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