xref: /netbsd-src/external/apache2/llvm/dist/llvm/lib/Target/ARM/MCTargetDesc/ARMMCTargetDesc.cpp (revision 181254a7b1bdde6873432bffef2d2decc4b5c22f)
1 //===-- ARMMCTargetDesc.cpp - ARM Target Descriptions ---------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file provides ARM specific target descriptions.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "ARMMCTargetDesc.h"
14 #include "ARMBaseInfo.h"
15 #include "ARMInstPrinter.h"
16 #include "ARMMCAsmInfo.h"
17 #include "TargetInfo/ARMTargetInfo.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 
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 
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 
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 
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 
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 
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 
177 static MCInstrInfo *createARMMCInstrInfo() {
178   MCInstrInfo *X = new MCInstrInfo();
179   InitARMMCInstrInfo(X);
180   return X;
181 }
182 
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 
189 static MCAsmInfo *createARMMCAsmInfo(const MCRegisterInfo &MRI,
190                                      const Triple &TheTriple,
191                                      const MCTargetOptions &Options) {
192   MCAsmInfo *MAI;
193   if (TheTriple.isOSDarwin() || TheTriple.isOSBinFormatMachO())
194     MAI = new ARMMCAsmInfoDarwin(TheTriple);
195   else if (TheTriple.isWindowsMSVCEnvironment())
196     MAI = new ARMCOFFMCAsmInfoMicrosoft();
197   else if (TheTriple.isOSWindows())
198     MAI = new ARMCOFFMCAsmInfoGNU();
199   else
200     MAI = new ARMELFMCAsmInfo(TheTriple);
201 
202   unsigned Reg = MRI.getDwarfRegNum(ARM::SP, true);
203   MAI->addInitialFrameState(MCCFIInstruction::createDefCfa(nullptr, Reg, 0));
204 
205   return MAI;
206 }
207 
208 static MCStreamer *createELFStreamer(const Triple &T, MCContext &Ctx,
209                                      std::unique_ptr<MCAsmBackend> &&MAB,
210                                      std::unique_ptr<MCObjectWriter> &&OW,
211                                      std::unique_ptr<MCCodeEmitter> &&Emitter,
212                                      bool RelaxAll) {
213   return createARMELFStreamer(
214       Ctx, std::move(MAB), std::move(OW), std::move(Emitter), false,
215       (T.getArch() == Triple::thumb || T.getArch() == Triple::thumbeb));
216 }
217 
218 static MCStreamer *
219 createARMMachOStreamer(MCContext &Ctx, std::unique_ptr<MCAsmBackend> &&MAB,
220                        std::unique_ptr<MCObjectWriter> &&OW,
221                        std::unique_ptr<MCCodeEmitter> &&Emitter, bool RelaxAll,
222                        bool DWARFMustBeAtTheEnd) {
223   return createMachOStreamer(Ctx, std::move(MAB), std::move(OW),
224                              std::move(Emitter), false, DWARFMustBeAtTheEnd);
225 }
226 
227 static MCInstPrinter *createARMMCInstPrinter(const Triple &T,
228                                              unsigned SyntaxVariant,
229                                              const MCAsmInfo &MAI,
230                                              const MCInstrInfo &MII,
231                                              const MCRegisterInfo &MRI) {
232   if (SyntaxVariant == 0)
233     return new ARMInstPrinter(MAI, MII, MRI);
234   return nullptr;
235 }
236 
237 static MCRelocationInfo *createARMMCRelocationInfo(const Triple &TT,
238                                                    MCContext &Ctx) {
239   if (TT.isOSBinFormatMachO())
240     return createARMMachORelocationInfo(Ctx);
241   // Default to the stock relocation info.
242   return llvm::createMCRelocationInfo(TT, Ctx);
243 }
244 
245 namespace {
246 
247 class ARMMCInstrAnalysis : public MCInstrAnalysis {
248 public:
249   ARMMCInstrAnalysis(const MCInstrInfo *Info) : MCInstrAnalysis(Info) {}
250 
251   bool isUnconditionalBranch(const MCInst &Inst) const override {
252     // BCCs with the "always" predicate are unconditional branches.
253     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
254       return true;
255     return MCInstrAnalysis::isUnconditionalBranch(Inst);
256   }
257 
258   bool isConditionalBranch(const MCInst &Inst) const override {
259     // BCCs with the "always" predicate are unconditional branches.
260     if (Inst.getOpcode() == ARM::Bcc && Inst.getOperand(1).getImm()==ARMCC::AL)
261       return false;
262     return MCInstrAnalysis::isConditionalBranch(Inst);
263   }
264 
265   bool evaluateBranch(const MCInst &Inst, uint64_t Addr,
266                       uint64_t Size, uint64_t &Target) const override {
267     // We only handle PCRel branches for now.
268     if (Info->get(Inst.getOpcode()).OpInfo[0].OperandType!=MCOI::OPERAND_PCREL)
269       return false;
270 
271     int64_t Imm = Inst.getOperand(0).getImm();
272     Target = Addr+Imm+8; // In ARM mode the PC is always off by 8 bytes.
273     return true;
274   }
275 };
276 
277 class ThumbMCInstrAnalysis : public ARMMCInstrAnalysis {
278 public:
279   ThumbMCInstrAnalysis(const MCInstrInfo *Info) : ARMMCInstrAnalysis(Info) {}
280 
281   bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size,
282                       uint64_t &Target) const override {
283     unsigned OpId;
284     switch (Inst.getOpcode()) {
285     default:
286       OpId = 0;
287       break;
288     case ARM::t2WLS:
289     case ARM::t2LEUpdate:
290       OpId = 2;
291       break;
292     case ARM::t2LE:
293       OpId = 1;
294       break;
295     }
296 
297     // We only handle PCRel branches for now.
298     if (Info->get(Inst.getOpcode()).OpInfo[OpId].OperandType !=
299         MCOI::OPERAND_PCREL)
300       return false;
301 
302     // In Thumb mode the PC is always off by 4 bytes.
303     Target = Addr + Inst.getOperand(OpId).getImm() + 4;
304     return true;
305   }
306 };
307 
308 }
309 
310 static MCInstrAnalysis *createARMMCInstrAnalysis(const MCInstrInfo *Info) {
311   return new ARMMCInstrAnalysis(Info);
312 }
313 
314 static MCInstrAnalysis *createThumbMCInstrAnalysis(const MCInstrInfo *Info) {
315   return new ThumbMCInstrAnalysis(Info);
316 }
317 
318 // Force static initialization.
319 extern "C" void LLVMInitializeARMTargetMC() {
320   for (Target *T : {&getTheARMLETarget(), &getTheARMBETarget(),
321                     &getTheThumbLETarget(), &getTheThumbBETarget()}) {
322     // Register the MC asm info.
323     RegisterMCAsmInfoFn X(*T, createARMMCAsmInfo);
324 
325     // Register the MC instruction info.
326     TargetRegistry::RegisterMCInstrInfo(*T, createARMMCInstrInfo);
327 
328     // Register the MC register info.
329     TargetRegistry::RegisterMCRegInfo(*T, createARMMCRegisterInfo);
330 
331     // Register the MC subtarget info.
332     TargetRegistry::RegisterMCSubtargetInfo(*T,
333                                             ARM_MC::createARMMCSubtargetInfo);
334 
335     TargetRegistry::RegisterELFStreamer(*T, createELFStreamer);
336     TargetRegistry::RegisterCOFFStreamer(*T, createARMWinCOFFStreamer);
337     TargetRegistry::RegisterMachOStreamer(*T, createARMMachOStreamer);
338 
339     // Register the obj target streamer.
340     TargetRegistry::RegisterObjectTargetStreamer(*T,
341                                                  createARMObjectTargetStreamer);
342 
343     // Register the asm streamer.
344     TargetRegistry::RegisterAsmTargetStreamer(*T, createARMTargetAsmStreamer);
345 
346     // Register the null TargetStreamer.
347     TargetRegistry::RegisterNullTargetStreamer(*T, createARMNullTargetStreamer);
348 
349     // Register the MCInstPrinter.
350     TargetRegistry::RegisterMCInstPrinter(*T, createARMMCInstPrinter);
351 
352     // Register the MC relocation info.
353     TargetRegistry::RegisterMCRelocationInfo(*T, createARMMCRelocationInfo);
354   }
355 
356   // Register the MC instruction analyzer.
357   for (Target *T : {&getTheARMLETarget(), &getTheARMBETarget()})
358     TargetRegistry::RegisterMCInstrAnalysis(*T, createARMMCInstrAnalysis);
359   for (Target *T : {&getTheThumbLETarget(), &getTheThumbBETarget()})
360     TargetRegistry::RegisterMCInstrAnalysis(*T, createThumbMCInstrAnalysis);
361 
362   for (Target *T : {&getTheARMLETarget(), &getTheThumbLETarget()}) {
363     TargetRegistry::RegisterMCCodeEmitter(*T, createARMLEMCCodeEmitter);
364     TargetRegistry::RegisterMCAsmBackend(*T, createARMLEAsmBackend);
365   }
366   for (Target *T : {&getTheARMBETarget(), &getTheThumbBETarget()}) {
367     TargetRegistry::RegisterMCCodeEmitter(*T, createARMBEMCCodeEmitter);
368     TargetRegistry::RegisterMCAsmBackend(*T, createARMBEAsmBackend);
369   }
370 }
371