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 15 using namespace llvm; 16 17 namespace { 18 class SPIRVObjectWriter : public MCObjectWriter { 19 ::support::endian::Writer W; 20 21 /// The target specific SPIR-V writer instance. 22 std::unique_ptr<MCSPIRVObjectTargetWriter> TargetObjectWriter; 23 24 public: 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 31 private: 32 void recordRelocation(MCAssembler &Asm, const MCFragment *Fragment, 33 const MCFixup &Fixup, MCValue Target, 34 uint64_t &FixedValue) override {} 35 36 void executePostLayoutBinding(MCAssembler &Asm, 37 const MCAsmLayout &Layout) override {} 38 39 uint64_t writeObject(MCAssembler &Asm) override; 40 void writeHeader(const MCAssembler &Asm); 41 }; 42 } // namespace 43 44 void SPIRVObjectWriter::writeHeader(const MCAssembler &Asm) { 45 constexpr uint32_t MagicNumber = 0x07230203; 46 constexpr uint32_t GeneratorID = 43; 47 constexpr uint32_t GeneratorMagicNumber = 48 (GeneratorID << 16) | (LLVM_VERSION_MAJOR); 49 constexpr uint32_t Schema = 0; 50 const MCAssembler::VersionInfoType &VIT = Asm.getVersionInfo(); 51 uint32_t VersionNumber = 0 | (VIT.Major << 16) | (VIT.Minor << 8); 52 uint32_t Bound = VIT.Update; 53 54 W.write<uint32_t>(MagicNumber); 55 W.write<uint32_t>(VersionNumber); 56 W.write<uint32_t>(GeneratorMagicNumber); 57 W.write<uint32_t>(Bound); 58 W.write<uint32_t>(Schema); 59 } 60 61 uint64_t SPIRVObjectWriter::writeObject(MCAssembler &Asm) { 62 uint64_t StartOffset = W.OS.tell(); 63 writeHeader(Asm); 64 for (const MCSection &S : Asm) 65 Asm.writeSectionData(W.OS, &S); 66 return W.OS.tell() - StartOffset; 67 } 68 69 std::unique_ptr<MCObjectWriter> 70 llvm::createSPIRVObjectWriter(std::unique_ptr<MCSPIRVObjectTargetWriter> MOTW, 71 raw_pwrite_stream &OS) { 72 return std::make_unique<SPIRVObjectWriter>(std::move(MOTW), OS); 73 } 74