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/MCELF.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/MCSymbol.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.
45 PPCTargetStreamer::~PPCTargetStreamer() {}
46 PPCTargetStreamer::PPCTargetStreamer(MCStreamer &S) : MCTargetStreamer(S) {}
47 
48 static MCInstrInfo *createPPCMCInstrInfo() {
49   MCInstrInfo *X = new MCInstrInfo();
50   InitPPCMCInstrInfo(X);
51   return X;
52 }
53 
54 static MCRegisterInfo *createPPCMCRegisterInfo(StringRef TT) {
55   Triple TheTriple(TT);
56   bool isPPC64 = (TheTriple.getArch() == Triple::ppc64 ||
57                   TheTriple.getArch() == Triple::ppc64le);
58   unsigned Flavour = isPPC64 ? 0 : 1;
59   unsigned RA = isPPC64 ? PPC::LR8 : PPC::LR;
60 
61   MCRegisterInfo *X = new MCRegisterInfo();
62   InitPPCMCRegisterInfo(X, RA, Flavour, Flavour);
63   return X;
64 }
65 
66 static MCSubtargetInfo *createPPCMCSubtargetInfo(StringRef TT, StringRef CPU,
67                                                  StringRef FS) {
68   MCSubtargetInfo *X = new MCSubtargetInfo();
69   InitPPCMCSubtargetInfo(X, TT, CPU, FS);
70   return X;
71 }
72 
73 static MCAsmInfo *createPPCMCAsmInfo(const MCRegisterInfo &MRI, StringRef TT) {
74   Triple TheTriple(TT);
75   bool isPPC64 = (TheTriple.getArch() == Triple::ppc64 ||
76                   TheTriple.getArch() == Triple::ppc64le);
77 
78   MCAsmInfo *MAI;
79   if (TheTriple.isOSDarwin())
80     MAI = new PPCMCAsmInfoDarwin(isPPC64, TheTriple);
81   else
82     MAI = new PPCLinuxMCAsmInfo(isPPC64, TheTriple);
83 
84   // Initial state of the frame pointer is R1.
85   unsigned Reg = isPPC64 ? PPC::X1 : PPC::R1;
86   MCCFIInstruction Inst =
87       MCCFIInstruction::createDefCfa(nullptr, MRI.getDwarfRegNum(Reg, true), 0);
88   MAI->addInitialFrameState(Inst);
89 
90   return MAI;
91 }
92 
93 static MCCodeGenInfo *createPPCMCCodeGenInfo(StringRef TT, Reloc::Model RM,
94                                              CodeModel::Model CM,
95                                              CodeGenOpt::Level OL) {
96   MCCodeGenInfo *X = new MCCodeGenInfo();
97 
98   if (RM == Reloc::Default) {
99     Triple T(TT);
100     if (T.isOSDarwin())
101       RM = Reloc::DynamicNoPIC;
102     else
103       RM = Reloc::Static;
104   }
105   if (CM == CodeModel::Default) {
106     Triple T(TT);
107     if (!T.isOSDarwin() &&
108         (T.getArch() == Triple::ppc64 || T.getArch() == Triple::ppc64le))
109       CM = CodeModel::Medium;
110   }
111   X->InitMCCodeGenInfo(RM, CM, OL);
112   return X;
113 }
114 
115 namespace {
116 class PPCTargetAsmStreamer : public PPCTargetStreamer {
117   formatted_raw_ostream &OS;
118 
119 public:
120   PPCTargetAsmStreamer(MCStreamer &S, formatted_raw_ostream &OS)
121       : PPCTargetStreamer(S), OS(OS) {}
122   void emitTCEntry(const MCSymbol &S) override {
123     OS << "\t.tc ";
124     OS << S.getName();
125     OS << "[TC],";
126     OS << S.getName();
127     OS << '\n';
128   }
129   void emitMachine(StringRef CPU) override {
130     OS << "\t.machine " << CPU << '\n';
131   }
132   virtual void emitAbiVersion(int AbiVersion) override {
133     OS << "\t.abiversion " << AbiVersion << '\n';
134   }
135   virtual void emitLocalEntry(MCSymbol *S, const MCExpr *LocalOffset) {
136     OS << "\t.localentry\t" << *S << ", " << *LocalOffset << '\n';
137   }
138 };
139 
140 class PPCTargetELFStreamer : public PPCTargetStreamer {
141 public:
142   PPCTargetELFStreamer(MCStreamer &S) : PPCTargetStreamer(S) {}
143   MCELFStreamer &getStreamer() {
144     return static_cast<MCELFStreamer &>(Streamer);
145   }
146   virtual void emitTCEntry(const MCSymbol &S) override {
147     // Creates a R_PPC64_TOC relocation
148     Streamer.EmitSymbolValue(&S, 8);
149   }
150   void emitMachine(StringRef CPU) override {
151     // FIXME: Is there anything to do in here or does this directive only
152     // limit the parser?
153   }
154   virtual void emitAbiVersion(int AbiVersion) override {
155     MCAssembler &MCA = getStreamer().getAssembler();
156     unsigned Flags = MCA.getELFHeaderEFlags();
157     Flags &= ~ELF::EF_PPC64_ABI;
158     Flags |= (AbiVersion & ELF::EF_PPC64_ABI);
159     MCA.setELFHeaderEFlags(Flags);
160   }
161   virtual void emitLocalEntry(MCSymbol *S, const MCExpr *LocalOffset) {
162     MCAssembler &MCA = getStreamer().getAssembler();
163     MCSymbolData &Data = getStreamer().getOrCreateSymbolData(S);
164 
165     int64_t Res;
166     if (!LocalOffset->EvaluateAsAbsolute(Res, MCA))
167       report_fatal_error(".localentry expression must be absolute.");
168 
169     unsigned Encoded = ELF::encodePPC64LocalEntryOffset(Res);
170     if (Res != ELF::decodePPC64LocalEntryOffset(Encoded))
171       report_fatal_error(".localentry expression cannot be encoded.");
172 
173     // The "other" values are stored in the last 6 bits of the second byte.
174     // The traditional defines for STO values assume the full byte and thus
175     // the shift to pack it.
176     unsigned Other = MCELF::getOther(Data) << 2;
177     Other &= ~ELF::STO_PPC64_LOCAL_MASK;
178     Other |= Encoded;
179     MCELF::setOther(Data, Other >> 2);
180 
181     // For GAS compatibility, unless we already saw a .abiversion directive,
182     // set e_flags to indicate ELFv2 ABI.
183     unsigned Flags = MCA.getELFHeaderEFlags();
184     if ((Flags & ELF::EF_PPC64_ABI) == 0)
185       MCA.setELFHeaderEFlags(Flags | 2);
186   }
187   void emitAssignment(MCSymbol *Symbol, const MCExpr *Value) override {
188     // When encoding an assignment to set symbol A to symbol B, also copy
189     // the st_other bits encoding the local entry point offset.
190     if (Value->getKind() != MCExpr::SymbolRef)
191       return;
192     const MCSymbol &RhsSym =
193         static_cast<const MCSymbolRefExpr *>(Value)->getSymbol();
194     MCSymbolData &Data = getStreamer().getOrCreateSymbolData(&RhsSym);
195     MCSymbolData &SymbolData = getStreamer().getOrCreateSymbolData(Symbol);
196     // The "other" values are stored in the last 6 bits of the second byte.
197     // The traditional defines for STO values assume the full byte and thus
198     // the shift to pack it.
199     unsigned Other = MCELF::getOther(SymbolData) << 2;
200     Other &= ~ELF::STO_PPC64_LOCAL_MASK;
201     Other |= (MCELF::getOther(Data) << 2) & ELF::STO_PPC64_LOCAL_MASK;
202     MCELF::setOther(SymbolData, Other >> 2);
203   }
204 };
205 
206 class PPCTargetMachOStreamer : public PPCTargetStreamer {
207 public:
208   PPCTargetMachOStreamer(MCStreamer &S) : PPCTargetStreamer(S) {}
209   void emitTCEntry(const MCSymbol &S) override {
210     llvm_unreachable("Unknown pseudo-op: .tc");
211   }
212   void emitMachine(StringRef CPU) override {
213     // FIXME: We should update the CPUType, CPUSubType in the Object file if
214     // the new values are different from the defaults.
215   }
216   virtual void emitAbiVersion(int AbiVersion) override {
217     llvm_unreachable("Unknown pseudo-op: .abiversion");
218   }
219   virtual void emitLocalEntry(MCSymbol *S, const MCExpr *LocalOffset) {
220     llvm_unreachable("Unknown pseudo-op: .localentry");
221   }
222 };
223 }
224 
225 // This is duplicated code. Refactor this.
226 static MCStreamer *createMCStreamer(const Target &T, StringRef TT,
227                                     MCContext &Ctx, MCAsmBackend &MAB,
228                                     raw_ostream &OS,
229                                     MCCodeEmitter *Emitter,
230                                     const MCSubtargetInfo &STI,
231                                     bool RelaxAll,
232                                     bool NoExecStack) {
233   if (Triple(TT).isOSDarwin()) {
234     MCStreamer *S = createMachOStreamer(Ctx, MAB, OS, Emitter, RelaxAll);
235     new PPCTargetMachOStreamer(*S);
236     return S;
237   }
238 
239   MCStreamer *S =
240       createELFStreamer(Ctx, MAB, OS, Emitter, RelaxAll, NoExecStack);
241   new PPCTargetELFStreamer(*S);
242   return S;
243 }
244 
245 static MCStreamer *
246 createMCAsmStreamer(MCContext &Ctx, formatted_raw_ostream &OS,
247                     bool isVerboseAsm, bool useDwarfDirectory,
248                     MCInstPrinter *InstPrint, MCCodeEmitter *CE,
249                     MCAsmBackend *TAB, bool ShowInst) {
250 
251   MCStreamer *S = llvm::createAsmStreamer(
252       Ctx, OS, isVerboseAsm, useDwarfDirectory, InstPrint, CE, TAB, ShowInst);
253   new PPCTargetAsmStreamer(*S, OS);
254   return S;
255 }
256 
257 static MCInstPrinter *createPPCMCInstPrinter(const Target &T,
258                                              unsigned SyntaxVariant,
259                                              const MCAsmInfo &MAI,
260                                              const MCInstrInfo &MII,
261                                              const MCRegisterInfo &MRI,
262                                              const MCSubtargetInfo &STI) {
263   bool isDarwin = Triple(STI.getTargetTriple()).isOSDarwin();
264   return new PPCInstPrinter(MAI, MII, MRI, isDarwin);
265 }
266 
267 extern "C" void LLVMInitializePowerPCTargetMC() {
268   // Register the MC asm info.
269   RegisterMCAsmInfoFn C(ThePPC32Target, createPPCMCAsmInfo);
270   RegisterMCAsmInfoFn D(ThePPC64Target, createPPCMCAsmInfo);
271   RegisterMCAsmInfoFn E(ThePPC64LETarget, createPPCMCAsmInfo);
272 
273   // Register the MC codegen info.
274   TargetRegistry::RegisterMCCodeGenInfo(ThePPC32Target, createPPCMCCodeGenInfo);
275   TargetRegistry::RegisterMCCodeGenInfo(ThePPC64Target, createPPCMCCodeGenInfo);
276   TargetRegistry::RegisterMCCodeGenInfo(ThePPC64LETarget,
277                                         createPPCMCCodeGenInfo);
278 
279   // Register the MC instruction info.
280   TargetRegistry::RegisterMCInstrInfo(ThePPC32Target, createPPCMCInstrInfo);
281   TargetRegistry::RegisterMCInstrInfo(ThePPC64Target, createPPCMCInstrInfo);
282   TargetRegistry::RegisterMCInstrInfo(ThePPC64LETarget,
283                                       createPPCMCInstrInfo);
284 
285   // Register the MC register info.
286   TargetRegistry::RegisterMCRegInfo(ThePPC32Target, createPPCMCRegisterInfo);
287   TargetRegistry::RegisterMCRegInfo(ThePPC64Target, createPPCMCRegisterInfo);
288   TargetRegistry::RegisterMCRegInfo(ThePPC64LETarget, createPPCMCRegisterInfo);
289 
290   // Register the MC subtarget info.
291   TargetRegistry::RegisterMCSubtargetInfo(ThePPC32Target,
292                                           createPPCMCSubtargetInfo);
293   TargetRegistry::RegisterMCSubtargetInfo(ThePPC64Target,
294                                           createPPCMCSubtargetInfo);
295   TargetRegistry::RegisterMCSubtargetInfo(ThePPC64LETarget,
296                                           createPPCMCSubtargetInfo);
297 
298   // Register the MC Code Emitter
299   TargetRegistry::RegisterMCCodeEmitter(ThePPC32Target, createPPCMCCodeEmitter);
300   TargetRegistry::RegisterMCCodeEmitter(ThePPC64Target, createPPCMCCodeEmitter);
301   TargetRegistry::RegisterMCCodeEmitter(ThePPC64LETarget,
302                                         createPPCMCCodeEmitter);
303 
304     // Register the asm backend.
305   TargetRegistry::RegisterMCAsmBackend(ThePPC32Target, createPPCAsmBackend);
306   TargetRegistry::RegisterMCAsmBackend(ThePPC64Target, createPPCAsmBackend);
307   TargetRegistry::RegisterMCAsmBackend(ThePPC64LETarget, createPPCAsmBackend);
308 
309   // Register the object streamer.
310   TargetRegistry::RegisterMCObjectStreamer(ThePPC32Target, createMCStreamer);
311   TargetRegistry::RegisterMCObjectStreamer(ThePPC64Target, createMCStreamer);
312   TargetRegistry::RegisterMCObjectStreamer(ThePPC64LETarget, createMCStreamer);
313 
314   // Register the asm streamer.
315   TargetRegistry::RegisterAsmStreamer(ThePPC32Target, createMCAsmStreamer);
316   TargetRegistry::RegisterAsmStreamer(ThePPC64Target, createMCAsmStreamer);
317   TargetRegistry::RegisterAsmStreamer(ThePPC64LETarget, createMCAsmStreamer);
318 
319   // Register the MCInstPrinter.
320   TargetRegistry::RegisterMCInstPrinter(ThePPC32Target, createPPCMCInstPrinter);
321   TargetRegistry::RegisterMCInstPrinter(ThePPC64Target, createPPCMCInstPrinter);
322   TargetRegistry::RegisterMCInstPrinter(ThePPC64LETarget,
323                                         createPPCMCInstPrinter);
324 }
325