1//===- llvm/MC/MCSPIRVObjectWriter.cpp - SPIR-V Object Writer ----*- 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#include "llvm/MC/MCAssembler.h"
10#include "llvm/MC/MCSPIRVObjectWriter.h"
11#include "llvm/MC/MCSection.h"
12#include "llvm/MC/MCValue.h"
13#include "llvm/Support/EndianStream.h"
14
15using namespace llvm;
16
17namespace {
18class SPIRVObjectWriter : public MCObjectWriter {
19 ::support::endian::Writer W;
20
21 /// The target specific SPIR-V writer instance.
22 std::unique_ptr<MCSPIRVObjectTargetWriter> TargetObjectWriter;
23
24public:
25 SPIRVObjectWriter(std::unique_ptr<MCSPIRVObjectTargetWriter> MOTW,
26 raw_pwrite_stream &OS)
27 : W(OS, llvm::endianness::little), TargetObjectWriter(std::move(MOTW)) {}
28
29 ~SPIRVObjectWriter() override {}
30
31private:
32 void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout,
33 const MCFragment *Fragment, const MCFixup &Fixup,
34 MCValue Target, uint64_t &FixedValue) override {}
35
36 void executePostLayoutBinding(MCAssembler &Asm,
37 const MCAsmLayout &Layout) override {}
38
39 uint64_t writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
40 void writeHeader(const MCAssembler &Asm);
41};
42} // namespace
43
44void SPIRVObjectWriter::writeHeader(const MCAssembler &Asm) {
45 constexpr uint32_t MagicNumber = 0x07230203;
46
47 // TODO: set the version on a min-necessary basis (just like the translator
48 // does) requires some refactoring of MCAssembler::VersionInfoType.
49 constexpr uint32_t Major = 1;
50 constexpr uint32_t Minor = 0;
51 constexpr uint32_t VersionNumber = 0 | (Major << 16) | (Minor << 8);
52 // TODO: check if we could use anything other than 0 (spec allows).
53 constexpr uint32_t GeneratorMagicNumber = 0;
54 // TODO: do not hardcode this as well.
55 constexpr uint32_t Bound = 900;
56 constexpr uint32_t Schema = 0;
57
58 W.write<uint32_t>(Val: MagicNumber);
59 W.write<uint32_t>(Val: VersionNumber);
60 W.write<uint32_t>(Val: GeneratorMagicNumber);
61 W.write<uint32_t>(Val: Bound);
62 W.write<uint32_t>(Val: Schema);
63}
64
65uint64_t SPIRVObjectWriter::writeObject(MCAssembler &Asm,
66 const MCAsmLayout &Layout) {
67 uint64_t StartOffset = W.OS.tell();
68 writeHeader(Asm);
69 for (const MCSection &S : Asm)
70 Asm.writeSectionData(OS&: W.OS, Section: &S, Layout);
71 return W.OS.tell() - StartOffset;
72}
73
74std::unique_ptr<MCObjectWriter>
75llvm::createSPIRVObjectWriter(std::unique_ptr<MCSPIRVObjectTargetWriter> MOTW,
76 raw_pwrite_stream &OS) {
77 return std::make_unique<SPIRVObjectWriter>(args: std::move(MOTW), args&: OS);
78}
79

source code of llvm/lib/MC/SPIRVObjectWriter.cpp