1 //===-- PPCMCTargetDesc.cpp - PowerPC Target Descriptions -----------------===//
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 provides PowerPC specific target descriptions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "PPCMCTargetDesc.h"
15 #include "InstPrinter/PPCInstPrinter.h"
16 #include "PPCMCAsmInfo.h"
17 #include "PPCTargetStreamer.h"
18 #include "llvm/MC/MCCodeGenInfo.h"
19 #include "llvm/MC/MCContext.h"
20 #include "llvm/MC/MCELFStreamer.h"
21 #include "llvm/MC/MCExpr.h"
22 #include "llvm/MC/MCInstrInfo.h"
23 #include "llvm/MC/MCRegisterInfo.h"
24 #include "llvm/MC/MCStreamer.h"
25 #include "llvm/MC/MCSubtargetInfo.h"
26 #include "llvm/MC/MCSymbolELF.h"
27 #include "llvm/MC/MachineLocation.h"
28 #include "llvm/Support/ELF.h"
29 #include "llvm/Support/ErrorHandling.h"
30 #include "llvm/Support/FormattedStream.h"
31 #include "llvm/Support/TargetRegistry.h"
32 
33 using namespace llvm;
34 
35 #define GET_INSTRINFO_MC_DESC
36 #include "PPCGenInstrInfo.inc"
37 
38 #define GET_SUBTARGETINFO_MC_DESC
39 #include "PPCGenSubtargetInfo.inc"
40 
41 #define GET_REGINFO_MC_DESC
42 #include "PPCGenRegisterInfo.inc"
43 
44 // Pin the vtable to this file.
~PPCTargetStreamer()45 PPCTargetStreamer::~PPCTargetStreamer() {}
PPCTargetStreamer(MCStreamer & S)46 PPCTargetStreamer::PPCTargetStreamer(MCStreamer &S) : MCTargetStreamer(S) {}
47 
createPPCMCInstrInfo()48 static MCInstrInfo *createPPCMCInstrInfo() {
49   MCInstrInfo *X = new MCInstrInfo();
50   InitPPCMCInstrInfo(X);
51   return X;
52 }
53 
createPPCMCRegisterInfo(const Triple & TT)54 static MCRegisterInfo *createPPCMCRegisterInfo(const Triple &TT) {
55   bool isPPC64 =
56       (TT.getArch() == Triple::ppc64 || TT.getArch() == Triple::ppc64le);
57   unsigned Flavour = isPPC64 ? 0 : 1;
58   unsigned RA = isPPC64 ? PPC::LR8 : PPC::LR;
59 
60   MCRegisterInfo *X = new MCRegisterInfo();
61   InitPPCMCRegisterInfo(X, RA, Flavour, Flavour);
62   return X;
63 }
64 
createPPCMCSubtargetInfo(const Triple & TT,StringRef CPU,StringRef FS)65 static MCSubtargetInfo *createPPCMCSubtargetInfo(const Triple &TT,
66                                                  StringRef CPU, StringRef FS) {
67   return createPPCMCSubtargetInfoImpl(TT, CPU, FS);
68 }
69 
createPPCMCAsmInfo(const MCRegisterInfo & MRI,const Triple & TheTriple)70 static MCAsmInfo *createPPCMCAsmInfo(const MCRegisterInfo &MRI,
71                                      const Triple &TheTriple) {
72   bool isPPC64 = (TheTriple.getArch() == Triple::ppc64 ||
73                   TheTriple.getArch() == Triple::ppc64le);
74 
75   MCAsmInfo *MAI;
76   if (TheTriple.isOSDarwin())
77     MAI = new PPCMCAsmInfoDarwin(isPPC64, TheTriple);
78   else
79     MAI = new PPCELFMCAsmInfo(isPPC64, TheTriple);
80 
81   // Initial state of the frame pointer is R1.
82   unsigned Reg = isPPC64 ? PPC::X1 : PPC::R1;
83   MCCFIInstruction Inst =
84       MCCFIInstruction::createDefCfa(nullptr, MRI.getDwarfRegNum(Reg, true), 0);
85   MAI->addInitialFrameState(Inst);
86 
87   return MAI;
88 }
89 
createPPCMCCodeGenInfo(const Triple & TT,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)90 static MCCodeGenInfo *createPPCMCCodeGenInfo(const Triple &TT, Reloc::Model RM,
91                                              CodeModel::Model CM,
92                                              CodeGenOpt::Level OL) {
93   MCCodeGenInfo *X = new MCCodeGenInfo();
94 
95   if (RM == Reloc::Default) {
96     if (TT.isOSDarwin())
97       RM = Reloc::DynamicNoPIC;
98     else
99       RM = Reloc::Static;
100   }
101   if (CM == CodeModel::Default) {
102     if (!TT.isOSDarwin() &&
103         (TT.getArch() == Triple::ppc64 || TT.getArch() == Triple::ppc64le))
104       CM = CodeModel::Medium;
105   }
106   X->initMCCodeGenInfo(RM, CM, OL);
107   return X;
108 }
109 
110 namespace {
111 class PPCTargetAsmStreamer : public PPCTargetStreamer {
112   formatted_raw_ostream &OS;
113 
114 public:
PPCTargetAsmStreamer(MCStreamer & S,formatted_raw_ostream & OS)115   PPCTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS)
116       : PPCTargetStreamer(S), OS(OS) {}
emitTCEntry(const MCSymbol & S)117   void emitTCEntry(const MCSymbol &S) override {
118     OS << "\t.tc ";
119     OS << S.getName();
120     OS << "[TC],";
121     OS << S.getName();
122     OS << '\n';
123   }
emitMachine(StringRef CPU)124   void emitMachine(StringRef CPU) override {
125     OS << "\t.machine " << CPU << '\n';
126   }
emitAbiVersion(int AbiVersion)127   void emitAbiVersion(int AbiVersion) override {
128     OS << "\t.abiversion " << AbiVersion << '\n';
129   }
emitLocalEntry(MCSymbolELF * S,const MCExpr * LocalOffset)130   void emitLocalEntry(MCSymbolELF *S, const MCExpr *LocalOffset) override {
131     const MCAsmInfo *MAI = Streamer.getContext().getAsmInfo();
132 
133     OS << "\t.localentry\t";
134     S->print(OS, MAI);
135     OS << ", ";
136     LocalOffset->print(OS, MAI);
137     OS << '\n';
138   }
139 };
140 
141 class PPCTargetELFStreamer : public PPCTargetStreamer {
142 public:
PPCTargetELFStreamer(MCStreamer & S)143   PPCTargetELFStreamer(MCStreamer &S) : PPCTargetStreamer(S) {}
getStreamer()144   MCELFStreamer &getStreamer() {
145     return static_cast<MCELFStreamer &>(Streamer);
146   }
emitTCEntry(const MCSymbol & S)147   void emitTCEntry(const MCSymbol &S) override {
148     // Creates a R_PPC64_TOC relocation
149     Streamer.EmitValueToAlignment(8);
150     Streamer.EmitSymbolValue(&S, 8);
151   }
emitMachine(StringRef CPU)152   void emitMachine(StringRef CPU) override {
153     // FIXME: Is there anything to do in here or does this directive only
154     // limit the parser?
155   }
emitAbiVersion(int AbiVersion)156   void emitAbiVersion(int AbiVersion) override {
157     MCAssembler &MCA = getStreamer().getAssembler();
158     unsigned Flags = MCA.getELFHeaderEFlags();
159     Flags &= ~ELF::EF_PPC64_ABI;
160     Flags |= (AbiVersion & ELF::EF_PPC64_ABI);
161     MCA.setELFHeaderEFlags(Flags);
162   }
emitLocalEntry(MCSymbolELF * S,const MCExpr * LocalOffset)163   void emitLocalEntry(MCSymbolELF *S, const MCExpr *LocalOffset) override {
164     MCAssembler &MCA = getStreamer().getAssembler();
165 
166     int64_t Res;
167     if (!LocalOffset->evaluateAsAbsolute(Res, MCA))
168       report_fatal_error(".localentry expression must be absolute.");
169 
170     unsigned Encoded = ELF::encodePPC64LocalEntryOffset(Res);
171     if (Res != ELF::decodePPC64LocalEntryOffset(Encoded))
172       report_fatal_error(".localentry expression cannot be encoded.");
173 
174     unsigned Other = S->getOther();
175     Other &= ~ELF::STO_PPC64_LOCAL_MASK;
176     Other |= Encoded;
177     S->setOther(Other);
178 
179     // For GAS compatibility, unless we already saw a .abiversion directive,
180     // set e_flags to indicate ELFv2 ABI.
181     unsigned Flags = MCA.getELFHeaderEFlags();
182     if ((Flags & ELF::EF_PPC64_ABI) == 0)
183       MCA.setELFHeaderEFlags(Flags | 2);
184   }
emitAssignment(MCSymbol * S,const MCExpr * Value)185   void emitAssignment(MCSymbol *S, const MCExpr *Value) override {
186     auto *Symbol = cast<MCSymbolELF>(S);
187     // When encoding an assignment to set symbol A to symbol B, also copy
188     // the st_other bits encoding the local entry point offset.
189     if (Value->getKind() != MCExpr::SymbolRef)
190       return;
191     const auto &RhsSym = cast<MCSymbolELF>(
192         static_cast<const MCSymbolRefExpr *>(Value)->getSymbol());
193     unsigned Other = Symbol->getOther();
194     Other &= ~ELF::STO_PPC64_LOCAL_MASK;
195     Other |= RhsSym.getOther() & ELF::STO_PPC64_LOCAL_MASK;
196     Symbol->setOther(Other);
197   }
198 };
199 
200 class PPCTargetMachOStreamer : public PPCTargetStreamer {
201 public:
PPCTargetMachOStreamer(MCStreamer & S)202   PPCTargetMachOStreamer(MCStreamer &S) : PPCTargetStreamer(S) {}
emitTCEntry(const MCSymbol & S)203   void emitTCEntry(const MCSymbol &S) override {
204     llvm_unreachable("Unknown pseudo-op: .tc");
205   }
emitMachine(StringRef CPU)206   void emitMachine(StringRef CPU) override {
207     // FIXME: We should update the CPUType, CPUSubType in the Object file if
208     // the new values are different from the defaults.
209   }
emitAbiVersion(int AbiVersion)210   void emitAbiVersion(int AbiVersion) override {
211     llvm_unreachable("Unknown pseudo-op: .abiversion");
212   }
emitLocalEntry(MCSymbolELF * S,const MCExpr * LocalOffset)213   void emitLocalEntry(MCSymbolELF *S, const MCExpr *LocalOffset) override {
214     llvm_unreachable("Unknown pseudo-op: .localentry");
215   }
216 };
217 }
218 
createAsmTargetStreamer(MCStreamer & S,formatted_raw_ostream & OS,MCInstPrinter * InstPrint,bool isVerboseAsm)219 static MCTargetStreamer *createAsmTargetStreamer(MCStreamer &S,
220                                                  formatted_raw_ostream &OS,
221                                                  MCInstPrinter *InstPrint,
222                                                  bool isVerboseAsm) {
223   return new PPCTargetAsmStreamer(S, OS);
224 }
225 
226 static MCTargetStreamer *
createObjectTargetStreamer(MCStreamer & S,const MCSubtargetInfo & STI)227 createObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
228   const Triple &TT = STI.getTargetTriple();
229   if (TT.isOSBinFormatELF())
230     return new PPCTargetELFStreamer(S);
231   return new PPCTargetMachOStreamer(S);
232 }
233 
createPPCMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)234 static MCInstPrinter *createPPCMCInstPrinter(const Triple &T,
235                                              unsigned SyntaxVariant,
236                                              const MCAsmInfo &MAI,
237                                              const MCInstrInfo &MII,
238                                              const MCRegisterInfo &MRI) {
239   return new PPCInstPrinter(MAI, MII, MRI, T.isOSDarwin());
240 }
241 
LLVMInitializePowerPCTargetMC()242 extern "C" void LLVMInitializePowerPCTargetMC() {
243   for (Target *T : {&ThePPC32Target, &ThePPC64Target, &ThePPC64LETarget}) {
244     // Register the MC asm info.
245     RegisterMCAsmInfoFn C(*T, createPPCMCAsmInfo);
246 
247     // Register the MC codegen info.
248     TargetRegistry::RegisterMCCodeGenInfo(*T, createPPCMCCodeGenInfo);
249 
250     // Register the MC instruction info.
251     TargetRegistry::RegisterMCInstrInfo(*T, createPPCMCInstrInfo);
252 
253     // Register the MC register info.
254     TargetRegistry::RegisterMCRegInfo(*T, createPPCMCRegisterInfo);
255 
256     // Register the MC subtarget info.
257     TargetRegistry::RegisterMCSubtargetInfo(*T, createPPCMCSubtargetInfo);
258 
259     // Register the MC Code Emitter
260     TargetRegistry::RegisterMCCodeEmitter(*T, createPPCMCCodeEmitter);
261 
262     // Register the asm backend.
263     TargetRegistry::RegisterMCAsmBackend(*T, createPPCAsmBackend);
264 
265     // Register the object target streamer.
266     TargetRegistry::RegisterObjectTargetStreamer(*T,
267                                                  createObjectTargetStreamer);
268 
269     // Register the asm target streamer.
270     TargetRegistry::RegisterAsmTargetStreamer(*T, createAsmTargetStreamer);
271 
272     // Register the MCInstPrinter.
273     TargetRegistry::RegisterMCInstPrinter(*T, createPPCMCInstPrinter);
274   }
275 }
276