xref: /freebsd/contrib/llvm-project/llvm/lib/Target/Hexagon/MCTargetDesc/HexagonMCELFStreamer.cpp (revision 7fdf597e96a02165cfe22ff357b857d5fa15ed8a)
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 "HexagonTargetStreamer.h"
16 #include "MCTargetDesc/HexagonMCChecker.h"
17 #include "MCTargetDesc/HexagonMCInstrInfo.h"
18 #include "MCTargetDesc/HexagonMCShuffler.h"
19 #include "llvm/ADT/StringRef.h"
20 #include "llvm/BinaryFormat/ELF.h"
21 #include "llvm/MC/MCAsmBackend.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCCodeEmitter.h"
24 #include "llvm/MC/MCContext.h"
25 #include "llvm/MC/MCExpr.h"
26 #include "llvm/MC/MCInst.h"
27 #include "llvm/MC/MCObjectStreamer.h"
28 #include "llvm/MC/MCObjectWriter.h"
29 #include "llvm/MC/MCSection.h"
30 #include "llvm/MC/MCSectionELF.h"
31 #include "llvm/MC/MCStreamer.h"
32 #include "llvm/MC/MCSubtargetInfo.h"
33 #include "llvm/MC/MCSymbol.h"
34 #include "llvm/MC/MCSymbolELF.h"
35 #include "llvm/Support/Casting.h"
36 #include "llvm/Support/CommandLine.h"
37 #include "llvm/Support/ErrorHandling.h"
38 #include "llvm/Support/HexagonAttributes.h"
39 #include "llvm/Support/MathExtras.h"
40 #include <cassert>
41 #include <cstdint>
42 
43 #define DEBUG_TYPE "hexagonmcelfstreamer"
44 
45 using namespace llvm;
46 
47 static cl::opt<unsigned> GPSize
48   ("gpsize", cl::NotHidden,
49    cl::desc("Global Pointer Addressing Size.  The default size is 8."),
50    cl::Prefix,
51    cl::init(8));
52 
53 HexagonMCELFStreamer::HexagonMCELFStreamer(
54     MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
55     std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter)
56     : MCELFStreamer(Context, std::move(TAB), std::move(OW), std::move(Emitter)),
57       MCII(createHexagonMCInstrInfo()) {}
58 
59 HexagonMCELFStreamer::HexagonMCELFStreamer(
60     MCContext &Context, std::unique_ptr<MCAsmBackend> TAB,
61     std::unique_ptr<MCObjectWriter> OW, std::unique_ptr<MCCodeEmitter> Emitter,
62     MCAssembler *Assembler)
63     : MCELFStreamer(Context, std::move(TAB), std::move(OW), std::move(Emitter)),
64       MCII(createHexagonMCInstrInfo()) {}
65 
66 void HexagonMCELFStreamer::emitInstruction(const MCInst &MCB,
67                                            const MCSubtargetInfo &STI) {
68   assert(MCB.getOpcode() == Hexagon::BUNDLE);
69   assert(HexagonMCInstrInfo::bundleSize(MCB) <= HEXAGON_PACKET_SIZE);
70   assert(HexagonMCInstrInfo::bundleSize(MCB) > 0);
71 
72   // At this point, MCB is a bundle
73   // Iterate through the bundle and assign addends for the instructions
74   for (auto const &I : HexagonMCInstrInfo::bundleInstructions(MCB)) {
75     MCInst *MCI = const_cast<MCInst *>(I.getInst());
76     EmitSymbol(*MCI);
77   }
78 
79   MCObjectStreamer::emitInstruction(MCB, STI);
80 }
81 
82 void HexagonMCELFStreamer::EmitSymbol(const MCInst &Inst) {
83   // Scan for values.
84   for (unsigned i = Inst.getNumOperands(); i--;)
85     if (Inst.getOperand(i).isExpr())
86       visitUsedExpr(*Inst.getOperand(i).getExpr());
87 }
88 
89 // EmitCommonSymbol and EmitLocalCommonSymbol are extended versions of the
90 // functions found in MCELFStreamer.cpp taking AccessSize as an additional
91 // parameter.
92 void HexagonMCELFStreamer::HexagonMCEmitCommonSymbol(MCSymbol *Symbol,
93                                                      uint64_t Size,
94                                                      Align ByteAlignment,
95                                                      unsigned AccessSize) {
96   getAssembler().registerSymbol(*Symbol);
97   StringRef sbss[4] = {".sbss.1", ".sbss.2", ".sbss.4", ".sbss.8"};
98 
99   auto ELFSymbol = cast<MCSymbolELF>(Symbol);
100   if (!ELFSymbol->isBindingSet())
101     ELFSymbol->setBinding(ELF::STB_GLOBAL);
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     MCSection &Section = *getAssembler().getContext().getELFSection(
111         SectionName, ELF::SHT_NOBITS, ELF::SHF_WRITE | ELF::SHF_ALLOC);
112     MCSectionSubPair P = getCurrentSection();
113     switchSection(&Section);
114 
115     if (ELFSymbol->isUndefined()) {
116       emitValueToAlignment(ByteAlignment, 0, 1, 0);
117       emitLabel(Symbol);
118       emitZeros(Size);
119     }
120 
121     // Update the maximum alignment of the section if necessary.
122     Section.ensureMinAlignment(ByteAlignment);
123 
124     switchSection(P.first, P.second);
125   } else {
126     if (ELFSymbol->declareCommon(Size, ByteAlignment))
127       report_fatal_error("Symbol: " + Symbol->getName() +
128                          " redeclared as different type");
129     if ((AccessSize) && (Size <= GPSize)) {
130       uint64_t SectionIndex =
131           (AccessSize <= GPSize)
132               ? ELF::SHN_HEXAGON_SCOMMON + llvm::bit_width(AccessSize)
133               : (unsigned)ELF::SHN_HEXAGON_SCOMMON;
134       ELFSymbol->setIndex(SectionIndex);
135     }
136   }
137 
138   ELFSymbol->setSize(MCConstantExpr::create(Size, getContext()));
139 }
140 
141 void HexagonMCELFStreamer::HexagonMCEmitLocalCommonSymbol(MCSymbol *Symbol,
142                                                           uint64_t Size,
143                                                           Align ByteAlignment,
144                                                           unsigned AccessSize) {
145   getAssembler().registerSymbol(*Symbol);
146   auto ELFSymbol = cast<MCSymbolELF>(Symbol);
147   ELFSymbol->setBinding(ELF::STB_LOCAL);
148   ELFSymbol->setExternal(false);
149   HexagonMCEmitCommonSymbol(Symbol, Size, ByteAlignment, AccessSize);
150 }
151 
152 static unsigned featureToArchVersion(unsigned Feature) {
153   switch (Feature) {
154   case Hexagon::ArchV5:
155     return 5;
156   case Hexagon::ArchV55:
157     return 55;
158   case Hexagon::ArchV60:
159   case Hexagon::ExtensionHVXV60:
160     return 60;
161   case Hexagon::ArchV62:
162   case Hexagon::ExtensionHVXV62:
163     return 62;
164   case Hexagon::ArchV65:
165   case Hexagon::ExtensionHVXV65:
166     return 65;
167   case Hexagon::ArchV66:
168   case Hexagon::ExtensionHVXV66:
169     return 66;
170   case Hexagon::ArchV67:
171   case Hexagon::ExtensionHVXV67:
172     return 67;
173   case Hexagon::ArchV68:
174   case Hexagon::ExtensionHVXV68:
175     return 68;
176   case Hexagon::ArchV69:
177   case Hexagon::ExtensionHVXV69:
178     return 69;
179   case Hexagon::ArchV71:
180   case Hexagon::ExtensionHVXV71:
181     return 71;
182   case Hexagon::ArchV73:
183   case Hexagon::ExtensionHVXV73:
184     return 73;
185   }
186   llvm_unreachable("Expected valid arch feature");
187   return 0;
188 }
189 
190 void HexagonTargetStreamer::emitTargetAttributes(const MCSubtargetInfo &STI) {
191   auto Features = STI.getFeatureBits();
192   unsigned Arch = featureToArchVersion(Hexagon_MC::getArchVersion(Features));
193   std::optional<unsigned> HVXArch = Hexagon_MC::getHVXVersion(Features);
194   emitAttribute(HexagonAttrs::ARCH, Arch);
195   if (HVXArch)
196     emitAttribute(HexagonAttrs::HVXARCH, featureToArchVersion(*HVXArch));
197   if (Features.test(Hexagon::ExtensionHVXIEEEFP))
198     emitAttribute(HexagonAttrs::HVXIEEEFP, 1);
199   if (Features.test(Hexagon::ExtensionHVXQFloat))
200     emitAttribute(HexagonAttrs::HVXQFLOAT, 1);
201   if (Features.test(Hexagon::ExtensionZReg))
202     emitAttribute(HexagonAttrs::ZREG, 1);
203   if (Features.test(Hexagon::ExtensionAudio))
204     emitAttribute(HexagonAttrs::AUDIO, 1);
205   if (Features.test(Hexagon::FeatureCabac))
206     emitAttribute(HexagonAttrs::CABAC, 1);
207 }
208 
209 namespace llvm {
210 MCStreamer *createHexagonELFStreamer(Triple const &TT, MCContext &Context,
211                                      std::unique_ptr<MCAsmBackend> MAB,
212                                      std::unique_ptr<MCObjectWriter> OW,
213                                      std::unique_ptr<MCCodeEmitter> CE) {
214   return new HexagonMCELFStreamer(Context, std::move(MAB), std::move(OW),
215                                   std::move(CE));
216   }
217 
218 } // end namespace llvm
219