1 //===-- RISCVMCTargetDesc.cpp - RISC-V 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 RISC-V specific target descriptions.
10 ///
11 //===----------------------------------------------------------------------===//
12
13 #include "RISCVMCTargetDesc.h"
14 #include "RISCVBaseInfo.h"
15 #include "RISCVELFStreamer.h"
16 #include "RISCVInstPrinter.h"
17 #include "RISCVMCAsmInfo.h"
18 #include "RISCVMCObjectFileInfo.h"
19 #include "RISCVTargetStreamer.h"
20 #include "TargetInfo/RISCVTargetInfo.h"
21 #include "llvm/ADT/STLExtras.h"
22 #include "llvm/MC/MCAsmBackend.h"
23 #include "llvm/MC/MCAsmInfo.h"
24 #include "llvm/MC/MCCodeEmitter.h"
25 #include "llvm/MC/MCInstrAnalysis.h"
26 #include "llvm/MC/MCInstrInfo.h"
27 #include "llvm/MC/MCObjectFileInfo.h"
28 #include "llvm/MC/MCObjectWriter.h"
29 #include "llvm/MC/MCRegisterInfo.h"
30 #include "llvm/MC/MCStreamer.h"
31 #include "llvm/MC/MCSubtargetInfo.h"
32 #include "llvm/MC/TargetRegistry.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include <bitset>
35
36 #define GET_INSTRINFO_MC_DESC
37 #define ENABLE_INSTR_PREDICATE_VERIFIER
38 #include "RISCVGenInstrInfo.inc"
39
40 #define GET_REGINFO_MC_DESC
41 #include "RISCVGenRegisterInfo.inc"
42
43 #define GET_SUBTARGETINFO_MC_DESC
44 #include "RISCVGenSubtargetInfo.inc"
45
46 namespace llvm::RISCVVInversePseudosTable {
47
48 using namespace RISCV;
49
50 #define GET_RISCVVInversePseudosTable_IMPL
51 #include "RISCVGenSearchableTables.inc"
52
53 } // namespace llvm::RISCVVInversePseudosTable
54
55 using namespace llvm;
56
createRISCVMCInstrInfo()57 static MCInstrInfo *createRISCVMCInstrInfo() {
58 MCInstrInfo *X = new MCInstrInfo();
59 InitRISCVMCInstrInfo(X);
60 return X;
61 }
62
createRISCVMCRegisterInfo(const Triple & TT)63 static MCRegisterInfo *createRISCVMCRegisterInfo(const Triple &TT) {
64 MCRegisterInfo *X = new MCRegisterInfo();
65 InitRISCVMCRegisterInfo(X, RISCV::X1);
66 return X;
67 }
68
createRISCVMCAsmInfo(const MCRegisterInfo & MRI,const Triple & TT,const MCTargetOptions & Options)69 static MCAsmInfo *createRISCVMCAsmInfo(const MCRegisterInfo &MRI,
70 const Triple &TT,
71 const MCTargetOptions &Options) {
72 MCAsmInfo *MAI = new RISCVMCAsmInfo(TT);
73
74 MCRegister SP = MRI.getDwarfRegNum(RISCV::X2, true);
75 MCCFIInstruction Inst = MCCFIInstruction::cfiDefCfa(nullptr, SP, 0);
76 MAI->addInitialFrameState(Inst);
77
78 return MAI;
79 }
80
81 static MCObjectFileInfo *
createRISCVMCObjectFileInfo(MCContext & Ctx,bool PIC,bool LargeCodeModel=false)82 createRISCVMCObjectFileInfo(MCContext &Ctx, bool PIC,
83 bool LargeCodeModel = false) {
84 MCObjectFileInfo *MOFI = new RISCVMCObjectFileInfo();
85 MOFI->initMCObjectFileInfo(Ctx, PIC, LargeCodeModel);
86 return MOFI;
87 }
88
createRISCVMCSubtargetInfo(const Triple & TT,StringRef CPU,StringRef FS)89 static MCSubtargetInfo *createRISCVMCSubtargetInfo(const Triple &TT,
90 StringRef CPU, StringRef FS) {
91 if (CPU.empty() || CPU == "generic")
92 CPU = TT.isArch64Bit() ? "generic-rv64" : "generic-rv32";
93
94 return createRISCVMCSubtargetInfoImpl(TT, CPU, /*TuneCPU*/ CPU, FS);
95 }
96
createRISCVMCInstPrinter(const Triple & T,unsigned SyntaxVariant,const MCAsmInfo & MAI,const MCInstrInfo & MII,const MCRegisterInfo & MRI)97 static MCInstPrinter *createRISCVMCInstPrinter(const Triple &T,
98 unsigned SyntaxVariant,
99 const MCAsmInfo &MAI,
100 const MCInstrInfo &MII,
101 const MCRegisterInfo &MRI) {
102 return new RISCVInstPrinter(MAI, MII, MRI);
103 }
104
105 static MCTargetStreamer *
createRISCVObjectTargetStreamer(MCStreamer & S,const MCSubtargetInfo & STI)106 createRISCVObjectTargetStreamer(MCStreamer &S, const MCSubtargetInfo &STI) {
107 const Triple &TT = STI.getTargetTriple();
108 if (TT.isOSBinFormatELF())
109 return new RISCVTargetELFStreamer(S, STI);
110 return nullptr;
111 }
112
113 static MCTargetStreamer *
createRISCVAsmTargetStreamer(MCStreamer & S,formatted_raw_ostream & OS,MCInstPrinter * InstPrint)114 createRISCVAsmTargetStreamer(MCStreamer &S, formatted_raw_ostream &OS,
115 MCInstPrinter *InstPrint) {
116 return new RISCVTargetAsmStreamer(S, OS);
117 }
118
createRISCVNullTargetStreamer(MCStreamer & S)119 static MCTargetStreamer *createRISCVNullTargetStreamer(MCStreamer &S) {
120 return new RISCVTargetStreamer(S);
121 }
122
123 namespace {
124
125 class RISCVMCInstrAnalysis : public MCInstrAnalysis {
126 int64_t GPRState[31] = {};
127 std::bitset<31> GPRValidMask;
128
isGPR(unsigned Reg)129 static bool isGPR(unsigned Reg) {
130 return Reg >= RISCV::X0 && Reg <= RISCV::X31;
131 }
132
getRegIndex(unsigned Reg)133 static unsigned getRegIndex(unsigned Reg) {
134 assert(isGPR(Reg) && Reg != RISCV::X0 && "Invalid GPR reg");
135 return Reg - RISCV::X1;
136 }
137
setGPRState(unsigned Reg,std::optional<int64_t> Value)138 void setGPRState(unsigned Reg, std::optional<int64_t> Value) {
139 if (Reg == RISCV::X0)
140 return;
141
142 auto Index = getRegIndex(Reg);
143
144 if (Value) {
145 GPRState[Index] = *Value;
146 GPRValidMask.set(Index);
147 } else {
148 GPRValidMask.reset(Index);
149 }
150 }
151
getGPRState(unsigned Reg) const152 std::optional<int64_t> getGPRState(unsigned Reg) const {
153 if (Reg == RISCV::X0)
154 return 0;
155
156 auto Index = getRegIndex(Reg);
157
158 if (GPRValidMask.test(Index))
159 return GPRState[Index];
160 return std::nullopt;
161 }
162
163 public:
RISCVMCInstrAnalysis(const MCInstrInfo * Info)164 explicit RISCVMCInstrAnalysis(const MCInstrInfo *Info)
165 : MCInstrAnalysis(Info) {}
166
resetState()167 void resetState() override { GPRValidMask.reset(); }
168
updateState(const MCInst & Inst,uint64_t Addr)169 void updateState(const MCInst &Inst, uint64_t Addr) override {
170 // Terminators mark the end of a basic block which means the sequentially
171 // next instruction will be the first of another basic block and the current
172 // state will typically not be valid anymore. For calls, we assume all
173 // registers may be clobbered by the callee (TODO: should we take the
174 // calling convention into account?).
175 if (isTerminator(Inst) || isCall(Inst)) {
176 resetState();
177 return;
178 }
179
180 switch (Inst.getOpcode()) {
181 default: {
182 // Clear the state of all defined registers for instructions that we don't
183 // explicitly support.
184 auto NumDefs = Info->get(Inst.getOpcode()).getNumDefs();
185 for (unsigned I = 0; I < NumDefs; ++I) {
186 auto DefReg = Inst.getOperand(I).getReg();
187 if (isGPR(DefReg))
188 setGPRState(DefReg, std::nullopt);
189 }
190 break;
191 }
192 case RISCV::AUIPC:
193 setGPRState(Inst.getOperand(0).getReg(),
194 Addr + (Inst.getOperand(1).getImm() << 12));
195 break;
196 }
197 }
198
evaluateBranch(const MCInst & Inst,uint64_t Addr,uint64_t Size,uint64_t & Target) const199 bool evaluateBranch(const MCInst &Inst, uint64_t Addr, uint64_t Size,
200 uint64_t &Target) const override {
201 if (isConditionalBranch(Inst)) {
202 int64_t Imm;
203 if (Size == 2)
204 Imm = Inst.getOperand(1).getImm();
205 else
206 Imm = Inst.getOperand(2).getImm();
207 Target = Addr + Imm;
208 return true;
209 }
210
211 if (Inst.getOpcode() == RISCV::C_JAL || Inst.getOpcode() == RISCV::C_J) {
212 Target = Addr + Inst.getOperand(0).getImm();
213 return true;
214 }
215
216 if (Inst.getOpcode() == RISCV::JAL) {
217 Target = Addr + Inst.getOperand(1).getImm();
218 return true;
219 }
220
221 if (Inst.getOpcode() == RISCV::JALR) {
222 if (auto TargetRegState = getGPRState(Inst.getOperand(1).getReg())) {
223 Target = *TargetRegState + Inst.getOperand(2).getImm();
224 return true;
225 }
226
227 return false;
228 }
229
230 return false;
231 }
232
isTerminator(const MCInst & Inst) const233 bool isTerminator(const MCInst &Inst) const override {
234 if (MCInstrAnalysis::isTerminator(Inst))
235 return true;
236
237 switch (Inst.getOpcode()) {
238 default:
239 return false;
240 case RISCV::JAL:
241 case RISCV::JALR:
242 return Inst.getOperand(0).getReg() == RISCV::X0;
243 }
244 }
245
isCall(const MCInst & Inst) const246 bool isCall(const MCInst &Inst) const override {
247 if (MCInstrAnalysis::isCall(Inst))
248 return true;
249
250 switch (Inst.getOpcode()) {
251 default:
252 return false;
253 case RISCV::JAL:
254 case RISCV::JALR:
255 return Inst.getOperand(0).getReg() != RISCV::X0;
256 }
257 }
258
isReturn(const MCInst & Inst) const259 bool isReturn(const MCInst &Inst) const override {
260 if (MCInstrAnalysis::isReturn(Inst))
261 return true;
262
263 switch (Inst.getOpcode()) {
264 default:
265 return false;
266 case RISCV::JALR:
267 return Inst.getOperand(0).getReg() == RISCV::X0 &&
268 maybeReturnAddress(Inst.getOperand(1).getReg());
269 case RISCV::C_JR:
270 return maybeReturnAddress(Inst.getOperand(0).getReg());
271 }
272 }
273
isBranch(const MCInst & Inst) const274 bool isBranch(const MCInst &Inst) const override {
275 if (MCInstrAnalysis::isBranch(Inst))
276 return true;
277
278 return isBranchImpl(Inst);
279 }
280
isUnconditionalBranch(const MCInst & Inst) const281 bool isUnconditionalBranch(const MCInst &Inst) const override {
282 if (MCInstrAnalysis::isUnconditionalBranch(Inst))
283 return true;
284
285 return isBranchImpl(Inst);
286 }
287
isIndirectBranch(const MCInst & Inst) const288 bool isIndirectBranch(const MCInst &Inst) const override {
289 if (MCInstrAnalysis::isIndirectBranch(Inst))
290 return true;
291
292 switch (Inst.getOpcode()) {
293 default:
294 return false;
295 case RISCV::JALR:
296 return Inst.getOperand(0).getReg() == RISCV::X0 &&
297 !maybeReturnAddress(Inst.getOperand(1).getReg());
298 case RISCV::C_JR:
299 return !maybeReturnAddress(Inst.getOperand(0).getReg());
300 }
301 }
302
303 private:
maybeReturnAddress(unsigned Reg)304 static bool maybeReturnAddress(unsigned Reg) {
305 // X1 is used for normal returns, X5 for returns from outlined functions.
306 return Reg == RISCV::X1 || Reg == RISCV::X5;
307 }
308
isBranchImpl(const MCInst & Inst)309 static bool isBranchImpl(const MCInst &Inst) {
310 switch (Inst.getOpcode()) {
311 default:
312 return false;
313 case RISCV::JAL:
314 return Inst.getOperand(0).getReg() == RISCV::X0;
315 case RISCV::JALR:
316 return Inst.getOperand(0).getReg() == RISCV::X0 &&
317 !maybeReturnAddress(Inst.getOperand(1).getReg());
318 case RISCV::C_JR:
319 return !maybeReturnAddress(Inst.getOperand(0).getReg());
320 }
321 }
322 };
323
324 } // end anonymous namespace
325
createRISCVInstrAnalysis(const MCInstrInfo * Info)326 static MCInstrAnalysis *createRISCVInstrAnalysis(const MCInstrInfo *Info) {
327 return new RISCVMCInstrAnalysis(Info);
328 }
329
330 namespace {
createRISCVELFStreamer(const Triple & T,MCContext & Context,std::unique_ptr<MCAsmBackend> && MAB,std::unique_ptr<MCObjectWriter> && MOW,std::unique_ptr<MCCodeEmitter> && MCE)331 MCStreamer *createRISCVELFStreamer(const Triple &T, MCContext &Context,
332 std::unique_ptr<MCAsmBackend> &&MAB,
333 std::unique_ptr<MCObjectWriter> &&MOW,
334 std::unique_ptr<MCCodeEmitter> &&MCE) {
335 return createRISCVELFStreamer(Context, std::move(MAB), std::move(MOW),
336 std::move(MCE));
337 }
338 } // end anonymous namespace
339
LLVMInitializeRISCVTargetMC()340 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVTargetMC() {
341 for (Target *T : {&getTheRISCV32Target(), &getTheRISCV64Target()}) {
342 TargetRegistry::RegisterMCAsmInfo(*T, createRISCVMCAsmInfo);
343 TargetRegistry::RegisterMCObjectFileInfo(*T, createRISCVMCObjectFileInfo);
344 TargetRegistry::RegisterMCInstrInfo(*T, createRISCVMCInstrInfo);
345 TargetRegistry::RegisterMCRegInfo(*T, createRISCVMCRegisterInfo);
346 TargetRegistry::RegisterMCAsmBackend(*T, createRISCVAsmBackend);
347 TargetRegistry::RegisterMCCodeEmitter(*T, createRISCVMCCodeEmitter);
348 TargetRegistry::RegisterMCInstPrinter(*T, createRISCVMCInstPrinter);
349 TargetRegistry::RegisterMCSubtargetInfo(*T, createRISCVMCSubtargetInfo);
350 TargetRegistry::RegisterELFStreamer(*T, createRISCVELFStreamer);
351 TargetRegistry::RegisterObjectTargetStreamer(
352 *T, createRISCVObjectTargetStreamer);
353 TargetRegistry::RegisterMCInstrAnalysis(*T, createRISCVInstrAnalysis);
354
355 // Register the asm target streamer.
356 TargetRegistry::RegisterAsmTargetStreamer(*T, createRISCVAsmTargetStreamer);
357 // Register the null target streamer.
358 TargetRegistry::RegisterNullTargetStreamer(*T,
359 createRISCVNullTargetStreamer);
360 }
361 }
362