1 //===----- CGCUDARuntime.h - Interface to CUDA Runtimes ---------*- C++ -*-===//
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 an abstract class for CUDA code generation.  Concrete
10 // subclasses of this implement code generation for specific CUDA
11 // runtime libraries.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_CLANG_LIB_CODEGEN_CGCUDARUNTIME_H
16 #define LLVM_CLANG_LIB_CODEGEN_CGCUDARUNTIME_H
17 
18 #include "clang/AST/GlobalDecl.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/Frontend/Offloading/Utility.h"
21 #include "llvm/IR/GlobalValue.h"
22 
23 namespace llvm {
24 class Function;
25 class GlobalVariable;
26 }
27 
28 namespace clang {
29 
30 class CUDAKernelCallExpr;
31 class NamedDecl;
32 class VarDecl;
33 
34 namespace CodeGen {
35 
36 class CodeGenFunction;
37 class CodeGenModule;
38 class FunctionArgList;
39 class ReturnValueSlot;
40 class RValue;
41 
42 class CGCUDARuntime {
43 protected:
44   CodeGenModule &CGM;
45 
46 public:
47   // Global variable properties that must be passed to CUDA runtime.
48   class DeviceVarFlags {
49   public:
50     enum DeviceVarKind {
51       Variable, // Variable
52       Surface,  // Builtin surface
53       Texture,  // Builtin texture
54     };
55 
56   private:
57     unsigned Kind : 2;
58     unsigned Extern : 1;
59     unsigned Constant : 1;   // Constant variable.
60     unsigned Managed : 1;    // Managed variable.
61     unsigned Normalized : 1; // Normalized texture.
62     int SurfTexType;         // Type of surface/texutre.
63 
64   public:
65     DeviceVarFlags(DeviceVarKind K, bool E, bool C, bool M, bool N, int T)
66         : Kind(K), Extern(E), Constant(C), Managed(M), Normalized(N),
67           SurfTexType(T) {}
68 
69     DeviceVarKind getKind() const { return static_cast<DeviceVarKind>(Kind); }
70     bool isExtern() const { return Extern; }
71     bool isConstant() const { return Constant; }
72     bool isManaged() const { return Managed; }
73     bool isNormalized() const { return Normalized; }
74     int getSurfTexType() const { return SurfTexType; }
75   };
76 
77   CGCUDARuntime(CodeGenModule &CGM) : CGM(CGM) {}
78   virtual ~CGCUDARuntime();
79 
80   virtual RValue EmitCUDAKernelCallExpr(CodeGenFunction &CGF,
81                                         const CUDAKernelCallExpr *E,
82                                         ReturnValueSlot ReturnValue);
83 
84   /// Emits a kernel launch stub.
85   virtual void emitDeviceStub(CodeGenFunction &CGF, FunctionArgList &Args) = 0;
86 
87   /// Check whether a variable is a device variable and register it if true.
88   virtual void handleVarRegistration(const VarDecl *VD,
89                                      llvm::GlobalVariable &Var) = 0;
90 
91   /// Finalize generated LLVM module. Returns a module constructor function
92   /// to be added or a null pointer.
93   virtual llvm::Function *finalizeModule() = 0;
94 
95   /// Returns function or variable name on device side even if the current
96   /// compilation is for host.
97   virtual std::string getDeviceSideName(const NamedDecl *ND) = 0;
98 
99   /// Get kernel handle by stub function.
100   virtual llvm::GlobalValue *getKernelHandle(llvm::Function *Stub,
101                                              GlobalDecl GD) = 0;
102 
103   /// Get kernel stub by kernel handle.
104   virtual llvm::Function *getKernelStub(llvm::GlobalValue *Handle) = 0;
105 
106   /// Adjust linkage of shadow variables in host compilation.
107   virtual void
108   internalizeDeviceSideVar(const VarDecl *D,
109                            llvm::GlobalValue::LinkageTypes &Linkage) = 0;
110 };
111 
112 /// Creates an instance of a CUDA runtime class.
113 CGCUDARuntime *CreateNVCUDARuntime(CodeGenModule &CGM);
114 
115 }
116 }
117 
118 #endif
119