llvm/lib/MC/SPIRVObjectWriter.cpp

   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 void SPIRVObjectWriter::writeHeader(const MCAssembler &Asm) {
  18   constexpr uint32_t MagicNumber = 0x07230203;
  19   constexpr uint32_t GeneratorID = 43;
  20   constexpr uint32_t GeneratorMagicNumber =
  21       (GeneratorID << 16) | (LLVM_VERSION_MAJOR);
  22   constexpr uint32_t Schema = 0;
  23
  24   W.write<uint32_t>(MagicNumber);
  25   W.write<uint32_t>((VersionInfo.Major << 16) | (VersionInfo.Minor << 8));
  26   W.write<uint32_t>(GeneratorMagicNumber);
  27   W.write<uint32_t>(VersionInfo.Bound);
  28   W.write<uint32_t>(Schema);
  29 }
  30
  31 void SPIRVObjectWriter::setBuildVersion(unsigned Major, unsigned Minor,
  32                                         unsigned Bound) {
  33   VersionInfo.Major = Major;
  34   VersionInfo.Minor = Minor;
  35   VersionInfo.Bound = Bound;
  36 }
  37
  38 uint64_t SPIRVObjectWriter::writeObject(MCAssembler &Asm) {
  39   uint64_t StartOffset = W.OS.tell();
  40   writeHeader(Asm);
  41   for (const MCSection &S : Asm)
  42     Asm.writeSectionData(W.OS, &S);
  43   return W.OS.tell() - StartOffset;
  44 }
  45
  46 std::unique_ptr<MCObjectWriter>
  47 llvm::createSPIRVObjectWriter(std::unique_ptr<MCSPIRVObjectTargetWriter> MOTW,
  48                               raw_pwrite_stream &OS) {
  49   return std::make_unique<SPIRVObjectWriter>(std::move(MOTW), OS);
  50 }