[cuda] Include GPU binary into host object file and generate init/deinit code.

- added -fcuda-include-gpubinary option to incorporate results of
  device-side compilation into host-side one.
- generate code to register GPU binaries and associated kernels
  with CUDA runtime and clean-up on exit.
- added test case for init/deinit code generation.

Differential Revision: http://reviews.llvm.org/D9507

llvm-svn: 236765

Author: Artem-B

clang/include/clang/Driver/CC1Options.td

@@ -631,6 +631,8 @@ def fcuda_allow_host_calls_from_host_device : Flag<["-"],
 def fcuda_disable_target_call_checks : Flag<["-"],
     "fcuda-disable-target-call-checks">,
   HelpText<"Disable all cross-target (host, device, etc.) call checks in CUDA">;
+def fcuda_include_gpubinary : Separate<["-"], "fcuda-include-gpubinary">,
+  HelpText<"Incorporate CUDA device-side binary into host object file.">;
 
 } // let Flags = [CC1Option]
 

clang/include/clang/Frontend/CodeGenOptions.h

@@ -163,6 +163,11 @@ class CodeGenOptions : public CodeGenOptionsBase {
   /// Name of the profile file to use as input for -fprofile-instr-use
   std::string InstrProfileInput;
 
+  /// A list of file names passed with -fcuda-include-gpubinary options to
+  /// forward to CUDA runtime back-end for incorporating them into host-side
+  /// object file.
+  std::vector<std::string> CudaGpuBinaryFileNames;
+
   /// Regular expression to select optimizations for which we should enable
   /// optimization remarks. Transformation passes whose name matches this
   /// expression (and support this feature), will emit a diagnostic

clang/lib/CodeGen/CGCUDANV.cpp

@@ -20,7 +20,6 @@
 #include "llvm/IR/CallSite.h"
 #include "llvm/IR/Constants.h"
 #include "llvm/IR/DerivedTypes.h"
-#include <vector>
 
 using namespace clang;
 using namespace CodeGen;
@@ -30,29 +29,66 @@ namespace {
 class CGNVCUDARuntime : public CGCUDARuntime {
 
 private:
-  llvm::Type *IntTy, *SizeTy;
-  llvm::PointerType *CharPtrTy, *VoidPtrTy;
+  llvm::Type *IntTy, *SizeTy, *VoidTy;
+  llvm::PointerType *CharPtrTy, *VoidPtrTy, *VoidPtrPtrTy;
+
+  /// Convenience reference to LLVM Context
+  llvm::LLVMContext &Context;
+  /// Convenience reference to the current module
+  llvm::Module &TheModule;
+  /// Keeps track of kernel launch stubs emitted in this module
+  llvm::SmallVector<llvm::Function *, 16> EmittedKernels;
+  /// Keeps track of variables containing handles of GPU binaries. Populated by
+  /// ModuleCtorFunction() and used to create corresponding cleanup calls in
+  /// ModuleDtorFunction()
+  llvm::SmallVector<llvm::GlobalVariable *, 16> GpuBinaryHandles;
 
   llvm::Constant *getSetupArgumentFn() const;
   llvm::Constant *getLaunchFn() const;
 
+  /// Creates a function to register all kernel stubs generated in this module.
+  llvm::Function *makeRegisterKernelsFn();
+
+  /// Helper function that generates a constant string and returns a pointer to
+  /// the start of the string.  The result of this function can be used anywhere
+  /// where the C code specifies const char*.
+  llvm::Constant *makeConstantString(const std::string &Str,
+                                     const std::string &Name = "",
+                                     unsigned Alignment = 0) {
+    llvm::Constant *Zeros[] = {llvm::ConstantInt::get(SizeTy, 0),
+                               llvm::ConstantInt::get(SizeTy, 0)};
+    auto *ConstStr = CGM.GetAddrOfConstantCString(Str, Name.c_str());
+    return llvm::ConstantExpr::getGetElementPtr(ConstStr->getValueType(),
+                                                ConstStr, Zeros);
+ }
+
+  void emitDeviceStubBody(CodeGenFunction &CGF, FunctionArgList &Args);
+
 public:
   CGNVCUDARuntime(CodeGenModule &CGM);
 
-  void EmitDeviceStubBody(CodeGenFunction &CGF, FunctionArgList &Args) override;
+  void emitDeviceStub(CodeGenFunction &CGF, FunctionArgList &Args) override;
+  /// Creates module constructor function
+  llvm::Function *makeModuleCtorFunction() override;
+  /// Creates module destructor function
+  llvm::Function *makeModuleDtorFunction() override;
 };
 
 }
 
-CGNVCUDARuntime::CGNVCUDARuntime(CodeGenModule &CGM) : CGCUDARuntime(CGM) {
+CGNVCUDARuntime::CGNVCUDARuntime(CodeGenModule &CGM)
+    : CGCUDARuntime(CGM), Context(CGM.getLLVMContext()),
+      TheModule(CGM.getModule()) {
   CodeGen::CodeGenTypes &Types = CGM.getTypes();
   ASTContext &Ctx = CGM.getContext();
 
   IntTy = Types.ConvertType(Ctx.IntTy);
   SizeTy = Types.ConvertType(Ctx.getSizeType());
+  VoidTy = llvm::Type::getVoidTy(Context);
 
   CharPtrTy = llvm::PointerType::getUnqual(Types.ConvertType(Ctx.CharTy));
   VoidPtrTy = cast<llvm::PointerType>(Types.ConvertType(Ctx.VoidPtrTy));
+  VoidPtrPtrTy = VoidPtrTy->getPointerTo();
 }
 
 llvm::Constant *CGNVCUDARuntime::getSetupArgumentFn() const {
@@ -68,14 +104,17 @@ llvm::Constant *CGNVCUDARuntime::getSetupArgumentFn() const {
 
 llvm::Constant *CGNVCUDARuntime::getLaunchFn() const {
   // cudaError_t cudaLaunch(char *)
-  std::vector<llvm::Type*> Params;
-  Params.push_back(CharPtrTy);
-  return CGM.CreateRuntimeFunction(llvm::FunctionType::get(IntTy,
-                                                           Params, false),
-                                   "cudaLaunch");
+  return CGM.CreateRuntimeFunction(
+      llvm::FunctionType::get(IntTy, CharPtrTy, false), "cudaLaunch");
+}
+
+void CGNVCUDARuntime::emitDeviceStub(CodeGenFunction &CGF,
+                                     FunctionArgList &Args) {
+  EmittedKernels.push_back(CGF.CurFn);
+  emitDeviceStubBody(CGF, Args);
 }
 
-void CGNVCUDARuntime::EmitDeviceStubBody(CodeGenFunction &CGF,
+void CGNVCUDARuntime::emitDeviceStubBody(CodeGenFunction &CGF,
                                          FunctionArgList &Args) {
   // Build the argument value list and the argument stack struct type.
   SmallVector<llvm::Value *, 16> ArgValues;
@@ -87,8 +126,7 @@ void CGNVCUDARuntime::EmitDeviceStubBody(CodeGenFunction &CGF,
     assert(isa<llvm::PointerType>(V->getType()) && "Arg type not PointerType");
     ArgTypes.push_back(cast<llvm::PointerType>(V->getType())->getElementType());
   }
-  llvm::StructType *ArgStackTy = llvm::StructType::get(
-      CGF.getLLVMContext(), ArgTypes);
+  llvm::StructType *ArgStackTy = llvm::StructType::get(Context, ArgTypes);
 
   llvm::BasicBlock *EndBlock = CGF.createBasicBlock("setup.end");
 
@@ -120,6 +158,160 @@ void CGNVCUDARuntime::EmitDeviceStubBody(CodeGenFunction &CGF,
   CGF.EmitBlock(EndBlock);
 }
 
+/// Creates internal function to register all kernel stubs generated in this
+/// module with the CUDA runtime.
+/// \code
+/// void __cuda_register_kernels(void** GpuBinaryHandle) {
+///    __cudaRegisterFunction(GpuBinaryHandle,Kernel0,...);
+///    ...
+///    __cudaRegisterFunction(GpuBinaryHandle,KernelM,...);
+/// }
+/// \endcode
+llvm::Function *CGNVCUDARuntime::makeRegisterKernelsFn() {
+  llvm::Function *RegisterKernelsFunc = llvm::Function::Create(
+      llvm::FunctionType::get(VoidTy, VoidPtrPtrTy, false),
+      llvm::GlobalValue::InternalLinkage, "__cuda_register_kernels", &TheModule);
+  llvm::BasicBlock *EntryBB =
+      llvm::BasicBlock::Create(Context, "entry", RegisterKernelsFunc);
+  CGBuilderTy Builder(Context);
+  Builder.SetInsertPoint(EntryBB);
+
+  // void __cudaRegisterFunction(void **, const char *, char *, const char *,
+  //                             int, uint3*, uint3*, dim3*, dim3*, int*)
+  std::vector<llvm::Type *> RegisterFuncParams = {
+      VoidPtrPtrTy, CharPtrTy, CharPtrTy, CharPtrTy, IntTy,
+      VoidPtrTy,    VoidPtrTy, VoidPtrTy, VoidPtrTy, IntTy->getPointerTo()};
+  llvm::Constant *RegisterFunc = CGM.CreateRuntimeFunction(
+      llvm::FunctionType::get(IntTy, RegisterFuncParams, false),
+      "__cudaRegisterFunction");
+
+  // Extract GpuBinaryHandle passed as the first argument passed to
+  // __cuda_register_kernels() and generate __cudaRegisterFunction() call for
+  // each emitted kernel.
+  llvm::Argument &GpuBinaryHandlePtr = *RegisterKernelsFunc->arg_begin();
+  for (llvm::Function *Kernel : EmittedKernels) {
+    llvm::Constant *KernelName = makeConstantString(Kernel->getName());
+    llvm::Constant *NullPtr = llvm::ConstantPointerNull::get(VoidPtrTy);
+    llvm::Value *args[] = {
+        &GpuBinaryHandlePtr, Builder.CreateBitCast(Kernel, VoidPtrTy),
+        KernelName, KernelName, llvm::ConstantInt::get(IntTy, -1), NullPtr,
+        NullPtr, NullPtr, NullPtr,
+        llvm::ConstantPointerNull::get(IntTy->getPointerTo())};
+    Builder.CreateCall(RegisterFunc, args);
+  }
+
+  Builder.CreateRetVoid();
+  return RegisterKernelsFunc;
+}
+
+/// Creates a global constructor function for the module:
+/// \code
+/// void __cuda_module_ctor(void*) {
+///     Handle0 = __cudaRegisterFatBinary(GpuBinaryBlob0);
+///     __cuda_register_kernels(Handle0);
+///     ...
+///     HandleN = __cudaRegisterFatBinary(GpuBinaryBlobN);
+///     __cuda_register_kernels(HandleN);
+/// }
+/// \endcode
+llvm::Function *CGNVCUDARuntime::makeModuleCtorFunction() {
+  // void __cuda_register_kernels(void* handle);
+  llvm::Function *RegisterKernelsFunc = makeRegisterKernelsFn();
+  // void ** __cudaRegisterFatBinary(void *);
+  llvm::Constant *RegisterFatbinFunc = CGM.CreateRuntimeFunction(
+      llvm::FunctionType::get(VoidPtrPtrTy, VoidPtrTy, false),
+      "__cudaRegisterFatBinary");
+  // struct { int magic, int version, void * gpu_binary, void * dont_care };
+  llvm::StructType *FatbinWrapperTy =
+      llvm::StructType::get(IntTy, IntTy, VoidPtrTy, VoidPtrTy, nullptr);
+
+  llvm::Function *ModuleCtorFunc = llvm::Function::Create(
+      llvm::FunctionType::get(VoidTy, VoidPtrTy, false),
+      llvm::GlobalValue::InternalLinkage, "__cuda_module_ctor", &TheModule);
+  llvm::BasicBlock *CtorEntryBB =
+      llvm::BasicBlock::Create(Context, "entry", ModuleCtorFunc);
+  CGBuilderTy CtorBuilder(Context);
+
+  CtorBuilder.SetInsertPoint(CtorEntryBB);
+
+  // For each GPU binary, register it with the CUDA runtime and store returned
+  // handle in a global variable and save the handle in GpuBinaryHandles vector
+  // to be cleaned up in destructor on exit. Then associate all known kernels
+  // with the GPU binary handle so CUDA runtime can figure out what to call on
+  // the GPU side.
+  for (const std::string &GpuBinaryFileName :
+       CGM.getCodeGenOpts().CudaGpuBinaryFileNames) {
+    llvm::ErrorOr<std::unique_ptr<llvm::MemoryBuffer>> GpuBinaryOrErr =
+        llvm::MemoryBuffer::getFileOrSTDIN(GpuBinaryFileName);
+    if (std::error_code EC = GpuBinaryOrErr.getError()) {
+      CGM.getDiags().Report(diag::err_cannot_open_file) << GpuBinaryFileName
+                                                        << EC.message();
+      continue;
+    }
+
+    // Create initialized wrapper structure that points to the loaded GPU binary
+    llvm::Constant *Values[] = {
+        llvm::ConstantInt::get(IntTy, 0x466243b1), // Fatbin wrapper magic.
+        llvm::ConstantInt::get(IntTy, 1),          // Fatbin version.
+        makeConstantString(GpuBinaryOrErr.get()->getBuffer(), "", 16), // Data.
+        llvm::ConstantPointerNull::get(VoidPtrTy)}; // Unused in fatbin v1.
+    llvm::GlobalVariable *FatbinWrapper = new llvm::GlobalVariable(
+        TheModule, FatbinWrapperTy, true, llvm::GlobalValue::InternalLinkage,
+        llvm::ConstantStruct::get(FatbinWrapperTy, Values),
+        "__cuda_fatbin_wrapper");
+
+    // GpuBinaryHandle = __cudaRegisterFatBinary(&FatbinWrapper);
+    llvm::CallInst *RegisterFatbinCall = CtorBuilder.CreateCall(
+        RegisterFatbinFunc,
+        CtorBuilder.CreateBitCast(FatbinWrapper, VoidPtrTy));
+    llvm::GlobalVariable *GpuBinaryHandle = new llvm::GlobalVariable(
+        TheModule, VoidPtrPtrTy, false, llvm::GlobalValue::InternalLinkage,
+        llvm::ConstantPointerNull::get(VoidPtrPtrTy), "__cuda_gpubin_handle");
+    CtorBuilder.CreateStore(RegisterFatbinCall, GpuBinaryHandle, false);
+
+    // Call __cuda_register_kernels(GpuBinaryHandle);
+    CtorBuilder.CreateCall(RegisterKernelsFunc, RegisterFatbinCall);
+
+    // Save GpuBinaryHandle so we can unregister it in destructor.
+    GpuBinaryHandles.push_back(GpuBinaryHandle);
+  }
+
+  CtorBuilder.CreateRetVoid();
+  return ModuleCtorFunc;
+}
+
+/// Creates a global destructor function that unregisters all GPU code blobs
+/// registered by constructor.
+/// \code
+/// void __cuda_module_dtor(void*) {
+///     __cudaUnregisterFatBinary(Handle0);
+///     ...
+///     __cudaUnregisterFatBinary(HandleN);
+/// }
+/// \endcode
+llvm::Function *CGNVCUDARuntime::makeModuleDtorFunction() {
+  // void __cudaUnregisterFatBinary(void ** handle);
+  llvm::Constant *UnregisterFatbinFunc = CGM.CreateRuntimeFunction(
+      llvm::FunctionType::get(VoidTy, VoidPtrPtrTy, false),
+      "__cudaUnregisterFatBinary");
+
+  llvm::Function *ModuleDtorFunc = llvm::Function::Create(
+      llvm::FunctionType::get(VoidTy, VoidPtrTy, false),
+      llvm::GlobalValue::InternalLinkage, "__cuda_module_dtor", &TheModule);
+  llvm::BasicBlock *DtorEntryBB =
+      llvm::BasicBlock::Create(Context, "entry", ModuleDtorFunc);
+  CGBuilderTy DtorBuilder(Context);
+  DtorBuilder.SetInsertPoint(DtorEntryBB);
+
+  for (llvm::GlobalVariable *GpuBinaryHandle : GpuBinaryHandles) {
+    DtorBuilder.CreateCall(UnregisterFatbinFunc,
+                           DtorBuilder.CreateLoad(GpuBinaryHandle, false));
+  }
+
+  DtorBuilder.CreateRetVoid();
+  return ModuleDtorFunc;
+}
+
 CGCUDARuntime *CodeGen::CreateNVCUDARuntime(CodeGenModule &CGM) {
   return new CGNVCUDARuntime(CGM);
 }

clang/lib/CodeGen/CGCUDARuntime.h

@@ -16,6 +16,10 @@
 #ifndef LLVM_CLANG_LIB_CODEGEN_CGCUDARUNTIME_H
 #define LLVM_CLANG_LIB_CODEGEN_CGCUDARUNTIME_H
 
+namespace llvm {
+class Function;
+}
+
 namespace clang {
 
 class CUDAKernelCallExpr;
@@ -39,10 +43,17 @@ class CGCUDARuntime {
   virtual RValue EmitCUDAKernelCallExpr(CodeGenFunction &CGF,
                                         const CUDAKernelCallExpr *E,
                                         ReturnValueSlot ReturnValue);
-  
-  virtual void EmitDeviceStubBody(CodeGenFunction &CGF,
-                                  FunctionArgList &Args) = 0;
 
+  /// Emits a kernel launch stub.
+  virtual void emitDeviceStub(CodeGenFunction &CGF, FunctionArgList &Args) = 0;
+
+  /// Constructs and returns a module initialization function or nullptr if it's
+  /// not needed. Must be called after all kernels have been emitted.
+  virtual llvm::Function *makeModuleCtorFunction() = 0;
+
+  /// Returns a module cleanup function or nullptr if it's not needed.
+  /// Must be called after ModuleCtorFunction
+  virtual llvm::Function *makeModuleDtorFunction() = 0;
 };
 
 /// Creates an instance of a CUDA runtime class.

clang/lib/CodeGen/CodeGenFunction.cpp

@@ -878,7 +878,7 @@ void CodeGenFunction::GenerateCode(GlobalDecl GD, llvm::Function *Fn,
   else if (getLangOpts().CUDA &&
            !getLangOpts().CUDAIsDevice &&
            FD->hasAttr<CUDAGlobalAttr>())
-    CGM.getCUDARuntime().EmitDeviceStubBody(*this, Args);
+    CGM.getCUDARuntime().emitDeviceStub(*this, Args);
   else if (isa<CXXConversionDecl>(FD) &&
            cast<CXXConversionDecl>(FD)->isLambdaToBlockPointerConversion()) {
     // The lambda conversion to block pointer is special; the semantics can't be

clang/lib/CodeGen/CodeGenModule.cpp

@@ -350,6 +350,13 @@ void CodeGenModule::Release() {
   if (ObjCRuntime)
     if (llvm::Function *ObjCInitFunction = ObjCRuntime->ModuleInitFunction())
       AddGlobalCtor(ObjCInitFunction);
+  if (Context.getLangOpts().CUDA && !Context.getLangOpts().CUDAIsDevice &&
+      CUDARuntime) {
+    if (llvm::Function *CudaCtorFunction = CUDARuntime->makeModuleCtorFunction())
+      AddGlobalCtor(CudaCtorFunction);
+    if (llvm::Function *CudaDtorFunction = CUDARuntime->makeModuleDtorFunction())
+      AddGlobalDtor(CudaDtorFunction);
+  }
   if (PGOReader && PGOStats.hasDiagnostics())
     PGOStats.reportDiagnostics(getDiags(), getCodeGenOpts().MainFileName);
   EmitCtorList(GlobalCtors, "llvm.global_ctors");
@@ -3678,4 +3685,3 @@ void CodeGenModule::EmitOMPThreadPrivateDecl(const OMPThreadPrivateDecl *D) {
       CXXGlobalInits.push_back(InitFunction);
   }
 }
-

clang/lib/Frontend/CompilerInvocation.cpp

@@ -651,6 +651,9 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
                       Args.getAllArgValues(OPT_fsanitize_recover_EQ), Diags,
                       Opts.SanitizeRecover);
 
+  Opts.CudaGpuBinaryFileNames =
+      Args.getAllArgValues(OPT_fcuda_include_gpubinary);
+
   return Success;
 }