diff options
| -rw-r--r-- | lib/CodeGen/CGExprScalar.cpp | 33 | ||||
| -rw-r--r-- | test/CodeGen/pointer-arithmetic.c | 21 |
2 files changed, 46 insertions, 8 deletions
diff --git a/lib/CodeGen/CGExprScalar.cpp b/lib/CodeGen/CGExprScalar.cpp index f21373a538..fc87726a21 100644 --- a/lib/CodeGen/CGExprScalar.cpp +++ b/lib/CodeGen/CGExprScalar.cpp @@ -872,11 +872,14 @@ Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { // FIXME: What about a pointer to a VLA? Value *Ptr, *Idx; Expr *IdxExp; - if (isa<llvm::PointerType>(Ops.LHS->getType())) { // pointer + int + const PointerType *PT; + if ((PT = Ops.E->getLHS()->getType()->getAsPointerType())) { Ptr = Ops.LHS; Idx = Ops.RHS; IdxExp = Ops.E->getRHS(); } else { // int + pointer + PT = Ops.E->getRHS()->getType()->getAsPointerType(); + assert(PT && "Invalid add expr"); Ptr = Ops.RHS; Idx = Ops.LHS; IdxExp = Ops.E->getLHS(); @@ -892,6 +895,17 @@ Value *ScalarExprEmitter::EmitAdd(const BinOpInfo &Ops) { else Idx = Builder.CreateZExt(Idx, IdxType, "idx.ext"); } + + // Explicitly handle GNU void* and function pointer arithmetic + // extensions. The GNU void* casts amount to no-ops since our void* + // type is i8*, but this is future proof. + const QualType ElementType = PT->getPointeeType(); + if (ElementType->isVoidType() || ElementType->isFunctionType()) { + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + Value *Casted = Builder.CreateBitCast(Ptr, i8Ty); + Value *Res = Builder.CreateGEP(Casted, Idx, "sub.ptr"); + return Builder.CreateBitCast(Res, Ptr->getType()); + } return Builder.CreateGEP(Ptr, Idx, "add.ptr"); } @@ -900,6 +914,8 @@ Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { if (!isa<llvm::PointerType>(Ops.LHS->getType())) return Builder.CreateSub(Ops.LHS, Ops.RHS, "sub"); + const QualType LHSType = Ops.E->getLHS()->getType(); + const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); if (!isa<llvm::PointerType>(Ops.RHS->getType())) { // pointer - int Value *Idx = Ops.RHS; @@ -916,16 +932,23 @@ Value *ScalarExprEmitter::EmitSub(const BinOpInfo &Ops) { Idx = Builder.CreateNeg(Idx, "sub.ptr.neg"); // FIXME: The pointer could point to a VLA. - // The GNU void* - int case is automatically handled here because - // our LLVM type for void* is i8*. + + // Explicitly handle GNU void* and function pointer arithmetic + // extensions. The GNU void* casts amount to no-ops since our + // void* type is i8*, but this is future proof. + if (LHSElementType->isVoidType() || LHSElementType->isFunctionType()) { + const llvm::Type *i8Ty = llvm::PointerType::getUnqual(llvm::Type::Int8Ty); + Value *LHSCasted = Builder.CreateBitCast(Ops.LHS, i8Ty); + Value *Res = Builder.CreateGEP(LHSCasted, Idx, "sub.ptr"); + return Builder.CreateBitCast(Res, Ops.LHS->getType()); + } + return Builder.CreateGEP(Ops.LHS, Idx, "sub.ptr"); } else { // pointer - pointer Value *LHS = Ops.LHS; Value *RHS = Ops.RHS; - const QualType LHSType = Ops.E->getLHS()->getType(); - const QualType LHSElementType = LHSType->getAsPointerType()->getPointeeType(); uint64_t ElementSize; // Handle GCC extension for pointer arithmetic on void* types. diff --git a/test/CodeGen/pointer-arithmetic.c b/test/CodeGen/pointer-arithmetic.c index 3133c9effe..23a6ab41a1 100644 --- a/test/CodeGen/pointer-arithmetic.c +++ b/test/CodeGen/pointer-arithmetic.c @@ -1,7 +1,22 @@ -// RUN: clang -emit-llvm %s -o %t +// RUN: clang -S %s -o %t typedef int Int; -int test1(int *a, Int *b) { return a - b; } +int f0(int *a, Int *b) { return a - b; } -int test2(const char *a, char *b) { return b - a; } +int f1(const char *a, char *b) { return b - a; } + +// GNU extensions +typedef void (*FP)(void); +void *f2(void *a, int b) { return a + b; } +void *f2_1(void *a, int b) { return (a += b); } +void *f3(int a, void *b) { return a + b; } +void *f3_1(int a, void *b) { return (a += b); } +void *f4(void *a, int b) { return a - b; } +void *f4_1(void *a, int b) { return (a -= b); } +FP f5(FP a, int b) { return a + b; } +FP f5_1(FP a, int b) { return (a += b); } +FP f6(int a, FP b) { return a + b; } +FP f6_1(int a, FP b) { return (a += b); } +FP f7(FP a, int b) { return a - b; } +FP f7_1(FP a, int b) { return (a -= b); } |