C++ Address::getPointer方法代码示例

void CGCXXABI::ReadArrayCookie(CodeGenFunction &CGF, Address ptr,
                               const CXXDeleteExpr *expr, QualType eltTy,
                               llvm::Value *&numElements,
                               llvm::Value *&allocPtr, CharUnits &cookieSize) {
  // Derive a char* in the same address space as the pointer.
  ptr = CGF.Builder.CreateElementBitCast(ptr, CGF.Int8Ty);

  // If we don't need an array cookie, bail out early.
  if (!requiresArrayCookie(expr, eltTy)) {
    allocPtr = ptr.getPointer();
    numElements = nullptr;
    cookieSize = CharUnits::Zero();
    return;
  }

  cookieSize = getArrayCookieSizeImpl(eltTy);
  Address allocAddr =
    CGF.Builder.CreateConstInBoundsByteGEP(ptr, -cookieSize);
  allocPtr = allocAddr.getPointer();
  numElements = readArrayCookieImpl(CGF, allocAddr, cookieSize);
}

DominatingValue<RValue>::saved_type
DominatingValue<RValue>::saved_type::save(CodeGenFunction &CGF, RValue rv) {
  if (rv.isScalar()) {
    llvm::Value *V = rv.getScalarVal();

    // These automatically dominate and don't need to be saved.
    if (!DominatingLLVMValue::needsSaving(V))
      return saved_type(V, ScalarLiteral);

    // Everything else needs an alloca.
    Address addr =
      CGF.CreateDefaultAlignTempAlloca(V->getType(), "saved-rvalue");
    CGF.Builder.CreateStore(V, addr);
    return saved_type(addr.getPointer(), ScalarAddress);
  }

  if (rv.isComplex()) {
    CodeGenFunction::ComplexPairTy V = rv.getComplexVal();
    llvm::Type *ComplexTy =
      llvm::StructType::get(V.first->getType(), V.second->getType(),
                            (void*) nullptr);
    Address addr = CGF.CreateDefaultAlignTempAlloca(ComplexTy, "saved-complex");
    CGF.Builder.CreateStore(V.first,
                            CGF.Builder.CreateStructGEP(addr, 0, CharUnits()));
    CharUnits offset = CharUnits::fromQuantity(
               CGF.CGM.getDataLayout().getTypeAllocSize(V.first->getType()));
    CGF.Builder.CreateStore(V.second,
                            CGF.Builder.CreateStructGEP(addr, 1, offset));
    return saved_type(addr.getPointer(), ComplexAddress);
  }

  assert(rv.isAggregate());
  Address V = rv.getAggregateAddress(); // TODO: volatile?
  if (!DominatingLLVMValue::needsSaving(V.getPointer()))
    return saved_type(V.getPointer(), AggregateLiteral,
                      V.getAlignment().getQuantity());

  Address addr =
    CGF.CreateTempAlloca(V.getType(), CGF.getPointerAlign(), "saved-rvalue");
  CGF.Builder.CreateStore(V.getPointer(), addr);
  return saved_type(addr.getPointer(), AggregateAddress,
                    V.getAlignment().getQuantity());
}

static void createStoreInstBefore(llvm::Value *value, Address addr,
                                  llvm::Instruction *beforeInst) {
  auto store = new llvm::StoreInst(value, addr.getPointer(), beforeInst);
  store->setAlignment(addr.getAlignment().getQuantity());
}

// CUDA 9.0+ uses new way to launch kernels. Parameters are packed in a local
// array and kernels are launched using cudaLaunchKernel().
void CGNVCUDARuntime::emitDeviceStubBodyNew(CodeGenFunction &CGF,
                                            FunctionArgList &Args) {
  // Build the shadow stack entry at the very start of the function.

  // Calculate amount of space we will need for all arguments.  If we have no
  // args, allocate a single pointer so we still have a valid pointer to the
  // argument array that we can pass to runtime, even if it will be unused.
  Address KernelArgs = CGF.CreateTempAlloca(
      VoidPtrTy, CharUnits::fromQuantity(16), "kernel_args",
      llvm::ConstantInt::get(SizeTy, std::max<size_t>(1, Args.size())));
  // Store pointers to the arguments in a locally allocated launch_args.
  for (unsigned i = 0; i < Args.size(); ++i) {
    llvm::Value* VarPtr = CGF.GetAddrOfLocalVar(Args[i]).getPointer();
    llvm::Value *VoidVarPtr = CGF.Builder.CreatePointerCast(VarPtr, VoidPtrTy);
    CGF.Builder.CreateDefaultAlignedStore(
        VoidVarPtr, CGF.Builder.CreateConstGEP1_32(KernelArgs.getPointer(), i));
  }

  llvm::BasicBlock *EndBlock = CGF.createBasicBlock("setup.end");

  // Lookup cudaLaunchKernel function.
  // cudaError_t cudaLaunchKernel(const void *func, dim3 gridDim, dim3 blockDim,
  //                              void **args, size_t sharedMem,
  //                              cudaStream_t stream);
  TranslationUnitDecl *TUDecl = CGM.getContext().getTranslationUnitDecl();
  DeclContext *DC = TranslationUnitDecl::castToDeclContext(TUDecl);
  IdentifierInfo &cudaLaunchKernelII =
      CGM.getContext().Idents.get("cudaLaunchKernel");
  FunctionDecl *cudaLaunchKernelFD = nullptr;
  for (const auto &Result : DC->lookup(&cudaLaunchKernelII)) {
    if (FunctionDecl *FD = dyn_cast<FunctionDecl>(Result))
      cudaLaunchKernelFD = FD;
  }

  if (cudaLaunchKernelFD == nullptr) {
    CGM.Error(CGF.CurFuncDecl->getLocation(),
              "Can't find declaration for cudaLaunchKernel()");
    return;
  }
  // Create temporary dim3 grid_dim, block_dim.
  ParmVarDecl *GridDimParam = cudaLaunchKernelFD->getParamDecl(1);
  QualType Dim3Ty = GridDimParam->getType();
  Address GridDim =
      CGF.CreateMemTemp(Dim3Ty, CharUnits::fromQuantity(8), "grid_dim");
  Address BlockDim =
      CGF.CreateMemTemp(Dim3Ty, CharUnits::fromQuantity(8), "block_dim");
  Address ShmemSize =
      CGF.CreateTempAlloca(SizeTy, CGM.getSizeAlign(), "shmem_size");
  Address Stream =
      CGF.CreateTempAlloca(VoidPtrTy, CGM.getPointerAlign(), "stream");
  llvm::FunctionCallee cudaPopConfigFn = CGM.CreateRuntimeFunction(
      llvm::FunctionType::get(IntTy,
                              {/*gridDim=*/GridDim.getType(),
                               /*blockDim=*/BlockDim.getType(),
                               /*ShmemSize=*/ShmemSize.getType(),
                               /*Stream=*/Stream.getType()},
                              /*isVarArg=*/false),
      "__cudaPopCallConfiguration");

  CGF.EmitRuntimeCallOrInvoke(cudaPopConfigFn,
                              {GridDim.getPointer(), BlockDim.getPointer(),
                               ShmemSize.getPointer(), Stream.getPointer()});

  // Emit the call to cudaLaunch
  llvm::Value *Kernel = CGF.Builder.CreatePointerCast(CGF.CurFn, VoidPtrTy);
  CallArgList LaunchKernelArgs;
  LaunchKernelArgs.add(RValue::get(Kernel),
                       cudaLaunchKernelFD->getParamDecl(0)->getType());
  LaunchKernelArgs.add(RValue::getAggregate(GridDim), Dim3Ty);
  LaunchKernelArgs.add(RValue::getAggregate(BlockDim), Dim3Ty);
  LaunchKernelArgs.add(RValue::get(KernelArgs.getPointer()),
                       cudaLaunchKernelFD->getParamDecl(3)->getType());
  LaunchKernelArgs.add(RValue::get(CGF.Builder.CreateLoad(ShmemSize)),
                       cudaLaunchKernelFD->getParamDecl(4)->getType());
  LaunchKernelArgs.add(RValue::get(CGF.Builder.CreateLoad(Stream)),
                       cudaLaunchKernelFD->getParamDecl(5)->getType());

  QualType QT = cudaLaunchKernelFD->getType();
  QualType CQT = QT.getCanonicalType();
  llvm::Type *Ty = CGM.getTypes().ConvertType(CQT);
  llvm::FunctionType *FTy = dyn_cast<llvm::FunctionType>(Ty);

  const CGFunctionInfo &FI =
      CGM.getTypes().arrangeFunctionDeclaration(cudaLaunchKernelFD);
  llvm::FunctionCallee cudaLaunchKernelFn =
      CGM.CreateRuntimeFunction(FTy, "cudaLaunchKernel");
  CGF.EmitCall(FI, CGCallee::forDirect(cudaLaunchKernelFn), ReturnValueSlot(),
               LaunchKernelArgs);
  CGF.EmitBranch(EndBlock);

  CGF.EmitBlock(EndBlock);
}