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
13#include "mlir/Target/SPIRV/SPIRVBinaryUtils.h"
14#include "mlir/Dialect/SPIRV/IR/SPIRVTypes.h"
15#include "llvm/Config/llvm-config.h" // for LLVM_VERSION_MAJOR
16#include "llvm/Support/Debug.h"
17
18#define DEBUG_TYPE "spirv-binary-utils"
19
20using namespace mlir;
21
22void spirv::appendModuleHeader(SmallVectorImpl<uint32_t> &header,
23 spirv::Version version, uint32_t idBound) {
24 uint32_t majorVersion = 1;
25 uint32_t minorVersion = 0;
26 switch (version) {
27#define MIN_VERSION_CASE(v) \
28 case spirv::Version::V_1_##v: \
29 minorVersion = v; \
30 break
31
32 MIN_VERSION_CASE(0);
33 MIN_VERSION_CASE(1);
34 MIN_VERSION_CASE(2);
35 MIN_VERSION_CASE(3);
36 MIN_VERSION_CASE(4);
37 MIN_VERSION_CASE(5);
38 MIN_VERSION_CASE(6);
39#undef MIN_VERSION_CASE
40 }
41
42 // See "2.3. Physical Layout of a SPIR-V Module and Instruction" in the SPIR-V
43 // spec for the definition of the binary module header.
44 //
45 // The first five words of a SPIR-V module must be:
46 // +-------------------------------------------------------------------------+
47 // | Magic number |
48 // +-------------------------------------------------------------------------+
49 // | Version number (bytes: 0 | major number | minor number | 0) |
50 // +-------------------------------------------------------------------------+
51 // | Generator magic number |
52 // +-------------------------------------------------------------------------+
53 // | Bound (all result <id>s in the module guaranteed to be less than it) |
54 // +-------------------------------------------------------------------------+
55 // | 0 (reserved for instruction schema) |
56 // +-------------------------------------------------------------------------+
57 header.push_back(Elt: spirv::kMagicNumber);
58 header.push_back(Elt: (majorVersion << 16) | (minorVersion << 8));
59 header.push_back(Elt: (kGeneratorNumber << 16) | LLVM_VERSION_MAJOR);
60 header.push_back(Elt: idBound); // <id> bound
61 header.push_back(Elt: 0); // Schema (reserved word)
62}
63
64/// Returns the word-count-prefixed opcode for an SPIR-V instruction.
65uint32_t spirv::getPrefixedOpcode(uint32_t wordCount, spirv::Opcode opcode) {
66 assert(((wordCount >> 16) == 0) && "word count out of range!");
67 return (wordCount << 16) | static_cast<uint32_t>(opcode);
68}
69
70void spirv::encodeStringLiteralInto(SmallVectorImpl<uint32_t> &binary,
71 StringRef literal) {
72 // We need to encode the literal and the null termination.
73 size_t encodingSize = literal.size() / 4 + 1;
74 size_t sizeOfDataToCopy = literal.size();
75 if (encodingSize >= kMaxLiteralWordCount) {
76 // Reserve one word for the null termination.
77 encodingSize = kMaxLiteralWordCount - 1;
78 // Do not override the last word (null termination) when copying.
79 sizeOfDataToCopy = (encodingSize - 1) * 4;
80 LLVM_DEBUG(llvm::dbgs()
81 << "Truncating string literal to max size ("
82 << (kMaxLiteralWordCount - 1) << "): " << literal << "\n");
83 }
84 size_t bufferStartSize = binary.size();
85 binary.resize(N: bufferStartSize + encodingSize, NV: 0);
86 std::memcpy(dest: binary.data() + bufferStartSize, src: literal.data(),
87 n: sizeOfDataToCopy);
88}
89

source code of mlir/lib/Target/SPIRV/SPIRVBinaryUtils.cpp