1 //===-- ARMMCTargetDesc.cpp - ARM 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 ARM specific target descriptions.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #include "ARMMCTargetDesc.h"
15 #include "ARMBaseInfo.h"
16 #include "ARMMCAsmInfo.h"
17 #include "InstPrinter/ARMInstPrinter.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/MC/MCAsmBackend.h"
20 #include "llvm/MC/MCCodeEmitter.h"
21 #include "llvm/MC/MCELFStreamer.h"
22 #include "llvm/MC/MCInstrAnalysis.h"
23 #include "llvm/MC/MCInstrInfo.h"
24 #include "llvm/MC/MCObjectWriter.h"
25 #include "llvm/MC/MCRegisterInfo.h"
26 #include "llvm/MC/MCStreamer.h"
27 #include "llvm/MC/MCSubtargetInfo.h"
28 #include "llvm/Support/ErrorHandling.h"
29 #include "llvm/Support/TargetParser.h"
30 #include "llvm/Support/TargetRegistry.h"
31 
32 using namespace llvm;
33 
34 #define GET_REGINFO_MC_DESC
35 #include "ARMGenRegisterInfo.inc"
36 
getMCRDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)37 static bool getMCRDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
38                                   std::string &Info) {
39   if (STI.getFeatureBits()[llvm::ARM::HasV7Ops] &&
40       (MI.getOperand(0).isImm() && MI.getOperand(0).getImm() == 15) &&
41       (MI.getOperand(1).isImm() && MI.getOperand(1).getImm() == 0) &&
42       // Checks for the deprecated CP15ISB encoding:
43       // mcr p15, #0, rX, c7, c5, #4
44       (MI.getOperand(3).isImm() && MI.getOperand(3).getImm() == 7)) {
45     if ((MI.getOperand(5).isImm() && MI.getOperand(5).getImm() == 4)) {
46       if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 5) {
47         Info = "deprecated since v7, use 'isb'";
48         return true;
49       }
50 
51       // Checks for the deprecated CP15DSB encoding:
52       // mcr p15, #0, rX, c7, c10, #4
53       if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 10) {
54         Info = "deprecated since v7, use 'dsb'";
55         return true;
56       }
57     }
58     // Checks for the deprecated CP15DMB encoding:
59     // mcr p15, #0, rX, c7, c10, #5
60     if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 10 &&
61         (MI.getOperand(5).isImm() && MI.getOperand(5).getImm() == 5)) {
62       Info = "deprecated since v7, use 'dmb'";
63       return true;
64     }
65   }
66   return false;
67 }
68 
getITDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)69 static bool getITDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
70                                  std::string &Info) {
71   if (STI.getFeatureBits()[llvm::ARM::HasV8Ops] && MI.getOperand(1).isImm() &&
72       MI.getOperand(1).getImm() != 8) {
73     Info = "applying IT instruction to more than one subsequent instruction is "
74            "deprecated";
75     return true;
76   }
77 
78   return false;
79 }
80 
getARMStoreDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)81 static bool getARMStoreDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
82                                        std::string &Info) {
83   assert(!STI.getFeatureBits()[llvm::ARM::ModeThumb] &&
84          "cannot predicate thumb instructions");
85 
86   assert(MI.getNumOperands() >= 4 && "expected >= 4 arguments");
87   for (unsigned OI = 4, OE = MI.getNumOperands(); OI < OE; ++OI) {
88     assert(MI.getOperand(OI).isReg() && "expected register");
89     if (MI.getOperand(OI).getReg() == ARM::SP ||
90         MI.getOperand(OI).getReg() == ARM::PC) {
91       Info = "use of SP or PC in the list is deprecated";
92       return true;
93     }
94   }
95   return false;
96 }
97 
getARMLoadDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)98 static bool getARMLoadDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
99                                       std::string &Info) {
100   assert(!STI.getFeatureBits()[llvm::ARM::ModeThumb] &&
101          "cannot predicate thumb instructions");
102 
103   assert(MI.getNumOperands() >= 4 && "expected >= 4 arguments");
104   bool ListContainsPC = false, ListContainsLR = false;
105   for (unsigned OI = 4, OE = MI.getNumOperands(); OI < OE; ++OI) {
106     assert(MI.getOperand(OI).isReg() && "expected register");
107     switch (MI.getOperand(OI).getReg()) {
108     default:
109       break;
110     case ARM::LR:
111       ListContainsLR = true;
112       break;
113     case ARM::PC:
114       ListContainsPC = true;
115       break;
116     case ARM::SP:
117       Info = "use of SP in the list is deprecated";
118       return true;
119     }
120   }
121 
122   if (ListContainsPC && ListContainsLR) {
123     Info = "use of LR and PC simultaneously in the list is deprecated";
124     return true;
125   }
126 
127   return false;
128 }
129 
130 #define GET_INSTRINFO_MC_DESC
131 #include "ARMGenInstrInfo.inc"
132 
133 #define GET_SUBTARGETINFO_MC_DESC
134 #include "ARMGenSubtargetInfo.inc"
135 
ParseARMTriple(const Triple & TT,StringRef CPU)136 std::string ARM_MC::ParseARMTriple(const Triple &TT, StringRef CPU) {
137   std::string ARMArchFeature;
138 
139   ARM::ArchKind ArchID = ARM::parseArch(TT.getArchName());
140   if (ArchID != ARM::ArchKind::INVALID &&  (CPU.empty() || CPU == "generic"))
141     ARMArchFeature = (ARMArchFeature + "+" + ARM::getArchName(ArchID)).str();
142 
143   if (TT.isThumb()) {
144     if (!ARMArchFeature.empty())
145       ARMArchFeature += ",";
146     ARMArchFeature += "+thumb-mode,+v4t";
147   }
148 
149   if (TT.isOSNaCl()) {
150     if (!ARMArchFeature.empty())
151       ARMArchFeature += ",";
152     ARMArchFeature += "+nacl-trap";
153   }
154 
155   if (TT.isOSWindows()) {
156     if (!ARMArchFeature.empty())
157       ARMArchFeature += ",";
158     ARMArchFeature += "+noarm";
159   }
160 
161   return ARMArchFeature;
162 }
163 
createARMMCSubtargetInfo(const Triple & TT,StringRef CPU,StringRef FS)164 MCSubtargetInfo *ARM_MC::createARMMCSubtargetInfo(const Triple &TT,
165                                                   StringRef CPU, StringRef FS) {
166   std::string ArchFS = ARM_MC::ParseARMTriple(TT, CPU);
167   if (!FS.empty()) {
168     if (!ArchFS.empty())
169       ArchFS = (Twine(ArchFS) + "," + FS).str();
170     else
171       ArchFS = FS;
172   }
173 
174   return createARMMCSubtargetInfoImpl(TT, CPU, ArchFS);
175 }
176 
createARMMCInstrInfo()177 static MCInstrInfo *createARMMCInstrInfo() {
178   MCInstrInfo *X = new MCInstrInfo();
179   InitARMMCInstrInfo(X);
180   return X;
181 }
182 
createARMMCRegisterInfo(const Triple & Triple)183 static MCRegisterInfo *createARMMCRegisterInfo(const Triple &Triple) {
184   MCRegisterInfo *X = new MCRegisterInfo();
185   InitARMMCRegisterInfo(X, ARM::LR, 0, 0, ARM::PC);
186   return X;
187 }
188 
createARMMCAsmInfo(const MCRegisterInfo & MRI,const Triple & TheTriple)189 static MCAsmInfo *createARMMCAsmInfo(const MCRegisterInfo &MRI,
190                                      const Triple &TheTriple) {
191   MCAsmInfo *MAI;
192   if (TheTriple.isOSDarwin() || TheTriple.isOSBinFormatMachO())
193     MAI = new ARMMCAsmInfoDarwin(TheTriple);
194   else if (TheTriple.isWindowsMSVCEnvironment())
195     MAI = new ARMCOFFMCAsmInfoMicrosoft();
196   else if (TheTriple.isOSWindows())
197     MAI = new ARMCOFFMCAsmInfoGNU();
198   else
199     MAI = new ARMELFMCAsmInfo(TheTriple);
200 
201   unsigned Reg = MRI.getDwarfRegNum(ARM::SP, true);
202   MAI->addInitialFrameState(MCCFIInstruction::createDefCfa(nullptr, Reg, 0));
203 
204   return MAI;
205 }
206 
createELFStreamer(const Triple & T,MCContext & Ctx,std::unique_ptr<MCAsmBackend> && MAB,std::unique_ptr<MCObjectWriter> && OW,std::unique_ptr<MCCodeEmitter> && Emitter,bool RelaxAll)207 static MCStreamer *createELFStreamer(const Triple &T, MCContext &Ctx,
208                                      std::unique_ptr<MCAsmBackend> &&MAB,
209                                      std::unique_ptr<MCObjectWriter> &&OW,
210                                      std::unique_ptr<MCCodeEmitter> &&Emitter,
211                                      bool RelaxAll) {
212   return createARMELFStreamer(
213       Ctx, std::move(MAB), std::move(OW), std::move(Emitter), false,
214       (T.getArch() == Triple::thumb || T.getArch() == Triple::thumbeb));
215 }
216 
217 static MCStreamer *
createARMMachOStreamer(MCContext & Ctx,std::unique_ptr<MCAsmBackend> && MAB,std::unique_ptr<MCObjectWriter> && OW,std::unique_ptr<MCCodeEmitter> && Emitter,bool RelaxAll,bool DWARFMustBeAtTheEnd)218 createARMMachOStreamer(MCContext &Ctx, std::unique_ptr<MCAsmBackend> &&MAB,
219                        std::unique_ptr<MCObjectWriter> &&OW,
220                        std::unique_ptr<MCCodeEmitter> &&Emitter, bool RelaxAll,
221                        bool DWARFMustBeAtTheEnd) {
222   return createMachOStreamer(Ctx, std::move(MAB), std::move(OW),
223                              std::move(Emitter), false, DWARFMustBeAtTheEnd);
224 }
225 
createARMMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)226 static MCInstPrinter *createARMMCInstPrinter(const Triple &T,
227                                              unsigned SyntaxVariant,
228                                              const MCAsmInfo &MAI,
229                                              const MCInstrInfo &MII,
230                                              const MCRegisterInfo &MRI) {
231   if (SyntaxVariant == 0)
232     return new ARMInstPrinter(MAI, MII, MRI);
233   return nullptr;
234 }
235 
createARMMCRelocationInfo(const Triple & TT,MCContext & Ctx)236 static MCRelocationInfo *createARMMCRelocationInfo(const Triple &TT,
237                                                    MCContext &Ctx) {
238   if (TT.isOSBinFormatMachO())
239     return createARMMachORelocationInfo(Ctx);
240   // Default to the stock relocation info.
241   return llvm::createMCRelocationInfo(TT, Ctx);
242 }
243 
244 namespace {
245 
246 class ARMMCInstrAnalysis : public MCInstrAnalysis {
247 public:
ARMMCInstrAnalysis(const MCInstrInfo * Info)248   ARMMCInstrAnalysis(const MCInstrInfo *Info) : MCInstrAnalysis(Info) {}
249 
isUnconditionalBranch(const MCInst & Inst) const250   bool isUnconditionalBranch(const MCInst &Inst) const override {
251     // BCCs with the "always" predicate are unconditional branches.
252     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
253       return true;
254     return MCInstrAnalysis::isUnconditionalBranch(Inst);
255   }
256 
isConditionalBranch(const MCInst & Inst) const257   bool isConditionalBranch(const MCInst &Inst) const override {
258     // BCCs with the "always" predicate are unconditional branches.
259     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
260       return false;
261     return MCInstrAnalysis::isConditionalBranch(Inst);
262   }
263 
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const264   bool evaluateBranch(const MCInst &Inst, uint64_t Addr,
265                       uint64_t Size, uint64_t &Target) const override {
266     // We only handle PCRel branches for now.
267     if (Info->get(Inst.getOpcode()).OpInfo[0].OperandType!=MCOI::OPERAND_PCREL)
268       return false;
269 
270     int64_t Imm = Inst.getOperand(0).getImm();
271     Target = Addr+Imm+8; // In ARM mode the PC is always off by 8 bytes.
272     return true;
273   }
274 };
275 
276 class ThumbMCInstrAnalysis : public ARMMCInstrAnalysis {
277 public:
ThumbMCInstrAnalysis(const MCInstrInfo * Info)278   ThumbMCInstrAnalysis(const MCInstrInfo *Info) : ARMMCInstrAnalysis(Info) {}
279 
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const280   bool evaluateBranch(const MCInst &Inst, uint64_t Addr,
281                       uint64_t Size, uint64_t &Target) const override {
282     // We only handle PCRel branches for now.
283     if (Info->get(Inst.getOpcode()).OpInfo[0].OperandType!=MCOI::OPERAND_PCREL)
284       return false;
285 
286     int64_t Imm = Inst.getOperand(0).getImm();
287     Target = Addr+Imm+4; // In Thumb mode the PC is always off by 4 bytes.
288     return true;
289   }
290 };
291 
292 }
293 
createARMMCInstrAnalysis(const MCInstrInfo * Info)294 static MCInstrAnalysis *createARMMCInstrAnalysis(const MCInstrInfo *Info) {
295   return new ARMMCInstrAnalysis(Info);
296 }
297 
createThumbMCInstrAnalysis(const MCInstrInfo * Info)298 static MCInstrAnalysis *createThumbMCInstrAnalysis(const MCInstrInfo *Info) {
299   return new ThumbMCInstrAnalysis(Info);
300 }
301 
302 // Force static initialization.
LLVMInitializeARMTargetMC()303 extern "C" void LLVMInitializeARMTargetMC() {
304   for (Target *T : {&getTheARMLETarget(), &getTheARMBETarget(),
305                     &getTheThumbLETarget(), &getTheThumbBETarget()}) {
306     // Register the MC asm info.
307     RegisterMCAsmInfoFn X(*T, createARMMCAsmInfo);
308 
309     // Register the MC instruction info.
310     TargetRegistry::RegisterMCInstrInfo(*T, createARMMCInstrInfo);
311 
312     // Register the MC register info.
313     TargetRegistry::RegisterMCRegInfo(*T, createARMMCRegisterInfo);
314 
315     // Register the MC subtarget info.
316     TargetRegistry::RegisterMCSubtargetInfo(*T,
317                                             ARM_MC::createARMMCSubtargetInfo);
318 
319     TargetRegistry::RegisterELFStreamer(*T, createELFStreamer);
320     TargetRegistry::RegisterCOFFStreamer(*T, createARMWinCOFFStreamer);
321     TargetRegistry::RegisterMachOStreamer(*T, createARMMachOStreamer);
322 
323     // Register the obj target streamer.
324     TargetRegistry::RegisterObjectTargetStreamer(*T,
325                                                  createARMObjectTargetStreamer);
326 
327     // Register the asm streamer.
328     TargetRegistry::RegisterAsmTargetStreamer(*T, createARMTargetAsmStreamer);
329 
330     // Register the null TargetStreamer.
331     TargetRegistry::RegisterNullTargetStreamer(*T, createARMNullTargetStreamer);
332 
333     // Register the MCInstPrinter.
334     TargetRegistry::RegisterMCInstPrinter(*T, createARMMCInstPrinter);
335 
336     // Register the MC relocation info.
337     TargetRegistry::RegisterMCRelocationInfo(*T, createARMMCRelocationInfo);
338   }
339 
340   // Register the MC instruction analyzer.
341   for (Target *T : {&getTheARMLETarget(), &getTheARMBETarget()})
342     TargetRegistry::RegisterMCInstrAnalysis(*T, createARMMCInstrAnalysis);
343   for (Target *T : {&getTheThumbLETarget(), &getTheThumbBETarget()})
344     TargetRegistry::RegisterMCInstrAnalysis(*T, createThumbMCInstrAnalysis);
345 
346   for (Target *T : {&getTheARMLETarget(), &getTheThumbLETarget()}) {
347     TargetRegistry::RegisterMCCodeEmitter(*T, createARMLEMCCodeEmitter);
348     TargetRegistry::RegisterMCAsmBackend(*T, createARMLEAsmBackend);
349   }
350   for (Target *T : {&getTheARMBETarget(), &getTheThumbBETarget()}) {
351     TargetRegistry::RegisterMCCodeEmitter(*T, createARMBEMCCodeEmitter);
352     TargetRegistry::RegisterMCAsmBackend(*T, createARMBEAsmBackend);
353   }
354 }
355