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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/TargetParser.h"
28 #include "llvm/Support/TargetRegistry.h"
29 
30 using namespace llvm;
31 
32 #define GET_REGINFO_MC_DESC
33 #include "ARMGenRegisterInfo.inc"
34 
getMCRDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)35 static bool getMCRDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
36                                   std::string &Info) {
37   if (STI.getFeatureBits()[llvm::ARM::HasV7Ops] &&
38       (MI.getOperand(0).isImm() && MI.getOperand(0).getImm() == 15) &&
39       (MI.getOperand(1).isImm() && MI.getOperand(1).getImm() == 0) &&
40       // Checks for the deprecated CP15ISB encoding:
41       // mcr p15, #0, rX, c7, c5, #4
42       (MI.getOperand(3).isImm() && MI.getOperand(3).getImm() == 7)) {
43     if ((MI.getOperand(5).isImm() && MI.getOperand(5).getImm() == 4)) {
44       if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 5) {
45         Info = "deprecated since v7, use 'isb'";
46         return true;
47       }
48 
49       // Checks for the deprecated CP15DSB encoding:
50       // mcr p15, #0, rX, c7, c10, #4
51       if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 10) {
52         Info = "deprecated since v7, use 'dsb'";
53         return true;
54       }
55     }
56     // Checks for the deprecated CP15DMB encoding:
57     // mcr p15, #0, rX, c7, c10, #5
58     if (MI.getOperand(4).isImm() && MI.getOperand(4).getImm() == 10 &&
59         (MI.getOperand(5).isImm() && MI.getOperand(5).getImm() == 5)) {
60       Info = "deprecated since v7, use 'dmb'";
61       return true;
62     }
63   }
64   return false;
65 }
66 
getITDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)67 static bool getITDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
68                                  std::string &Info) {
69   if (STI.getFeatureBits()[llvm::ARM::HasV8Ops] && MI.getOperand(1).isImm() &&
70       MI.getOperand(1).getImm() != 8) {
71     Info = "applying IT instruction to more than one subsequent instruction is "
72            "deprecated";
73     return true;
74   }
75 
76   return false;
77 }
78 
getARMStoreDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)79 static bool getARMStoreDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
80                                        std::string &Info) {
81   assert(!STI.getFeatureBits()[llvm::ARM::ModeThumb] &&
82          "cannot predicate thumb instructions");
83 
84   assert(MI.getNumOperands() >= 4 && "expected >= 4 arguments");
85   for (unsigned OI = 4, OE = MI.getNumOperands(); OI < OE; ++OI) {
86     assert(MI.getOperand(OI).isReg() && "expected register");
87     if (MI.getOperand(OI).getReg() == ARM::SP ||
88         MI.getOperand(OI).getReg() == ARM::PC) {
89       Info = "use of SP or PC in the list is deprecated";
90       return true;
91     }
92   }
93   return false;
94 }
95 
getARMLoadDeprecationInfo(MCInst & MI,const MCSubtargetInfo & STI,std::string & Info)96 static bool getARMLoadDeprecationInfo(MCInst &MI, const MCSubtargetInfo &STI,
97                                       std::string &Info) {
98   assert(!STI.getFeatureBits()[llvm::ARM::ModeThumb] &&
99          "cannot predicate thumb instructions");
100 
101   assert(MI.getNumOperands() >= 4 && "expected >= 4 arguments");
102   bool ListContainsPC = false, ListContainsLR = false;
103   for (unsigned OI = 4, OE = MI.getNumOperands(); OI < OE; ++OI) {
104     assert(MI.getOperand(OI).isReg() && "expected register");
105     switch (MI.getOperand(OI).getReg()) {
106     default:
107       break;
108     case ARM::LR:
109       ListContainsLR = true;
110       break;
111     case ARM::PC:
112       ListContainsPC = true;
113       break;
114     case ARM::SP:
115       Info = "use of SP in the list is deprecated";
116       return true;
117     }
118   }
119 
120   if (ListContainsPC && ListContainsLR) {
121     Info = "use of LR and PC simultaneously in the list is deprecated";
122     return true;
123   }
124 
125   return false;
126 }
127 
128 #define GET_INSTRINFO_MC_DESC
129 #include "ARMGenInstrInfo.inc"
130 
131 #define GET_SUBTARGETINFO_MC_DESC
132 #include "ARMGenSubtargetInfo.inc"
133 
ParseARMTriple(const Triple & TT,StringRef CPU)134 std::string ARM_MC::ParseARMTriple(const Triple &TT, StringRef CPU) {
135   bool isThumb =
136       TT.getArch() == Triple::thumb || TT.getArch() == Triple::thumbeb;
137 
138   std::string ARMArchFeature;
139 
140   unsigned ArchID = ARM::parseArch(TT.getArchName());
141   if (ArchID != ARM::AK_INVALID &&  (CPU.empty() || CPU == "generic"))
142     ARMArchFeature = (ARMArchFeature + "+" + ARM::getArchName(ArchID)).str();
143 
144   if (isThumb) {
145     if (ARMArchFeature.empty())
146       ARMArchFeature = "+thumb-mode";
147     else
148       ARMArchFeature += ",+thumb-mode";
149   }
150 
151   if (TT.isOSNaCl()) {
152     if (ARMArchFeature.empty())
153       ARMArchFeature = "+nacl-trap";
154     else
155       ARMArchFeature += ",+nacl-trap";
156   }
157 
158   return ARMArchFeature;
159 }
160 
createARMMCSubtargetInfo(const Triple & TT,StringRef CPU,StringRef FS)161 MCSubtargetInfo *ARM_MC::createARMMCSubtargetInfo(const Triple &TT,
162                                                   StringRef CPU, StringRef FS) {
163   std::string ArchFS = ARM_MC::ParseARMTriple(TT, CPU);
164   if (!FS.empty()) {
165     if (!ArchFS.empty())
166       ArchFS = (Twine(ArchFS) + "," + FS).str();
167     else
168       ArchFS = FS;
169   }
170 
171   return createARMMCSubtargetInfoImpl(TT, CPU, ArchFS);
172 }
173 
createARMMCInstrInfo()174 static MCInstrInfo *createARMMCInstrInfo() {
175   MCInstrInfo *X = new MCInstrInfo();
176   InitARMMCInstrInfo(X);
177   return X;
178 }
179 
createARMMCRegisterInfo(const Triple & Triple)180 static MCRegisterInfo *createARMMCRegisterInfo(const Triple &Triple) {
181   MCRegisterInfo *X = new MCRegisterInfo();
182   InitARMMCRegisterInfo(X, ARM::LR, 0, 0, ARM::PC);
183   return X;
184 }
185 
createARMMCAsmInfo(const MCRegisterInfo & MRI,const Triple & TheTriple)186 static MCAsmInfo *createARMMCAsmInfo(const MCRegisterInfo &MRI,
187                                      const Triple &TheTriple) {
188   MCAsmInfo *MAI;
189   if (TheTriple.isOSDarwin() || TheTriple.isOSBinFormatMachO())
190     MAI = new ARMMCAsmInfoDarwin(TheTriple);
191   else if (TheTriple.isWindowsMSVCEnvironment())
192     MAI = new ARMCOFFMCAsmInfoMicrosoft();
193   else if (TheTriple.isOSWindows())
194     MAI = new ARMCOFFMCAsmInfoGNU();
195   else
196     MAI = new ARMELFMCAsmInfo(TheTriple);
197 
198   unsigned Reg = MRI.getDwarfRegNum(ARM::SP, true);
199   MAI->addInitialFrameState(MCCFIInstruction::createDefCfa(nullptr, Reg, 0));
200 
201   return MAI;
202 }
203 
createARMMCCodeGenInfo(const Triple & TT,Reloc::Model RM,CodeModel::Model CM,CodeGenOpt::Level OL)204 static MCCodeGenInfo *createARMMCCodeGenInfo(const Triple &TT, Reloc::Model RM,
205                                              CodeModel::Model CM,
206                                              CodeGenOpt::Level OL) {
207   MCCodeGenInfo *X = new MCCodeGenInfo();
208   if (RM == Reloc::Default) {
209     // Default relocation model on Darwin is PIC, not DynamicNoPIC.
210     RM = TT.isOSDarwin() ? Reloc::PIC_ : Reloc::DynamicNoPIC;
211   }
212   X->initMCCodeGenInfo(RM, CM, OL);
213   return X;
214 }
215 
createELFStreamer(const Triple & T,MCContext & Ctx,MCAsmBackend & MAB,raw_pwrite_stream & OS,MCCodeEmitter * Emitter,bool RelaxAll)216 static MCStreamer *createELFStreamer(const Triple &T, MCContext &Ctx,
217                                      MCAsmBackend &MAB, raw_pwrite_stream &OS,
218                                      MCCodeEmitter *Emitter, bool RelaxAll) {
219   return createARMELFStreamer(Ctx, MAB, OS, Emitter, false,
220                               T.getArch() == Triple::thumb);
221 }
222 
createARMMachOStreamer(MCContext & Ctx,MCAsmBackend & MAB,raw_pwrite_stream & OS,MCCodeEmitter * Emitter,bool RelaxAll,bool DWARFMustBeAtTheEnd)223 static MCStreamer *createARMMachOStreamer(MCContext &Ctx, MCAsmBackend &MAB,
224                                           raw_pwrite_stream &OS,
225                                           MCCodeEmitter *Emitter, bool RelaxAll,
226                                           bool DWARFMustBeAtTheEnd) {
227   return createMachOStreamer(Ctx, MAB, OS, Emitter, false, DWARFMustBeAtTheEnd);
228 }
229 
createARMMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)230 static MCInstPrinter *createARMMCInstPrinter(const Triple &T,
231                                              unsigned SyntaxVariant,
232                                              const MCAsmInfo &MAI,
233                                              const MCInstrInfo &MII,
234                                              const MCRegisterInfo &MRI) {
235   if (SyntaxVariant == 0)
236     return new ARMInstPrinter(MAI, MII, MRI);
237   return nullptr;
238 }
239 
createARMMCRelocationInfo(const Triple & TT,MCContext & Ctx)240 static MCRelocationInfo *createARMMCRelocationInfo(const Triple &TT,
241                                                    MCContext &Ctx) {
242   if (TT.isOSBinFormatMachO())
243     return createARMMachORelocationInfo(Ctx);
244   // Default to the stock relocation info.
245   return llvm::createMCRelocationInfo(TT, Ctx);
246 }
247 
248 namespace {
249 
250 class ARMMCInstrAnalysis : public MCInstrAnalysis {
251 public:
ARMMCInstrAnalysis(const MCInstrInfo * Info)252   ARMMCInstrAnalysis(const MCInstrInfo *Info) : MCInstrAnalysis(Info) {}
253 
isUnconditionalBranch(const MCInst & Inst) const254   bool isUnconditionalBranch(const MCInst &Inst) const override {
255     // BCCs with the "always" predicate are unconditional branches.
256     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
257       return true;
258     return MCInstrAnalysis::isUnconditionalBranch(Inst);
259   }
260 
isConditionalBranch(const MCInst & Inst) const261   bool isConditionalBranch(const MCInst &Inst) const override {
262     // BCCs with the "always" predicate are unconditional branches.
263     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
264       return false;
265     return MCInstrAnalysis::isConditionalBranch(Inst);
266   }
267 
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const268   bool evaluateBranch(const MCInst &Inst, uint64_t Addr,
269                       uint64_t Size, uint64_t &Target) const override {
270     // We only handle PCRel branches for now.
271     if (Info->get(Inst.getOpcode()).OpInfo[0].OperandType!=MCOI::OPERAND_PCREL)
272       return false;
273 
274     int64_t Imm = Inst.getOperand(0).getImm();
275     // FIXME: This is not right for thumb.
276     Target = Addr+Imm+8; // In ARM mode the PC is always off by 8 bytes.
277     return true;
278   }
279 };
280 
281 }
282 
createARMMCInstrAnalysis(const MCInstrInfo * Info)283 static MCInstrAnalysis *createARMMCInstrAnalysis(const MCInstrInfo *Info) {
284   return new ARMMCInstrAnalysis(Info);
285 }
286 
287 // Force static initialization.
LLVMInitializeARMTargetMC()288 extern "C" void LLVMInitializeARMTargetMC() {
289   for (Target *T : {&TheARMLETarget, &TheARMBETarget, &TheThumbLETarget,
290                     &TheThumbBETarget}) {
291     // Register the MC asm info.
292     RegisterMCAsmInfoFn X(*T, createARMMCAsmInfo);
293 
294     // Register the MC codegen info.
295     TargetRegistry::RegisterMCCodeGenInfo(*T, createARMMCCodeGenInfo);
296 
297     // Register the MC instruction info.
298     TargetRegistry::RegisterMCInstrInfo(*T, createARMMCInstrInfo);
299 
300     // Register the MC register info.
301     TargetRegistry::RegisterMCRegInfo(*T, createARMMCRegisterInfo);
302 
303     // Register the MC subtarget info.
304     TargetRegistry::RegisterMCSubtargetInfo(*T,
305                                             ARM_MC::createARMMCSubtargetInfo);
306 
307     // Register the MC instruction analyzer.
308     TargetRegistry::RegisterMCInstrAnalysis(*T, createARMMCInstrAnalysis);
309 
310     TargetRegistry::RegisterELFStreamer(*T, createELFStreamer);
311     TargetRegistry::RegisterCOFFStreamer(*T, createARMWinCOFFStreamer);
312     TargetRegistry::RegisterMachOStreamer(*T, createARMMachOStreamer);
313 
314     // Register the obj target streamer.
315     TargetRegistry::RegisterObjectTargetStreamer(*T,
316                                                  createARMObjectTargetStreamer);
317 
318     // Register the asm streamer.
319     TargetRegistry::RegisterAsmTargetStreamer(*T, createARMTargetAsmStreamer);
320 
321     // Register the null TargetStreamer.
322     TargetRegistry::RegisterNullTargetStreamer(*T, createARMNullTargetStreamer);
323 
324     // Register the MCInstPrinter.
325     TargetRegistry::RegisterMCInstPrinter(*T, createARMMCInstPrinter);
326 
327     // Register the MC relocation info.
328     TargetRegistry::RegisterMCRelocationInfo(*T, createARMMCRelocationInfo);
329   }
330 
331   // Register the MC Code Emitter
332   for (Target *T : {&TheARMLETarget, &TheThumbLETarget})
333     TargetRegistry::RegisterMCCodeEmitter(*T, createARMLEMCCodeEmitter);
334   for (Target *T : {&TheARMBETarget, &TheThumbBETarget})
335     TargetRegistry::RegisterMCCodeEmitter(*T, createARMBEMCCodeEmitter);
336 
337   // Register the asm backend.
338   TargetRegistry::RegisterMCAsmBackend(TheARMLETarget, createARMLEAsmBackend);
339   TargetRegistry::RegisterMCAsmBackend(TheARMBETarget, createARMBEAsmBackend);
340   TargetRegistry::RegisterMCAsmBackend(TheThumbLETarget,
341                                        createThumbLEAsmBackend);
342   TargetRegistry::RegisterMCAsmBackend(TheThumbBETarget,
343                                        createThumbBEAsmBackend);
344 }
345