From f666b7780d04186521adcaedb0e15dfa4d5e6933 Mon Sep 17 00:00:00 2001 From: Anders Carlsson Date: Sat, 20 Dec 2008 20:27:15 +0000 Subject: [PATCH] Split up emitting of VLA sizes and getting the size of a VLA. git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@61284 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/CodeGen/CGDecl.cpp | 2 +- lib/CodeGen/CodeGenFunction.cpp | 42 ++++++++++++++++++++------------- lib/CodeGen/CodeGenFunction.h | 6 ++++- 3 files changed, 31 insertions(+), 19 deletions(-) diff --git a/lib/CodeGen/CGDecl.cpp b/lib/CodeGen/CGDecl.cpp index 62684bae49..7f4e34d0f9 100644 --- a/lib/CodeGen/CGDecl.cpp +++ b/lib/CodeGen/CGDecl.cpp @@ -180,7 +180,7 @@ void CodeGenFunction::EmitLocalBlockVarDecl(const VarDecl &D) { const llvm::Type *LElemPtrTy = llvm::PointerType::get(LElemTy, D.getType().getAddressSpace()); - llvm::Value *VLASize = GetVLASize(VAT); + llvm::Value *VLASize = EmitVLASize(VAT); // Allocate memory for the array. llvm::Value *VLA = Builder.CreateAlloca(llvm::Type::Int8Ty, VLASize, "vla"); diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp index bcb51a3efc..4a3bb3f6ca 100644 --- a/lib/CodeGen/CodeGenFunction.cpp +++ b/lib/CodeGen/CodeGenFunction.cpp @@ -401,30 +401,38 @@ llvm::Value *CodeGenFunction::EmitVAArg(llvm::Value *VAListAddr, QualType Ty) return AddrTyped; } + llvm::Value *CodeGenFunction::GetVLASize(const VariableArrayType *VAT) { llvm::Value *&SizeEntry = VLASizeMap[VAT]; - - if (!SizeEntry) { - // Get the element size; - llvm::Value *ElemSize; - QualType ElemTy = VAT->getElementType(); - - if (const VariableArrayType *ElemVAT = - getContext().getAsVariableArrayType(ElemTy)) - ElemSize = GetVLASize(ElemVAT); - else { - // FIXME: We use Int32Ty here because the alloca instruction takes a - // 32-bit integer. What should we do about overflow? - ElemSize = llvm::ConstantInt::get(llvm::Type::Int32Ty, - getContext().getTypeSize(ElemTy) / 8); - } + assert(SizeEntry && "Did not emit size for type"); + return SizeEntry; +} - llvm::Value *NumElements = EmitScalarExpr(VAT->getSizeExpr()); +llvm::Value *CodeGenFunction::EmitVLASize(const VariableArrayType *VAT) +{ + llvm::Value *&SizeEntry = VLASizeMap[VAT]; - SizeEntry = Builder.CreateMul(ElemSize, NumElements); + assert(!SizeEntry && "Must not emit the same VLA size more than once!"); + // Get the element size; + llvm::Value *ElemSize; + + QualType ElemTy = VAT->getElementType(); + + if (const VariableArrayType *ElemVAT = + getContext().getAsVariableArrayType(ElemTy)) + ElemSize = EmitVLASize(ElemVAT); + else { + // FIXME: We use Int32Ty here because the alloca instruction takes a + // 32-bit integer. What should we do about overflow? + ElemSize = llvm::ConstantInt::get(llvm::Type::Int32Ty, + getContext().getTypeSize(ElemTy) / 8); } + llvm::Value *NumElements = EmitScalarExpr(VAT->getSizeExpr()); + + SizeEntry = Builder.CreateMul(ElemSize, NumElements); + return SizeEntry; } diff --git a/lib/CodeGen/CodeGenFunction.h b/lib/CodeGen/CodeGenFunction.h index a92bac7f1e..9500068814 100644 --- a/lib/CodeGen/CodeGenFunction.h +++ b/lib/CodeGen/CodeGenFunction.h @@ -349,7 +349,11 @@ public: // FIXME: We should be able to get rid of this method and use the va_arg // instruction in LLVM instead once it works well enough. llvm::Value *EmitVAArg(llvm::Value *VAListAddr, QualType Ty); - + + // EmitVLASize - Generate code for the VLA type. Returns an + // lLVM value that corresponds to the size in bytes of the + llvm::Value *EmitVLASize(const VariableArrayType *); + // GetVLASize - Returns an LLVM value that corresponds to the size in bytes // of a variable length array type. llvm::Value *GetVLASize(const VariableArrayType *); -- 2.40.0