clang  9.0.0svn
CGCUDANV.cpp
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1 //===----- CGCUDANV.cpp - Interface to NVIDIA CUDA Runtime ----------------===//
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 // This provides a class for CUDA code generation targeting the NVIDIA CUDA
10 // runtime library.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "CGCUDARuntime.h"
15 #include "CodeGenFunction.h"
16 #include "CodeGenModule.h"
17 #include "clang/AST/Decl.h"
18 #include "clang/Basic/Cuda.h"
21 #include "llvm/IR/BasicBlock.h"
22 #include "llvm/IR/Constants.h"
23 #include "llvm/IR/DerivedTypes.h"
24 #include "llvm/Support/Format.h"
25 
26 using namespace clang;
27 using namespace CodeGen;
28 
29 namespace {
30 constexpr unsigned CudaFatMagic = 0x466243b1;
31 constexpr unsigned HIPFatMagic = 0x48495046; // "HIPF"
32 
33 class CGNVCUDARuntime : public CGCUDARuntime {
34 
35 private:
36  llvm::IntegerType *IntTy, *SizeTy;
37  llvm::Type *VoidTy;
38  llvm::PointerType *CharPtrTy, *VoidPtrTy, *VoidPtrPtrTy;
39 
40  /// Convenience reference to LLVM Context
41  llvm::LLVMContext &Context;
42  /// Convenience reference to the current module
43  llvm::Module &TheModule;
44  /// Keeps track of kernel launch stubs emitted in this module
45  struct KernelInfo {
46  llvm::Function *Kernel;
47  const Decl *D;
48  };
49  llvm::SmallVector<KernelInfo, 16> EmittedKernels;
50  struct VarInfo {
51  llvm::GlobalVariable *Var;
52  const VarDecl *D;
53  unsigned Flag;
54  };
56  /// Keeps track of variable containing handle of GPU binary. Populated by
57  /// ModuleCtorFunction() and used to create corresponding cleanup calls in
58  /// ModuleDtorFunction()
59  llvm::GlobalVariable *GpuBinaryHandle = nullptr;
60  /// Whether we generate relocatable device code.
61  bool RelocatableDeviceCode;
62  /// Mangle context for device.
63  std::unique_ptr<MangleContext> DeviceMC;
64 
65  llvm::FunctionCallee getSetupArgumentFn() const;
66  llvm::FunctionCallee getLaunchFn() const;
67 
68  llvm::FunctionType *getRegisterGlobalsFnTy() const;
69  llvm::FunctionType *getCallbackFnTy() const;
70  llvm::FunctionType *getRegisterLinkedBinaryFnTy() const;
71  std::string addPrefixToName(StringRef FuncName) const;
72  std::string addUnderscoredPrefixToName(StringRef FuncName) const;
73 
74  /// Creates a function to register all kernel stubs generated in this module.
75  llvm::Function *makeRegisterGlobalsFn();
76 
77  /// Helper function that generates a constant string and returns a pointer to
78  /// the start of the string. The result of this function can be used anywhere
79  /// where the C code specifies const char*.
80  llvm::Constant *makeConstantString(const std::string &Str,
81  const std::string &Name = "",
82  const std::string &SectionName = "",
83  unsigned Alignment = 0) {
84  llvm::Constant *Zeros[] = {llvm::ConstantInt::get(SizeTy, 0),
85  llvm::ConstantInt::get(SizeTy, 0)};
86  auto ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str());
87  llvm::GlobalVariable *GV =
88  cast<llvm::GlobalVariable>(ConstStr.getPointer());
89  if (!SectionName.empty()) {
90  GV->setSection(SectionName);
91  // Mark the address as used which make sure that this section isn't
92  // merged and we will really have it in the object file.
93  GV->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::None);
94  }
95  if (Alignment)
96  GV->setAlignment(Alignment);
97 
98  return llvm::ConstantExpr::getGetElementPtr(ConstStr.getElementType(),
99  ConstStr.getPointer(), Zeros);
100  }
101 
102  /// Helper function that generates an empty dummy function returning void.
103  llvm::Function *makeDummyFunction(llvm::FunctionType *FnTy) {
104  assert(FnTy->getReturnType()->isVoidTy() &&
105  "Can only generate dummy functions returning void!");
106  llvm::Function *DummyFunc = llvm::Function::Create(
107  FnTy, llvm::GlobalValue::InternalLinkage, "dummy", &TheModule);
108 
109  llvm::BasicBlock *DummyBlock =
110  llvm::BasicBlock::Create(Context, "", DummyFunc);
111  CGBuilderTy FuncBuilder(CGM, Context);
112  FuncBuilder.SetInsertPoint(DummyBlock);
113  FuncBuilder.CreateRetVoid();
114 
115  return DummyFunc;
116  }
117 
118  void emitDeviceStubBodyLegacy(CodeGenFunction &CGF, FunctionArgList &Args);
119  void emitDeviceStubBodyNew(CodeGenFunction &CGF, FunctionArgList &Args);
120  std::string getDeviceSideName(const Decl *ND);
121 
122 public:
123  CGNVCUDARuntime(CodeGenModule &CGM);
124 
125  void emitDeviceStub(CodeGenFunction &CGF, FunctionArgList &Args) override;
126  void registerDeviceVar(const VarDecl *VD, llvm::GlobalVariable &Var,
127  unsigned Flags) override {
128  DeviceVars.push_back({&Var, VD, Flags});
129  }
130 
131  /// Creates module constructor function
132  llvm::Function *makeModuleCtorFunction() override;
133  /// Creates module destructor function
134  llvm::Function *makeModuleDtorFunction() override;
135 };
136 
137 }
138 
139 std::string CGNVCUDARuntime::addPrefixToName(StringRef FuncName) const {
140  if (CGM.getLangOpts().HIP)
141  return ((Twine("hip") + Twine(FuncName)).str());
142  return ((Twine("cuda") + Twine(FuncName)).str());
143 }
144 std::string
145 CGNVCUDARuntime::addUnderscoredPrefixToName(StringRef FuncName) const {
146  if (CGM.getLangOpts().HIP)
147  return ((Twine("__hip") + Twine(FuncName)).str());
148  return ((Twine("__cuda") + Twine(FuncName)).str());
149 }
150 
151 CGNVCUDARuntime::CGNVCUDARuntime(CodeGenModule &CGM)
152  : CGCUDARuntime(CGM), Context(CGM.getLLVMContext()),
153  TheModule(CGM.getModule()),
154  RelocatableDeviceCode(CGM.getLangOpts().GPURelocatableDeviceCode),
155  DeviceMC(CGM.getContext().createMangleContext(
156  CGM.getContext().getAuxTargetInfo())) {
157  CodeGen::CodeGenTypes &Types = CGM.getTypes();
158  ASTContext &Ctx = CGM.getContext();
159 
160  IntTy = CGM.IntTy;
161  SizeTy = CGM.SizeTy;
162  VoidTy = CGM.VoidTy;
163 
164  CharPtrTy = llvm::PointerType::getUnqual(Types.ConvertType(Ctx.CharTy));
165  VoidPtrTy = cast<llvm::PointerType>(Types.ConvertType(Ctx.VoidPtrTy));
166  VoidPtrPtrTy = VoidPtrTy->getPointerTo();
167 }
168 
169 llvm::FunctionCallee CGNVCUDARuntime::getSetupArgumentFn() const {
170  // cudaError_t cudaSetupArgument(void *, size_t, size_t)
171  llvm::Type *Params[] = {VoidPtrTy, SizeTy, SizeTy};
172  return CGM.CreateRuntimeFunction(
173  llvm::FunctionType::get(IntTy, Params, false),
174  addPrefixToName("SetupArgument"));
175 }
176 
177 llvm::FunctionCallee CGNVCUDARuntime::getLaunchFn() const {
178  if (CGM.getLangOpts().HIP) {
179  // hipError_t hipLaunchByPtr(char *);
180  return CGM.CreateRuntimeFunction(
181  llvm::FunctionType::get(IntTy, CharPtrTy, false), "hipLaunchByPtr");
182  } else {
183  // cudaError_t cudaLaunch(char *);
184  return CGM.CreateRuntimeFunction(
185  llvm::FunctionType::get(IntTy, CharPtrTy, false), "cudaLaunch");
186  }
187 }
188 
189 llvm::FunctionType *CGNVCUDARuntime::getRegisterGlobalsFnTy() const {
190  return llvm::FunctionType::get(VoidTy, VoidPtrPtrTy, false);
191 }
192 
193 llvm::FunctionType *CGNVCUDARuntime::getCallbackFnTy() const {
194  return llvm::FunctionType::get(VoidTy, VoidPtrTy, false);
195 }
196 
197 llvm::FunctionType *CGNVCUDARuntime::getRegisterLinkedBinaryFnTy() const {
198  auto CallbackFnTy = getCallbackFnTy();
199  auto RegisterGlobalsFnTy = getRegisterGlobalsFnTy();
200  llvm::Type *Params[] = {RegisterGlobalsFnTy->getPointerTo(), VoidPtrTy,
201  VoidPtrTy, CallbackFnTy->getPointerTo()};
202  return llvm::FunctionType::get(VoidTy, Params, false);
203 }
204 
205 std::string CGNVCUDARuntime::getDeviceSideName(const Decl *D) {
206  auto *ND = cast<const NamedDecl>(D);
207  std::string DeviceSideName;
208  if (DeviceMC->shouldMangleDeclName(ND)) {
209  SmallString<256> Buffer;
210  llvm::raw_svector_ostream Out(Buffer);
211  DeviceMC->mangleName(ND, Out);
212  DeviceSideName = Out.str();
213  } else
214  DeviceSideName = ND->getIdentifier()->getName();
215  return DeviceSideName;
216 }
217 
218 void CGNVCUDARuntime::emitDeviceStub(CodeGenFunction &CGF,
219  FunctionArgList &Args) {
220  assert(getDeviceSideName(CGF.CurFuncDecl) == CGF.CurFn->getName() ||
221  getDeviceSideName(CGF.CurFuncDecl) + ".stub" == CGF.CurFn->getName() ||
224 
225  EmittedKernels.push_back({CGF.CurFn, CGF.CurFuncDecl});
228  emitDeviceStubBodyNew(CGF, Args);
229  else
230  emitDeviceStubBodyLegacy(CGF, Args);
231 }
232 
233 // CUDA 9.0+ uses new way to launch kernels. Parameters are packed in a local
234 // array and kernels are launched using cudaLaunchKernel().
235 void CGNVCUDARuntime::emitDeviceStubBodyNew(CodeGenFunction &CGF,
236  FunctionArgList &Args) {
237  // Build the shadow stack entry at the very start of the function.
238 
239  // Calculate amount of space we will need for all arguments. If we have no
240  // args, allocate a single pointer so we still have a valid pointer to the
241  // argument array that we can pass to runtime, even if it will be unused.
242  Address KernelArgs = CGF.CreateTempAlloca(
243  VoidPtrTy, CharUnits::fromQuantity(16), "kernel_args",
244  llvm::ConstantInt::get(SizeTy, std::max<size_t>(1, Args.size())));
245  // Store pointers to the arguments in a locally allocated launch_args.
246  for (unsigned i = 0; i < Args.size(); ++i) {
247  llvm::Value* VarPtr = CGF.GetAddrOfLocalVar(Args[i]).getPointer();
248  llvm::Value *VoidVarPtr = CGF.Builder.CreatePointerCast(VarPtr, VoidPtrTy);
250  VoidVarPtr, CGF.Builder.CreateConstGEP1_32(KernelArgs.getPointer(), i));
251  }
252 
253  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("setup.end");
254 
255  // Lookup cudaLaunchKernel function.
256  // cudaError_t cudaLaunchKernel(const void *func, dim3 gridDim, dim3 blockDim,
257  // void **args, size_t sharedMem,
258  // cudaStream_t stream);
261  IdentifierInfo &cudaLaunchKernelII =
262  CGM.getContext().Idents.get("cudaLaunchKernel");
263  FunctionDecl *cudaLaunchKernelFD = nullptr;
264  for (const auto &Result : DC->lookup(&cudaLaunchKernelII)) {
265  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Result))
266  cudaLaunchKernelFD = FD;
267  }
268 
269  if (cudaLaunchKernelFD == nullptr) {
270  CGM.Error(CGF.CurFuncDecl->getLocation(),
271  "Can't find declaration for cudaLaunchKernel()");
272  return;
273  }
274  // Create temporary dim3 grid_dim, block_dim.
275  ParmVarDecl *GridDimParam = cudaLaunchKernelFD->getParamDecl(1);
276  QualType Dim3Ty = GridDimParam->getType();
277  Address GridDim =
278  CGF.CreateMemTemp(Dim3Ty, CharUnits::fromQuantity(8), "grid_dim");
279  Address BlockDim =
280  CGF.CreateMemTemp(Dim3Ty, CharUnits::fromQuantity(8), "block_dim");
281  Address ShmemSize =
282  CGF.CreateTempAlloca(SizeTy, CGM.getSizeAlign(), "shmem_size");
283  Address Stream =
284  CGF.CreateTempAlloca(VoidPtrTy, CGM.getPointerAlign(), "stream");
285  llvm::FunctionCallee cudaPopConfigFn = CGM.CreateRuntimeFunction(
286  llvm::FunctionType::get(IntTy,
287  {/*gridDim=*/GridDim.getType(),
288  /*blockDim=*/BlockDim.getType(),
289  /*ShmemSize=*/ShmemSize.getType(),
290  /*Stream=*/Stream.getType()},
291  /*isVarArg=*/false),
292  "__cudaPopCallConfiguration");
293 
294  CGF.EmitRuntimeCallOrInvoke(cudaPopConfigFn,
295  {GridDim.getPointer(), BlockDim.getPointer(),
296  ShmemSize.getPointer(), Stream.getPointer()});
297 
298  // Emit the call to cudaLaunch
299  llvm::Value *Kernel = CGF.Builder.CreatePointerCast(CGF.CurFn, VoidPtrTy);
300  CallArgList LaunchKernelArgs;
301  LaunchKernelArgs.add(RValue::get(Kernel),
302  cudaLaunchKernelFD->getParamDecl(0)->getType());
303  LaunchKernelArgs.add(RValue::getAggregate(GridDim), Dim3Ty);
304  LaunchKernelArgs.add(RValue::getAggregate(BlockDim), Dim3Ty);
305  LaunchKernelArgs.add(RValue::get(KernelArgs.getPointer()),
306  cudaLaunchKernelFD->getParamDecl(3)->getType());
307  LaunchKernelArgs.add(RValue::get(CGF.Builder.CreateLoad(ShmemSize)),
308  cudaLaunchKernelFD->getParamDecl(4)->getType());
309  LaunchKernelArgs.add(RValue::get(CGF.Builder.CreateLoad(Stream)),
310  cudaLaunchKernelFD->getParamDecl(5)->getType());
311 
312  QualType QT = cudaLaunchKernelFD->getType();
313  QualType CQT = QT.getCanonicalType();
314  llvm::Type *Ty = CGM.getTypes().ConvertType(CQT);
315  llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(Ty);
316 
317  const CGFunctionInfo &FI =
318  CGM.getTypes().arrangeFunctionDeclaration(cudaLaunchKernelFD);
319  llvm::FunctionCallee cudaLaunchKernelFn =
320  CGM.CreateRuntimeFunction(FTy, "cudaLaunchKernel");
321  CGF.EmitCall(FI, CGCallee::forDirect(cudaLaunchKernelFn), ReturnValueSlot(),
322  LaunchKernelArgs);
323  CGF.EmitBranch(EndBlock);
324 
325  CGF.EmitBlock(EndBlock);
326 }
327 
328 void CGNVCUDARuntime::emitDeviceStubBodyLegacy(CodeGenFunction &CGF,
329  FunctionArgList &Args) {
330  // Emit a call to cudaSetupArgument for each arg in Args.
331  llvm::FunctionCallee cudaSetupArgFn = getSetupArgumentFn();
332  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("setup.end");
334  for (const VarDecl *A : Args) {
335  CharUnits TyWidth, TyAlign;
336  std::tie(TyWidth, TyAlign) =
337  CGM.getContext().getTypeInfoInChars(A->getType());
338  Offset = Offset.alignTo(TyAlign);
339  llvm::Value *Args[] = {
340  CGF.Builder.CreatePointerCast(CGF.GetAddrOfLocalVar(A).getPointer(),
341  VoidPtrTy),
342  llvm::ConstantInt::get(SizeTy, TyWidth.getQuantity()),
343  llvm::ConstantInt::get(SizeTy, Offset.getQuantity()),
344  };
345  llvm::CallBase *CB = CGF.EmitRuntimeCallOrInvoke(cudaSetupArgFn, Args);
346  llvm::Constant *Zero = llvm::ConstantInt::get(IntTy, 0);
347  llvm::Value *CBZero = CGF.Builder.CreateICmpEQ(CB, Zero);
348  llvm::BasicBlock *NextBlock = CGF.createBasicBlock("setup.next");
349  CGF.Builder.CreateCondBr(CBZero, NextBlock, EndBlock);
350  CGF.EmitBlock(NextBlock);
351  Offset += TyWidth;
352  }
353 
354  // Emit the call to cudaLaunch
355  llvm::FunctionCallee cudaLaunchFn = getLaunchFn();
356  llvm::Value *Arg = CGF.Builder.CreatePointerCast(CGF.CurFn, CharPtrTy);
357  CGF.EmitRuntimeCallOrInvoke(cudaLaunchFn, Arg);
358  CGF.EmitBranch(EndBlock);
359 
360  CGF.EmitBlock(EndBlock);
361 }
362 
363 /// Creates a function that sets up state on the host side for CUDA objects that
364 /// have a presence on both the host and device sides. Specifically, registers
365 /// the host side of kernel functions and device global variables with the CUDA
366 /// runtime.
367 /// \code
368 /// void __cuda_register_globals(void** GpuBinaryHandle) {
369 /// __cudaRegisterFunction(GpuBinaryHandle,Kernel0,...);
370 /// ...
371 /// __cudaRegisterFunction(GpuBinaryHandle,KernelM,...);
372 /// __cudaRegisterVar(GpuBinaryHandle, GlobalVar0, ...);
373 /// ...
374 /// __cudaRegisterVar(GpuBinaryHandle, GlobalVarN, ...);
375 /// }
376 /// \endcode
377 llvm::Function *CGNVCUDARuntime::makeRegisterGlobalsFn() {
378  // No need to register anything
379  if (EmittedKernels.empty() && DeviceVars.empty())
380  return nullptr;
381 
382  llvm::Function *RegisterKernelsFunc = llvm::Function::Create(
383  getRegisterGlobalsFnTy(), llvm::GlobalValue::InternalLinkage,
384  addUnderscoredPrefixToName("_register_globals"), &TheModule);
385  llvm::BasicBlock *EntryBB =
386  llvm::BasicBlock::Create(Context, "entry", RegisterKernelsFunc);
387  CGBuilderTy Builder(CGM, Context);
388  Builder.SetInsertPoint(EntryBB);
389 
390  // void __cudaRegisterFunction(void **, const char *, char *, const char *,
391  // int, uint3*, uint3*, dim3*, dim3*, int*)
392  llvm::Type *RegisterFuncParams[] = {
393  VoidPtrPtrTy, CharPtrTy, CharPtrTy, CharPtrTy, IntTy,
394  VoidPtrTy, VoidPtrTy, VoidPtrTy, VoidPtrTy, IntTy->getPointerTo()};
395  llvm::FunctionCallee RegisterFunc = CGM.CreateRuntimeFunction(
396  llvm::FunctionType::get(IntTy, RegisterFuncParams, false),
397  addUnderscoredPrefixToName("RegisterFunction"));
398 
399  // Extract GpuBinaryHandle passed as the first argument passed to
400  // __cuda_register_globals() and generate __cudaRegisterFunction() call for
401  // each emitted kernel.
402  llvm::Argument &GpuBinaryHandlePtr = *RegisterKernelsFunc->arg_begin();
403  for (auto &&I : EmittedKernels) {
404  llvm::Constant *KernelName = makeConstantString(getDeviceSideName(I.D));
405  llvm::Constant *NullPtr = llvm::ConstantPointerNull::get(VoidPtrTy);
406  llvm::Value *Args[] = {
407  &GpuBinaryHandlePtr,
408  Builder.CreateBitCast(I.Kernel, VoidPtrTy),
409  KernelName,
410  KernelName,
411  llvm::ConstantInt::get(IntTy, -1),
412  NullPtr,
413  NullPtr,
414  NullPtr,
415  NullPtr,
416  llvm::ConstantPointerNull::get(IntTy->getPointerTo())};
417  Builder.CreateCall(RegisterFunc, Args);
418  }
419 
420  // void __cudaRegisterVar(void **, char *, char *, const char *,
421  // int, int, int, int)
422  llvm::Type *RegisterVarParams[] = {VoidPtrPtrTy, CharPtrTy, CharPtrTy,
423  CharPtrTy, IntTy, IntTy,
424  IntTy, IntTy};
425  llvm::FunctionCallee RegisterVar = CGM.CreateRuntimeFunction(
426  llvm::FunctionType::get(IntTy, RegisterVarParams, false),
427  addUnderscoredPrefixToName("RegisterVar"));
428  for (auto &&Info : DeviceVars) {
429  llvm::GlobalVariable *Var = Info.Var;
430  unsigned Flags = Info.Flag;
431  llvm::Constant *VarName = makeConstantString(getDeviceSideName(Info.D));
432  uint64_t VarSize =
433  CGM.getDataLayout().getTypeAllocSize(Var->getValueType());
434  llvm::Value *Args[] = {
435  &GpuBinaryHandlePtr,
436  Builder.CreateBitCast(Var, VoidPtrTy),
437  VarName,
438  VarName,
439  llvm::ConstantInt::get(IntTy, (Flags & ExternDeviceVar) ? 1 : 0),
440  llvm::ConstantInt::get(IntTy, VarSize),
441  llvm::ConstantInt::get(IntTy, (Flags & ConstantDeviceVar) ? 1 : 0),
442  llvm::ConstantInt::get(IntTy, 0)};
443  Builder.CreateCall(RegisterVar, Args);
444  }
445 
446  Builder.CreateRetVoid();
447  return RegisterKernelsFunc;
448 }
449 
450 /// Creates a global constructor function for the module:
451 ///
452 /// For CUDA:
453 /// \code
454 /// void __cuda_module_ctor(void*) {
455 /// Handle = __cudaRegisterFatBinary(GpuBinaryBlob);
456 /// __cuda_register_globals(Handle);
457 /// }
458 /// \endcode
459 ///
460 /// For HIP:
461 /// \code
462 /// void __hip_module_ctor(void*) {
463 /// if (__hip_gpubin_handle == 0) {
464 /// __hip_gpubin_handle = __hipRegisterFatBinary(GpuBinaryBlob);
465 /// __hip_register_globals(__hip_gpubin_handle);
466 /// }
467 /// }
468 /// \endcode
469 llvm::Function *CGNVCUDARuntime::makeModuleCtorFunction() {
470  bool IsHIP = CGM.getLangOpts().HIP;
471  // No need to generate ctors/dtors if there is no GPU binary.
472  StringRef CudaGpuBinaryFileName = CGM.getCodeGenOpts().CudaGpuBinaryFileName;
473  if (CudaGpuBinaryFileName.empty() && !IsHIP)
474  return nullptr;
475 
476  // void __{cuda|hip}_register_globals(void* handle);
477  llvm::Function *RegisterGlobalsFunc = makeRegisterGlobalsFn();
478  // We always need a function to pass in as callback. Create a dummy
479  // implementation if we don't need to register anything.
480  if (RelocatableDeviceCode && !RegisterGlobalsFunc)
481  RegisterGlobalsFunc = makeDummyFunction(getRegisterGlobalsFnTy());
482 
483  // void ** __{cuda|hip}RegisterFatBinary(void *);
484  llvm::FunctionCallee RegisterFatbinFunc = CGM.CreateRuntimeFunction(
485  llvm::FunctionType::get(VoidPtrPtrTy, VoidPtrTy, false),
486  addUnderscoredPrefixToName("RegisterFatBinary"));
487  // struct { int magic, int version, void * gpu_binary, void * dont_care };
488  llvm::StructType *FatbinWrapperTy =
489  llvm::StructType::get(IntTy, IntTy, VoidPtrTy, VoidPtrTy);
490 
491  // Register GPU binary with the CUDA runtime, store returned handle in a
492  // global variable and save a reference in GpuBinaryHandle to be cleaned up
493  // in destructor on exit. Then associate all known kernels with the GPU binary
494  // handle so CUDA runtime can figure out what to call on the GPU side.
495  std::unique_ptr<llvm::MemoryBuffer> CudaGpuBinary = nullptr;
496  if (!CudaGpuBinaryFileName.empty()) {
497  llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> CudaGpuBinaryOrErr =
498  llvm::MemoryBuffer::getFileOrSTDIN(CudaGpuBinaryFileName);
499  if (std::error_code EC = CudaGpuBinaryOrErr.getError()) {
500  CGM.getDiags().Report(diag::err_cannot_open_file)
501  << CudaGpuBinaryFileName << EC.message();
502  return nullptr;
503  }
504  CudaGpuBinary = std::move(CudaGpuBinaryOrErr.get());
505  }
506 
507  llvm::Function *ModuleCtorFunc = llvm::Function::Create(
508  llvm::FunctionType::get(VoidTy, VoidPtrTy, false),
510  addUnderscoredPrefixToName("_module_ctor"), &TheModule);
511  llvm::BasicBlock *CtorEntryBB =
512  llvm::BasicBlock::Create(Context, "entry", ModuleCtorFunc);
513  CGBuilderTy CtorBuilder(CGM, Context);
514 
515  CtorBuilder.SetInsertPoint(CtorEntryBB);
516 
517  const char *FatbinConstantName;
518  const char *FatbinSectionName;
519  const char *ModuleIDSectionName;
520  StringRef ModuleIDPrefix;
521  llvm::Constant *FatBinStr;
522  unsigned FatMagic;
523  if (IsHIP) {
524  FatbinConstantName = ".hip_fatbin";
525  FatbinSectionName = ".hipFatBinSegment";
526 
527  ModuleIDSectionName = "__hip_module_id";
528  ModuleIDPrefix = "__hip_";
529 
530  if (CudaGpuBinary) {
531  // If fatbin is available from early finalization, create a string
532  // literal containing the fat binary loaded from the given file.
533  FatBinStr = makeConstantString(CudaGpuBinary->getBuffer(), "",
534  FatbinConstantName, 8);
535  } else {
536  // If fatbin is not available, create an external symbol
537  // __hip_fatbin in section .hip_fatbin. The external symbol is supposed
538  // to contain the fat binary but will be populated somewhere else,
539  // e.g. by lld through link script.
540  FatBinStr = new llvm::GlobalVariable(
541  CGM.getModule(), CGM.Int8Ty,
542  /*isConstant=*/true, llvm::GlobalValue::ExternalLinkage, nullptr,
543  "__hip_fatbin", nullptr,
544  llvm::GlobalVariable::NotThreadLocal);
545  cast<llvm::GlobalVariable>(FatBinStr)->setSection(FatbinConstantName);
546  }
547 
548  FatMagic = HIPFatMagic;
549  } else {
550  if (RelocatableDeviceCode)
551  FatbinConstantName = CGM.getTriple().isMacOSX()
552  ? "__NV_CUDA,__nv_relfatbin"
553  : "__nv_relfatbin";
554  else
555  FatbinConstantName =
556  CGM.getTriple().isMacOSX() ? "__NV_CUDA,__nv_fatbin" : ".nv_fatbin";
557  // NVIDIA's cuobjdump looks for fatbins in this section.
558  FatbinSectionName =
559  CGM.getTriple().isMacOSX() ? "__NV_CUDA,__fatbin" : ".nvFatBinSegment";
560 
561  ModuleIDSectionName = CGM.getTriple().isMacOSX()
562  ? "__NV_CUDA,__nv_module_id"
563  : "__nv_module_id";
564  ModuleIDPrefix = "__nv_";
565 
566  // For CUDA, create a string literal containing the fat binary loaded from
567  // the given file.
568  FatBinStr = makeConstantString(CudaGpuBinary->getBuffer(), "",
569  FatbinConstantName, 8);
570  FatMagic = CudaFatMagic;
571  }
572 
573  // Create initialized wrapper structure that points to the loaded GPU binary
575  auto Values = Builder.beginStruct(FatbinWrapperTy);
576  // Fatbin wrapper magic.
577  Values.addInt(IntTy, FatMagic);
578  // Fatbin version.
579  Values.addInt(IntTy, 1);
580  // Data.
581  Values.add(FatBinStr);
582  // Unused in fatbin v1.
583  Values.add(llvm::ConstantPointerNull::get(VoidPtrTy));
584  llvm::GlobalVariable *FatbinWrapper = Values.finishAndCreateGlobal(
585  addUnderscoredPrefixToName("_fatbin_wrapper"), CGM.getPointerAlign(),
586  /*constant*/ true);
587  FatbinWrapper->setSection(FatbinSectionName);
588 
589  // There is only one HIP fat binary per linked module, however there are
590  // multiple constructor functions. Make sure the fat binary is registered
591  // only once. The constructor functions are executed by the dynamic loader
592  // before the program gains control. The dynamic loader cannot execute the
593  // constructor functions concurrently since doing that would not guarantee
594  // thread safety of the loaded program. Therefore we can assume sequential
595  // execution of constructor functions here.
596  if (IsHIP) {
597  auto Linkage = CudaGpuBinary ? llvm::GlobalValue::InternalLinkage :
598  llvm::GlobalValue::LinkOnceAnyLinkage;
599  llvm::BasicBlock *IfBlock =
600  llvm::BasicBlock::Create(Context, "if", ModuleCtorFunc);
601  llvm::BasicBlock *ExitBlock =
602  llvm::BasicBlock::Create(Context, "exit", ModuleCtorFunc);
603  // The name, size, and initialization pattern of this variable is part
604  // of HIP ABI.
605  GpuBinaryHandle = new llvm::GlobalVariable(
606  TheModule, VoidPtrPtrTy, /*isConstant=*/false,
607  Linkage,
608  /*Initializer=*/llvm::ConstantPointerNull::get(VoidPtrPtrTy),
609  "__hip_gpubin_handle");
610  GpuBinaryHandle->setAlignment(CGM.getPointerAlign().getQuantity());
611  // Prevent the weak symbol in different shared libraries being merged.
613  GpuBinaryHandle->setVisibility(llvm::GlobalValue::HiddenVisibility);
614  Address GpuBinaryAddr(
615  GpuBinaryHandle,
616  CharUnits::fromQuantity(GpuBinaryHandle->getAlignment()));
617  {
618  auto HandleValue = CtorBuilder.CreateLoad(GpuBinaryAddr);
619  llvm::Constant *Zero =
620  llvm::Constant::getNullValue(HandleValue->getType());
621  llvm::Value *EQZero = CtorBuilder.CreateICmpEQ(HandleValue, Zero);
622  CtorBuilder.CreateCondBr(EQZero, IfBlock, ExitBlock);
623  }
624  {
625  CtorBuilder.SetInsertPoint(IfBlock);
626  // GpuBinaryHandle = __hipRegisterFatBinary(&FatbinWrapper);
627  llvm::CallInst *RegisterFatbinCall = CtorBuilder.CreateCall(
628  RegisterFatbinFunc,
629  CtorBuilder.CreateBitCast(FatbinWrapper, VoidPtrTy));
630  CtorBuilder.CreateStore(RegisterFatbinCall, GpuBinaryAddr);
631  CtorBuilder.CreateBr(ExitBlock);
632  }
633  {
634  CtorBuilder.SetInsertPoint(ExitBlock);
635  // Call __hip_register_globals(GpuBinaryHandle);
636  if (RegisterGlobalsFunc) {
637  auto HandleValue = CtorBuilder.CreateLoad(GpuBinaryAddr);
638  CtorBuilder.CreateCall(RegisterGlobalsFunc, HandleValue);
639  }
640  }
641  } else if (!RelocatableDeviceCode) {
642  // Register binary with CUDA runtime. This is substantially different in
643  // default mode vs. separate compilation!
644  // GpuBinaryHandle = __cudaRegisterFatBinary(&FatbinWrapper);
645  llvm::CallInst *RegisterFatbinCall = CtorBuilder.CreateCall(
646  RegisterFatbinFunc,
647  CtorBuilder.CreateBitCast(FatbinWrapper, VoidPtrTy));
648  GpuBinaryHandle = new llvm::GlobalVariable(
649  TheModule, VoidPtrPtrTy, false, llvm::GlobalValue::InternalLinkage,
650  llvm::ConstantPointerNull::get(VoidPtrPtrTy), "__cuda_gpubin_handle");
651  GpuBinaryHandle->setAlignment(CGM.getPointerAlign().getQuantity());
652  CtorBuilder.CreateAlignedStore(RegisterFatbinCall, GpuBinaryHandle,
653  CGM.getPointerAlign());
654 
655  // Call __cuda_register_globals(GpuBinaryHandle);
656  if (RegisterGlobalsFunc)
657  CtorBuilder.CreateCall(RegisterGlobalsFunc, RegisterFatbinCall);
658 
659  // Call __cudaRegisterFatBinaryEnd(Handle) if this CUDA version needs it.
662  // void __cudaRegisterFatBinaryEnd(void **);
663  llvm::FunctionCallee RegisterFatbinEndFunc = CGM.CreateRuntimeFunction(
664  llvm::FunctionType::get(VoidTy, VoidPtrPtrTy, false),
665  "__cudaRegisterFatBinaryEnd");
666  CtorBuilder.CreateCall(RegisterFatbinEndFunc, RegisterFatbinCall);
667  }
668  } else {
669  // Generate a unique module ID.
670  SmallString<64> ModuleID;
671  llvm::raw_svector_ostream OS(ModuleID);
672  OS << ModuleIDPrefix << llvm::format("%" PRIx64, FatbinWrapper->getGUID());
673  llvm::Constant *ModuleIDConstant =
674  makeConstantString(ModuleID.str(), "", ModuleIDSectionName, 32);
675 
676  // Create an alias for the FatbinWrapper that nvcc will look for.
678  Twine("__fatbinwrap") + ModuleID, FatbinWrapper);
679 
680  // void __cudaRegisterLinkedBinary%ModuleID%(void (*)(void *), void *,
681  // void *, void (*)(void **))
682  SmallString<128> RegisterLinkedBinaryName("__cudaRegisterLinkedBinary");
683  RegisterLinkedBinaryName += ModuleID;
684  llvm::FunctionCallee RegisterLinkedBinaryFunc = CGM.CreateRuntimeFunction(
685  getRegisterLinkedBinaryFnTy(), RegisterLinkedBinaryName);
686 
687  assert(RegisterGlobalsFunc && "Expecting at least dummy function!");
688  llvm::Value *Args[] = {RegisterGlobalsFunc,
689  CtorBuilder.CreateBitCast(FatbinWrapper, VoidPtrTy),
690  ModuleIDConstant,
691  makeDummyFunction(getCallbackFnTy())};
692  CtorBuilder.CreateCall(RegisterLinkedBinaryFunc, Args);
693  }
694 
695  // Create destructor and register it with atexit() the way NVCC does it. Doing
696  // it during regular destructor phase worked in CUDA before 9.2 but results in
697  // double-free in 9.2.
698  if (llvm::Function *CleanupFn = makeModuleDtorFunction()) {
699  // extern "C" int atexit(void (*f)(void));
700  llvm::FunctionType *AtExitTy =
701  llvm::FunctionType::get(IntTy, CleanupFn->getType(), false);
702  llvm::FunctionCallee AtExitFunc =
703  CGM.CreateRuntimeFunction(AtExitTy, "atexit", llvm::AttributeList(),
704  /*Local=*/true);
705  CtorBuilder.CreateCall(AtExitFunc, CleanupFn);
706  }
707 
708  CtorBuilder.CreateRetVoid();
709  return ModuleCtorFunc;
710 }
711 
712 /// Creates a global destructor function that unregisters the GPU code blob
713 /// registered by constructor.
714 ///
715 /// For CUDA:
716 /// \code
717 /// void __cuda_module_dtor(void*) {
718 /// __cudaUnregisterFatBinary(Handle);
719 /// }
720 /// \endcode
721 ///
722 /// For HIP:
723 /// \code
724 /// void __hip_module_dtor(void*) {
725 /// if (__hip_gpubin_handle) {
726 /// __hipUnregisterFatBinary(__hip_gpubin_handle);
727 /// __hip_gpubin_handle = 0;
728 /// }
729 /// }
730 /// \endcode
731 llvm::Function *CGNVCUDARuntime::makeModuleDtorFunction() {
732  // No need for destructor if we don't have a handle to unregister.
733  if (!GpuBinaryHandle)
734  return nullptr;
735 
736  // void __cudaUnregisterFatBinary(void ** handle);
737  llvm::FunctionCallee UnregisterFatbinFunc = CGM.CreateRuntimeFunction(
738  llvm::FunctionType::get(VoidTy, VoidPtrPtrTy, false),
739  addUnderscoredPrefixToName("UnregisterFatBinary"));
740 
741  llvm::Function *ModuleDtorFunc = llvm::Function::Create(
742  llvm::FunctionType::get(VoidTy, VoidPtrTy, false),
744  addUnderscoredPrefixToName("_module_dtor"), &TheModule);
745 
746  llvm::BasicBlock *DtorEntryBB =
747  llvm::BasicBlock::Create(Context, "entry", ModuleDtorFunc);
748  CGBuilderTy DtorBuilder(CGM, Context);
749  DtorBuilder.SetInsertPoint(DtorEntryBB);
750 
751  Address GpuBinaryAddr(GpuBinaryHandle, CharUnits::fromQuantity(
752  GpuBinaryHandle->getAlignment()));
753  auto HandleValue = DtorBuilder.CreateLoad(GpuBinaryAddr);
754  // There is only one HIP fat binary per linked module, however there are
755  // multiple destructor functions. Make sure the fat binary is unregistered
756  // only once.
757  if (CGM.getLangOpts().HIP) {
758  llvm::BasicBlock *IfBlock =
759  llvm::BasicBlock::Create(Context, "if", ModuleDtorFunc);
760  llvm::BasicBlock *ExitBlock =
761  llvm::BasicBlock::Create(Context, "exit", ModuleDtorFunc);
762  llvm::Constant *Zero = llvm::Constant::getNullValue(HandleValue->getType());
763  llvm::Value *NEZero = DtorBuilder.CreateICmpNE(HandleValue, Zero);
764  DtorBuilder.CreateCondBr(NEZero, IfBlock, ExitBlock);
765 
766  DtorBuilder.SetInsertPoint(IfBlock);
767  DtorBuilder.CreateCall(UnregisterFatbinFunc, HandleValue);
768  DtorBuilder.CreateStore(Zero, GpuBinaryAddr);
769  DtorBuilder.CreateBr(ExitBlock);
770 
771  DtorBuilder.SetInsertPoint(ExitBlock);
772  } else {
773  DtorBuilder.CreateCall(UnregisterFatbinFunc, HandleValue);
774  }
775  DtorBuilder.CreateRetVoid();
776  return ModuleDtorFunc;
777 }
778 
780  return new CGNVCUDARuntime(CGM);
781 }
const llvm::DataLayout & getDataLayout() const
ReturnValueSlot - Contains the address where the return value of a function can be stored...
Definition: CGCall.h:363
CharUnits alignTo(const CharUnits &Align) const
alignTo - Returns the next integer (mod 2**64) that is greater than or equal to this quantity and is ...
Definition: CharUnits.h:183
llvm::StoreInst * CreateDefaultAlignedStore(llvm::Value *Val, llvm::Value *Addr, bool IsVolatile=false)
Definition: CGBuilder.h:121
Represents a function declaration or definition.
Definition: Decl.h:1737
llvm::IntegerType * IntTy
int
External linkage, which indicates that the entity can be referred to from other translation units...
Definition: Linkage.h:59
CanQualType VoidPtrTy
Definition: ASTContext.h:1043
A (possibly-)qualified type.
Definition: Type.h:639
const CodeGenOptions & getCodeGenOpts() const
Address CreateMemTemp(QualType T, const Twine &Name="tmp", Address *Alloca=nullptr)
CreateMemTemp - Create a temporary memory object of the given type, with appropriate alignmen and cas...
Definition: CGExpr.cpp:138
The standard implementation of ConstantInitBuilder used in Clang.
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
DiagnosticBuilder Report(SourceLocation Loc, unsigned DiagID)
Issue the message to the client.
Definition: Diagnostic.h:1296
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:689
llvm::IntegerType * Int8Ty
i8, i16, i32, and i64
Address GetAddrOfLocalVar(const VarDecl *VD)
GetAddrOfLocalVar - Return the address of a local variable.
Represents a variable declaration or definition.
Definition: Decl.h:812
Objects with "hidden" visibility are not seen by the dynamic linker.
Definition: Visibility.h:36
DiagnosticsEngine & getDiags() const
llvm::Value * getPointer() const
Definition: Address.h:37
Represents a parameter to a function.
Definition: Decl.h:1549
Linkage
Describes the different kinds of linkage (C++ [basic.link], C99 6.2.2) that an entity may have...
Definition: Linkage.h:23
void add(RValue rvalue, QualType type)
Definition: CGCall.h:287
One of these records is kept for each identifier that is lexed.
TargetCXXABI getCXXABI() const
Get the C++ ABI currently in use.
Definition: TargetInfo.h:1035
CodeGenFunction - This class organizes the per-function state that is used while generating LLVM code...
llvm::Type * ConvertType(QualType T)
ConvertType - Convert type T into a llvm::Type.
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:154
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:52
IdentifierTable & Idents
Definition: ASTContext.h:565
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:37
llvm::BasicBlock * createBasicBlock(const Twine &name="", llvm::Function *parent=nullptr, llvm::BasicBlock *before=nullptr)
createBasicBlock - Create an LLVM basic block.
llvm::AllocaInst * CreateTempAlloca(llvm::Type *Ty, const Twine &Name="tmp", llvm::Value *ArraySize=nullptr)
CreateTempAlloca - This creates an alloca and inserts it into the entry block if ArraySize is nullptr...
Definition: CGExpr.cpp:105
lookup_result lookup(DeclarationName Name) const
lookup - Find the declarations (if any) with the given Name in this context.
Definition: DeclBase.cpp:1601
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
unsigned Offset
Definition: Format.cpp:1676
static CGCallee forDirect(llvm::Constant *functionPtr, const CGCalleeInfo &abstractInfo=CGCalleeInfo())
Definition: CGCall.h:133
llvm::PointerType * getType() const
Return the type of the pointer value.
Definition: Address.h:43
static CharUnits fromQuantity(QuantityType Quantity)
fromQuantity - Construct a CharUnits quantity from a raw integer type.
Definition: CharUnits.h:62
const TargetInfo & getTarget() const
const LangOptions & getLangOpts() const
ASTContext & getContext() const
The l-value was considered opaque, so the alignment was determined from a type.
const llvm::VersionTuple & getSDKVersion() const
Definition: TargetInfo.h:1343
Address CreateBitCast(Address Addr, llvm::Type *Ty, const llvm::Twine &Name="")
Definition: CGBuilder.h:141
QualType getCanonicalType() const
Definition: Type.h:6121
static DeclContext * castToDeclContext(const TranslationUnitDecl *D)
Definition: Decl.h:129
IdentifierInfo & get(StringRef Name)
Return the identifier token info for the specified named identifier.
RValue EmitCall(const CGFunctionInfo &CallInfo, const CGCallee &Callee, ReturnValueSlot ReturnValue, const CallArgList &Args, llvm::CallBase **callOrInvoke, SourceLocation Loc)
EmitCall - Generate a call of the given function, expecting the given result type, and using the given argument list which specifies both the LLVM arguments and the types they were derived from.
Definition: CGCall.cpp:3787
const ParmVarDecl * getParamDecl(unsigned i) const
Definition: Decl.h:2284
An aligned address.
Definition: Address.h:24
bool CudaFeatureEnabled(llvm::VersionTuple, CudaFeature)
Definition: Cuda.cpp:365
constexpr XRayInstrMask None
Definition: XRayInstr.h:37
void Error(SourceLocation loc, StringRef error)
Emit a general error that something can&#39;t be done.
std::pair< CharUnits, CharUnits > getTypeInfoInChars(const Type *T) const
FunctionArgList - Type for representing both the decl and type of parameters to a function...
Definition: CGCall.h:358
CanQualType CharTy
Definition: ASTContext.h:1017
CGFunctionInfo - Class to encapsulate the information about a function definition.
This class organizes the cross-function state that is used while generating LLVM code.
std::string CudaGpuBinaryFileName
Name of file passed with -fcuda-include-gpubinary option to forward to CUDA runtime back-end for inco...
Dataflow Directional Tag Classes.
DeclContext - This is used only as base class of specific decl types that can act as declaration cont...
Definition: DeclBase.h:1265
const CGFunctionInfo & arrangeFunctionDeclaration(const FunctionDecl *FD)
Free functions are functions that are compatible with an ordinary C function pointer type...
Definition: CGCall.cpp:433
std::unique_ptr< DiagnosticConsumer > create(StringRef OutputFile, DiagnosticOptions *Diags, bool MergeChildRecords=false)
Returns a DiagnosticConsumer that serializes diagnostics to a bitcode file.
llvm::LoadInst * CreateLoad(Address Addr, const llvm::Twine &Name="")
Definition: CGBuilder.h:69
llvm::Module & getModule() const
Indicates that the tracking object is a descendant of a referenced-counted OSObject, used in the Darwin kernel.
This class organizes the cross-module state that is used while lowering AST types to LLVM types...
Definition: CodeGenTypes.h:59
Internal linkage, which indicates that the entity can be referred to from within the translation unit...
Definition: Linkage.h:31
llvm::FunctionCallee CreateRuntimeFunction(llvm::FunctionType *Ty, StringRef Name, llvm::AttributeList ExtraAttrs=llvm::AttributeList(), bool Local=false)
Create or return a runtime function declaration with the specified type and name. ...
void EmitBlock(llvm::BasicBlock *BB, bool IsFinished=false)
EmitBlock - Emit the given block.
Definition: CGStmt.cpp:450
CGCUDARuntime * CreateNVCUDARuntime(CodeGenModule &CGM)
Creates an instance of a CUDA runtime class.
Definition: CGCUDANV.cpp:779
const Decl * CurFuncDecl
CurFuncDecl - Holds the Decl for the current outermost non-closure context.
TranslationUnitDecl * getTranslationUnitDecl() const
Definition: ASTContext.h:1008
void EmitBranch(llvm::BasicBlock *Block)
EmitBranch - Emit a branch to the specified basic block from the current insert block, taking care to avoid creation of branches from dummy blocks.
Definition: CGStmt.cpp:470
The top declaration context.
Definition: Decl.h:107
static RValue get(llvm::Value *V)
Definition: CGValue.h:85
QualType getType() const
Definition: Decl.h:647
static RValue getAggregate(Address addr, bool isVolatile=false)
Definition: CGValue.h:106
const TargetInfo * getAuxTargetInfo() const
Definition: ASTContext.h:690
llvm::CallBase * EmitRuntimeCallOrInvoke(llvm::FunctionCallee callee, ArrayRef< llvm::Value *> args, const Twine &name="")
Emits a call or invoke instruction to the given runtime function.
Definition: CGCall.cpp:3747
CallArgList - Type for representing both the value and type of arguments in a call.
Definition: CGCall.h:262
SourceLocation getLocation() const
Definition: DeclBase.h:420
static OMPLinearClause * Create(const ASTContext &C, SourceLocation StartLoc, SourceLocation LParenLoc, OpenMPLinearClauseKind Modifier, SourceLocation ModifierLoc, SourceLocation ColonLoc, SourceLocation EndLoc, ArrayRef< Expr *> VL, ArrayRef< Expr *> PL, ArrayRef< Expr *> IL, Expr *Step, Expr *CalcStep, Stmt *PreInit, Expr *PostUpdate)
Creates clause with a list of variables VL and a linear step Step.
const llvm::Triple & getTriple() const