1 //=== HexagonMCELFStreamer.cpp - Hexagon subclass of MCELFStreamer -------===//
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 // This file is a stub that parses a MCInst bundle and passes the
10 // instructions on to the real streamer.
11 //
12 //===----------------------------------------------------------------------===//
13
14 #include "MCTargetDesc/HexagonMCELFStreamer.h"
15 #include "MCTargetDesc/HexagonMCInstrInfo.h"
16 #include "MCTargetDesc/HexagonMCShuffler.h"
17 #include "llvm/ADT/StringRef.h"
18 #include "llvm/BinaryFormat/ELF.h"
19 #include "llvm/MC/MCAsmBackend.h"
20 #include "llvm/MC/MCAssembler.h"
21 #include "llvm/MC/MCCodeEmitter.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCExpr.h"
24 #include "llvm/MC/MCInst.h"
25 #include "llvm/MC/MCObjectStreamer.h"
26 #include "llvm/MC/MCObjectWriter.h"
27 #include "llvm/MC/MCSection.h"
28 #include "llvm/MC/MCSectionELF.h"
29 #include "llvm/MC/MCStreamer.h"
30 #include "llvm/MC/MCSymbol.h"
31 #include "llvm/MC/MCSymbolELF.h"
32 #include "llvm/Support/Casting.h"
33 #include "llvm/Support/CommandLine.h"
34 #include "llvm/Support/ErrorHandling.h"
35 #include "llvm/Support/MathExtras.h"
36 #include <cassert>
37 #include <cstdint>
38
39 #define DEBUG_TYPE "hexagonmcelfstreamer"
40
41 using namespace llvm;
42
43 static cl::opt<unsigned> GPSize
44 ("gpsize", cl::NotHidden,
45 cl::desc("Global Pointer Addressing Size. The default size is 8."),
46 cl::Prefix,
47 cl::init(8));
48
HexagonMCELFStreamer(MCContext & Context,std::unique_ptr<MCAsmBackend> TAB,std::unique_ptr<MCObjectWriter> OW,std::unique_ptr<MCCodeEmitter> Emitter)49 HexagonMCELFStreamer::HexagonMCELFStreamer(
50 MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
51 std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter)
52 : MCELFStreamer(Context, std::move(TAB), std::move(OW), std::move(Emitter)),
53 MCII(createHexagonMCInstrInfo()) {}
54
HexagonMCELFStreamer(MCContext & Context,std::unique_ptr<MCAsmBackend> TAB,std::unique_ptr<MCObjectWriter> OW,std::unique_ptr<MCCodeEmitter> Emitter,MCAssembler * Assembler)55 HexagonMCELFStreamer::HexagonMCELFStreamer(
56 MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
57 std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter,
58 MCAssembler *Assembler)
59 : MCELFStreamer(Context, std::move(TAB), std::move(OW), std::move(Emitter)),
60 MCII(createHexagonMCInstrInfo()) {}
61
emitInstruction(const MCInst & MCB,const MCSubtargetInfo & STI)62 void HexagonMCELFStreamer::emitInstruction(const MCInst &MCB,
63 const MCSubtargetInfo &STI) {
64 assert(MCB.getOpcode() == Hexagon::BUNDLE);
65 assert(HexagonMCInstrInfo::bundleSize(MCB) <= HEXAGON_PACKET_SIZE);
66 assert(HexagonMCInstrInfo::bundleSize(MCB) > 0);
67
68 // At this point, MCB is a bundle
69 // Iterate through the bundle and assign addends for the instructions
70 for (auto const &I : HexagonMCInstrInfo::bundleInstructions(MCB)) {
71 MCInst *MCI = const_cast<MCInst *>(I.getInst());
72 EmitSymbol(*MCI);
73 }
74
75 MCObjectStreamer::emitInstruction(MCB, STI);
76 }
77
EmitSymbol(const MCInst & Inst)78 void HexagonMCELFStreamer::EmitSymbol(const MCInst &Inst) {
79 // Scan for values.
80 for (unsigned i = Inst.getNumOperands(); i--;)
81 if (Inst.getOperand(i).isExpr())
82 visitUsedExpr(*Inst.getOperand(i).getExpr());
83 }
84
85 // EmitCommonSymbol and EmitLocalCommonSymbol are extended versions of the
86 // functions found in MCELFStreamer.cpp taking AccessSize as an additional
87 // parameter.
HexagonMCEmitCommonSymbol(MCSymbol * Symbol,uint64_t Size,Align ByteAlignment,unsigned AccessSize)88 void HexagonMCELFStreamer::HexagonMCEmitCommonSymbol(MCSymbol *Symbol,
89 uint64_t Size,
90 Align ByteAlignment,
91 unsigned AccessSize) {
92 getAssembler().registerSymbol(*Symbol);
93 StringRef sbss[4] = {".sbss.1", ".sbss.2", ".sbss.4", ".sbss.8"};
94
95 auto ELFSymbol = cast<MCSymbolELF>(Symbol);
96 if (!ELFSymbol->isBindingSet()) {
97 ELFSymbol->setBinding(ELF::STB_GLOBAL);
98 ELFSymbol->setExternal(true);
99 }
100
101 ELFSymbol->setType(ELF::STT_OBJECT);
102
103 if (ELFSymbol->getBinding() == ELF::STB_LOCAL) {
104 StringRef SectionName =
105 ((AccessSize == 0) || (Size == 0) || (Size > GPSize))
106 ? ".bss"
107 : sbss[(Log2_64(AccessSize))];
108 MCSection &Section = *getAssembler().getContext().getELFSection(
109 SectionName, ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
110 MCSectionSubPair P = getCurrentSection();
111 switchSection(&Section);
112
113 if (ELFSymbol->isUndefined()) {
114 emitValueToAlignment(ByteAlignment, 0, 1, 0);
115 emitLabel(Symbol);
116 emitZeros(Size);
117 }
118
119 // Update the maximum alignment of the section if necessary.
120 Section.ensureMinAlignment(ByteAlignment);
121
122 switchSection(P.first, P.second);
123 } else {
124 if (ELFSymbol->declareCommon(Size, ByteAlignment))
125 report_fatal_error("Symbol: " + Symbol->getName() +
126 " redeclared as different type");
127 if ((AccessSize) && (Size <= GPSize)) {
128 uint64_t SectionIndex =
129 (AccessSize <= GPSize)
130 ? ELF::SHN_HEXAGON_SCOMMON + llvm::bit_width(AccessSize)
131 : (unsigned)ELF::SHN_HEXAGON_SCOMMON;
132 ELFSymbol->setIndex(SectionIndex);
133 }
134 }
135
136 ELFSymbol->setSize(MCConstantExpr::create(Size, getContext()));
137 }
138
HexagonMCEmitLocalCommonSymbol(MCSymbol * Symbol,uint64_t Size,Align ByteAlignment,unsigned AccessSize)139 void HexagonMCELFStreamer::HexagonMCEmitLocalCommonSymbol(MCSymbol *Symbol,
140 uint64_t Size,
141 Align ByteAlignment,
142 unsigned AccessSize) {
143 getAssembler().registerSymbol(*Symbol);
144 auto ELFSymbol = cast<MCSymbolELF>(Symbol);
145 ELFSymbol->setBinding(ELF::STB_LOCAL);
146 ELFSymbol->setExternal(false);
147 HexagonMCEmitCommonSymbol(Symbol, Size, ByteAlignment, AccessSize);
148 }
149
150 namespace llvm {
createHexagonELFStreamer(Triple const & TT,MCContext & Context,std::unique_ptr<MCAsmBackend> MAB,std::unique_ptr<MCObjectWriter> OW,std::unique_ptr<MCCodeEmitter> CE)151 MCStreamer *createHexagonELFStreamer(Triple const &TT, MCContext &Context,
152 std::unique_ptr<MCAsmBackend> MAB,
153 std::unique_ptr<MCObjectWriter> OW,
154 std::unique_ptr<MCCodeEmitter> CE) {
155 return new HexagonMCELFStreamer(Context, std::move(MAB), std::move(OW),
156 std::move(CE));
157 }
158
159 } // end namespace llvm
160