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/Dialect/SPIRV/SPIRVBinaryUtils.h"
14 #include "mlir/Dialect/SPIRV/SPIRVTypes.h"
15
16 using namespace mlir;
17
appendModuleHeader(SmallVectorImpl<uint32_t> & header,spirv::Version version,uint32_t idBound)18 void spirv::appendModuleHeader(SmallVectorImpl<uint32_t> &header,
19 spirv::Version version, uint32_t idBound) {
20 uint32_t majorVersion = 1;
21 uint32_t minorVersion = 0;
22 switch (version) {
23 #define MIN_VERSION_CASE(v) \
24 case spirv::Version::V_1_##v: \
25 minorVersion = v; \
26 break
27
28 MIN_VERSION_CASE(0);
29 MIN_VERSION_CASE(1);
30 MIN_VERSION_CASE(2);
31 MIN_VERSION_CASE(3);
32 MIN_VERSION_CASE(4);
33 MIN_VERSION_CASE(5);
34 #undef MIN_VERSION_CASE
35 }
36
37 // See "2.3. Physical Layout of a SPIR-V Module and Instruction" in the SPIR-V
38 // spec for the definition of the binary module header.
39 //
40 // The first five words of a SPIR-V module must be:
41 // +-------------------------------------------------------------------------+
42 // | Magic number |
43 // +-------------------------------------------------------------------------+
44 // | Version number (bytes: 0 | major number | minor number | 0) |
45 // +-------------------------------------------------------------------------+
46 // | Generator magic number |
47 // +-------------------------------------------------------------------------+
48 // | Bound (all result <id>s in the module guaranteed to be less than it) |
49 // +-------------------------------------------------------------------------+
50 // | 0 (reserved for instruction schema) |
51 // +-------------------------------------------------------------------------+
52 header.push_back(spirv::kMagicNumber);
53 header.push_back((majorVersion << 16) | (minorVersion << 8));
54 header.push_back(kGeneratorNumber);
55 header.push_back(idBound); // <id> bound
56 header.push_back(0); // Schema (reserved word)
57 }
58
59 /// Returns the word-count-prefixed opcode for an SPIR-V instruction.
getPrefixedOpcode(uint32_t wordCount,spirv::Opcode opcode)60 uint32_t spirv::getPrefixedOpcode(uint32_t wordCount, spirv::Opcode opcode) {
61 assert(((wordCount >> 16) == 0) && "word count out of range!");
62 return (wordCount << 16) | static_cast<uint32_t>(opcode);
63 }
64
encodeStringLiteralInto(SmallVectorImpl<uint32_t> & binary,StringRef literal)65 LogicalResult spirv::encodeStringLiteralInto(SmallVectorImpl<uint32_t> &binary,
66 StringRef literal) {
67 // We need to encode the literal and the null termination.
68 auto encodingSize = literal.size() / 4 + 1;
69 auto bufferStartSize = binary.size();
70 binary.resize(bufferStartSize + encodingSize, 0);
71 std::memcpy(binary.data() + bufferStartSize, literal.data(), literal.size());
72 return success();
73 }
74