1 //=== HexagonMCELFStreamer.cpp - Hexagon subclass of MCELFStreamer -------===//
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 //
10 // This file is a stub that parses a MCInst bundle and passes the
11 // instructions on to the real streamer.
12 //
13 //===----------------------------------------------------------------------===//
14 #define DEBUG_TYPE "hexagonmcelfstreamer"
15
16 #include "Hexagon.h"
17 #include "HexagonMCELFStreamer.h"
18 #include "MCTargetDesc/HexagonBaseInfo.h"
19 #include "MCTargetDesc/HexagonMCShuffler.h"
20 #include "llvm/ADT/StringExtras.h"
21 #include "llvm/MC/MCAssembler.h"
22 #include "llvm/MC/MCContext.h"
23 #include "llvm/MC/MCSectionELF.h"
24 #include "llvm/MC/MCStreamer.h"
25 #include "llvm/MC/MCSymbol.h"
26 #include "llvm/MC/MCSymbolELF.h"
27 #include "llvm/Support/CommandLine.h"
28 #include "llvm/Support/Debug.h"
29 #include "llvm/Support/raw_ostream.h"
30
31 using namespace llvm;
32
33 static cl::opt<unsigned>
34 GPSize("gpsize", cl::NotHidden,
35 cl::desc("Global Pointer Addressing Size. The default size is 8."),
36 cl::Prefix, cl::init(8));
37
EmitInstruction(const MCInst & MCK,const MCSubtargetInfo & STI)38 void HexagonMCELFStreamer::EmitInstruction(const MCInst &MCK,
39 const MCSubtargetInfo &STI) {
40 MCInst HMI = HexagonMCInstrInfo::createBundle();
41 MCInst *MCB;
42
43 if (MCK.getOpcode() != Hexagon::BUNDLE) {
44 HMI.addOperand(MCOperand::createInst(&MCK));
45 MCB = &HMI;
46 } else
47 MCB = const_cast<MCInst *>(&MCK);
48
49 // Examines packet and pad the packet, if needed, when an
50 // end-loop is in the bundle.
51 HexagonMCInstrInfo::padEndloop(getContext(), *MCB);
52 HexagonMCShuffle(*MCII, STI, *MCB);
53
54 assert(HexagonMCInstrInfo::bundleSize(*MCB) <= HEXAGON_PACKET_SIZE);
55 bool Extended = false;
56 for (auto &I : HexagonMCInstrInfo::bundleInstructions(*MCB)) {
57 MCInst *MCI = const_cast<MCInst *>(I.getInst());
58 if (Extended) {
59 if (HexagonMCInstrInfo::isDuplex(*MCII, *MCI)) {
60 MCInst *SubInst = const_cast<MCInst *>(MCI->getOperand(1).getInst());
61 HexagonMCInstrInfo::clampExtended(*MCII, getContext(), *SubInst);
62 } else {
63 HexagonMCInstrInfo::clampExtended(*MCII, getContext(), *MCI);
64 }
65 Extended = false;
66 } else {
67 Extended = HexagonMCInstrInfo::isImmext(*MCI);
68 }
69 }
70
71 // At this point, MCB is a bundle
72 // Iterate through the bundle and assign addends for the instructions
73 for (auto const &I : HexagonMCInstrInfo::bundleInstructions(*MCB)) {
74 MCInst *MCI = const_cast<MCInst *>(I.getInst());
75 EmitSymbol(*MCI);
76 }
77 MCObjectStreamer::EmitInstruction(*MCB, STI);
78 }
79
EmitSymbol(const MCInst & Inst)80 void HexagonMCELFStreamer::EmitSymbol(const MCInst &Inst) {
81 // Scan for values.
82 for (unsigned i = Inst.getNumOperands(); i--;)
83 if (Inst.getOperand(i).isExpr())
84 visitUsedExpr(*Inst.getOperand(i).getExpr());
85 }
86
87 // EmitCommonSymbol and EmitLocalCommonSymbol are extended versions of the
88 // functions found in MCELFStreamer.cpp taking AccessSize as an additional
89 // parameter.
HexagonMCEmitCommonSymbol(MCSymbol * Symbol,uint64_t Size,unsigned ByteAlignment,unsigned AccessSize)90 void HexagonMCELFStreamer::HexagonMCEmitCommonSymbol(MCSymbol *Symbol,
91 uint64_t Size,
92 unsigned ByteAlignment,
93 unsigned AccessSize) {
94 getAssembler().registerSymbol(*Symbol);
95 StringRef sbss[4] = {".sbss.1", ".sbss.2", ".sbss.4", ".sbss.8"};
96
97 auto ELFSymbol = cast<MCSymbolELF>(Symbol);
98 if (!ELFSymbol->isBindingSet()) {
99 ELFSymbol->setBinding(ELF::STB_GLOBAL);
100 ELFSymbol->setExternal(true);
101 }
102
103 ELFSymbol->setType(ELF::STT_OBJECT);
104
105 if (ELFSymbol->getBinding() == ELF::STB_LOCAL) {
106 StringRef SectionName =
107 ((AccessSize == 0) || (Size == 0) || (Size > GPSize))
108 ? ".bss"
109 : sbss[(Log2_64(AccessSize))];
110
111 MCSection *CrntSection = getCurrentSection().first;
112 MCSection *Section = getAssembler().getContext().getELFSection(
113 SectionName, ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
114 SwitchSection(Section);
115 AssignFragment(Symbol, getCurrentFragment());
116
117 MCELFStreamer::EmitCommonSymbol(Symbol, Size, ByteAlignment);
118 SwitchSection(CrntSection);
119 } else {
120 if (ELFSymbol->declareCommon(Size, ByteAlignment))
121 report_fatal_error("Symbol: " + Symbol->getName() +
122 " redeclared as different type");
123 if ((AccessSize) && (Size <= GPSize)) {
124 uint64_t SectionIndex =
125 (AccessSize <= GPSize)
126 ? ELF::SHN_HEXAGON_SCOMMON + (Log2_64(AccessSize) + 1)
127 : (unsigned)ELF::SHN_HEXAGON_SCOMMON;
128 ELFSymbol->setIndex(SectionIndex);
129 }
130 }
131
132 ELFSymbol->setSize(MCConstantExpr::create(Size, getContext()));
133 }
134
HexagonMCEmitLocalCommonSymbol(MCSymbol * Symbol,uint64_t Size,unsigned ByteAlignment,unsigned AccessSize)135 void HexagonMCELFStreamer::HexagonMCEmitLocalCommonSymbol(
136 MCSymbol *Symbol, uint64_t Size, unsigned ByteAlignment,
137 unsigned AccessSize) {
138 getAssembler().registerSymbol(*Symbol);
139 auto ELFSymbol = cast<MCSymbolELF>(Symbol);
140 ELFSymbol->setBinding(ELF::STB_LOCAL);
141 ELFSymbol->setExternal(false);
142 HexagonMCEmitCommonSymbol(Symbol, Size, ByteAlignment, AccessSize);
143 }
144
145 namespace llvm {
createHexagonELFStreamer(MCContext & Context,MCAsmBackend & MAB,raw_pwrite_stream & OS,MCCodeEmitter * CE)146 MCStreamer *createHexagonELFStreamer(MCContext &Context, MCAsmBackend &MAB,
147 raw_pwrite_stream &OS, MCCodeEmitter *CE) {
148 return new HexagonMCELFStreamer(Context, MAB, OS, CE);
149 }
150 }
151