xref: /llvm-project/llvm/include/llvm/Frontend/Offloading/Utility.h (revision 13dcc95dcd4999ff99f2de89d881f1aed5b21709)
1 //===- Utility.h - Collection of geneirc offloading utilities -------------===//
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 #ifndef LLVM_FRONTEND_OFFLOADING_UTILITY_H
10 #define LLVM_FRONTEND_OFFLOADING_UTILITY_H
11 
12 #include <cstdint>
13 
14 #include "llvm/ADT/StringMap.h"
15 #include "llvm/ADT/StringRef.h"
16 #include "llvm/IR/Module.h"
17 #include "llvm/Object/OffloadBinary.h"
18 #include "llvm/Support/Error.h"
19 #include "llvm/Support/MemoryBufferRef.h"
20 
21 namespace llvm {
22 namespace offloading {
23 
24 /// This is the record of an object that just be registered with the offloading
25 /// runtime.
26 struct EntryTy {
27   /// Reserved bytes used to detect an older version of the struct, always zero.
28   uint64_t Reserved = 0x0;
29   /// The current version of the struct for runtime forward compatibility.
30   uint16_t Version = 0x1;
31   /// The expected consumer of this entry, e.g. CUDA or OpenMP.
32   uint16_t Kind;
33   /// Flags associated with the global.
34   uint32_t Flags;
35   /// The address of the global to be registered by the runtime.
36   void *Address;
37   /// The name of the symbol in the device image.
38   char *SymbolName;
39   /// The number of bytes the symbol takes.
40   uint64_t Size;
41   /// Extra generic data used to register this entry.
42   uint64_t Data;
43   /// An extra pointer, usually null.
44   void *AuxAddr;
45 };
46 
47 /// Offloading entry flags for CUDA / HIP. The first three bits indicate the
48 /// type of entry while the others are a bit field for additional information.
49 enum OffloadEntryKindFlag : uint32_t {
50   /// Mark the entry as a global entry. This indicates the presense of a
51   /// kernel if the size size field is zero and a variable otherwise.
52   OffloadGlobalEntry = 0x0,
53   /// Mark the entry as a managed global variable.
54   OffloadGlobalManagedEntry = 0x1,
55   /// Mark the entry as a surface variable.
56   OffloadGlobalSurfaceEntry = 0x2,
57   /// Mark the entry as a texture variable.
58   OffloadGlobalTextureEntry = 0x3,
59   /// Mark the entry as being extern.
60   OffloadGlobalExtern = 0x1 << 3,
61   /// Mark the entry as being constant.
62   OffloadGlobalConstant = 0x1 << 4,
63   /// Mark the entry as being a normalized surface.
64   OffloadGlobalNormalized = 0x1 << 5,
65 };
66 
67 /// Returns the type of the offloading entry we use to store kernels and
68 /// globals that will be registered with the offloading runtime.
69 StructType *getEntryTy(Module &M);
70 
71 /// Create an offloading section struct used to register this global at
72 /// runtime.
73 ///
74 /// \param M The module to be used
75 /// \param Addr The pointer to the global being registered.
76 /// \param Kind The offloading language expected to consume this.
77 /// \param Name The symbol name associated with the global.
78 /// \param Size The size in bytes of the global (0 for functions).
79 /// \param Flags Flags associated with the entry.
80 /// \param Data Extra data storage associated with the entry.
81 /// \param SectionName The section this entry will be placed at.
82 /// \param AuxAddr An extra pointer if needed.
83 void emitOffloadingEntry(Module &M, object::OffloadKind Kind, Constant *Addr,
84                          StringRef Name, uint64_t Size, uint32_t Flags,
85                          uint64_t Data, StringRef SectionName,
86                          Constant *AuxAddr = nullptr);
87 
88 /// Create a constant struct initializer used to register this global at
89 /// runtime.
90 /// \return the constant struct and the global variable holding the symbol name.
91 std::pair<Constant *, GlobalVariable *>
92 getOffloadingEntryInitializer(Module &M, object::OffloadKind Kind,
93                               Constant *Addr, StringRef Name, uint64_t Size,
94                               uint32_t Flags, uint64_t Data, Constant *AuxAddr);
95 
96 /// Creates a pair of globals used to iterate the array of offloading entries by
97 /// accessing the section variables provided by the linker.
98 std::pair<GlobalVariable *, GlobalVariable *>
99 getOffloadEntryArray(Module &M, StringRef SectionName);
100 
101 namespace amdgpu {
102 /// Check if an image is compatible with current system's environment. The
103 /// system environment is given as a 'target-id' which has the form:
104 ///
105 /// <target-id> := <processor> ( ":" <target-feature> ( "+" | "-" ) )*
106 ///
107 /// If a feature is not specific as '+' or '-' it is assumed to be in an 'any'
108 /// and is compatible with either '+' or '-'. The HSA runtime returns this
109 /// information using the target-id, while we use the ELF header to determine
110 /// these features.
111 bool isImageCompatibleWithEnv(StringRef ImageArch, uint32_t ImageFlags,
112                               StringRef EnvTargetID);
113 
114 /// Struct for holding metadata related to AMDGPU kernels, for more information
115 /// about the metadata and its meaning see:
116 /// https://llvm.org/docs/AMDGPUUsage.html#code-object-v3
117 struct AMDGPUKernelMetaData {
118   /// Constant indicating that a value is invalid.
119   static constexpr uint32_t KInvalidValue =
120       std::numeric_limits<uint32_t>::max();
121   /// The amount of group segment memory required by a work-group in bytes.
122   uint32_t GroupSegmentList = KInvalidValue;
123   /// The amount of fixed private address space memory required for a work-item
124   /// in bytes.
125   uint32_t PrivateSegmentSize = KInvalidValue;
126   /// Number of scalar registers required by a wavefront.
127   uint32_t SGPRCount = KInvalidValue;
128   /// Number of vector registers required by each work-item.
129   uint32_t VGPRCount = KInvalidValue;
130   /// Number of stores from a scalar register to a register allocator created
131   /// spill location.
132   uint32_t SGPRSpillCount = KInvalidValue;
133   /// Number of stores from a vector register to a register allocator created
134   /// spill location.
135   uint32_t VGPRSpillCount = KInvalidValue;
136   /// Number of accumulator registers required by each work-item.
137   uint32_t AGPRCount = KInvalidValue;
138   /// Corresponds to the OpenCL reqd_work_group_size attribute.
139   uint32_t RequestedWorkgroupSize[3] = {KInvalidValue, KInvalidValue,
140                                         KInvalidValue};
141   /// Corresponds to the OpenCL work_group_size_hint attribute.
142   uint32_t WorkgroupSizeHint[3] = {KInvalidValue, KInvalidValue, KInvalidValue};
143   /// Wavefront size.
144   uint32_t WavefrontSize = KInvalidValue;
145   /// Maximum flat work-group size supported by the kernel in work-items.
146   uint32_t MaxFlatWorkgroupSize = KInvalidValue;
147 };
148 
149 /// Reads AMDGPU specific metadata from the ELF file and propagates the
150 /// KernelInfoMap.
151 Error getAMDGPUMetaDataFromImage(MemoryBufferRef MemBuffer,
152                                  StringMap<AMDGPUKernelMetaData> &KernelInfoMap,
153                                  uint16_t &ELFABIVersion);
154 } // namespace amdgpu
155 } // namespace offloading
156 } // namespace llvm
157 
158 #endif // LLVM_FRONTEND_OFFLOADING_UTILITY_H
159