MLIR  22.0.0git
SPIRVBinaryUtils.cpp
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1 //===- SPIRVBinaryUtils.cpp - MLIR SPIR-V Binary Module 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 // This file defines common utilities for SPIR-V binary module.
10 //
11 //===----------------------------------------------------------------------===//
12 
14 #include "llvm/Config/llvm-config.h" // for LLVM_VERSION_MAJOR
15 #include "llvm/Support/Debug.h"
16 
17 #define DEBUG_TYPE "spirv-binary-utils"
18 
19 using namespace mlir;
20 
22  spirv::Version version, uint32_t idBound) {
23  uint32_t majorVersion = 1;
24  uint32_t minorVersion = 0;
25  switch (version) {
26 #define MIN_VERSION_CASE(v) \
27  case spirv::Version::V_1_##v: \
28  minorVersion = v; \
29  break
30 
38 #undef MIN_VERSION_CASE
39  }
40 
41  // See "2.3. Physical Layout of a SPIR-V Module and Instruction" in the SPIR-V
42  // spec for the definition of the binary module header.
43  //
44  // The first five words of a SPIR-V module must be:
45  // +-------------------------------------------------------------------------+
46  // | Magic number |
47  // +-------------------------------------------------------------------------+
48  // | Version number (bytes: 0 | major number | minor number | 0) |
49  // +-------------------------------------------------------------------------+
50  // | Generator magic number |
51  // +-------------------------------------------------------------------------+
52  // | Bound (all result <id>s in the module guaranteed to be less than it) |
53  // +-------------------------------------------------------------------------+
54  // | 0 (reserved for instruction schema) |
55  // +-------------------------------------------------------------------------+
56  header.push_back(spirv::kMagicNumber);
57  header.push_back((majorVersion << 16) | (minorVersion << 8));
58  header.push_back((kGeneratorNumber << 16) | LLVM_VERSION_MAJOR);
59  header.push_back(idBound); // <id> bound
60  header.push_back(0); // Schema (reserved word)
61 }
62 
63 /// Returns the word-count-prefixed opcode for an SPIR-V instruction.
64 uint32_t spirv::getPrefixedOpcode(uint32_t wordCount, spirv::Opcode opcode) {
65  assert(((wordCount >> 16) == 0) && "word count out of range!");
66  return (wordCount << 16) | static_cast<uint32_t>(opcode);
67 }
68 
70  StringRef literal) {
71  // We need to encode the literal and the null termination.
72  size_t encodingSize = literal.size() / 4 + 1;
73  size_t sizeOfDataToCopy = literal.size();
74  if (encodingSize >= kMaxLiteralWordCount) {
75  // Reserve one word for the null termination.
76  encodingSize = kMaxLiteralWordCount - 1;
77  // Do not override the last word (null termination) when copying.
78  sizeOfDataToCopy = (encodingSize - 1) * 4;
79  LLVM_DEBUG(llvm::dbgs()
80  << "Truncating string literal to max size ("
81  << (kMaxLiteralWordCount - 1) << "): " << literal << "\n");
82  }
83  size_t bufferStartSize = binary.size();
84  binary.resize(bufferStartSize + encodingSize, 0);
85  std::memcpy(binary.data() + bufferStartSize, literal.data(),
86  sizeOfDataToCopy);
87 }
#define MIN_VERSION_CASE(v)
void encodeStringLiteralInto(SmallVectorImpl< uint32_t > &binary, StringRef literal)
Encodes an SPIR-V literal string into the given binary vector.
constexpr uint32_t kMaxLiteralWordCount
Max number of words for literal.
constexpr uint32_t kGeneratorNumber
The serializer tool ID registered to the Khronos Group.
constexpr uint32_t kMagicNumber
SPIR-V magic number.
uint32_t getPrefixedOpcode(uint32_t wordCount, spirv::Opcode opcode)
Returns the word-count-prefixed opcode for an SPIR-V instruction.
void appendModuleHeader(SmallVectorImpl< uint32_t > &header, spirv::Version version, uint32_t idBound)
Appends a SPRI-V module header to header with the given version and idBound.
Include the generated interface declarations.