HexagonMCELFStreamer.cpp
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//=== HexagonMCELFStreamer.cpp - Hexagon subclass of MCELFStreamer -------===//
//
// 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 is a stub that parses a MCInst bundle and passes the
// instructions on to the real streamer.
//
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "hexagonmcelfstreamer"
#include "MCTargetDesc/HexagonMCELFStreamer.h"
#include "MCTargetDesc/HexagonMCInstrInfo.h"
#include "MCTargetDesc/HexagonMCShuffler.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/BinaryFormat/ELF.h"
#include "llvm/MC/MCAsmBackend.h"
#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCCodeEmitter.h"
#include "llvm/MC/MCContext.h"
#include "llvm/MC/MCExpr.h"
#include "llvm/MC/MCInst.h"
#include "llvm/MC/MCObjectStreamer.h"
#include "llvm/MC/MCObjectWriter.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSectionELF.h"
#include "llvm/MC/MCStreamer.h"
#include "llvm/MC/MCSymbol.h"
#include "llvm/MC/MCSymbolELF.h"
#include "llvm/Support/Casting.h"
#include "llvm/Support/CommandLine.h"
#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/MathExtras.h"
#include <cassert>
#include <cstdint>
using namespace llvm;
static cl::opt<unsigned> GPSize
("gpsize", cl::NotHidden,
cl::desc("Global Pointer Addressing Size. The default size is 8."),
cl::Prefix,
cl::init(8));
HexagonMCELFStreamer::HexagonMCELFStreamer(
MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter)
: MCELFStreamer(Context, std::move(TAB), std::move(OW), std::move(Emitter)),
MCII(createHexagonMCInstrInfo()) {}
HexagonMCELFStreamer::HexagonMCELFStreamer(
MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter,
MCAssembler *Assembler)
: MCELFStreamer(Context, std::move(TAB), std::move(OW), std::move(Emitter)),
MCII(createHexagonMCInstrInfo()) {}
void HexagonMCELFStreamer::emitInstruction(const MCInst &MCB,
const MCSubtargetInfo &STI) {
assert(MCB.getOpcode() == Hexagon::BUNDLE);
assert(HexagonMCInstrInfo::bundleSize(MCB) <= HEXAGON_PACKET_SIZE);
assert(HexagonMCInstrInfo::bundleSize(MCB) > 0);
// At this point, MCB is a bundle
// Iterate through the bundle and assign addends for the instructions
for (auto const &I : HexagonMCInstrInfo::bundleInstructions(MCB)) {
MCInst *MCI = const_cast<MCInst *>(I.getInst());
EmitSymbol(*MCI);
}
MCObjectStreamer::emitInstruction(MCB, STI);
}
void HexagonMCELFStreamer::EmitSymbol(const MCInst &Inst) {
// Scan for values.
for (unsigned i = Inst.getNumOperands(); i--;)
if (Inst.getOperand(i).isExpr())
visitUsedExpr(*Inst.getOperand(i).getExpr());
}
// EmitCommonSymbol and EmitLocalCommonSymbol are extended versions of the
// functions found in MCELFStreamer.cpp taking AccessSize as an additional
// parameter.
void HexagonMCELFStreamer::HexagonMCEmitCommonSymbol(MCSymbol *Symbol,
uint64_t Size,
unsigned ByteAlignment,
unsigned AccessSize) {
getAssembler().registerSymbol(*Symbol);
StringRef sbss[4] = {".sbss.1", ".sbss.2", ".sbss.4", ".sbss.8"};
auto ELFSymbol = cast<MCSymbolELF>(Symbol);
if (!ELFSymbol->isBindingSet()) {
ELFSymbol->setBinding(ELF::STB_GLOBAL);
ELFSymbol->setExternal(true);
}
ELFSymbol->setType(ELF::STT_OBJECT);
if (ELFSymbol->getBinding() == ELF::STB_LOCAL) {
StringRef SectionName =
((AccessSize == 0) || (Size == 0) || (Size > GPSize))
? ".bss"
: sbss[(Log2_64(AccessSize))];
MCSection &Section = *getAssembler().getContext().getELFSection(
SectionName, ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
MCSectionSubPair P = getCurrentSection();
SwitchSection(&Section);
if (ELFSymbol->isUndefined()) {
emitValueToAlignment(ByteAlignment, 0, 1, 0);
emitLabel(Symbol);
emitZeros(Size);
}
// Update the maximum alignment of the section if necessary.
if (Align(ByteAlignment) > Section.getAlignment())
Section.setAlignment(Align(ByteAlignment));
SwitchSection(P.first, P.second);
} else {
if (ELFSymbol->declareCommon(Size, ByteAlignment))
report_fatal_error("Symbol: " + Symbol->getName() +
" redeclared as different type");
if ((AccessSize) && (Size <= GPSize)) {
uint64_t SectionIndex =
(AccessSize <= GPSize)
? ELF::SHN_HEXAGON_SCOMMON + (Log2_64(AccessSize) + 1)
: (unsigned)ELF::SHN_HEXAGON_SCOMMON;
ELFSymbol->setIndex(SectionIndex);
}
}
ELFSymbol->setSize(MCConstantExpr::create(Size, getContext()));
}
void HexagonMCELFStreamer::HexagonMCEmitLocalCommonSymbol(MCSymbol *Symbol,
uint64_t Size,
unsigned ByteAlignment,
unsigned AccessSize) {
getAssembler().registerSymbol(*Symbol);
auto ELFSymbol = cast<MCSymbolELF>(Symbol);
ELFSymbol->setBinding(ELF::STB_LOCAL);
ELFSymbol->setExternal(false);
HexagonMCEmitCommonSymbol(Symbol, Size, ByteAlignment, AccessSize);
}
namespace llvm {
MCStreamer *createHexagonELFStreamer(Triple const &TT, MCContext &Context,
std::unique_ptr<MCAsmBackend> MAB,
std::unique_ptr<MCObjectWriter> OW,
std::unique_ptr<MCCodeEmitter> CE) {
return new HexagonMCELFStreamer(Context, std::move(MAB), std::move(OW),
std::move(CE));
}
} // end namespace llvm