CGCUDANV.cpp revision a4ae2294b6ebfb2554aacb6a6a0682fb5ed1f276
1//===----- CGCUDANV.cpp - Interface to NVIDIA CUDA Runtime ----------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// This provides a class for CUDA code generation targeting the NVIDIA CUDA
11// runtime library.
12//
13//===----------------------------------------------------------------------===//
14
15#include "CGCUDARuntime.h"
16#include "CodeGenFunction.h"
17#include "CodeGenModule.h"
18#include "clang/AST/Decl.h"
19#include "llvm/BasicBlock.h"
20#include "llvm/Constants.h"
21#include "llvm/DerivedTypes.h"
22#include "llvm/Support/CallSite.h"
23
24#include <vector>
25
26using namespace clang;
27using namespace CodeGen;
28
29namespace {
30
31class CGNVCUDARuntime : public CGCUDARuntime {
32
33private:
34  llvm::Type *IntTy, *SizeTy;
35  llvm::PointerType *CharPtrTy, *VoidPtrTy;
36
37  llvm::Constant *getSetupArgumentFn() const;
38  llvm::Constant *getLaunchFn() const;
39
40public:
41  CGNVCUDARuntime(CodeGenModule &CGM);
42
43  void EmitDeviceStubBody(CodeGenFunction &CGF, FunctionArgList &Args);
44};
45
46}
47
48CGNVCUDARuntime::CGNVCUDARuntime(CodeGenModule &CGM) : CGCUDARuntime(CGM) {
49  CodeGen::CodeGenTypes &Types = CGM.getTypes();
50  ASTContext &Ctx = CGM.getContext();
51
52  IntTy = Types.ConvertType(Ctx.IntTy);
53  SizeTy = Types.ConvertType(Ctx.getSizeType());
54
55  CharPtrTy = llvm::PointerType::getUnqual(Types.ConvertType(Ctx.CharTy));
56  VoidPtrTy = cast<llvm::PointerType>(Types.ConvertType(Ctx.VoidPtrTy));
57}
58
59llvm::Constant *CGNVCUDARuntime::getSetupArgumentFn() const {
60  // cudaError_t cudaSetupArgument(void *, size_t, size_t)
61  std::vector<llvm::Type*> Params;
62  Params.push_back(VoidPtrTy);
63  Params.push_back(SizeTy);
64  Params.push_back(SizeTy);
65  return CGM.CreateRuntimeFunction(llvm::FunctionType::get(IntTy,
66                                                           Params, false),
67                                   "cudaSetupArgument");
68}
69
70llvm::Constant *CGNVCUDARuntime::getLaunchFn() const {
71  // cudaError_t cudaLaunch(char *)
72  std::vector<llvm::Type*> Params;
73  Params.push_back(CharPtrTy);
74  return CGM.CreateRuntimeFunction(llvm::FunctionType::get(IntTy,
75                                                           Params, false),
76                                   "cudaLaunch");
77}
78
79void CGNVCUDARuntime::EmitDeviceStubBody(CodeGenFunction &CGF,
80                                         FunctionArgList &Args) {
81  // Build the argument value list and the argument stack struct type.
82  llvm::SmallVector<llvm::Value *, 16> ArgValues;
83  std::vector<llvm::Type *> ArgTypes;
84  for (FunctionArgList::const_iterator I = Args.begin(), E = Args.end();
85       I != E; ++I) {
86    llvm::Value *V = CGF.GetAddrOfLocalVar(*I);
87    ArgValues.push_back(V);
88    assert(isa<llvm::PointerType>(V->getType()) && "Arg type not PointerType");
89    ArgTypes.push_back(cast<llvm::PointerType>(V->getType())->getElementType());
90  }
91  llvm::StructType *ArgStackTy = llvm::StructType::get(
92      CGF.getLLVMContext(), ArgTypes);
93
94  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("setup.end");
95
96  // Emit the calls to cudaSetupArgument
97  llvm::Constant *cudaSetupArgFn = getSetupArgumentFn();
98  for (unsigned I = 0, E = Args.size(); I != E; ++I) {
99    llvm::Value *Args[3];
100    llvm::BasicBlock *NextBlock = CGF.createBasicBlock("setup.next");
101    Args[0] = CGF.Builder.CreatePointerCast(ArgValues[I], VoidPtrTy);
102    Args[1] = CGF.Builder.CreateIntCast(
103        llvm::ConstantExpr::getSizeOf(ArgTypes[I]),
104        SizeTy, false);
105    Args[2] = CGF.Builder.CreateIntCast(
106        llvm::ConstantExpr::getOffsetOf(ArgStackTy, I),
107        SizeTy, false);
108    llvm::CallSite CS = CGF.EmitCallOrInvoke(cudaSetupArgFn, Args);
109    llvm::Constant *Zero = llvm::ConstantInt::get(IntTy, 0);
110    llvm::Value *CSZero = CGF.Builder.CreateICmpEQ(CS.getInstruction(), Zero);
111    CGF.Builder.CreateCondBr(CSZero, NextBlock, EndBlock);
112    CGF.EmitBlock(NextBlock);
113  }
114
115  // Emit the call to cudaLaunch
116  llvm::Constant *cudaLaunchFn = getLaunchFn();
117  llvm::Value *Arg = CGF.Builder.CreatePointerCast(CGF.CurFn, CharPtrTy);
118  CGF.EmitCallOrInvoke(cudaLaunchFn, Arg);
119  CGF.EmitBranch(EndBlock);
120
121  CGF.EmitBlock(EndBlock);
122}
123
124CGCUDARuntime *CodeGen::CreateNVCUDARuntime(CodeGenModule &CGM) {
125  return new CGNVCUDARuntime(CGM);
126}
127