreOfScalar - Store a scalar value to an address, taking
/// care to appropriately convert from the memory representation to
/// the LLVM value representation. The l-value must be a simple
/// l-value.
void EmitStoreOfScalar(llvm::Value *value, LValue lvalue);
/// l-value. The isInit flag indicates whether this is an initialization.
/// If so, atomic qualifiers are ignored and the store is always non-atomic.
void EmitStoreOfScalar(llvm::Value *value, LValue lvalue, bool isInit=false);
/// EmitLoadOfLValue - Given an expression that represents a value lvalue,
/// this method emits the address of the lvalue, then loads the result as an
@ -2047,7 +2048,7 @@ public:
/// EmitStoreThroughLValue - Store the specified rvalue into the specified
/// lvalue, where both are guaranteed to the have the same type, and that type
/// is 'Ty'.
void EmitStoreThroughLValue(RValue Src, LValue Dst);
void EmitStoreThroughLValue(RValue Src, LValue Dst, bool isInit=false);
void EmitStoreThroughExtVectorComponentLValue(RValue Src, LValue Dst);
/// EmitStoreThroughLValue - Store Src into Dst with same constraints as

8
clang/lib/Frontend/InitPreprocessor.cpp
View File

@ -325,6 +325,14 @@ static void InitializePredefinedMacros(const TargetInfo &TI,
Builder.defineMacro("__GNUC__", "4");
Builder.defineMacro("__GXX_ABI_VERSION", "1002");
// Define macros for the C11 / C++11 memory orderings
Builder.defineMacro("__ATOMIC_RELAXED", "0");
Builder.defineMacro("__ATOMIC_CONSUME", "1");
Builder.defineMacro("__ATOMIC_ACQUIRE", "2");
Builder.defineMacro("__ATOMIC_RELEASE", "3");
Builder.defineMacro("__ATOMIC_ACQ_REL", "4");
Builder.defineMacro("__ATOMIC_SEQ_CST", "5");
// As sad as it is, enough software depends on the __VERSION__ for version
// checks that it is necessary to report 4.2.1 (the base GCC version we claim
// compatibility with) first.

4
clang/lib/Lex/PPMacroExpansion.cpp
View File

@ -626,12 +626,14 @@ static bool HasFeature(const Preprocessor &PP, const IdentifierInfo *II) {
.Case("arc_cf_code_audited", true)
// C11 features
.Case("c_alignas", LangOpts.C11)
.Case("c_atomic", LangOpts.C11)
.Case("c_generic_selections", LangOpts.C11)
.Case("c_static_assert", LangOpts.C11)
// C++0x features
.Case("cxx_access_control_sfinae", LangOpts.CPlusPlus0x)
.Case("cxx_alias_templates", LangOpts.CPlusPlus0x)
.Case("cxx_alignas", LangOpts.CPlusPlus0x)
.Case("cxx_atomic", LangOpts.CPlusPlus0x)
.Case("cxx_attributes", LangOpts.CPlusPlus0x)
.Case("cxx_auto_type", LangOpts.CPlusPlus0x)
//.Case("cxx_constexpr", false);
@ -724,9 +726,11 @@ static bool HasExtension(const Preprocessor &PP, const IdentifierInfo *II) {
return llvm::StringSwitch<bool>(II->getName())
// C11 features supported by other languages as extensions.
.Case("c_alignas", true)
.Case("c_atomic", true)
.Case("c_generic_selections", true)
.Case("c_static_assert", true)
// C++0x features supported by other languages as extensions.
.Case("cxx_atomic", LangOpts.CPlusPlus)
.Case("cxx_deleted_functions", LangOpts.CPlusPlus)
.Case("cxx_explicit_conversions", LangOpts.CPlusPlus)
.Case("cxx_inline_namespaces", LangOpts.CPlusPlus)

5
clang/lib/Sema/SemaCast.cpp
View File

@ -1897,6 +1897,11 @@ void CastOperation::CheckCStyleCast() {
if (SrcExpr.isInvalid())
return;
QualType SrcType = SrcExpr.get()->getType();
// You can cast an _Atomic(T) to anything you can cast a T to.
if (const AtomicType *AtomicSrcType = SrcType->getAs<AtomicType>())
SrcType = AtomicSrcType->getValueType();
assert(!SrcType->isPlaceholderType());
if (Self.RequireCompleteType(OpRange.getBegin(), DestType,

8
clang/lib/Sema/SemaChecking.cpp
View File

@ -277,6 +277,8 @@ Sema::CheckBuiltinFunctionCall(unsigned BuiltinID, CallExpr *TheCall) {
return SemaAtomicOpsOverloaded(move(TheCallResult), AtomicExpr::Load);
case Builtin::BI__atomic_store:
return SemaAtomicOpsOverloaded(move(TheCallResult), AtomicExpr::Store);
case Builtin::BI__atomic_init:
return SemaAtomicOpsOverloaded(move(TheCallResult), AtomicExpr::Init);
case Builtin::BI__atomic_exchange:
return SemaAtomicOpsOverloaded(move(TheCallResult), AtomicExpr::Xchg);
case Builtin::BI__atomic_compare_exchange_strong:
@ -538,6 +540,8 @@ Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult, AtomicExpr::AtomicOp Op)
NumVals = 2;
NumOrders = 2;
}
if (Op == AtomicExpr::Init)
NumOrders = 0;
if (TheCall->getNumArgs() < NumVals+NumOrders+1) {
Diag(TheCall->getLocEnd(), diag::err_typecheck_call_too_few_args)
@ -600,7 +604,7 @@ Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult, AtomicExpr::AtomicOp Op)
}
QualType ResultType = ValType;
if (Op == AtomicExpr::Store)
if (Op == AtomicExpr::Store || Op == AtomicExpr::Init)
ResultType = Context.VoidTy;
else if (Op == AtomicExpr::CmpXchgWeak || Op == AtomicExpr::CmpXchgStrong)
ResultType = Context.BoolTy;
@ -641,6 +645,8 @@ Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult, AtomicExpr::AtomicOp Op)
SubExprs.push_back(Ptr);
if (Op == AtomicExpr::Load) {
SubExprs.push_back(TheCall->getArg(1)); // Order
} else if (Op == AtomicExpr::Init) {
SubExprs.push_back(TheCall->getArg(1)); // Val1
} else if (Op != AtomicExpr::CmpXchgWeak && Op != AtomicExpr::CmpXchgStrong) {
SubExprs.push_back(TheCall->getArg(2)); // Order
SubExprs.push_back(TheCall->getArg(1)); // Val1

49
clang/lib/Sema/SemaExpr.cpp
View File

@ -4066,6 +4066,11 @@ CastKind Sema::PrepareScalarCast(ExprResult &Src, QualType DestTy) {
// pointers. Everything else should be possible.
QualType SrcTy = Src.get()->getType();
if (const AtomicType *SrcAtomicTy = SrcTy->getAs<AtomicType>())
SrcTy = SrcAtomicTy->getValueType();
if (const AtomicType *DestAtomicTy = DestTy->getAs<AtomicType>())
DestTy = DestAtomicTy->getValueType();
if (Context.hasSameUnqualifiedType(SrcTy, DestTy))
return CK_NoOp;
@ -5358,9 +5363,6 @@ Sema::CheckAssignmentConstraints(QualType LHSType, ExprResult &RHS,
LHSType = Context.getCanonicalType(LHSType).getUnqualifiedType();
RHSType = Context.getCanonicalType(RHSType).getUnqualifiedType();
// We can't do assignment from/to atomics yet.
if (LHSType->isAtomicType())
return Incompatible;
// Common case: no conversion required.
if (LHSType == RHSType) {
@ -5368,6 +5370,21 @@ Sema::CheckAssignmentConstraints(QualType LHSType, ExprResult &RHS,
return Compatible;
}
if (const AtomicType *AtomicTy = dyn_cast<AtomicType>(LHSType)) {
if (AtomicTy->getValueType() == RHSType) {
Kind = CK_NonAtomicToAtomic;
return Compatible;
}
}
if (const AtomicType *AtomicTy = dyn_cast<AtomicType>(RHSType)) {
if (AtomicTy->getValueType() == LHSType) {
Kind = CK_AtomicToNonAtomic;
return Compatible;
}
}
// If the left-hand side is a reference type, then we are in a
// (rare!) case where we've allowed the use of references in C,
// e.g., as a parameter type in a built-in function. In this case,
@ -5906,9 +5923,15 @@ QualType Sema::CheckMultiplyDivideOperands(ExprResult &LHS, ExprResult &RHS,
if (LHS.isInvalid() || RHS.isInvalid())
return QualType();
if (!LHS.get()->getType()->isArithmeticType() ||
!RHS.get()->getType()->isArithmeticType())
!RHS.get()->getType()->isArithmeticType()) {
if (IsCompAssign &&
LHS.get()->getType()->isAtomicType() &&
RHS.get()->getType()->isArithmeticType())
return compType;
return InvalidOperands(Loc, LHS, RHS);
}
// Check for division by zero.
if (IsDiv &&
@ -6134,6 +6157,12 @@ QualType Sema::CheckAdditionOperands( // C99 6.5.6
return compType;
}
if (LHS.get()->getType()->isAtomicType() &&
RHS.get()->getType()->isArithmeticType()) {
*CompLHSTy = LHS.get()->getType();
return compType;
}
// Put any potential pointer into PExp
Expr* PExp = LHS.get(), *IExp = RHS.get();
if (IExp->getType()->isAnyPointerType())
@ -6194,6 +6223,12 @@ QualType Sema::CheckSubtractionOperands(ExprResult &LHS, ExprResult &RHS,
return compType;
}
if (LHS.get()->getType()->isAtomicType() &&
RHS.get()->getType()->isArithmeticType()) {
*CompLHSTy = LHS.get()->getType();
return compType;
}
// Either ptr - int or ptr - ptr.
if (LHS.get()->getType()->isAnyPointerType()) {
QualType lpointee = LHS.get()->getType()->getPointeeType();
@ -7290,6 +7325,12 @@ static QualType CheckIncrementDecrementOperand(Sema &S, Expr *Op,
return S.Context.DependentTy;
QualType ResType = Op->getType();
// Atomic types can be used for increment / decrement where the non-atomic
// versions can, so ignore the _Atomic() specifier for the purpose of
// checking.
if (const AtomicType *ResAtomicType = ResType->getAs<AtomicType>())
ResType = ResAtomicType->getValueType();
assert(!ResType.isNull() && "no type for increment/decrement expression");
if (S.getLangOptions().CPlusPlus && ResType->isBooleanType()) {

5
clang/lib/StaticAnalyzer/Core/ExprEngineC.cpp
View File

@ -218,6 +218,11 @@ void ExprEngine::VisitCast(const CastExpr *CastE, const Expr *Ex,
case CK_ARCConsumeObject:
case CK_ARCReclaimReturnedObject:
case CK_ARCExtendBlockObject: // Fall-through.
// The analyser can ignore atomic casts for now, although some future
// checkers may want to make certain that you're not modifying the same
// value through atomic and nonatomic pointers.
case CK_AtomicToNonAtomic:
case CK_NonAtomicToAtomic:
// True no-ops.
case CK_NoOp:
case CK_FunctionToPointerDecay: {

14
clang/test/CodeGen/atomic_init.c Normal file
View File

@ -0,0 +1,14 @@
// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
// Check that no atomic operations are used in any initialisation of _Atomic
// types.
_Atomic(int) i = 42;
void foo()
{
_Atomic(int) j = 12; // CHECK: store
// CHECK-NOT: atomic
__atomic_init(&j, 42); // CHECK: store
// CHECK-NOT: atomic
}

14
clang/test/CodeGen/atomic_ops.c Normal file
View File

@ -0,0 +1,14 @@
// RUN: %clang_cc1 -emit-llvm %s -o - | FileCheck %s
void foo(void)
{
_Atomic(int) i = 0;
// Check that multiply / divides on atomics produce a cmpxchg loop
i *= 2; // CHECK: cmpxchg
i /= 2; // CHECK: cmpxchg
// These should be emitting atomicrmw instructions, but they aren't yet
i += 2; // CHECK: cmpxchg
i -= 2; // CHECK: cmpxchg
i++; // CHECK: cmpxchg
i--; // CHECK: cmpxchg
}

9
clang/test/Lexer/has_feature_c1x.c
View File

@ -1,6 +1,15 @@
// RUN: %clang_cc1 -E -std=c1x %s -o - | FileCheck --check-prefix=CHECK-1X %s
// RUN: %clang_cc1 -E %s -o - | FileCheck --check-prefix=CHECK-NO-1X %s
#if __has_feature(c_atomic)
int has_atomic();
#else
int no_atomic();
#endif
// CHECK-1X: has_atomic
// CHECK-NO-1X: no_atomic
#if __has_feature(c_static_assert)
int has_static_assert();
#else

9
clang/test/Lexer/has_feature_cxx0x.cpp
View File

@ -1,6 +1,15 @@
// RUN: %clang_cc1 -E -std=c++11 %s -o - | FileCheck --check-prefix=CHECK-0X %s
// RUN: %clang_cc1 -E %s -o - | FileCheck --check-prefix=CHECK-NO-0X %s
#if __has_feature(cxx_atomic)
int has_atomic();
#else
int no_atomic();
#endif
// CHECK-0X: has_atomic
// CHECK-NO-0X: no_atomic
#if __has_feature(cxx_lambdas)
int has_lambdas();
#else