1 //===- SPIR.cpp -----------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "ABIInfoImpl.h"
10 #include "TargetInfo.h"
11 
12 using namespace clang;
13 using namespace clang::CodeGen;
14 
15 //===----------------------------------------------------------------------===//
16 // Base ABI and target codegen info implementation common between SPIR and
17 // SPIR-V.
18 //===----------------------------------------------------------------------===//
19 
20 namespace {
21 class CommonSPIRABIInfo : public DefaultABIInfo {
22 public:
23   CommonSPIRABIInfo(CodeGenTypes &CGT) : DefaultABIInfo(CGT) { setCCs(); }
24 
25 private:
26   void setCCs();
27 };
28 
29 class SPIRVABIInfo : public CommonSPIRABIInfo {
30 public:
31   SPIRVABIInfo(CodeGenTypes &CGT) : CommonSPIRABIInfo(CGT) {}
32   void computeInfo(CGFunctionInfo &FI) const override;
33 
34 private:
35   ABIArgInfo classifyKernelArgumentType(QualType Ty) const;
36 };
37 } // end anonymous namespace
38 namespace {
39 class CommonSPIRTargetCodeGenInfo : public TargetCodeGenInfo {
40 public:
41   CommonSPIRTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
42       : TargetCodeGenInfo(std::make_unique<CommonSPIRABIInfo>(CGT)) {}
43   CommonSPIRTargetCodeGenInfo(std::unique_ptr<ABIInfo> ABIInfo)
44       : TargetCodeGenInfo(std::move(ABIInfo)) {}
45 
46   LangAS getASTAllocaAddressSpace() const override {
47     return getLangASFromTargetAS(
48         getABIInfo().getDataLayout().getAllocaAddrSpace());
49   }
50 
51   unsigned getOpenCLKernelCallingConv() const override;
52   llvm::Type *getOpenCLType(CodeGenModule &CGM, const Type *T) const override;
53 };
54 class SPIRVTargetCodeGenInfo : public CommonSPIRTargetCodeGenInfo {
55 public:
56   SPIRVTargetCodeGenInfo(CodeGen::CodeGenTypes &CGT)
57       : CommonSPIRTargetCodeGenInfo(std::make_unique<SPIRVABIInfo>(CGT)) {}
58   void setCUDAKernelCallingConvention(const FunctionType *&FT) const override;
59 };
60 } // End anonymous namespace.
61 
62 void CommonSPIRABIInfo::setCCs() {
63   assert(getRuntimeCC() == llvm::CallingConv::C);
64   RuntimeCC = llvm::CallingConv::SPIR_FUNC;
65 }
66 
67 ABIArgInfo SPIRVABIInfo::classifyKernelArgumentType(QualType Ty) const {
68   if (getContext().getLangOpts().CUDAIsDevice) {
69     // Coerce pointer arguments with default address space to CrossWorkGroup
70     // pointers for HIPSPV/CUDASPV. When the language mode is HIP/CUDA, the
71     // SPIRTargetInfo maps cuda_device to SPIR-V's CrossWorkGroup address space.
72     llvm::Type *LTy = CGT.ConvertType(Ty);
73     auto DefaultAS = getContext().getTargetAddressSpace(LangAS::Default);
74     auto GlobalAS = getContext().getTargetAddressSpace(LangAS::cuda_device);
75     auto *PtrTy = llvm::dyn_cast<llvm::PointerType>(LTy);
76     if (PtrTy && PtrTy->getAddressSpace() == DefaultAS) {
77       LTy = llvm::PointerType::get(PtrTy->getContext(), GlobalAS);
78       return ABIArgInfo::getDirect(LTy, 0, nullptr, false);
79     }
80 
81     // Force copying aggregate type in kernel arguments by value when
82     // compiling CUDA targeting SPIR-V. This is required for the object
83     // copied to be valid on the device.
84     // This behavior follows the CUDA spec
85     // https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#global-function-argument-processing,
86     // and matches the NVPTX implementation.
87     if (isAggregateTypeForABI(Ty))
88       return getNaturalAlignIndirect(Ty, /* byval */ true);
89   }
90   return classifyArgumentType(Ty);
91 }
92 
93 void SPIRVABIInfo::computeInfo(CGFunctionInfo &FI) const {
94   // The logic is same as in DefaultABIInfo with an exception on the kernel
95   // arguments handling.
96   llvm::CallingConv::ID CC = FI.getCallingConvention();
97 
98   if (!getCXXABI().classifyReturnType(FI))
99     FI.getReturnInfo() = classifyReturnType(FI.getReturnType());
100 
101   for (auto &I : FI.arguments()) {
102     if (CC == llvm::CallingConv::SPIR_KERNEL) {
103       I.info = classifyKernelArgumentType(I.type);
104     } else {
105       I.info = classifyArgumentType(I.type);
106     }
107   }
108 }
109 
110 namespace clang {
111 namespace CodeGen {
112 void computeSPIRKernelABIInfo(CodeGenModule &CGM, CGFunctionInfo &FI) {
113   if (CGM.getTarget().getTriple().isSPIRV())
114     SPIRVABIInfo(CGM.getTypes()).computeInfo(FI);
115   else
116     CommonSPIRABIInfo(CGM.getTypes()).computeInfo(FI);
117 }
118 }
119 }
120 
121 unsigned CommonSPIRTargetCodeGenInfo::getOpenCLKernelCallingConv() const {
122   return llvm::CallingConv::SPIR_KERNEL;
123 }
124 
125 void SPIRVTargetCodeGenInfo::setCUDAKernelCallingConvention(
126     const FunctionType *&FT) const {
127   // Convert HIP kernels to SPIR-V kernels.
128   if (getABIInfo().getContext().getLangOpts().HIP) {
129     FT = getABIInfo().getContext().adjustFunctionType(
130         FT, FT->getExtInfo().withCallingConv(CC_OpenCLKernel));
131     return;
132   }
133 }
134 
135 /// Construct a SPIR-V target extension type for the given OpenCL image type.
136 static llvm::Type *getSPIRVImageType(llvm::LLVMContext &Ctx, StringRef BaseType,
137                                      StringRef OpenCLName,
138                                      unsigned AccessQualifier) {
139   // These parameters compare to the operands of OpTypeImage (see
140   // https://registry.khronos.org/SPIR-V/specs/unified1/SPIRV.html#OpTypeImage
141   // for more details). The first 6 integer parameters all default to 0, and
142   // will be changed to 1 only for the image type(s) that set the parameter to
143   // one. The 7th integer parameter is the access qualifier, which is tacked on
144   // at the end.
145   SmallVector<unsigned, 7> IntParams = {0, 0, 0, 0, 0, 0};
146 
147   // Choose the dimension of the image--this corresponds to the Dim enum in
148   // SPIR-V (first integer parameter of OpTypeImage).
149   if (OpenCLName.startswith("image2d"))
150     IntParams[0] = 1; // 1D
151   else if (OpenCLName.startswith("image3d"))
152     IntParams[0] = 2; // 2D
153   else if (OpenCLName == "image1d_buffer")
154     IntParams[0] = 5; // Buffer
155   else
156     assert(OpenCLName.startswith("image1d") && "Unknown image type");
157 
158   // Set the other integer parameters of OpTypeImage if necessary. Note that the
159   // OpenCL image types don't provide any information for the Sampled or
160   // Image Format parameters.
161   if (OpenCLName.contains("_depth"))
162     IntParams[1] = 1;
163   if (OpenCLName.contains("_array"))
164     IntParams[2] = 1;
165   if (OpenCLName.contains("_msaa"))
166     IntParams[3] = 1;
167 
168   // Access qualifier
169   IntParams.push_back(AccessQualifier);
170 
171   return llvm::TargetExtType::get(Ctx, BaseType, {llvm::Type::getVoidTy(Ctx)},
172                                   IntParams);
173 }
174 
175 llvm::Type *CommonSPIRTargetCodeGenInfo::getOpenCLType(CodeGenModule &CGM,
176                                                        const Type *Ty) const {
177   llvm::LLVMContext &Ctx = CGM.getLLVMContext();
178   if (auto *PipeTy = dyn_cast<PipeType>(Ty))
179     return llvm::TargetExtType::get(Ctx, "spirv.Pipe", {},
180                                     {!PipeTy->isReadOnly()});
181   if (auto *BuiltinTy = dyn_cast<BuiltinType>(Ty)) {
182     enum AccessQualifier : unsigned { AQ_ro = 0, AQ_wo = 1, AQ_rw = 2 };
183     switch (BuiltinTy->getKind()) {
184 #define IMAGE_TYPE(ImgType, Id, SingletonId, Access, Suffix)                   \
185     case BuiltinType::Id:                                                      \
186       return getSPIRVImageType(Ctx, "spirv.Image", #ImgType, AQ_##Suffix);
187 #include "clang/Basic/OpenCLImageTypes.def"
188     case BuiltinType::OCLSampler:
189       return llvm::TargetExtType::get(Ctx, "spirv.Sampler");
190     case BuiltinType::OCLEvent:
191       return llvm::TargetExtType::get(Ctx, "spirv.Event");
192     case BuiltinType::OCLClkEvent:
193       return llvm::TargetExtType::get(Ctx, "spirv.DeviceEvent");
194     case BuiltinType::OCLQueue:
195       return llvm::TargetExtType::get(Ctx, "spirv.Queue");
196     case BuiltinType::OCLReserveID:
197       return llvm::TargetExtType::get(Ctx, "spirv.ReserveId");
198 #define INTEL_SUBGROUP_AVC_TYPE(Name, Id)                                      \
199     case BuiltinType::OCLIntelSubgroupAVC##Id:                                 \
200       return llvm::TargetExtType::get(Ctx, "spirv.Avc" #Id "INTEL");
201 #include "clang/Basic/OpenCLExtensionTypes.def"
202     default:
203       return nullptr;
204     }
205   }
206 
207   return nullptr;
208 }
209 
210 std::unique_ptr<TargetCodeGenInfo>
211 CodeGen::createCommonSPIRTargetCodeGenInfo(CodeGenModule &CGM) {
212   return std::make_unique<CommonSPIRTargetCodeGenInfo>(CGM.getTypes());
213 }
214 
215 std::unique_ptr<TargetCodeGenInfo>
216 CodeGen::createSPIRVTargetCodeGenInfo(CodeGenModule &CGM) {
217   return std::make_unique<SPIRVTargetCodeGenInfo>(CGM.getTypes());
218 }
219