[OPENMP 4.0] Fixed support of array sections/array subscripts.
Codegen for array sections/array subscripts worked only for expressions with arrays as base. Patch fixes codegen for bases with pointer/reference types.
llvm-svn: 259776
diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 0855b45..051fa3c 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/clang/lib/CodeGen/CGExpr.cpp
@@ -1949,6 +1949,21 @@
return MakeAddrLValue(Addr, RefTy->getPointeeType(), Source);
}
+Address CodeGenFunction::EmitLoadOfPointer(Address Ptr,
+ const PointerType *PtrTy,
+ AlignmentSource *Source) {
+ llvm::Value *Addr = Builder.CreateLoad(Ptr);
+ return Address(Addr, getNaturalTypeAlignment(PtrTy->getPointeeType(), Source,
+ /*forPointeeType=*/true));
+}
+
+LValue CodeGenFunction::EmitLoadOfPointerLValue(Address PtrAddr,
+ const PointerType *PtrTy) {
+ AlignmentSource Source;
+ Address Addr = EmitLoadOfPointer(PtrAddr, PtrTy, &Source);
+ return MakeAddrLValue(Addr, PtrTy->getPointeeType(), Source);
+}
+
static LValue EmitGlobalVarDeclLValue(CodeGenFunction &CGF,
const Expr *E, const VarDecl *VD) {
QualType T = E->getType();
@@ -2934,21 +2949,54 @@
return LV;
}
+static Address emitOMPArraySectionBase(CodeGenFunction &CGF, const Expr *Base,
+ AlignmentSource &AlignSource,
+ QualType BaseTy, QualType ElTy,
+ bool IsLowerBound) {
+ LValue BaseLVal;
+ if (auto *ASE = dyn_cast<OMPArraySectionExpr>(Base->IgnoreParenImpCasts())) {
+ BaseLVal = CGF.EmitOMPArraySectionExpr(ASE, IsLowerBound);
+ if (BaseTy->isArrayType()) {
+ Address Addr = BaseLVal.getAddress();
+ AlignSource = BaseLVal.getAlignmentSource();
+
+ // If the array type was an incomplete type, we need to make sure
+ // the decay ends up being the right type.
+ llvm::Type *NewTy = CGF.ConvertType(BaseTy);
+ Addr = CGF.Builder.CreateElementBitCast(Addr, NewTy);
+
+ // Note that VLA pointers are always decayed, so we don't need to do
+ // anything here.
+ if (!BaseTy->isVariableArrayType()) {
+ assert(isa<llvm::ArrayType>(Addr.getElementType()) &&
+ "Expected pointer to array");
+ Addr = CGF.Builder.CreateStructGEP(Addr, 0, CharUnits::Zero(),
+ "arraydecay");
+ }
+
+ return CGF.Builder.CreateElementBitCast(Addr,
+ CGF.ConvertTypeForMem(ElTy));
+ }
+ CharUnits Align = CGF.getNaturalTypeAlignment(ElTy, &AlignSource);
+ return Address(CGF.Builder.CreateLoad(BaseLVal.getAddress()), Align);
+ }
+ return CGF.EmitPointerWithAlignment(Base, &AlignSource);
+}
+
LValue CodeGenFunction::EmitOMPArraySectionExpr(const OMPArraySectionExpr *E,
bool IsLowerBound) {
- LValue Base;
+ QualType BaseTy;
if (auto *ASE =
dyn_cast<OMPArraySectionExpr>(E->getBase()->IgnoreParenImpCasts()))
- Base = EmitOMPArraySectionExpr(ASE, IsLowerBound);
+ BaseTy = OMPArraySectionExpr::getBaseOriginalType(ASE);
else
- Base = EmitLValue(E->getBase());
- QualType BaseTy = Base.getType();
- llvm::Value *Idx = nullptr;
+ BaseTy = E->getBase()->getType();
QualType ResultExprTy;
if (auto *AT = getContext().getAsArrayType(BaseTy))
ResultExprTy = AT->getElementType();
else
ResultExprTy = BaseTy->getPointeeType();
+ llvm::Value *Idx = nullptr;
if (IsLowerBound || (!IsLowerBound && E->getColonLoc().isInvalid())) {
// Requesting lower bound or upper bound, but without provided length and
// without ':' symbol for the default length -> length = 1.
@@ -2960,9 +3008,9 @@
} else
Idx = llvm::ConstantInt::getNullValue(IntPtrTy);
} else {
- // Try to emit length or lower bound as constant. If this is possible, 1 is
- // subtracted from constant length or lower bound. Otherwise, emit LLVM IR
- // (LB + Len) - 1.
+ // Try to emit length or lower bound as constant. If this is possible, 1
+ // is subtracted from constant length or lower bound. Otherwise, emit LLVM
+ // IR (LB + Len) - 1.
auto &C = CGM.getContext();
auto *Length = E->getLength();
llvm::APSInt ConstLength;
@@ -3008,12 +3056,15 @@
Idx = llvm::ConstantInt::get(IntPtrTy, ConstLength + ConstLowerBound);
} else {
// Idx = ArraySize - 1;
- if (auto *VAT = C.getAsVariableArrayType(BaseTy)) {
+ QualType ArrayTy = BaseTy->isPointerType()
+ ? E->getBase()->IgnoreParenImpCasts()->getType()
+ : BaseTy;
+ if (auto *VAT = C.getAsVariableArrayType(ArrayTy)) {
Length = VAT->getSizeExpr();
if (Length->isIntegerConstantExpr(ConstLength, C))
Length = nullptr;
} else {
- auto *CAT = C.getAsConstantArrayType(BaseTy);
+ auto *CAT = C.getAsConstantArrayType(ArrayTy);
ConstLength = CAT->getSize();
}
if (Length) {
@@ -3032,52 +3083,56 @@
}
assert(Idx);
- llvm::Value *EltPtr;
- QualType FixedSizeEltType = ResultExprTy;
+ Address EltPtr = Address::invalid();
+ AlignmentSource AlignSource;
if (auto *VLA = getContext().getAsVariableArrayType(ResultExprTy)) {
+ // The base must be a pointer, which is not an aggregate. Emit
+ // it. It needs to be emitted first in case it's what captures
+ // the VLA bounds.
+ Address Base =
+ emitOMPArraySectionBase(*this, E->getBase(), AlignSource, BaseTy,
+ VLA->getElementType(), IsLowerBound);
// The element count here is the total number of non-VLA elements.
- llvm::Value *numElements = getVLASize(VLA).first;
- FixedSizeEltType = getFixedSizeElementType(getContext(), VLA);
+ llvm::Value *NumElements = getVLASize(VLA).first;
// Effectively, the multiply by the VLA size is part of the GEP.
// GEP indexes are signed, and scaling an index isn't permitted to
// signed-overflow, so we use the same semantics for our explicit
// multiply. We suppress this if overflow is not undefined behavior.
- if (getLangOpts().isSignedOverflowDefined()) {
- Idx = Builder.CreateMul(Idx, numElements);
- EltPtr = Builder.CreateGEP(Base.getPointer(), Idx, "arrayidx");
- } else {
- Idx = Builder.CreateNSWMul(Idx, numElements);
- EltPtr = Builder.CreateInBoundsGEP(Base.getPointer(), Idx, "arrayidx");
- }
- } else if (BaseTy->isConstantArrayType()) {
- llvm::Value *ArrayPtr = Base.getPointer();
- llvm::Value *Zero = llvm::ConstantInt::getNullValue(IntPtrTy);
- llvm::Value *Args[] = {Zero, Idx};
+ if (getLangOpts().isSignedOverflowDefined())
+ Idx = Builder.CreateMul(Idx, NumElements);
+ else
+ Idx = Builder.CreateNSWMul(Idx, NumElements);
+ EltPtr = emitArraySubscriptGEP(*this, Base, Idx, VLA->getElementType(),
+ !getLangOpts().isSignedOverflowDefined());
+ } else if (const Expr *Array = isSimpleArrayDecayOperand(E->getBase())) {
+ // If this is A[i] where A is an array, the frontend will have decayed the
+ // base to be a ArrayToPointerDecay implicit cast. While correct, it is
+ // inefficient at -O0 to emit a "gep A, 0, 0" when codegen'ing it, then a
+ // "gep x, i" here. Emit one "gep A, 0, i".
+ assert(Array->getType()->isArrayType() &&
+ "Array to pointer decay must have array source type!");
+ LValue ArrayLV;
+ // For simple multidimensional array indexing, set the 'accessed' flag for
+ // better bounds-checking of the base expression.
+ if (const auto *ASE = dyn_cast<ArraySubscriptExpr>(Array))
+ ArrayLV = EmitArraySubscriptExpr(ASE, /*Accessed*/ true);
+ else
+ ArrayLV = EmitLValue(Array);
- if (getLangOpts().isSignedOverflowDefined())
- EltPtr = Builder.CreateGEP(ArrayPtr, Args, "arrayidx");
- else
- EltPtr = Builder.CreateInBoundsGEP(ArrayPtr, Args, "arrayidx");
+ // Propagate the alignment from the array itself to the result.
+ EltPtr = emitArraySubscriptGEP(
+ *this, ArrayLV.getAddress(), {CGM.getSize(CharUnits::Zero()), Idx},
+ ResultExprTy, !getLangOpts().isSignedOverflowDefined());
+ AlignSource = ArrayLV.getAlignmentSource();
} else {
- // The base must be a pointer, which is not an aggregate. Emit it.
- if (getLangOpts().isSignedOverflowDefined())
- EltPtr = Builder.CreateGEP(Base.getPointer(), Idx, "arrayidx");
- else
- EltPtr = Builder.CreateInBoundsGEP(Base.getPointer(), Idx, "arrayidx");
+ Address Base = emitOMPArraySectionBase(*this, E->getBase(), AlignSource,
+ BaseTy, ResultExprTy, IsLowerBound);
+ EltPtr = emitArraySubscriptGEP(*this, Base, Idx, ResultExprTy,
+ !getLangOpts().isSignedOverflowDefined());
}
- CharUnits EltAlign =
- Base.getAlignment().alignmentOfArrayElement(
- getContext().getTypeSizeInChars(FixedSizeEltType));
-
- // Limit the alignment to that of the result type.
- LValue LV = MakeAddrLValue(Address(EltPtr, EltAlign), ResultExprTy,
- Base.getAlignmentSource());
-
- LV.getQuals().setAddressSpace(BaseTy.getAddressSpace());
-
- return LV;
+ return MakeAddrLValue(EltPtr, ResultExprTy, AlignSource);
}
LValue CodeGenFunction::