LoongArchELFStreamer.cpp

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//===-- LoongArchELFStreamer.cpp - LoongArch ELF Target Streamer Methods --===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file provides LoongArch specific target streamer methods.
//
//===----------------------------------------------------------------------===//
 
#include "LoongArchELFStreamer.h"
#include "LoongArchAsmBackend.h"
#include "LoongArchBaseInfo.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/MC/MCSection.h"
 
using namespace llvm;
 
// This part is for ELF object output.
LoongArchTargetELFStreamer::LoongArchTargetELFStreamer(
    MCStreamer &S, const MCSubtargetInfo &STI)
    : LoongArchTargetStreamer(S) {
  auto &MAB = static_cast<LoongArchAsmBackend &>(
      getStreamer().getAssembler().getBackend());
  setTargetABI(LoongArchABI::computeTargetABI(
      STI.getTargetTriple(), STI.getFeatureBits(),
      MAB.getTargetOptions().getABIName()));
}
 
MCELFStreamer &LoongArchTargetELFStreamer::getStreamer() {
  return static_cast<MCELFStreamer &>(Streamer);
}
 
void LoongArchTargetELFStreamer::emitDirectiveOptionPush() {}
void LoongArchTargetELFStreamer::emitDirectiveOptionPop() {}
void LoongArchTargetELFStreamer::emitDirectiveOptionRelax() {}
void LoongArchTargetELFStreamer::emitDirectiveOptionNoRelax() {}
 
void LoongArchTargetELFStreamer::emitDTPRel32Value(const MCExpr *Value) {
  auto &S = getStreamer();
  S.ensureHeadroom(4);
  S.addFixup(Value, LoongArch::fixup_loongarch_dtprel32);
  S.appendContents(4, 0);
}
 
void LoongArchTargetELFStreamer::emitDTPRel64Value(const MCExpr *Value) {
  auto &S = getStreamer();
  S.ensureHeadroom(8);
  S.addFixup(Value, LoongArch::fixup_loongarch_dtprel64);
  S.appendContents(8, 0);
}
 
void LoongArchTargetELFStreamer::finish() {
  LoongArchTargetStreamer::finish();
  ELFObjectWriter &W = getStreamer().getWriter();
  LoongArchABI::ABI ABI = getTargetABI();
 
  // Figure out the e_flags.
  //
  // Bitness is already represented with the EI_CLASS byte in the current spec,
  // so here we only record the base ABI modifier. Also set the object file ABI
  // version to v1, as upstream LLVM cannot handle the previous stack-machine-
  // based relocs from day one.
  //
  // Refer to LoongArch ELF psABI v2.01 for details.
  unsigned EFlags = W.getELFHeaderEFlags();
  EFlags |= ELF::EF_LOONGARCH_OBJABI_V1;
  switch (ABI) {
  case LoongArchABI::ABI_ILP32S:
  case LoongArchABI::ABI_LP64S:
    EFlags |= ELF::EF_LOONGARCH_ABI_SOFT_FLOAT;
    break;
  case LoongArchABI::ABI_ILP32F:
  case LoongArchABI::ABI_LP64F:
    EFlags |= ELF::EF_LOONGARCH_ABI_SINGLE_FLOAT;
    break;
  case LoongArchABI::ABI_ILP32D:
  case LoongArchABI::ABI_LP64D:
    EFlags |= ELF::EF_LOONGARCH_ABI_DOUBLE_FLOAT;
    break;
  case LoongArchABI::ABI_Unknown:
    llvm_unreachable("Improperly initialized target ABI");
  }
  W.setELFHeaderEFlags(EFlags);
}
 
void LoongArchELFStreamer::emitCodeAlignment(Align Alignment,
                                             const MCSubtargetInfo &STI,
                                             unsigned MaxBytesToEmit) {
  // Save the Align fragment.
  auto *AlignFrag = getCurrentFragment();
  MCELFStreamer::emitCodeAlignment(Alignment, STI, MaxBytesToEmit);
 
  // Pre-mark the Align fragment as linker-relaxable.
  if (LoongArchAsmBackend::shouldRelaxAlign(*AlignFrag))
    AlignFrag->setLinkerRelaxable();
}
 
namespace llvm {
MCELFStreamer *createLoongArchELFStreamer(MCContext &C,
                                          std::unique_ptr<MCAsmBackend> MAB,
                                          std::unique_ptr<MCObjectWriter> MOW,
                                          std::unique_ptr<MCCodeEmitter> MCE) {
  LoongArchELFStreamer *S = new LoongArchELFStreamer(
      C, std::move(MAB), std::move(MOW), std::move(MCE));
  return S;
}
} // end namespace llvm