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 "ARMBaseInfo.h"
15 #include "ARMMCAsmInfo.h"
16 #include "ARMMCTargetDesc.h"
17 #include "InstPrinter/ARMInstPrinter.h"
18 #include "llvm/ADT/Triple.h"
19 #include "llvm/MC/MCCodeGenInfo.h"
20 #include "llvm/MC/MCELFStreamer.h"
21 #include "llvm/MC/MCInstrAnalysis.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/Support/ErrorHandling.h"
27 #include "llvm/Support/TargetRegistry.h"
28 
29 using namespace llvm;
30 
31 #define GET_REGINFO_MC_DESC
32 #include "ARMGenRegisterInfo.inc"
33 
getMCRDeprecationInfo(MCInst & MI,MCSubtargetInfo & STI,std::string & Info)34 static bool getMCRDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
35                                   std::string &Info) {
36   if (STI.getFeatureBits() & llvm::ARM::HasV7Ops &&
37       (MI.getOperand(0).isImm() && MI.getOperand(0).getImm() == 15) &&
38       (MI.getOperand(1).isImm() && MI.getOperand(1).getImm() == 0) &&
39       // Checks for the deprecated CP15ISB encoding:
40       // mcr p15, #0, rX, c7, c5, #4
41       (MI.getOperand(3).isImm() && MI.getOperand(3).getImm() == 7)) {
42     if ((MI.getOperand(5).isImm() && MI.getOperand(5).getImm() == 4)) {
43       if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 5) {
44         Info = "deprecated since v7, use 'isb'";
45         return true;
46       }
47 
48       // Checks for the deprecated CP15DSB encoding:
49       // mcr p15, #0, rX, c7, c10, #4
50       if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 10) {
51         Info = "deprecated since v7, use 'dsb'";
52         return true;
53       }
54     }
55     // Checks for the deprecated CP15DMB encoding:
56     // mcr p15, #0, rX, c7, c10, #5
57     if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 10 &&
58         (MI.getOperand(5).isImm() && MI.getOperand(5).getImm() == 5)) {
59       Info = "deprecated since v7, use 'dmb'";
60       return true;
61     }
62   }
63   return false;
64 }
65 
getITDeprecationInfo(MCInst & MI,MCSubtargetInfo & STI,std::string & Info)66 static bool getITDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
67                                  std::string &Info) {
68   if (STI.getFeatureBits() & llvm::ARM::HasV8Ops && MI.getOperand(1).isImm() &&
69       MI.getOperand(1).getImm() != 8) {
70     Info = "applying IT instruction to more than one subsequent instruction is "
71            "deprecated";
72     return true;
73   }
74 
75   return false;
76 }
77 
getARMStoreDeprecationInfo(MCInst & MI,MCSubtargetInfo & STI,std::string & Info)78 static bool getARMStoreDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
79                                        std::string &Info) {
80   assert((~STI.getFeatureBits() & llvm::ARM::ModeThumb) &&
81          "cannot predicate thumb instructions");
82 
83   assert(MI.getNumOperands() >= 4 && "expected >= 4 arguments");
84   for (unsigned OI = 4, OE = MI.getNumOperands(); OI < OE; ++OI) {
85     assert(MI.getOperand(OI).isReg() && "expected register");
86     if (MI.getOperand(OI).getReg() == ARM::SP ||
87         MI.getOperand(OI).getReg() == ARM::PC) {
88       Info = "use of SP or PC in the list is deprecated";
89       return true;
90     }
91   }
92   return false;
93 }
94 
getARMLoadDeprecationInfo(MCInst & MI,MCSubtargetInfo & STI,std::string & Info)95 static bool getARMLoadDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
96                                       std::string &Info) {
97   assert((~STI.getFeatureBits() & llvm::ARM::ModeThumb) &&
98          "cannot predicate thumb instructions");
99 
100   assert(MI.getNumOperands() >= 4 && "expected >= 4 arguments");
101   bool ListContainsPC = false, ListContainsLR = false;
102   for (unsigned OI = 4, OE = MI.getNumOperands(); OI < OE; ++OI) {
103     assert(MI.getOperand(OI).isReg() && "expected register");
104     switch (MI.getOperand(OI).getReg()) {
105     default:
106       break;
107     case ARM::LR:
108       ListContainsLR = true;
109       break;
110     case ARM::PC:
111       ListContainsPC = true;
112       break;
113     case ARM::SP:
114       Info = "use of SP in the list is deprecated";
115       return true;
116     }
117   }
118 
119   if (ListContainsPC && ListContainsLR) {
120     Info = "use of LR and PC simultaneously in the list is deprecated";
121     return true;
122   }
123 
124   return false;
125 }
126 
127 #define GET_INSTRINFO_MC_DESC
128 #include "ARMGenInstrInfo.inc"
129 
130 #define GET_SUBTARGETINFO_MC_DESC
131 #include "ARMGenSubtargetInfo.inc"
132 
133 
ParseARMTriple(StringRef TT,StringRef CPU)134 std::string ARM_MC::ParseARMTriple(StringRef TT, StringRef CPU) {
135   Triple triple(TT);
136 
137   bool isThumb = triple.getArch() == Triple::thumb ||
138                  triple.getArch() == Triple::thumbeb;
139 
140   bool NoCPU = CPU == "generic" || CPU.empty();
141   std::string ARMArchFeature;
142   switch (triple.getSubArch()) {
143   default:
144     llvm_unreachable("invalid sub-architecture for ARM");
145   case Triple::ARMSubArch_v8:
146     if (NoCPU)
147       // v8a: FeatureDB, FeatureFPARMv8, FeatureNEON, FeatureDSPThumb2,
148       //      FeatureMP, FeatureHWDiv, FeatureHWDivARM, FeatureTrustZone,
149       //      FeatureT2XtPk, FeatureCrypto, FeatureCRC
150       ARMArchFeature = "+v8,+db,+fp-armv8,+neon,+t2dsp,+mp,+hwdiv,+hwdiv-arm,"
151                        "+trustzone,+t2xtpk,+crypto,+crc";
152     else
153       // Use CPU to figure out the exact features
154       ARMArchFeature = "+v8";
155     break;
156   case Triple::ARMSubArch_v8_1a:
157     if (NoCPU)
158       // v8.1a: FeatureDB, FeatureFPARMv8, FeatureNEON, FeatureDSPThumb2,
159       //      FeatureMP, FeatureHWDiv, FeatureHWDivARM, FeatureTrustZone,
160       //      FeatureT2XtPk, FeatureCrypto, FeatureCRC, FeatureV8_1a
161       ARMArchFeature = "+v8.1a,+db,+fp-armv8,+neon,+t2dsp,+mp,+hwdiv,+hwdiv-arm,"
162                        "+trustzone,+t2xtpk,+crypto,+crc";
163     else
164       // Use CPU to figure out the exact features
165       ARMArchFeature = "+v8.1a";
166     break;
167   case Triple::ARMSubArch_v7m:
168     isThumb = true;
169     if (NoCPU)
170       // v7m: FeatureNoARM, FeatureDB, FeatureHWDiv, FeatureMClass
171       ARMArchFeature = "+v7,+noarm,+db,+hwdiv,+mclass";
172     else
173       // Use CPU to figure out the exact features.
174       ARMArchFeature = "+v7";
175     break;
176   case Triple::ARMSubArch_v7em:
177     if (NoCPU)
178       // v7em: FeatureNoARM, FeatureDB, FeatureHWDiv, FeatureDSPThumb2,
179       //       FeatureT2XtPk, FeatureMClass
180       ARMArchFeature = "+v7,+noarm,+db,+hwdiv,+t2dsp,t2xtpk,+mclass";
181     else
182       // Use CPU to figure out the exact features.
183       ARMArchFeature = "+v7";
184     break;
185   case Triple::ARMSubArch_v7s:
186     if (NoCPU)
187       // v7s: FeatureNEON, FeatureDB, FeatureDSPThumb2, FeatureHasRAS
188       //      Swift
189       ARMArchFeature = "+v7,+swift,+neon,+db,+t2dsp,+ras";
190     else
191       // Use CPU to figure out the exact features.
192       ARMArchFeature = "+v7";
193     break;
194   case Triple::ARMSubArch_v7:
195     // v7 CPUs have lots of different feature sets. If no CPU is specified,
196     // then assume v7a (e.g. cortex-a8) feature set. Otherwise, return
197     // the "minimum" feature set and use CPU string to figure out the exact
198     // features.
199     if (NoCPU)
200       // v7a: FeatureNEON, FeatureDB, FeatureDSPThumb2, FeatureT2XtPk
201       ARMArchFeature = "+v7,+neon,+db,+t2dsp,+t2xtpk";
202     else
203       // Use CPU to figure out the exact features.
204       ARMArchFeature = "+v7";
205     break;
206   case Triple::ARMSubArch_v6t2:
207     ARMArchFeature = "+v6t2";
208     break;
209   case Triple::ARMSubArch_v6k:
210     ARMArchFeature = "+v6k";
211     break;
212   case Triple::ARMSubArch_v6m:
213     isThumb = true;
214     if (NoCPU)
215       // v6m: FeatureNoARM, FeatureMClass
216       ARMArchFeature = "+v6m,+noarm,+mclass";
217     else
218       ARMArchFeature = "+v6";
219     break;
220   case Triple::ARMSubArch_v6:
221     ARMArchFeature = "+v6";
222     break;
223   case Triple::ARMSubArch_v5te:
224     ARMArchFeature = "+v5te";
225     break;
226   case Triple::ARMSubArch_v5:
227     ARMArchFeature = "+v5t";
228     break;
229   case Triple::ARMSubArch_v4t:
230     ARMArchFeature = "+v4t";
231     break;
232   case Triple::NoSubArch:
233     break;
234   }
235 
236   if (isThumb) {
237     if (ARMArchFeature.empty())
238       ARMArchFeature = "+thumb-mode";
239     else
240       ARMArchFeature += ",+thumb-mode";
241   }
242 
243   if (triple.isOSNaCl()) {
244     if (ARMArchFeature.empty())
245       ARMArchFeature = "+nacl-trap";
246     else
247       ARMArchFeature += ",+nacl-trap";
248   }
249 
250   return ARMArchFeature;
251 }
252 
createARMMCSubtargetInfo(StringRef TT,StringRef CPU,StringRef FS)253 MCSubtargetInfo *ARM_MC::createARMMCSubtargetInfo(StringRef TT, StringRef CPU,
254                                                   StringRef FS) {
255   std::string ArchFS = ARM_MC::ParseARMTriple(TT, CPU);
256   if (!FS.empty()) {
257     if (!ArchFS.empty())
258       ArchFS = (Twine(ArchFS) + "," + FS).str();
259     else
260       ArchFS = FS;
261   }
262 
263   MCSubtargetInfo *X = new MCSubtargetInfo();
264   InitARMMCSubtargetInfo(X, TT, CPU, ArchFS);
265   return X;
266 }
267 
createARMMCInstrInfo()268 static MCInstrInfo *createARMMCInstrInfo() {
269   MCInstrInfo *X = new MCInstrInfo();
270   InitARMMCInstrInfo(X);
271   return X;
272 }
273 
createARMMCRegisterInfo(StringRef Triple)274 static MCRegisterInfo *createARMMCRegisterInfo(StringRef Triple) {
275   MCRegisterInfo *X = new MCRegisterInfo();
276   InitARMMCRegisterInfo(X, ARM::LR, 0, 0, ARM::PC);
277   return X;
278 }
279 
createARMMCAsmInfo(const MCRegisterInfo & MRI,StringRef TT)280 static MCAsmInfo *createARMMCAsmInfo(const MCRegisterInfo &MRI, StringRef TT) {
281   Triple TheTriple(TT);
282 
283   MCAsmInfo *MAI;
284   if (TheTriple.isOSDarwin() || TheTriple.isOSBinFormatMachO())
285     MAI = new ARMMCAsmInfoDarwin(TT);
286   else if (TheTriple.isWindowsItaniumEnvironment())
287     MAI = new ARMCOFFMCAsmInfoGNU();
288   else if (TheTriple.isWindowsMSVCEnvironment())
289     MAI = new ARMCOFFMCAsmInfoMicrosoft();
290   else
291     MAI = new ARMELFMCAsmInfo(TT);
292 
293   unsigned Reg = MRI.getDwarfRegNum(ARM::SP, true);
294   MAI->addInitialFrameState(MCCFIInstruction::createDefCfa(nullptr, Reg, 0));
295 
296   return MAI;
297 }
298 
createARMMCCodeGenInfo(StringRef TT,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)299 static MCCodeGenInfo *createARMMCCodeGenInfo(StringRef TT, Reloc::Model RM,
300                                              CodeModel::Model CM,
301                                              CodeGenOpt::Level OL) {
302   MCCodeGenInfo *X = new MCCodeGenInfo();
303   if (RM == Reloc::Default) {
304     Triple TheTriple(TT);
305     // Default relocation model on Darwin is PIC, not DynamicNoPIC.
306     RM = TheTriple.isOSDarwin() ? Reloc::PIC_ : Reloc::DynamicNoPIC;
307   }
308   X->InitMCCodeGenInfo(RM, CM, OL);
309   return X;
310 }
311 
createELFStreamer(const Triple & T,MCContext & Ctx,MCAsmBackend & MAB,raw_pwrite_stream & OS,MCCodeEmitter * Emitter,bool RelaxAll)312 static MCStreamer *createELFStreamer(const Triple &T, MCContext &Ctx,
313                                      MCAsmBackend &MAB, raw_pwrite_stream &OS,
314                                      MCCodeEmitter *Emitter, bool RelaxAll) {
315   return createARMELFStreamer(Ctx, MAB, OS, Emitter, false,
316                               T.getArch() == Triple::thumb);
317 }
318 
createARMMachOStreamer(MCContext & Ctx,MCAsmBackend & MAB,raw_pwrite_stream & OS,MCCodeEmitter * Emitter,bool RelaxAll,bool DWARFMustBeAtTheEnd)319 static MCStreamer *createARMMachOStreamer(MCContext &Ctx, MCAsmBackend &MAB,
320                                           raw_pwrite_stream &OS,
321                                           MCCodeEmitter *Emitter, bool RelaxAll,
322                                           bool DWARFMustBeAtTheEnd) {
323   return createMachOStreamer(Ctx, MAB, OS, Emitter, false, DWARFMustBeAtTheEnd);
324 }
325 
createARMMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)326 static MCInstPrinter *createARMMCInstPrinter(const Triple &T,
327                                              unsigned SyntaxVariant,
328                                              const MCAsmInfo &MAI,
329                                              const MCInstrInfo &MII,
330                                              const MCRegisterInfo &MRI) {
331   if (SyntaxVariant == 0)
332     return new ARMInstPrinter(MAI, MII, MRI);
333   return nullptr;
334 }
335 
createARMMCRelocationInfo(StringRef TT,MCContext & Ctx)336 static MCRelocationInfo *createARMMCRelocationInfo(StringRef TT,
337                                                    MCContext &Ctx) {
338   Triple TheTriple(TT);
339   if (TheTriple.isOSBinFormatMachO())
340     return createARMMachORelocationInfo(Ctx);
341   // Default to the stock relocation info.
342   return llvm::createMCRelocationInfo(TT, Ctx);
343 }
344 
345 namespace {
346 
347 class ARMMCInstrAnalysis : public MCInstrAnalysis {
348 public:
ARMMCInstrAnalysis(const MCInstrInfo * Info)349   ARMMCInstrAnalysis(const MCInstrInfo *Info) : MCInstrAnalysis(Info) {}
350 
isUnconditionalBranch(const MCInst & Inst) const351   bool isUnconditionalBranch(const MCInst &Inst) const override {
352     // BCCs with the "always" predicate are unconditional branches.
353     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
354       return true;
355     return MCInstrAnalysis::isUnconditionalBranch(Inst);
356   }
357 
isConditionalBranch(const MCInst & Inst) const358   bool isConditionalBranch(const MCInst &Inst) const override {
359     // BCCs with the "always" predicate are unconditional branches.
360     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
361       return false;
362     return MCInstrAnalysis::isConditionalBranch(Inst);
363   }
364 
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const365   bool evaluateBranch(const MCInst &Inst, uint64_t Addr,
366                       uint64_t Size, uint64_t &Target) const override {
367     // We only handle PCRel branches for now.
368     if (Info->get(Inst.getOpcode()).OpInfo[0].OperandType!=MCOI::OPERAND_PCREL)
369       return false;
370 
371     int64_t Imm = Inst.getOperand(0).getImm();
372     // FIXME: This is not right for thumb.
373     Target = Addr+Imm+8; // In ARM mode the PC is always off by 8 bytes.
374     return true;
375   }
376 };
377 
378 }
379 
createARMMCInstrAnalysis(const MCInstrInfo * Info)380 static MCInstrAnalysis *createARMMCInstrAnalysis(const MCInstrInfo *Info) {
381   return new ARMMCInstrAnalysis(Info);
382 }
383 
384 // Force static initialization.
LLVMInitializeARMTargetMC()385 extern "C" void LLVMInitializeARMTargetMC() {
386   for (Target *T : {&TheARMLETarget, &TheARMBETarget, &TheThumbLETarget,
387                     &TheThumbBETarget}) {
388     // Register the MC asm info.
389     RegisterMCAsmInfoFn X(*T, createARMMCAsmInfo);
390 
391     // Register the MC codegen info.
392     TargetRegistry::RegisterMCCodeGenInfo(*T, createARMMCCodeGenInfo);
393 
394     // Register the MC instruction info.
395     TargetRegistry::RegisterMCInstrInfo(*T, createARMMCInstrInfo);
396 
397     // Register the MC register info.
398     TargetRegistry::RegisterMCRegInfo(*T, createARMMCRegisterInfo);
399 
400     // Register the MC subtarget info.
401     TargetRegistry::RegisterMCSubtargetInfo(*T,
402                                             ARM_MC::createARMMCSubtargetInfo);
403 
404     // Register the MC instruction analyzer.
405     TargetRegistry::RegisterMCInstrAnalysis(*T, createARMMCInstrAnalysis);
406 
407     TargetRegistry::RegisterELFStreamer(*T, createELFStreamer);
408     TargetRegistry::RegisterCOFFStreamer(*T, createARMWinCOFFStreamer);
409     TargetRegistry::RegisterMachOStreamer(*T, createARMMachOStreamer);
410 
411     // Register the obj target streamer.
412     TargetRegistry::RegisterObjectTargetStreamer(*T,
413                                                  createARMObjectTargetStreamer);
414 
415     // Register the asm streamer.
416     TargetRegistry::RegisterAsmTargetStreamer(*T, createARMTargetAsmStreamer);
417 
418     // Register the null TargetStreamer.
419     TargetRegistry::RegisterNullTargetStreamer(*T, createARMNullTargetStreamer);
420 
421     // Register the MCInstPrinter.
422     TargetRegistry::RegisterMCInstPrinter(*T, createARMMCInstPrinter);
423 
424     // Register the MC relocation info.
425     TargetRegistry::RegisterMCRelocationInfo(*T, createARMMCRelocationInfo);
426   }
427 
428   // Register the MC Code Emitter
429   for (Target *T : {&TheARMLETarget, &TheThumbLETarget})
430     TargetRegistry::RegisterMCCodeEmitter(*T, createARMLEMCCodeEmitter);
431   for (Target *T : {&TheARMBETarget, &TheThumbBETarget})
432     TargetRegistry::RegisterMCCodeEmitter(*T, createARMBEMCCodeEmitter);
433 
434   // Register the asm backend.
435   TargetRegistry::RegisterMCAsmBackend(TheARMLETarget, createARMLEAsmBackend);
436   TargetRegistry::RegisterMCAsmBackend(TheARMBETarget, createARMBEAsmBackend);
437   TargetRegistry::RegisterMCAsmBackend(TheThumbLETarget,
438                                        createThumbLEAsmBackend);
439   TargetRegistry::RegisterMCAsmBackend(TheThumbBETarget,
440                                        createThumbBEAsmBackend);
441 }
442