1 //===-- RISCVAsmParser.cpp - Parse RISCV assembly to MCInst instructions --===//
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 #include "MCTargetDesc/RISCVAsmBackend.h"
10 #include "MCTargetDesc/RISCVMCExpr.h"
11 #include "MCTargetDesc/RISCVMCTargetDesc.h"
12 #include "MCTargetDesc/RISCVTargetStreamer.h"
13 #include "TargetInfo/RISCVTargetInfo.h"
14 #include "Utils/RISCVBaseInfo.h"
15 #include "Utils/RISCVMatInt.h"
16 #include "llvm/ADT/STLExtras.h"
17 #include "llvm/ADT/SmallBitVector.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/ADT/SmallVector.h"
20 #include "llvm/ADT/Statistic.h"
21 #include "llvm/ADT/StringSwitch.h"
22 #include "llvm/MC/MCAssembler.h"
23 #include "llvm/MC/MCContext.h"
24 #include "llvm/MC/MCExpr.h"
25 #include "llvm/MC/MCInst.h"
26 #include "llvm/MC/MCInstBuilder.h"
27 #include "llvm/MC/MCObjectFileInfo.h"
28 #include "llvm/MC/MCParser/MCAsmLexer.h"
29 #include "llvm/MC/MCParser/MCParsedAsmOperand.h"
30 #include "llvm/MC/MCParser/MCTargetAsmParser.h"
31 #include "llvm/MC/MCRegisterInfo.h"
32 #include "llvm/MC/MCStreamer.h"
33 #include "llvm/MC/MCSubtargetInfo.h"
34 #include "llvm/Support/Casting.h"
35 #include "llvm/Support/MathExtras.h"
36 #include "llvm/Support/RISCVAttributes.h"
37 #include "llvm/Support/TargetRegistry.h"
38 
39 #include <limits>
40 
41 using namespace llvm;
42 
43 #define DEBUG_TYPE "riscv-asm-parser"
44 
45 // Include the auto-generated portion of the compress emitter.
46 #define GEN_COMPRESS_INSTR
47 #include "RISCVGenCompressInstEmitter.inc"
48 
49 STATISTIC(RISCVNumInstrsCompressed,
50           "Number of RISC-V Compressed instructions emitted");
51 
52 namespace {
53 struct RISCVOperand;
54 
55 struct ParserOptionsSet {
56   bool IsPicEnabled;
57 };
58 
59 class RISCVAsmParser : public MCTargetAsmParser {
60   SmallVector<FeatureBitset, 4> FeatureBitStack;
61 
62   SmallVector<ParserOptionsSet, 4> ParserOptionsStack;
63   ParserOptionsSet ParserOptions;
64 
65   SMLoc getLoc() const { return getParser().getTok().getLoc(); }
66   bool isRV64() const { return getSTI().hasFeature(RISCV::Feature64Bit); }
67   bool isRV32E() const { return getSTI().hasFeature(RISCV::FeatureRV32E); }
68 
69   RISCVTargetStreamer &getTargetStreamer() {
70     MCTargetStreamer &TS = *getParser().getStreamer().getTargetStreamer();
71     return static_cast<RISCVTargetStreamer &>(TS);
72   }
73 
74   unsigned validateTargetOperandClass(MCParsedAsmOperand &Op,
75                                       unsigned Kind) override;
76 
77   bool generateImmOutOfRangeError(OperandVector &Operands, uint64_t ErrorInfo,
78                                   int64_t Lower, int64_t Upper, Twine Msg);
79 
80   bool MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
81                                OperandVector &Operands, MCStreamer &Out,
82                                uint64_t &ErrorInfo,
83                                bool MatchingInlineAsm) override;
84 
85   bool ParseRegister(unsigned &RegNo, SMLoc &StartLoc, SMLoc &EndLoc) override;
86   OperandMatchResultTy tryParseRegister(unsigned &RegNo, SMLoc &StartLoc,
87                                         SMLoc &EndLoc) override;
88 
89   bool ParseInstruction(ParseInstructionInfo &Info, StringRef Name,
90                         SMLoc NameLoc, OperandVector &Operands) override;
91 
92   bool ParseDirective(AsmToken DirectiveID) override;
93 
94   // Helper to actually emit an instruction to the MCStreamer. Also, when
95   // possible, compression of the instruction is performed.
96   void emitToStreamer(MCStreamer &S, const MCInst &Inst);
97 
98   // Helper to emit a combination of LUI, ADDI(W), and SLLI instructions that
99   // synthesize the desired immedate value into the destination register.
100   void emitLoadImm(MCRegister DestReg, int64_t Value, MCStreamer &Out);
101 
102   // Helper to emit a combination of AUIPC and SecondOpcode. Used to implement
103   // helpers such as emitLoadLocalAddress and emitLoadAddress.
104   void emitAuipcInstPair(MCOperand DestReg, MCOperand TmpReg,
105                          const MCExpr *Symbol, RISCVMCExpr::VariantKind VKHi,
106                          unsigned SecondOpcode, SMLoc IDLoc, MCStreamer &Out);
107 
108   // Helper to emit pseudo instruction "lla" used in PC-rel addressing.
109   void emitLoadLocalAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
110 
111   // Helper to emit pseudo instruction "la" used in GOT/PC-rel addressing.
112   void emitLoadAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
113 
114   // Helper to emit pseudo instruction "la.tls.ie" used in initial-exec TLS
115   // addressing.
116   void emitLoadTLSIEAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
117 
118   // Helper to emit pseudo instruction "la.tls.gd" used in global-dynamic TLS
119   // addressing.
120   void emitLoadTLSGDAddress(MCInst &Inst, SMLoc IDLoc, MCStreamer &Out);
121 
122   // Helper to emit pseudo load/store instruction with a symbol.
123   void emitLoadStoreSymbol(MCInst &Inst, unsigned Opcode, SMLoc IDLoc,
124                            MCStreamer &Out, bool HasTmpReg);
125 
126   // Checks that a PseudoAddTPRel is using x4/tp in its second input operand.
127   // Enforcing this using a restricted register class for the second input
128   // operand of PseudoAddTPRel results in a poor diagnostic due to the fact
129   // 'add' is an overloaded mnemonic.
130   bool checkPseudoAddTPRel(MCInst &Inst, OperandVector &Operands);
131 
132   // Check instruction constraints.
133   bool validateInstruction(MCInst &Inst, OperandVector &Operands);
134 
135   /// Helper for processing MC instructions that have been successfully matched
136   /// by MatchAndEmitInstruction. Modifications to the emitted instructions,
137   /// like the expansion of pseudo instructions (e.g., "li"), can be performed
138   /// in this method.
139   bool processInstruction(MCInst &Inst, SMLoc IDLoc, OperandVector &Operands,
140                           MCStreamer &Out);
141 
142 // Auto-generated instruction matching functions
143 #define GET_ASSEMBLER_HEADER
144 #include "RISCVGenAsmMatcher.inc"
145 
146   OperandMatchResultTy parseCSRSystemRegister(OperandVector &Operands);
147   OperandMatchResultTy parseImmediate(OperandVector &Operands);
148   OperandMatchResultTy parseRegister(OperandVector &Operands,
149                                      bool AllowParens = false);
150   OperandMatchResultTy parseMemOpBaseReg(OperandVector &Operands);
151   OperandMatchResultTy parseAtomicMemOp(OperandVector &Operands);
152   OperandMatchResultTy parseOperandWithModifier(OperandVector &Operands);
153   OperandMatchResultTy parseBareSymbol(OperandVector &Operands);
154   OperandMatchResultTy parseCallSymbol(OperandVector &Operands);
155   OperandMatchResultTy parsePseudoJumpSymbol(OperandVector &Operands);
156   OperandMatchResultTy parseJALOffset(OperandVector &Operands);
157   OperandMatchResultTy parseVTypeI(OperandVector &Operands);
158   OperandMatchResultTy parseMaskReg(OperandVector &Operands);
159 
160   bool parseOperand(OperandVector &Operands, StringRef Mnemonic);
161 
162   bool parseDirectiveOption();
163   bool parseDirectiveAttribute();
164 
165   void setFeatureBits(uint64_t Feature, StringRef FeatureString) {
166     if (!(getSTI().getFeatureBits()[Feature])) {
167       MCSubtargetInfo &STI = copySTI();
168       setAvailableFeatures(
169           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
170     }
171   }
172 
173   bool getFeatureBits(uint64_t Feature) {
174     return getSTI().getFeatureBits()[Feature];
175   }
176 
177   void clearFeatureBits(uint64_t Feature, StringRef FeatureString) {
178     if (getSTI().getFeatureBits()[Feature]) {
179       MCSubtargetInfo &STI = copySTI();
180       setAvailableFeatures(
181           ComputeAvailableFeatures(STI.ToggleFeature(FeatureString)));
182     }
183   }
184 
185   void pushFeatureBits() {
186     assert(FeatureBitStack.size() == ParserOptionsStack.size() &&
187            "These two stacks must be kept synchronized");
188     FeatureBitStack.push_back(getSTI().getFeatureBits());
189     ParserOptionsStack.push_back(ParserOptions);
190   }
191 
192   bool popFeatureBits() {
193     assert(FeatureBitStack.size() == ParserOptionsStack.size() &&
194            "These two stacks must be kept synchronized");
195     if (FeatureBitStack.empty())
196       return true;
197 
198     FeatureBitset FeatureBits = FeatureBitStack.pop_back_val();
199     copySTI().setFeatureBits(FeatureBits);
200     setAvailableFeatures(ComputeAvailableFeatures(FeatureBits));
201 
202     ParserOptions = ParserOptionsStack.pop_back_val();
203 
204     return false;
205   }
206 
207   std::unique_ptr<RISCVOperand> defaultMaskRegOp() const;
208 
209 public:
210   enum RISCVMatchResultTy {
211     Match_Dummy = FIRST_TARGET_MATCH_RESULT_TY,
212 #define GET_OPERAND_DIAGNOSTIC_TYPES
213 #include "RISCVGenAsmMatcher.inc"
214 #undef GET_OPERAND_DIAGNOSTIC_TYPES
215   };
216 
217   static bool classifySymbolRef(const MCExpr *Expr,
218                                 RISCVMCExpr::VariantKind &Kind);
219 
220   RISCVAsmParser(const MCSubtargetInfo &STI, MCAsmParser &Parser,
221                  const MCInstrInfo &MII, const MCTargetOptions &Options)
222       : MCTargetAsmParser(Options, STI, MII) {
223     Parser.addAliasForDirective(".half", ".2byte");
224     Parser.addAliasForDirective(".hword", ".2byte");
225     Parser.addAliasForDirective(".word", ".4byte");
226     Parser.addAliasForDirective(".dword", ".8byte");
227     setAvailableFeatures(ComputeAvailableFeatures(STI.getFeatureBits()));
228 
229     auto ABIName = StringRef(Options.ABIName);
230     if (ABIName.endswith("f") &&
231         !getSTI().getFeatureBits()[RISCV::FeatureStdExtF]) {
232       errs() << "Hard-float 'f' ABI can't be used for a target that "
233                 "doesn't support the F instruction set extension (ignoring "
234                 "target-abi)\n";
235     } else if (ABIName.endswith("d") &&
236                !getSTI().getFeatureBits()[RISCV::FeatureStdExtD]) {
237       errs() << "Hard-float 'd' ABI can't be used for a target that "
238                 "doesn't support the D instruction set extension (ignoring "
239                 "target-abi)\n";
240     }
241 
242     const MCObjectFileInfo *MOFI = Parser.getContext().getObjectFileInfo();
243     ParserOptions.IsPicEnabled = MOFI->isPositionIndependent();
244   }
245 };
246 
247 /// RISCVOperand - Instances of this class represent a parsed machine
248 /// instruction
249 struct RISCVOperand : public MCParsedAsmOperand {
250 
251   enum class KindTy {
252     Token,
253     Register,
254     Immediate,
255     SystemRegister,
256     VType,
257   } Kind;
258 
259   bool IsRV64;
260 
261   struct RegOp {
262     MCRegister RegNum;
263   };
264 
265   struct ImmOp {
266     const MCExpr *Val;
267   };
268 
269   struct SysRegOp {
270     const char *Data;
271     unsigned Length;
272     unsigned Encoding;
273     // FIXME: Add the Encoding parsed fields as needed for checks,
274     // e.g.: read/write or user/supervisor/machine privileges.
275   };
276 
277   enum class VSEW {
278     SEW_8 = 0,
279     SEW_16,
280     SEW_32,
281     SEW_64,
282     SEW_128,
283     SEW_256,
284     SEW_512,
285     SEW_1024,
286   };
287 
288   enum class VLMUL {
289     LMUL_1 = 0,
290     LMUL_2,
291     LMUL_4,
292     LMUL_8,
293     LMUL_F8 = 5,
294     LMUL_F4,
295     LMUL_F2
296   };
297 
298   struct VTypeOp {
299     VSEW Sew;
300     VLMUL Lmul;
301     bool TailAgnostic;
302     bool MaskedoffAgnostic;
303     unsigned Encoding;
304   };
305 
306   SMLoc StartLoc, EndLoc;
307   union {
308     StringRef Tok;
309     RegOp Reg;
310     ImmOp Imm;
311     struct SysRegOp SysReg;
312     struct VTypeOp VType;
313   };
314 
315   RISCVOperand(KindTy K) : MCParsedAsmOperand(), Kind(K) {}
316 
317 public:
318   RISCVOperand(const RISCVOperand &o) : MCParsedAsmOperand() {
319     Kind = o.Kind;
320     IsRV64 = o.IsRV64;
321     StartLoc = o.StartLoc;
322     EndLoc = o.EndLoc;
323     switch (Kind) {
324     case KindTy::Register:
325       Reg = o.Reg;
326       break;
327     case KindTy::Immediate:
328       Imm = o.Imm;
329       break;
330     case KindTy::Token:
331       Tok = o.Tok;
332       break;
333     case KindTy::SystemRegister:
334       SysReg = o.SysReg;
335       break;
336     case KindTy::VType:
337       VType = o.VType;
338       break;
339     }
340   }
341 
342   bool isToken() const override { return Kind == KindTy::Token; }
343   bool isReg() const override { return Kind == KindTy::Register; }
344   bool isV0Reg() const {
345     return Kind == KindTy::Register && Reg.RegNum == RISCV::V0;
346   }
347   bool isImm() const override { return Kind == KindTy::Immediate; }
348   bool isMem() const override { return false; }
349   bool isSystemRegister() const { return Kind == KindTy::SystemRegister; }
350   bool isVType() const { return Kind == KindTy::VType; }
351 
352   bool isGPR() const {
353     return Kind == KindTy::Register &&
354            RISCVMCRegisterClasses[RISCV::GPRRegClassID].contains(Reg.RegNum);
355   }
356 
357   static bool evaluateConstantImm(const MCExpr *Expr, int64_t &Imm,
358                                   RISCVMCExpr::VariantKind &VK) {
359     if (auto *RE = dyn_cast<RISCVMCExpr>(Expr)) {
360       VK = RE->getKind();
361       return RE->evaluateAsConstant(Imm);
362     }
363 
364     if (auto CE = dyn_cast<MCConstantExpr>(Expr)) {
365       VK = RISCVMCExpr::VK_RISCV_None;
366       Imm = CE->getValue();
367       return true;
368     }
369 
370     return false;
371   }
372 
373   // True if operand is a symbol with no modifiers, or a constant with no
374   // modifiers and isShiftedInt<N-1, 1>(Op).
375   template <int N> bool isBareSimmNLsb0() const {
376     int64_t Imm;
377     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
378     if (!isImm())
379       return false;
380     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
381     bool IsValid;
382     if (!IsConstantImm)
383       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
384     else
385       IsValid = isShiftedInt<N - 1, 1>(Imm);
386     return IsValid && VK == RISCVMCExpr::VK_RISCV_None;
387   }
388 
389   // Predicate methods for AsmOperands defined in RISCVInstrInfo.td
390 
391   bool isBareSymbol() const {
392     int64_t Imm;
393     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
394     // Must be of 'immediate' type but not a constant.
395     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
396       return false;
397     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
398            VK == RISCVMCExpr::VK_RISCV_None;
399   }
400 
401   bool isCallSymbol() const {
402     int64_t Imm;
403     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
404     // Must be of 'immediate' type but not a constant.
405     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
406       return false;
407     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
408            (VK == RISCVMCExpr::VK_RISCV_CALL ||
409             VK == RISCVMCExpr::VK_RISCV_CALL_PLT);
410   }
411 
412   bool isPseudoJumpSymbol() const {
413     int64_t Imm;
414     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
415     // Must be of 'immediate' type but not a constant.
416     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
417       return false;
418     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
419            VK == RISCVMCExpr::VK_RISCV_CALL;
420   }
421 
422   bool isTPRelAddSymbol() const {
423     int64_t Imm;
424     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
425     // Must be of 'immediate' type but not a constant.
426     if (!isImm() || evaluateConstantImm(getImm(), Imm, VK))
427       return false;
428     return RISCVAsmParser::classifySymbolRef(getImm(), VK) &&
429            VK == RISCVMCExpr::VK_RISCV_TPREL_ADD;
430   }
431 
432   bool isCSRSystemRegister() const { return isSystemRegister(); }
433 
434   bool isVTypeI() const { return isVType(); }
435 
436   /// Return true if the operand is a valid for the fence instruction e.g.
437   /// ('iorw').
438   bool isFenceArg() const {
439     if (!isImm())
440       return false;
441     const MCExpr *Val = getImm();
442     auto *SVal = dyn_cast<MCSymbolRefExpr>(Val);
443     if (!SVal || SVal->getKind() != MCSymbolRefExpr::VK_None)
444       return false;
445 
446     StringRef Str = SVal->getSymbol().getName();
447     // Letters must be unique, taken from 'iorw', and in ascending order. This
448     // holds as long as each individual character is one of 'iorw' and is
449     // greater than the previous character.
450     char Prev = '\0';
451     for (char c : Str) {
452       if (c != 'i' && c != 'o' && c != 'r' && c != 'w')
453         return false;
454       if (c <= Prev)
455         return false;
456       Prev = c;
457     }
458     return true;
459   }
460 
461   /// Return true if the operand is a valid floating point rounding mode.
462   bool isFRMArg() const {
463     if (!isImm())
464       return false;
465     const MCExpr *Val = getImm();
466     auto *SVal = dyn_cast<MCSymbolRefExpr>(Val);
467     if (!SVal || SVal->getKind() != MCSymbolRefExpr::VK_None)
468       return false;
469 
470     StringRef Str = SVal->getSymbol().getName();
471 
472     return RISCVFPRndMode::stringToRoundingMode(Str) != RISCVFPRndMode::Invalid;
473   }
474 
475   bool isImmXLenLI() const {
476     int64_t Imm;
477     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
478     if (!isImm())
479       return false;
480     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
481     if (VK == RISCVMCExpr::VK_RISCV_LO || VK == RISCVMCExpr::VK_RISCV_PCREL_LO)
482       return true;
483     // Given only Imm, ensuring that the actually specified constant is either
484     // a signed or unsigned 64-bit number is unfortunately impossible.
485     return IsConstantImm && VK == RISCVMCExpr::VK_RISCV_None &&
486            (isRV64() || (isInt<32>(Imm) || isUInt<32>(Imm)));
487   }
488 
489   bool isUImmLog2XLen() const {
490     int64_t Imm;
491     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
492     if (!isImm())
493       return false;
494     if (!evaluateConstantImm(getImm(), Imm, VK) ||
495         VK != RISCVMCExpr::VK_RISCV_None)
496       return false;
497     return (isRV64() && isUInt<6>(Imm)) || isUInt<5>(Imm);
498   }
499 
500   bool isUImmLog2XLenNonZero() const {
501     int64_t Imm;
502     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
503     if (!isImm())
504       return false;
505     if (!evaluateConstantImm(getImm(), Imm, VK) ||
506         VK != RISCVMCExpr::VK_RISCV_None)
507       return false;
508     if (Imm == 0)
509       return false;
510     return (isRV64() && isUInt<6>(Imm)) || isUInt<5>(Imm);
511   }
512 
513   bool isUImmLog2XLenHalf() const {
514     int64_t Imm;
515     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
516     if (!isImm())
517       return false;
518     if (!evaluateConstantImm(getImm(), Imm, VK) ||
519         VK != RISCVMCExpr::VK_RISCV_None)
520       return false;
521     return (isRV64() && isUInt<5>(Imm)) || isUInt<4>(Imm);
522   }
523 
524   bool isUImm5() const {
525     int64_t Imm;
526     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
527     if (!isImm())
528       return false;
529     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
530     return IsConstantImm && isUInt<5>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
531   }
532 
533   bool isUImm5NonZero() const {
534     int64_t Imm;
535     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
536     if (!isImm())
537       return false;
538     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
539     return IsConstantImm && isUInt<5>(Imm) && (Imm != 0) &&
540            VK == RISCVMCExpr::VK_RISCV_None;
541   }
542 
543   bool isSImm5() const {
544     if (!isImm())
545       return false;
546     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
547     int64_t Imm;
548     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
549     return IsConstantImm && isInt<5>(Imm) && VK == RISCVMCExpr::VK_RISCV_None;
550   }
551 
552   bool isSImm6() const {
553     if (!isImm())
554       return false;
555     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
556     int64_t Imm;
557     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
558     return IsConstantImm && isInt<6>(Imm) &&
559 	    VK == RISCVMCExpr::VK_RISCV_None;
560   }
561 
562   bool isSImm6NonZero() const {
563     if (!isImm())
564       return false;
565     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
566     int64_t Imm;
567     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
568     return IsConstantImm && isInt<6>(Imm) && (Imm != 0) &&
569            VK == RISCVMCExpr::VK_RISCV_None;
570   }
571 
572   bool isCLUIImm() const {
573     if (!isImm())
574       return false;
575     int64_t Imm;
576     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
577     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
578     return IsConstantImm && (Imm != 0) &&
579            (isUInt<5>(Imm) || (Imm >= 0xfffe0 && Imm <= 0xfffff)) &&
580            VK == RISCVMCExpr::VK_RISCV_None;
581   }
582 
583   bool isUImm7Lsb00() const {
584     if (!isImm())
585       return false;
586     int64_t Imm;
587     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
588     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
589     return IsConstantImm && isShiftedUInt<5, 2>(Imm) &&
590            VK == RISCVMCExpr::VK_RISCV_None;
591   }
592 
593   bool isUImm8Lsb00() const {
594     if (!isImm())
595       return false;
596     int64_t Imm;
597     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
598     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
599     return IsConstantImm && isShiftedUInt<6, 2>(Imm) &&
600            VK == RISCVMCExpr::VK_RISCV_None;
601   }
602 
603   bool isUImm8Lsb000() const {
604     if (!isImm())
605       return false;
606     int64_t Imm;
607     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
608     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
609     return IsConstantImm && isShiftedUInt<5, 3>(Imm) &&
610            VK == RISCVMCExpr::VK_RISCV_None;
611   }
612 
613   bool isSImm9Lsb0() const { return isBareSimmNLsb0<9>(); }
614 
615   bool isUImm9Lsb000() const {
616     if (!isImm())
617       return false;
618     int64_t Imm;
619     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
620     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
621     return IsConstantImm && isShiftedUInt<6, 3>(Imm) &&
622            VK == RISCVMCExpr::VK_RISCV_None;
623   }
624 
625   bool isUImm10Lsb00NonZero() const {
626     if (!isImm())
627       return false;
628     int64_t Imm;
629     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
630     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
631     return IsConstantImm && isShiftedUInt<8, 2>(Imm) && (Imm != 0) &&
632            VK == RISCVMCExpr::VK_RISCV_None;
633   }
634 
635   bool isSImm12() const {
636     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
637     int64_t Imm;
638     bool IsValid;
639     if (!isImm())
640       return false;
641     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
642     if (!IsConstantImm)
643       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
644     else
645       IsValid = isInt<12>(Imm);
646     return IsValid && ((IsConstantImm && VK == RISCVMCExpr::VK_RISCV_None) ||
647                        VK == RISCVMCExpr::VK_RISCV_LO ||
648                        VK == RISCVMCExpr::VK_RISCV_PCREL_LO ||
649                        VK == RISCVMCExpr::VK_RISCV_TPREL_LO);
650   }
651 
652   bool isSImm12Lsb0() const { return isBareSimmNLsb0<12>(); }
653 
654   bool isSImm13Lsb0() const { return isBareSimmNLsb0<13>(); }
655 
656   bool isSImm10Lsb0000NonZero() const {
657     if (!isImm())
658       return false;
659     int64_t Imm;
660     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
661     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
662     return IsConstantImm && (Imm != 0) && isShiftedInt<6, 4>(Imm) &&
663            VK == RISCVMCExpr::VK_RISCV_None;
664   }
665 
666   bool isUImm20LUI() const {
667     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
668     int64_t Imm;
669     bool IsValid;
670     if (!isImm())
671       return false;
672     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
673     if (!IsConstantImm) {
674       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
675       return IsValid && (VK == RISCVMCExpr::VK_RISCV_HI ||
676                          VK == RISCVMCExpr::VK_RISCV_TPREL_HI);
677     } else {
678       return isUInt<20>(Imm) && (VK == RISCVMCExpr::VK_RISCV_None ||
679                                  VK == RISCVMCExpr::VK_RISCV_HI ||
680                                  VK == RISCVMCExpr::VK_RISCV_TPREL_HI);
681     }
682   }
683 
684   bool isUImm20AUIPC() const {
685     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
686     int64_t Imm;
687     bool IsValid;
688     if (!isImm())
689       return false;
690     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
691     if (!IsConstantImm) {
692       IsValid = RISCVAsmParser::classifySymbolRef(getImm(), VK);
693       return IsValid && (VK == RISCVMCExpr::VK_RISCV_PCREL_HI ||
694                          VK == RISCVMCExpr::VK_RISCV_GOT_HI ||
695                          VK == RISCVMCExpr::VK_RISCV_TLS_GOT_HI ||
696                          VK == RISCVMCExpr::VK_RISCV_TLS_GD_HI);
697     } else {
698       return isUInt<20>(Imm) && (VK == RISCVMCExpr::VK_RISCV_None ||
699                                  VK == RISCVMCExpr::VK_RISCV_PCREL_HI ||
700                                  VK == RISCVMCExpr::VK_RISCV_GOT_HI ||
701                                  VK == RISCVMCExpr::VK_RISCV_TLS_GOT_HI ||
702                                  VK == RISCVMCExpr::VK_RISCV_TLS_GD_HI);
703     }
704   }
705 
706   bool isSImm21Lsb0JAL() const { return isBareSimmNLsb0<21>(); }
707 
708   bool isImmZero() const {
709     if (!isImm())
710       return false;
711     int64_t Imm;
712     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
713     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
714     return IsConstantImm && (Imm == 0) && VK == RISCVMCExpr::VK_RISCV_None;
715   }
716 
717   bool isSImm5Plus1() const {
718     if (!isImm())
719       return false;
720     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
721     int64_t Imm;
722     bool IsConstantImm = evaluateConstantImm(getImm(), Imm, VK);
723     return IsConstantImm && isInt<5>(Imm - 1) &&
724            VK == RISCVMCExpr::VK_RISCV_None;
725   }
726 
727   /// getStartLoc - Gets location of the first token of this operand
728   SMLoc getStartLoc() const override { return StartLoc; }
729   /// getEndLoc - Gets location of the last token of this operand
730   SMLoc getEndLoc() const override { return EndLoc; }
731   /// True if this operand is for an RV64 instruction
732   bool isRV64() const { return IsRV64; }
733 
734   unsigned getReg() const override {
735     assert(Kind == KindTy::Register && "Invalid type access!");
736     return Reg.RegNum.id();
737   }
738 
739   StringRef getSysReg() const {
740     assert(Kind == KindTy::SystemRegister && "Invalid access!");
741     return StringRef(SysReg.Data, SysReg.Length);
742   }
743 
744   const MCExpr *getImm() const {
745     assert(Kind == KindTy::Immediate && "Invalid type access!");
746     return Imm.Val;
747   }
748 
749   StringRef getToken() const {
750     assert(Kind == KindTy::Token && "Invalid type access!");
751     return Tok;
752   }
753 
754   static StringRef getSEWStr(VSEW Sew) {
755     switch (Sew) {
756     case VSEW::SEW_8:
757       return "e8";
758     case VSEW::SEW_16:
759       return "e16";
760     case VSEW::SEW_32:
761       return "e32";
762     case VSEW::SEW_64:
763       return "e64";
764     case VSEW::SEW_128:
765       return "e128";
766     case VSEW::SEW_256:
767       return "e256";
768     case VSEW::SEW_512:
769       return "e512";
770     case VSEW::SEW_1024:
771       return "e1024";
772     }
773     llvm_unreachable("Unknown SEW.");
774   }
775 
776   static StringRef getLMULStr(VLMUL Lmul) {
777     switch (Lmul) {
778     case VLMUL::LMUL_1:
779       return "m1";
780     case VLMUL::LMUL_2:
781       return "m2";
782     case VLMUL::LMUL_4:
783       return "m4";
784     case VLMUL::LMUL_8:
785       return "m8";
786     case VLMUL::LMUL_F2:
787       return "mf2";
788     case VLMUL::LMUL_F4:
789       return "mf4";
790     case VLMUL::LMUL_F8:
791       return "mf8";
792     }
793     llvm_unreachable("Unknown LMUL.");
794   }
795 
796   StringRef getVType(SmallString<32> &Buf) const {
797     assert(Kind == KindTy::VType && "Invalid access!");
798     Buf.append(getSEWStr(VType.Sew));
799     Buf.append(",");
800     Buf.append(getLMULStr(VType.Lmul));
801 
802     return Buf.str();
803   }
804 
805   void print(raw_ostream &OS) const override {
806     switch (Kind) {
807     case KindTy::Immediate:
808       OS << *getImm();
809       break;
810     case KindTy::Register:
811       OS << "<register x";
812       OS << getReg() << ">";
813       break;
814     case KindTy::Token:
815       OS << "'" << getToken() << "'";
816       break;
817     case KindTy::SystemRegister:
818       OS << "<sysreg: " << getSysReg() << '>';
819       break;
820     case KindTy::VType:
821       SmallString<32> VTypeBuf;
822       OS << "<vtype: " << getVType(VTypeBuf) << '>';
823       break;
824     }
825   }
826 
827   static std::unique_ptr<RISCVOperand> createToken(StringRef Str, SMLoc S,
828                                                    bool IsRV64) {
829     auto Op = std::make_unique<RISCVOperand>(KindTy::Token);
830     Op->Tok = Str;
831     Op->StartLoc = S;
832     Op->EndLoc = S;
833     Op->IsRV64 = IsRV64;
834     return Op;
835   }
836 
837   static std::unique_ptr<RISCVOperand> createReg(unsigned RegNo, SMLoc S,
838                                                  SMLoc E, bool IsRV64) {
839     auto Op = std::make_unique<RISCVOperand>(KindTy::Register);
840     Op->Reg.RegNum = RegNo;
841     Op->StartLoc = S;
842     Op->EndLoc = E;
843     Op->IsRV64 = IsRV64;
844     return Op;
845   }
846 
847   static std::unique_ptr<RISCVOperand> createImm(const MCExpr *Val, SMLoc S,
848                                                  SMLoc E, bool IsRV64) {
849     auto Op = std::make_unique<RISCVOperand>(KindTy::Immediate);
850     Op->Imm.Val = Val;
851     Op->StartLoc = S;
852     Op->EndLoc = E;
853     Op->IsRV64 = IsRV64;
854     return Op;
855   }
856 
857   static std::unique_ptr<RISCVOperand>
858   createSysReg(StringRef Str, SMLoc S, unsigned Encoding, bool IsRV64) {
859     auto Op = std::make_unique<RISCVOperand>(KindTy::SystemRegister);
860     Op->SysReg.Data = Str.data();
861     Op->SysReg.Length = Str.size();
862     Op->SysReg.Encoding = Encoding;
863     Op->StartLoc = S;
864     Op->IsRV64 = IsRV64;
865     return Op;
866   }
867 
868   static std::unique_ptr<RISCVOperand>
869   createVType(APInt Sew, APInt Lmul, bool Fractional, bool TailAgnostic,
870               bool MaskedoffAgnostic, SMLoc S, bool IsRV64) {
871     auto Op = std::make_unique<RISCVOperand>(KindTy::VType);
872     Sew.ashrInPlace(3);
873     unsigned SewLog2 = Sew.logBase2();
874     unsigned LmulLog2 = Lmul.logBase2();
875     Op->VType.Sew = static_cast<VSEW>(SewLog2);
876     if (Fractional) {
877       unsigned Flmul = 8 - LmulLog2;
878       Op->VType.Lmul = static_cast<VLMUL>(Flmul);
879       Op->VType.Encoding =
880           ((Flmul & 0x4) << 3) | ((SewLog2 & 0x7) << 2) | (Flmul & 0x3);
881     } else {
882       Op->VType.Lmul = static_cast<VLMUL>(LmulLog2);
883       Op->VType.Encoding = (SewLog2 << 2) | LmulLog2;
884     }
885     if (TailAgnostic) {
886       Op->VType.Encoding |= 0x40;
887     }
888     if (MaskedoffAgnostic) {
889       Op->VType.Encoding |= 0x80;
890     }
891     Op->VType.TailAgnostic = TailAgnostic;
892     Op->VType.MaskedoffAgnostic = MaskedoffAgnostic;
893     Op->StartLoc = S;
894     Op->IsRV64 = IsRV64;
895     return Op;
896   }
897 
898   void addExpr(MCInst &Inst, const MCExpr *Expr) const {
899     assert(Expr && "Expr shouldn't be null!");
900     int64_t Imm = 0;
901     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
902     bool IsConstant = evaluateConstantImm(Expr, Imm, VK);
903 
904     if (IsConstant)
905       Inst.addOperand(MCOperand::createImm(Imm));
906     else
907       Inst.addOperand(MCOperand::createExpr(Expr));
908   }
909 
910   // Used by the TableGen Code
911   void addRegOperands(MCInst &Inst, unsigned N) const {
912     assert(N == 1 && "Invalid number of operands!");
913     Inst.addOperand(MCOperand::createReg(getReg()));
914   }
915 
916   void addImmOperands(MCInst &Inst, unsigned N) const {
917     assert(N == 1 && "Invalid number of operands!");
918     addExpr(Inst, getImm());
919   }
920 
921   void addSImm5Plus1Operands(MCInst &Inst, unsigned N) const {
922     assert(N == 1 && "Invalid number of operands!");
923     int64_t Imm = 0;
924     RISCVMCExpr::VariantKind VK = RISCVMCExpr::VK_RISCV_None;
925     bool IsConstant = evaluateConstantImm(getImm(), Imm, VK);
926     assert(IsConstant && "Expect constant value!");
927     (void)IsConstant;
928     Inst.addOperand(MCOperand::createImm(Imm - 1));
929   }
930 
931   void addFenceArgOperands(MCInst &Inst, unsigned N) const {
932     assert(N == 1 && "Invalid number of operands!");
933     // isFenceArg has validated the operand, meaning this cast is safe
934     auto SE = cast<MCSymbolRefExpr>(getImm());
935 
936     unsigned Imm = 0;
937     for (char c : SE->getSymbol().getName()) {
938       switch (c) {
939       default:
940         llvm_unreachable("FenceArg must contain only [iorw]");
941       case 'i': Imm |= RISCVFenceField::I; break;
942       case 'o': Imm |= RISCVFenceField::O; break;
943       case 'r': Imm |= RISCVFenceField::R; break;
944       case 'w': Imm |= RISCVFenceField::W; break;
945       }
946     }
947     Inst.addOperand(MCOperand::createImm(Imm));
948   }
949 
950   void addCSRSystemRegisterOperands(MCInst &Inst, unsigned N) const {
951     assert(N == 1 && "Invalid number of operands!");
952     Inst.addOperand(MCOperand::createImm(SysReg.Encoding));
953   }
954 
955   void addVTypeIOperands(MCInst &Inst, unsigned N) const {
956     assert(N == 1 && "Invalid number of operands!");
957     Inst.addOperand(MCOperand::createImm(VType.Encoding));
958   }
959 
960   // Returns the rounding mode represented by this RISCVOperand. Should only
961   // be called after checking isFRMArg.
962   RISCVFPRndMode::RoundingMode getRoundingMode() const {
963     // isFRMArg has validated the operand, meaning this cast is safe.
964     auto SE = cast<MCSymbolRefExpr>(getImm());
965     RISCVFPRndMode::RoundingMode FRM =
966         RISCVFPRndMode::stringToRoundingMode(SE->getSymbol().getName());
967     assert(FRM != RISCVFPRndMode::Invalid && "Invalid rounding mode");
968     return FRM;
969   }
970 
971   void addFRMArgOperands(MCInst &Inst, unsigned N) const {
972     assert(N == 1 && "Invalid number of operands!");
973     Inst.addOperand(MCOperand::createImm(getRoundingMode()));
974   }
975 };
976 } // end anonymous namespace.
977 
978 #define GET_REGISTER_MATCHER
979 #define GET_SUBTARGET_FEATURE_NAME
980 #define GET_MATCHER_IMPLEMENTATION
981 #define GET_MNEMONIC_SPELL_CHECKER
982 #include "RISCVGenAsmMatcher.inc"
983 
984 static MCRegister convertFPR64ToFPR32(MCRegister Reg) {
985   assert(Reg >= RISCV::F0_D && Reg <= RISCV::F31_D && "Invalid register");
986   return Reg - RISCV::F0_D + RISCV::F0_F;
987 }
988 
989 unsigned RISCVAsmParser::validateTargetOperandClass(MCParsedAsmOperand &AsmOp,
990                                                     unsigned Kind) {
991   RISCVOperand &Op = static_cast<RISCVOperand &>(AsmOp);
992   if (!Op.isReg())
993     return Match_InvalidOperand;
994 
995   MCRegister Reg = Op.getReg();
996   bool IsRegFPR64 =
997       RISCVMCRegisterClasses[RISCV::FPR64RegClassID].contains(Reg);
998   bool IsRegFPR64C =
999       RISCVMCRegisterClasses[RISCV::FPR64CRegClassID].contains(Reg);
1000 
1001   // As the parser couldn't differentiate an FPR32 from an FPR64, coerce the
1002   // register from FPR64 to FPR32 or FPR64C to FPR32C if necessary.
1003   if ((IsRegFPR64 && Kind == MCK_FPR32) ||
1004       (IsRegFPR64C && Kind == MCK_FPR32C)) {
1005     Op.Reg.RegNum = convertFPR64ToFPR32(Reg);
1006     return Match_Success;
1007   }
1008   return Match_InvalidOperand;
1009 }
1010 
1011 bool RISCVAsmParser::generateImmOutOfRangeError(
1012     OperandVector &Operands, uint64_t ErrorInfo, int64_t Lower, int64_t Upper,
1013     Twine Msg = "immediate must be an integer in the range") {
1014   SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1015   return Error(ErrorLoc, Msg + " [" + Twine(Lower) + ", " + Twine(Upper) + "]");
1016 }
1017 
1018 static std::string RISCVMnemonicSpellCheck(StringRef S,
1019                                           const FeatureBitset &FBS,
1020                                           unsigned VariantID = 0);
1021 
1022 bool RISCVAsmParser::MatchAndEmitInstruction(SMLoc IDLoc, unsigned &Opcode,
1023                                              OperandVector &Operands,
1024                                              MCStreamer &Out,
1025                                              uint64_t &ErrorInfo,
1026                                              bool MatchingInlineAsm) {
1027   MCInst Inst;
1028   FeatureBitset MissingFeatures;
1029 
1030   auto Result =
1031     MatchInstructionImpl(Operands, Inst, ErrorInfo, MissingFeatures,
1032                          MatchingInlineAsm);
1033   switch (Result) {
1034   default:
1035     break;
1036   case Match_Success:
1037     if (validateInstruction(Inst, Operands))
1038       return true;
1039     return processInstruction(Inst, IDLoc, Operands, Out);
1040   case Match_MissingFeature: {
1041     assert(MissingFeatures.any() && "Unknown missing features!");
1042     bool FirstFeature = true;
1043     std::string Msg = "instruction requires the following:";
1044     for (unsigned i = 0, e = MissingFeatures.size(); i != e; ++i) {
1045       if (MissingFeatures[i]) {
1046         Msg += FirstFeature ? " " : ", ";
1047         Msg += getSubtargetFeatureName(i);
1048         FirstFeature = false;
1049       }
1050     }
1051     return Error(IDLoc, Msg);
1052   }
1053   case Match_MnemonicFail: {
1054     FeatureBitset FBS = ComputeAvailableFeatures(getSTI().getFeatureBits());
1055     std::string Suggestion = RISCVMnemonicSpellCheck(
1056       ((RISCVOperand &)*Operands[0]).getToken(), FBS);
1057     return Error(IDLoc, "unrecognized instruction mnemonic" + Suggestion);
1058   }
1059   case Match_InvalidOperand: {
1060     SMLoc ErrorLoc = IDLoc;
1061     if (ErrorInfo != ~0U) {
1062       if (ErrorInfo >= Operands.size())
1063         return Error(ErrorLoc, "too few operands for instruction");
1064 
1065       ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1066       if (ErrorLoc == SMLoc())
1067         ErrorLoc = IDLoc;
1068     }
1069     return Error(ErrorLoc, "invalid operand for instruction");
1070   }
1071   }
1072 
1073   // Handle the case when the error message is of specific type
1074   // other than the generic Match_InvalidOperand, and the
1075   // corresponding operand is missing.
1076   if (Result > FIRST_TARGET_MATCH_RESULT_TY) {
1077     SMLoc ErrorLoc = IDLoc;
1078     if (ErrorInfo != ~0U && ErrorInfo >= Operands.size())
1079         return Error(ErrorLoc, "too few operands for instruction");
1080   }
1081 
1082   switch(Result) {
1083   default:
1084     break;
1085   case Match_InvalidImmXLenLI:
1086     if (isRV64()) {
1087       SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1088       return Error(ErrorLoc, "operand must be a constant 64-bit integer");
1089     }
1090     return generateImmOutOfRangeError(Operands, ErrorInfo,
1091                                       std::numeric_limits<int32_t>::min(),
1092                                       std::numeric_limits<uint32_t>::max());
1093   case Match_InvalidImmZero: {
1094     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1095     return Error(ErrorLoc, "immediate must be zero");
1096   }
1097   case Match_InvalidUImmLog2XLen:
1098     if (isRV64())
1099       return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 6) - 1);
1100     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
1101   case Match_InvalidUImmLog2XLenNonZero:
1102     if (isRV64())
1103       return generateImmOutOfRangeError(Operands, ErrorInfo, 1, (1 << 6) - 1);
1104     return generateImmOutOfRangeError(Operands, ErrorInfo, 1, (1 << 5) - 1);
1105   case Match_InvalidUImmLog2XLenHalf:
1106     if (isRV64())
1107       return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
1108     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 4) - 1);
1109   case Match_InvalidUImm5:
1110     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 5) - 1);
1111   case Match_InvalidSImm6:
1112     return generateImmOutOfRangeError(Operands, ErrorInfo, -(1 << 5),
1113                                       (1 << 5) - 1);
1114   case Match_InvalidSImm6NonZero:
1115     return generateImmOutOfRangeError(
1116         Operands, ErrorInfo, -(1 << 5), (1 << 5) - 1,
1117         "immediate must be non-zero in the range");
1118   case Match_InvalidCLUIImm:
1119     return generateImmOutOfRangeError(
1120         Operands, ErrorInfo, 1, (1 << 5) - 1,
1121         "immediate must be in [0xfffe0, 0xfffff] or");
1122   case Match_InvalidUImm7Lsb00:
1123     return generateImmOutOfRangeError(
1124         Operands, ErrorInfo, 0, (1 << 7) - 4,
1125         "immediate must be a multiple of 4 bytes in the range");
1126   case Match_InvalidUImm8Lsb00:
1127     return generateImmOutOfRangeError(
1128         Operands, ErrorInfo, 0, (1 << 8) - 4,
1129         "immediate must be a multiple of 4 bytes in the range");
1130   case Match_InvalidUImm8Lsb000:
1131     return generateImmOutOfRangeError(
1132         Operands, ErrorInfo, 0, (1 << 8) - 8,
1133         "immediate must be a multiple of 8 bytes in the range");
1134   case Match_InvalidSImm9Lsb0:
1135     return generateImmOutOfRangeError(
1136         Operands, ErrorInfo, -(1 << 8), (1 << 8) - 2,
1137         "immediate must be a multiple of 2 bytes in the range");
1138   case Match_InvalidUImm9Lsb000:
1139     return generateImmOutOfRangeError(
1140         Operands, ErrorInfo, 0, (1 << 9) - 8,
1141         "immediate must be a multiple of 8 bytes in the range");
1142   case Match_InvalidUImm10Lsb00NonZero:
1143     return generateImmOutOfRangeError(
1144         Operands, ErrorInfo, 4, (1 << 10) - 4,
1145         "immediate must be a multiple of 4 bytes in the range");
1146   case Match_InvalidSImm10Lsb0000NonZero:
1147     return generateImmOutOfRangeError(
1148         Operands, ErrorInfo, -(1 << 9), (1 << 9) - 16,
1149         "immediate must be a multiple of 16 bytes and non-zero in the range");
1150   case Match_InvalidSImm12:
1151     return generateImmOutOfRangeError(
1152         Operands, ErrorInfo, -(1 << 11), (1 << 11) - 1,
1153         "operand must be a symbol with %lo/%pcrel_lo/%tprel_lo modifier or an "
1154         "integer in the range");
1155   case Match_InvalidSImm12Lsb0:
1156     return generateImmOutOfRangeError(
1157         Operands, ErrorInfo, -(1 << 11), (1 << 11) - 2,
1158         "immediate must be a multiple of 2 bytes in the range");
1159   case Match_InvalidSImm13Lsb0:
1160     return generateImmOutOfRangeError(
1161         Operands, ErrorInfo, -(1 << 12), (1 << 12) - 2,
1162         "immediate must be a multiple of 2 bytes in the range");
1163   case Match_InvalidUImm20LUI:
1164     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 20) - 1,
1165                                       "operand must be a symbol with "
1166                                       "%hi/%tprel_hi modifier or an integer in "
1167                                       "the range");
1168   case Match_InvalidUImm20AUIPC:
1169     return generateImmOutOfRangeError(
1170         Operands, ErrorInfo, 0, (1 << 20) - 1,
1171         "operand must be a symbol with a "
1172         "%pcrel_hi/%got_pcrel_hi/%tls_ie_pcrel_hi/%tls_gd_pcrel_hi modifier or "
1173         "an integer in the range");
1174   case Match_InvalidSImm21Lsb0JAL:
1175     return generateImmOutOfRangeError(
1176         Operands, ErrorInfo, -(1 << 20), (1 << 20) - 2,
1177         "immediate must be a multiple of 2 bytes in the range");
1178   case Match_InvalidCSRSystemRegister: {
1179     return generateImmOutOfRangeError(Operands, ErrorInfo, 0, (1 << 12) - 1,
1180                                       "operand must be a valid system register "
1181                                       "name or an integer in the range");
1182   }
1183   case Match_InvalidFenceArg: {
1184     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1185     return Error(
1186         ErrorLoc,
1187         "operand must be formed of letters selected in-order from 'iorw'");
1188   }
1189   case Match_InvalidFRMArg: {
1190     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1191     return Error(
1192         ErrorLoc,
1193         "operand must be a valid floating point rounding mode mnemonic");
1194   }
1195   case Match_InvalidBareSymbol: {
1196     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1197     return Error(ErrorLoc, "operand must be a bare symbol name");
1198   }
1199   case Match_InvalidPseudoJumpSymbol: {
1200     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1201     return Error(ErrorLoc, "operand must be a valid jump target");
1202   }
1203   case Match_InvalidCallSymbol: {
1204     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1205     return Error(ErrorLoc, "operand must be a bare symbol name");
1206   }
1207   case Match_InvalidTPRelAddSymbol: {
1208     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1209     return Error(ErrorLoc, "operand must be a symbol with %tprel_add modifier");
1210   }
1211   case Match_InvalidVTypeI: {
1212     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1213     return Error(
1214         ErrorLoc,
1215         "operand must be "
1216         "e[8|16|32|64|128|256|512|1024],m[1|2|4|8|f2|f4|f8],[ta|tu],[ma|mu]");
1217   }
1218   case Match_InvalidVMaskRegister: {
1219     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[ErrorInfo]).getStartLoc();
1220     return Error(ErrorLoc, "operand must be v0.t");
1221   }
1222   case Match_InvalidSImm5Plus1: {
1223     return generateImmOutOfRangeError(Operands, ErrorInfo, -(1 << 4) + 1,
1224                                       (1 << 4),
1225                                       "immediate must be in the range");
1226   }
1227   }
1228 
1229   llvm_unreachable("Unknown match type detected!");
1230 }
1231 
1232 // Attempts to match Name as a register (either using the default name or
1233 // alternative ABI names), setting RegNo to the matching register. Upon
1234 // failure, returns true and sets RegNo to 0. If IsRV32E then registers
1235 // x16-x31 will be rejected.
1236 static bool matchRegisterNameHelper(bool IsRV32E, MCRegister &RegNo,
1237                                     StringRef Name) {
1238   RegNo = MatchRegisterName(Name);
1239   // The 32- and 64-bit FPRs have the same asm name. Check that the initial
1240   // match always matches the 64-bit variant, and not the 32-bit one.
1241   assert(!(RegNo >= RISCV::F0_F && RegNo <= RISCV::F31_F));
1242   // The default FPR register class is based on the tablegen enum ordering.
1243   static_assert(RISCV::F0_D < RISCV::F0_F, "FPR matching must be updated");
1244   if (RegNo == RISCV::NoRegister)
1245     RegNo = MatchRegisterAltName(Name);
1246   if (IsRV32E && RegNo >= RISCV::X16 && RegNo <= RISCV::X31)
1247     RegNo = RISCV::NoRegister;
1248   return RegNo == RISCV::NoRegister;
1249 }
1250 
1251 bool RISCVAsmParser::ParseRegister(unsigned &RegNo, SMLoc &StartLoc,
1252                                    SMLoc &EndLoc) {
1253   if (tryParseRegister(RegNo, StartLoc, EndLoc) != MatchOperand_Success)
1254     return Error(StartLoc, "invalid register name");
1255   return false;
1256 }
1257 
1258 OperandMatchResultTy RISCVAsmParser::tryParseRegister(unsigned &RegNo,
1259                                                       SMLoc &StartLoc,
1260                                                       SMLoc &EndLoc) {
1261   const AsmToken &Tok = getParser().getTok();
1262   StartLoc = Tok.getLoc();
1263   EndLoc = Tok.getEndLoc();
1264   RegNo = 0;
1265   StringRef Name = getLexer().getTok().getIdentifier();
1266 
1267   if (matchRegisterNameHelper(isRV32E(), (MCRegister &)RegNo, Name))
1268     return MatchOperand_NoMatch;
1269 
1270   getParser().Lex(); // Eat identifier token.
1271   return MatchOperand_Success;
1272 }
1273 
1274 OperandMatchResultTy RISCVAsmParser::parseRegister(OperandVector &Operands,
1275                                                    bool AllowParens) {
1276   SMLoc FirstS = getLoc();
1277   bool HadParens = false;
1278   AsmToken LParen;
1279 
1280   // If this is an LParen and a parenthesised register name is allowed, parse it
1281   // atomically.
1282   if (AllowParens && getLexer().is(AsmToken::LParen)) {
1283     AsmToken Buf[2];
1284     size_t ReadCount = getLexer().peekTokens(Buf);
1285     if (ReadCount == 2 && Buf[1].getKind() == AsmToken::RParen) {
1286       HadParens = true;
1287       LParen = getParser().getTok();
1288       getParser().Lex(); // Eat '('
1289     }
1290   }
1291 
1292   switch (getLexer().getKind()) {
1293   default:
1294     if (HadParens)
1295       getLexer().UnLex(LParen);
1296     return MatchOperand_NoMatch;
1297   case AsmToken::Identifier:
1298     StringRef Name = getLexer().getTok().getIdentifier();
1299     MCRegister RegNo;
1300     matchRegisterNameHelper(isRV32E(), RegNo, Name);
1301 
1302     if (RegNo == RISCV::NoRegister) {
1303       if (HadParens)
1304         getLexer().UnLex(LParen);
1305       return MatchOperand_NoMatch;
1306     }
1307     if (HadParens)
1308       Operands.push_back(RISCVOperand::createToken("(", FirstS, isRV64()));
1309     SMLoc S = getLoc();
1310     SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1311     getLexer().Lex();
1312     Operands.push_back(RISCVOperand::createReg(RegNo, S, E, isRV64()));
1313   }
1314 
1315   if (HadParens) {
1316     getParser().Lex(); // Eat ')'
1317     Operands.push_back(RISCVOperand::createToken(")", getLoc(), isRV64()));
1318   }
1319 
1320   return MatchOperand_Success;
1321 }
1322 
1323 OperandMatchResultTy
1324 RISCVAsmParser::parseCSRSystemRegister(OperandVector &Operands) {
1325   SMLoc S = getLoc();
1326   const MCExpr *Res;
1327 
1328   switch (getLexer().getKind()) {
1329   default:
1330     return MatchOperand_NoMatch;
1331   case AsmToken::LParen:
1332   case AsmToken::Minus:
1333   case AsmToken::Plus:
1334   case AsmToken::Exclaim:
1335   case AsmToken::Tilde:
1336   case AsmToken::Integer:
1337   case AsmToken::String: {
1338     if (getParser().parseExpression(Res))
1339       return MatchOperand_ParseFail;
1340 
1341     auto *CE = dyn_cast<MCConstantExpr>(Res);
1342     if (CE) {
1343       int64_t Imm = CE->getValue();
1344       if (isUInt<12>(Imm)) {
1345         auto SysReg = RISCVSysReg::lookupSysRegByEncoding(Imm);
1346         // Accept an immediate representing a named or un-named Sys Reg
1347         // if the range is valid, regardless of the required features.
1348         Operands.push_back(RISCVOperand::createSysReg(
1349             SysReg ? SysReg->Name : "", S, Imm, isRV64()));
1350         return MatchOperand_Success;
1351       }
1352     }
1353 
1354     Twine Msg = "immediate must be an integer in the range";
1355     Error(S, Msg + " [" + Twine(0) + ", " + Twine((1 << 12) - 1) + "]");
1356     return MatchOperand_ParseFail;
1357   }
1358   case AsmToken::Identifier: {
1359     StringRef Identifier;
1360     if (getParser().parseIdentifier(Identifier))
1361       return MatchOperand_ParseFail;
1362 
1363     auto SysReg = RISCVSysReg::lookupSysRegByName(Identifier);
1364     if (!SysReg)
1365       SysReg = RISCVSysReg::lookupSysRegByAltName(Identifier);
1366     // Accept a named Sys Reg if the required features are present.
1367     if (SysReg) {
1368       if (!SysReg->haveRequiredFeatures(getSTI().getFeatureBits())) {
1369         Error(S, "system register use requires an option to be enabled");
1370         return MatchOperand_ParseFail;
1371       }
1372       Operands.push_back(RISCVOperand::createSysReg(
1373           Identifier, S, SysReg->Encoding, isRV64()));
1374       return MatchOperand_Success;
1375     }
1376 
1377     Twine Msg = "operand must be a valid system register name "
1378                 "or an integer in the range";
1379     Error(S, Msg + " [" + Twine(0) + ", " + Twine((1 << 12) - 1) + "]");
1380     return MatchOperand_ParseFail;
1381   }
1382   case AsmToken::Percent: {
1383     // Discard operand with modifier.
1384     Twine Msg = "immediate must be an integer in the range";
1385     Error(S, Msg + " [" + Twine(0) + ", " + Twine((1 << 12) - 1) + "]");
1386     return MatchOperand_ParseFail;
1387   }
1388   }
1389 
1390   return MatchOperand_NoMatch;
1391 }
1392 
1393 OperandMatchResultTy RISCVAsmParser::parseImmediate(OperandVector &Operands) {
1394   SMLoc S = getLoc();
1395   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1396   const MCExpr *Res;
1397 
1398   switch (getLexer().getKind()) {
1399   default:
1400     return MatchOperand_NoMatch;
1401   case AsmToken::LParen:
1402   case AsmToken::Dot:
1403   case AsmToken::Minus:
1404   case AsmToken::Plus:
1405   case AsmToken::Exclaim:
1406   case AsmToken::Tilde:
1407   case AsmToken::Integer:
1408   case AsmToken::String:
1409   case AsmToken::Identifier:
1410     if (getParser().parseExpression(Res))
1411       return MatchOperand_ParseFail;
1412     break;
1413   case AsmToken::Percent:
1414     return parseOperandWithModifier(Operands);
1415   }
1416 
1417   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1418   return MatchOperand_Success;
1419 }
1420 
1421 OperandMatchResultTy
1422 RISCVAsmParser::parseOperandWithModifier(OperandVector &Operands) {
1423   SMLoc S = getLoc();
1424   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1425 
1426   if (getLexer().getKind() != AsmToken::Percent) {
1427     Error(getLoc(), "expected '%' for operand modifier");
1428     return MatchOperand_ParseFail;
1429   }
1430 
1431   getParser().Lex(); // Eat '%'
1432 
1433   if (getLexer().getKind() != AsmToken::Identifier) {
1434     Error(getLoc(), "expected valid identifier for operand modifier");
1435     return MatchOperand_ParseFail;
1436   }
1437   StringRef Identifier = getParser().getTok().getIdentifier();
1438   RISCVMCExpr::VariantKind VK = RISCVMCExpr::getVariantKindForName(Identifier);
1439   if (VK == RISCVMCExpr::VK_RISCV_Invalid) {
1440     Error(getLoc(), "unrecognized operand modifier");
1441     return MatchOperand_ParseFail;
1442   }
1443 
1444   getParser().Lex(); // Eat the identifier
1445   if (getLexer().getKind() != AsmToken::LParen) {
1446     Error(getLoc(), "expected '('");
1447     return MatchOperand_ParseFail;
1448   }
1449   getParser().Lex(); // Eat '('
1450 
1451   const MCExpr *SubExpr;
1452   if (getParser().parseParenExpression(SubExpr, E)) {
1453     return MatchOperand_ParseFail;
1454   }
1455 
1456   const MCExpr *ModExpr = RISCVMCExpr::create(SubExpr, VK, getContext());
1457   Operands.push_back(RISCVOperand::createImm(ModExpr, S, E, isRV64()));
1458   return MatchOperand_Success;
1459 }
1460 
1461 OperandMatchResultTy RISCVAsmParser::parseBareSymbol(OperandVector &Operands) {
1462   SMLoc S = getLoc();
1463   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1464   const MCExpr *Res;
1465 
1466   if (getLexer().getKind() != AsmToken::Identifier)
1467     return MatchOperand_NoMatch;
1468 
1469   StringRef Identifier;
1470   AsmToken Tok = getLexer().getTok();
1471 
1472   if (getParser().parseIdentifier(Identifier))
1473     return MatchOperand_ParseFail;
1474 
1475   if (Identifier.consume_back("@plt")) {
1476     Error(getLoc(), "'@plt' operand not valid for instruction");
1477     return MatchOperand_ParseFail;
1478   }
1479 
1480   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
1481 
1482   if (Sym->isVariable()) {
1483     const MCExpr *V = Sym->getVariableValue(/*SetUsed=*/false);
1484     if (!isa<MCSymbolRefExpr>(V)) {
1485       getLexer().UnLex(Tok); // Put back if it's not a bare symbol.
1486       return MatchOperand_NoMatch;
1487     }
1488     Res = V;
1489   } else
1490     Res = MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, getContext());
1491 
1492   MCBinaryExpr::Opcode Opcode;
1493   switch (getLexer().getKind()) {
1494   default:
1495     Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1496     return MatchOperand_Success;
1497   case AsmToken::Plus:
1498     Opcode = MCBinaryExpr::Add;
1499     break;
1500   case AsmToken::Minus:
1501     Opcode = MCBinaryExpr::Sub;
1502     break;
1503   }
1504 
1505   const MCExpr *Expr;
1506   if (getParser().parseExpression(Expr))
1507     return MatchOperand_ParseFail;
1508   Res = MCBinaryExpr::create(Opcode, Res, Expr, getContext());
1509   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1510   return MatchOperand_Success;
1511 }
1512 
1513 OperandMatchResultTy RISCVAsmParser::parseCallSymbol(OperandVector &Operands) {
1514   SMLoc S = getLoc();
1515   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1516   const MCExpr *Res;
1517 
1518   if (getLexer().getKind() != AsmToken::Identifier)
1519     return MatchOperand_NoMatch;
1520 
1521   // Avoid parsing the register in `call rd, foo` as a call symbol.
1522   if (getLexer().peekTok().getKind() != AsmToken::EndOfStatement)
1523     return MatchOperand_NoMatch;
1524 
1525   StringRef Identifier;
1526   if (getParser().parseIdentifier(Identifier))
1527     return MatchOperand_ParseFail;
1528 
1529   RISCVMCExpr::VariantKind Kind = RISCVMCExpr::VK_RISCV_CALL;
1530   if (Identifier.consume_back("@plt"))
1531     Kind = RISCVMCExpr::VK_RISCV_CALL_PLT;
1532 
1533   MCSymbol *Sym = getContext().getOrCreateSymbol(Identifier);
1534   Res = MCSymbolRefExpr::create(Sym, MCSymbolRefExpr::VK_None, getContext());
1535   Res = RISCVMCExpr::create(Res, Kind, getContext());
1536   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1537   return MatchOperand_Success;
1538 }
1539 
1540 OperandMatchResultTy
1541 RISCVAsmParser::parsePseudoJumpSymbol(OperandVector &Operands) {
1542   SMLoc S = getLoc();
1543   SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1544   const MCExpr *Res;
1545 
1546   if (getParser().parseExpression(Res))
1547     return MatchOperand_ParseFail;
1548 
1549   if (Res->getKind() != MCExpr::ExprKind::SymbolRef ||
1550       cast<MCSymbolRefExpr>(Res)->getKind() ==
1551           MCSymbolRefExpr::VariantKind::VK_PLT) {
1552     Error(S, "operand must be a valid jump target");
1553     return MatchOperand_ParseFail;
1554   }
1555 
1556   Res = RISCVMCExpr::create(Res, RISCVMCExpr::VK_RISCV_CALL, getContext());
1557   Operands.push_back(RISCVOperand::createImm(Res, S, E, isRV64()));
1558   return MatchOperand_Success;
1559 }
1560 
1561 OperandMatchResultTy RISCVAsmParser::parseJALOffset(OperandVector &Operands) {
1562   // Parsing jal operands is fiddly due to the `jal foo` and `jal ra, foo`
1563   // both being acceptable forms. When parsing `jal ra, foo` this function
1564   // will be called for the `ra` register operand in an attempt to match the
1565   // single-operand alias. parseJALOffset must fail for this case. It would
1566   // seem logical to try parse the operand using parseImmediate and return
1567   // NoMatch if the next token is a comma (meaning we must be parsing a jal in
1568   // the second form rather than the first). We can't do this as there's no
1569   // way of rewinding the lexer state. Instead, return NoMatch if this operand
1570   // is an identifier and is followed by a comma.
1571   if (getLexer().is(AsmToken::Identifier) &&
1572       getLexer().peekTok().is(AsmToken::Comma))
1573     return MatchOperand_NoMatch;
1574 
1575   return parseImmediate(Operands);
1576 }
1577 
1578 OperandMatchResultTy RISCVAsmParser::parseVTypeI(OperandVector &Operands) {
1579   SMLoc S = getLoc();
1580   if (getLexer().getKind() != AsmToken::Identifier)
1581     return MatchOperand_NoMatch;
1582 
1583   // Parse "e8,m1,t[a|u],m[a|u]"
1584   StringRef Name = getLexer().getTok().getIdentifier();
1585   if (!Name.consume_front("e"))
1586     return MatchOperand_NoMatch;
1587   APInt Sew(16, Name, 10);
1588   if (Sew != 8 && Sew != 16 && Sew != 32 && Sew != 64 && Sew != 128 &&
1589       Sew != 256 && Sew != 512 && Sew != 1024)
1590     return MatchOperand_NoMatch;
1591   getLexer().Lex();
1592 
1593   if (!getLexer().is(AsmToken::Comma))
1594     return MatchOperand_NoMatch;
1595   getLexer().Lex();
1596 
1597   Name = getLexer().getTok().getIdentifier();
1598   if (!Name.consume_front("m"))
1599     return MatchOperand_NoMatch;
1600   // "m" or "mf"
1601   bool Fractional = false;
1602   if (Name.consume_front("f")) {
1603     Fractional = true;
1604   }
1605   APInt Lmul(16, Name, 10);
1606   if (Lmul != 1 && Lmul != 2 && Lmul != 4 && Lmul != 8)
1607     return MatchOperand_NoMatch;
1608   getLexer().Lex();
1609 
1610   if (!getLexer().is(AsmToken::Comma))
1611     return MatchOperand_NoMatch;
1612   getLexer().Lex();
1613 
1614   Name = getLexer().getTok().getIdentifier();
1615   // ta or tu
1616   bool TailAgnostic;
1617   if (Name.consume_front("ta"))
1618     TailAgnostic = true;
1619   else if (Name.consume_front("tu"))
1620     TailAgnostic = false;
1621   else
1622     return MatchOperand_NoMatch;
1623   getLexer().Lex();
1624 
1625   if (!getLexer().is(AsmToken::Comma))
1626     return MatchOperand_NoMatch;
1627   getLexer().Lex();
1628 
1629   Name = getLexer().getTok().getIdentifier();
1630   // ma or mu
1631   bool MaskedoffAgnostic;
1632   if (Name.consume_front("ma"))
1633     MaskedoffAgnostic = true;
1634   else if (Name.consume_front("mu"))
1635     MaskedoffAgnostic = false;
1636   else
1637     return MatchOperand_NoMatch;
1638   getLexer().Lex();
1639 
1640   if (getLexer().getKind() != AsmToken::EndOfStatement)
1641     return MatchOperand_NoMatch;
1642 
1643   Operands.push_back(RISCVOperand::createVType(
1644       Sew, Lmul, Fractional, TailAgnostic, MaskedoffAgnostic, S, isRV64()));
1645 
1646   return MatchOperand_Success;
1647 }
1648 
1649 OperandMatchResultTy RISCVAsmParser::parseMaskReg(OperandVector &Operands) {
1650   switch (getLexer().getKind()) {
1651   default:
1652     return MatchOperand_NoMatch;
1653   case AsmToken::Identifier:
1654     StringRef Name = getLexer().getTok().getIdentifier();
1655     if (!Name.consume_back(".t")) {
1656       Error(getLoc(), "expected '.t' suffix");
1657       return MatchOperand_ParseFail;
1658     }
1659     MCRegister RegNo;
1660     matchRegisterNameHelper(isRV32E(), RegNo, Name);
1661 
1662     if (RegNo == RISCV::NoRegister)
1663       return MatchOperand_NoMatch;
1664     if (RegNo != RISCV::V0)
1665       return MatchOperand_NoMatch;
1666     SMLoc S = getLoc();
1667     SMLoc E = SMLoc::getFromPointer(S.getPointer() - 1);
1668     getLexer().Lex();
1669     Operands.push_back(RISCVOperand::createReg(RegNo, S, E, isRV64()));
1670   }
1671 
1672   return MatchOperand_Success;
1673 }
1674 
1675 OperandMatchResultTy
1676 RISCVAsmParser::parseMemOpBaseReg(OperandVector &Operands) {
1677   if (getLexer().isNot(AsmToken::LParen)) {
1678     Error(getLoc(), "expected '('");
1679     return MatchOperand_ParseFail;
1680   }
1681 
1682   getParser().Lex(); // Eat '('
1683   Operands.push_back(RISCVOperand::createToken("(", getLoc(), isRV64()));
1684 
1685   if (parseRegister(Operands) != MatchOperand_Success) {
1686     Error(getLoc(), "expected register");
1687     return MatchOperand_ParseFail;
1688   }
1689 
1690   if (getLexer().isNot(AsmToken::RParen)) {
1691     Error(getLoc(), "expected ')'");
1692     return MatchOperand_ParseFail;
1693   }
1694 
1695   getParser().Lex(); // Eat ')'
1696   Operands.push_back(RISCVOperand::createToken(")", getLoc(), isRV64()));
1697 
1698   return MatchOperand_Success;
1699 }
1700 
1701 OperandMatchResultTy RISCVAsmParser::parseAtomicMemOp(OperandVector &Operands) {
1702   // Atomic operations such as lr.w, sc.w, and amo*.w accept a "memory operand"
1703   // as one of their register operands, such as `(a0)`. This just denotes that
1704   // the register (in this case `a0`) contains a memory address.
1705   //
1706   // Normally, we would be able to parse these by putting the parens into the
1707   // instruction string. However, GNU as also accepts a zero-offset memory
1708   // operand (such as `0(a0)`), and ignores the 0. Normally this would be parsed
1709   // with parseImmediate followed by parseMemOpBaseReg, but these instructions
1710   // do not accept an immediate operand, and we do not want to add a "dummy"
1711   // operand that is silently dropped.
1712   //
1713   // Instead, we use this custom parser. This will: allow (and discard) an
1714   // offset if it is zero; require (and discard) parentheses; and add only the
1715   // parsed register operand to `Operands`.
1716   //
1717   // These operands are printed with RISCVInstPrinter::printAtomicMemOp, which
1718   // will only print the register surrounded by parentheses (which GNU as also
1719   // uses as its canonical representation for these operands).
1720   std::unique_ptr<RISCVOperand> OptionalImmOp;
1721 
1722   if (getLexer().isNot(AsmToken::LParen)) {
1723     // Parse an Integer token. We do not accept arbritrary constant expressions
1724     // in the offset field (because they may include parens, which complicates
1725     // parsing a lot).
1726     int64_t ImmVal;
1727     SMLoc ImmStart = getLoc();
1728     if (getParser().parseIntToken(ImmVal,
1729                                   "expected '(' or optional integer offset"))
1730       return MatchOperand_ParseFail;
1731 
1732     // Create a RISCVOperand for checking later (so the error messages are
1733     // nicer), but we don't add it to Operands.
1734     SMLoc ImmEnd = getLoc();
1735     OptionalImmOp =
1736         RISCVOperand::createImm(MCConstantExpr::create(ImmVal, getContext()),
1737                                 ImmStart, ImmEnd, isRV64());
1738   }
1739 
1740   if (getLexer().isNot(AsmToken::LParen)) {
1741     Error(getLoc(), OptionalImmOp ? "expected '(' after optional integer offset"
1742                                   : "expected '(' or optional integer offset");
1743     return MatchOperand_ParseFail;
1744   }
1745   getParser().Lex(); // Eat '('
1746 
1747   if (parseRegister(Operands) != MatchOperand_Success) {
1748     Error(getLoc(), "expected register");
1749     return MatchOperand_ParseFail;
1750   }
1751 
1752   if (getLexer().isNot(AsmToken::RParen)) {
1753     Error(getLoc(), "expected ')'");
1754     return MatchOperand_ParseFail;
1755   }
1756   getParser().Lex(); // Eat ')'
1757 
1758   // Deferred Handling of non-zero offsets. This makes the error messages nicer.
1759   if (OptionalImmOp && !OptionalImmOp->isImmZero()) {
1760     Error(OptionalImmOp->getStartLoc(), "optional integer offset must be 0",
1761           SMRange(OptionalImmOp->getStartLoc(), OptionalImmOp->getEndLoc()));
1762     return MatchOperand_ParseFail;
1763   }
1764 
1765   return MatchOperand_Success;
1766 }
1767 
1768 /// Looks at a token type and creates the relevant operand from this
1769 /// information, adding to Operands. If operand was parsed, returns false, else
1770 /// true.
1771 bool RISCVAsmParser::parseOperand(OperandVector &Operands, StringRef Mnemonic) {
1772   // Check if the current operand has a custom associated parser, if so, try to
1773   // custom parse the operand, or fallback to the general approach.
1774   OperandMatchResultTy Result =
1775       MatchOperandParserImpl(Operands, Mnemonic, /*ParseForAllFeatures=*/true);
1776   if (Result == MatchOperand_Success)
1777     return false;
1778   if (Result == MatchOperand_ParseFail)
1779     return true;
1780 
1781   // Attempt to parse token as a register.
1782   if (parseRegister(Operands, true) == MatchOperand_Success)
1783     return false;
1784 
1785   // Attempt to parse token as an immediate
1786   if (parseImmediate(Operands) == MatchOperand_Success) {
1787     // Parse memory base register if present
1788     if (getLexer().is(AsmToken::LParen))
1789       return parseMemOpBaseReg(Operands) != MatchOperand_Success;
1790     return false;
1791   }
1792 
1793   // Finally we have exhausted all options and must declare defeat.
1794   Error(getLoc(), "unknown operand");
1795   return true;
1796 }
1797 
1798 bool RISCVAsmParser::ParseInstruction(ParseInstructionInfo &Info,
1799                                       StringRef Name, SMLoc NameLoc,
1800                                       OperandVector &Operands) {
1801   // Ensure that if the instruction occurs when relaxation is enabled,
1802   // relocations are forced for the file. Ideally this would be done when there
1803   // is enough information to reliably determine if the instruction itself may
1804   // cause relaxations. Unfortunately instruction processing stage occurs in the
1805   // same pass as relocation emission, so it's too late to set a 'sticky bit'
1806   // for the entire file.
1807   if (getSTI().getFeatureBits()[RISCV::FeatureRelax]) {
1808     auto *Assembler = getTargetStreamer().getStreamer().getAssemblerPtr();
1809     if (Assembler != nullptr) {
1810       RISCVAsmBackend &MAB =
1811           static_cast<RISCVAsmBackend &>(Assembler->getBackend());
1812       MAB.setForceRelocs();
1813     }
1814   }
1815 
1816   // First operand is token for instruction
1817   Operands.push_back(RISCVOperand::createToken(Name, NameLoc, isRV64()));
1818 
1819   // If there are no more operands, then finish
1820   if (getLexer().is(AsmToken::EndOfStatement))
1821     return false;
1822 
1823   // Parse first operand
1824   if (parseOperand(Operands, Name))
1825     return true;
1826 
1827   // Parse until end of statement, consuming commas between operands
1828   unsigned OperandIdx = 1;
1829   while (getLexer().is(AsmToken::Comma)) {
1830     // Consume comma token
1831     getLexer().Lex();
1832 
1833     // Parse next operand
1834     if (parseOperand(Operands, Name))
1835       return true;
1836 
1837     ++OperandIdx;
1838   }
1839 
1840   if (getLexer().isNot(AsmToken::EndOfStatement)) {
1841     SMLoc Loc = getLexer().getLoc();
1842     getParser().eatToEndOfStatement();
1843     return Error(Loc, "unexpected token");
1844   }
1845 
1846   getParser().Lex(); // Consume the EndOfStatement.
1847   return false;
1848 }
1849 
1850 bool RISCVAsmParser::classifySymbolRef(const MCExpr *Expr,
1851                                        RISCVMCExpr::VariantKind &Kind) {
1852   Kind = RISCVMCExpr::VK_RISCV_None;
1853 
1854   if (const RISCVMCExpr *RE = dyn_cast<RISCVMCExpr>(Expr)) {
1855     Kind = RE->getKind();
1856     Expr = RE->getSubExpr();
1857   }
1858 
1859   // It's a simple symbol reference or constant with no addend.
1860   if (isa<MCConstantExpr>(Expr) || isa<MCSymbolRefExpr>(Expr))
1861     return true;
1862 
1863   const MCBinaryExpr *BE = dyn_cast<MCBinaryExpr>(Expr);
1864   if (!BE)
1865     return false;
1866 
1867   if (!isa<MCSymbolRefExpr>(BE->getLHS()))
1868     return false;
1869 
1870   if (BE->getOpcode() != MCBinaryExpr::Add &&
1871       BE->getOpcode() != MCBinaryExpr::Sub)
1872     return false;
1873 
1874   // We are able to support the subtraction of two symbol references
1875   if (BE->getOpcode() == MCBinaryExpr::Sub &&
1876       isa<MCSymbolRefExpr>(BE->getRHS()))
1877     return true;
1878 
1879   // See if the addend is a constant, otherwise there's more going
1880   // on here than we can deal with.
1881   auto AddendExpr = dyn_cast<MCConstantExpr>(BE->getRHS());
1882   if (!AddendExpr)
1883     return false;
1884 
1885   // It's some symbol reference + a constant addend
1886   return Kind != RISCVMCExpr::VK_RISCV_Invalid;
1887 }
1888 
1889 bool RISCVAsmParser::ParseDirective(AsmToken DirectiveID) {
1890   // This returns false if this function recognizes the directive
1891   // regardless of whether it is successfully handles or reports an
1892   // error. Otherwise it returns true to give the generic parser a
1893   // chance at recognizing it.
1894   StringRef IDVal = DirectiveID.getString();
1895 
1896   if (IDVal == ".option")
1897     return parseDirectiveOption();
1898   else if (IDVal == ".attribute")
1899     return parseDirectiveAttribute();
1900 
1901   return true;
1902 }
1903 
1904 bool RISCVAsmParser::parseDirectiveOption() {
1905   MCAsmParser &Parser = getParser();
1906   // Get the option token.
1907   AsmToken Tok = Parser.getTok();
1908   // At the moment only identifiers are supported.
1909   if (Tok.isNot(AsmToken::Identifier))
1910     return Error(Parser.getTok().getLoc(),
1911                  "unexpected token, expected identifier");
1912 
1913   StringRef Option = Tok.getIdentifier();
1914 
1915   if (Option == "push") {
1916     getTargetStreamer().emitDirectiveOptionPush();
1917 
1918     Parser.Lex();
1919     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1920       return Error(Parser.getTok().getLoc(),
1921                    "unexpected token, expected end of statement");
1922 
1923     pushFeatureBits();
1924     return false;
1925   }
1926 
1927   if (Option == "pop") {
1928     SMLoc StartLoc = Parser.getTok().getLoc();
1929     getTargetStreamer().emitDirectiveOptionPop();
1930 
1931     Parser.Lex();
1932     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1933       return Error(Parser.getTok().getLoc(),
1934                    "unexpected token, expected end of statement");
1935 
1936     if (popFeatureBits())
1937       return Error(StartLoc, ".option pop with no .option push");
1938 
1939     return false;
1940   }
1941 
1942   if (Option == "rvc") {
1943     getTargetStreamer().emitDirectiveOptionRVC();
1944 
1945     Parser.Lex();
1946     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1947       return Error(Parser.getTok().getLoc(),
1948                    "unexpected token, expected end of statement");
1949 
1950     setFeatureBits(RISCV::FeatureStdExtC, "c");
1951     return false;
1952   }
1953 
1954   if (Option == "norvc") {
1955     getTargetStreamer().emitDirectiveOptionNoRVC();
1956 
1957     Parser.Lex();
1958     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1959       return Error(Parser.getTok().getLoc(),
1960                    "unexpected token, expected end of statement");
1961 
1962     clearFeatureBits(RISCV::FeatureStdExtC, "c");
1963     return false;
1964   }
1965 
1966   if (Option == "pic") {
1967     getTargetStreamer().emitDirectiveOptionPIC();
1968 
1969     Parser.Lex();
1970     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1971       return Error(Parser.getTok().getLoc(),
1972                    "unexpected token, expected end of statement");
1973 
1974     ParserOptions.IsPicEnabled = true;
1975     return false;
1976   }
1977 
1978   if (Option == "nopic") {
1979     getTargetStreamer().emitDirectiveOptionNoPIC();
1980 
1981     Parser.Lex();
1982     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1983       return Error(Parser.getTok().getLoc(),
1984                    "unexpected token, expected end of statement");
1985 
1986     ParserOptions.IsPicEnabled = false;
1987     return false;
1988   }
1989 
1990   if (Option == "relax") {
1991     getTargetStreamer().emitDirectiveOptionRelax();
1992 
1993     Parser.Lex();
1994     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
1995       return Error(Parser.getTok().getLoc(),
1996                    "unexpected token, expected end of statement");
1997 
1998     setFeatureBits(RISCV::FeatureRelax, "relax");
1999     return false;
2000   }
2001 
2002   if (Option == "norelax") {
2003     getTargetStreamer().emitDirectiveOptionNoRelax();
2004 
2005     Parser.Lex();
2006     if (Parser.getTok().isNot(AsmToken::EndOfStatement))
2007       return Error(Parser.getTok().getLoc(),
2008                    "unexpected token, expected end of statement");
2009 
2010     clearFeatureBits(RISCV::FeatureRelax, "relax");
2011     return false;
2012   }
2013 
2014   // Unknown option.
2015   Warning(Parser.getTok().getLoc(),
2016           "unknown option, expected 'push', 'pop', 'rvc', 'norvc', 'relax' or "
2017           "'norelax'");
2018   Parser.eatToEndOfStatement();
2019   return false;
2020 }
2021 
2022 /// parseDirectiveAttribute
2023 ///  ::= .attribute expression ',' ( expression | "string" )
2024 ///  ::= .attribute identifier ',' ( expression | "string" )
2025 bool RISCVAsmParser::parseDirectiveAttribute() {
2026   MCAsmParser &Parser = getParser();
2027   int64_t Tag;
2028   SMLoc TagLoc;
2029   TagLoc = Parser.getTok().getLoc();
2030   if (Parser.getTok().is(AsmToken::Identifier)) {
2031     StringRef Name = Parser.getTok().getIdentifier();
2032     Optional<unsigned> Ret =
2033         ELFAttrs::attrTypeFromString(Name, RISCVAttrs::RISCVAttributeTags);
2034     if (!Ret.hasValue()) {
2035       Error(TagLoc, "attribute name not recognised: " + Name);
2036       return false;
2037     }
2038     Tag = Ret.getValue();
2039     Parser.Lex();
2040   } else {
2041     const MCExpr *AttrExpr;
2042 
2043     TagLoc = Parser.getTok().getLoc();
2044     if (Parser.parseExpression(AttrExpr))
2045       return true;
2046 
2047     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(AttrExpr);
2048     if (check(!CE, TagLoc, "expected numeric constant"))
2049       return true;
2050 
2051     Tag = CE->getValue();
2052   }
2053 
2054   if (Parser.parseToken(AsmToken::Comma, "comma expected"))
2055     return true;
2056 
2057   StringRef StringValue;
2058   int64_t IntegerValue = 0;
2059   bool IsIntegerValue = true;
2060 
2061   // RISC-V attributes have a string value if the tag number is odd
2062   // and an integer value if the tag number is even.
2063   if (Tag % 2)
2064     IsIntegerValue = false;
2065 
2066   SMLoc ValueExprLoc = Parser.getTok().getLoc();
2067   if (IsIntegerValue) {
2068     const MCExpr *ValueExpr;
2069     if (Parser.parseExpression(ValueExpr))
2070       return true;
2071 
2072     const MCConstantExpr *CE = dyn_cast<MCConstantExpr>(ValueExpr);
2073     if (!CE)
2074       return Error(ValueExprLoc, "expected numeric constant");
2075     IntegerValue = CE->getValue();
2076   } else {
2077     if (Parser.getTok().isNot(AsmToken::String))
2078       return Error(Parser.getTok().getLoc(), "expected string constant");
2079 
2080     StringValue = Parser.getTok().getStringContents();
2081     Parser.Lex();
2082   }
2083 
2084   if (Parser.parseToken(AsmToken::EndOfStatement,
2085                         "unexpected token in '.attribute' directive"))
2086     return true;
2087 
2088   if (Tag == RISCVAttrs::ARCH) {
2089     StringRef Arch = StringValue;
2090     if (Arch.consume_front("rv32"))
2091       clearFeatureBits(RISCV::Feature64Bit, "64bit");
2092     else if (Arch.consume_front("rv64"))
2093       setFeatureBits(RISCV::Feature64Bit, "64bit");
2094     else
2095       return Error(ValueExprLoc, "bad arch string " + Arch);
2096 
2097     while (!Arch.empty()) {
2098       if (Arch[0] == 'i')
2099         clearFeatureBits(RISCV::FeatureRV32E, "e");
2100       else if (Arch[0] == 'e')
2101         setFeatureBits(RISCV::FeatureRV32E, "e");
2102       else if (Arch[0] == 'g') {
2103         clearFeatureBits(RISCV::FeatureRV32E, "e");
2104         setFeatureBits(RISCV::FeatureStdExtM, "m");
2105         setFeatureBits(RISCV::FeatureStdExtA, "a");
2106         setFeatureBits(RISCV::FeatureStdExtF, "f");
2107         setFeatureBits(RISCV::FeatureStdExtD, "d");
2108       } else if (Arch[0] == 'm')
2109         setFeatureBits(RISCV::FeatureStdExtM, "m");
2110       else if (Arch[0] == 'a')
2111         setFeatureBits(RISCV::FeatureStdExtA, "a");
2112       else if (Arch[0] == 'f')
2113         setFeatureBits(RISCV::FeatureStdExtF, "f");
2114       else if (Arch[0] == 'd') {
2115         setFeatureBits(RISCV::FeatureStdExtF, "f");
2116         setFeatureBits(RISCV::FeatureStdExtD, "d");
2117       } else if (Arch[0] == 'c') {
2118         setFeatureBits(RISCV::FeatureStdExtC, "c");
2119       } else
2120         return Error(ValueExprLoc, "bad arch string " + Arch);
2121 
2122       Arch = Arch.drop_front(1);
2123       int major = 0;
2124       int minor = 0;
2125       Arch.consumeInteger(10, major);
2126       Arch.consume_front("p");
2127       Arch.consumeInteger(10, minor);
2128       if (major != 0 || minor != 0) {
2129         Arch = Arch.drop_until([](char c) { return c == '_' || c == '"'; });
2130         Arch = Arch.drop_while([](char c) { return c == '_'; });
2131       }
2132     }
2133   }
2134 
2135   if (IsIntegerValue)
2136     getTargetStreamer().emitAttribute(Tag, IntegerValue);
2137   else {
2138     if (Tag != RISCVAttrs::ARCH) {
2139       getTargetStreamer().emitTextAttribute(Tag, StringValue);
2140     } else {
2141       std::string formalArchStr = "rv32";
2142       if (getFeatureBits(RISCV::Feature64Bit))
2143         formalArchStr = "rv64";
2144       if (getFeatureBits(RISCV::FeatureRV32E))
2145         formalArchStr = (Twine(formalArchStr) + "e1p9").str();
2146       else
2147         formalArchStr = (Twine(formalArchStr) + "i2p0").str();
2148 
2149       if (getFeatureBits(RISCV::FeatureStdExtM))
2150         formalArchStr = (Twine(formalArchStr) + "_m2p0").str();
2151       if (getFeatureBits(RISCV::FeatureStdExtA))
2152         formalArchStr = (Twine(formalArchStr) + "_a2p0").str();
2153       if (getFeatureBits(RISCV::FeatureStdExtF))
2154         formalArchStr = (Twine(formalArchStr) + "_f2p0").str();
2155       if (getFeatureBits(RISCV::FeatureStdExtD))
2156         formalArchStr = (Twine(formalArchStr) + "_d2p0").str();
2157       if (getFeatureBits(RISCV::FeatureStdExtC))
2158         formalArchStr = (Twine(formalArchStr) + "_c2p0").str();
2159 
2160       getTargetStreamer().emitTextAttribute(Tag, formalArchStr);
2161     }
2162   }
2163 
2164   return false;
2165 }
2166 
2167 void RISCVAsmParser::emitToStreamer(MCStreamer &S, const MCInst &Inst) {
2168   MCInst CInst;
2169   bool Res = compressInst(CInst, Inst, getSTI(), S.getContext());
2170   if (Res)
2171     ++RISCVNumInstrsCompressed;
2172   S.emitInstruction((Res ? CInst : Inst), getSTI());
2173 }
2174 
2175 void RISCVAsmParser::emitLoadImm(MCRegister DestReg, int64_t Value,
2176                                  MCStreamer &Out) {
2177   RISCVMatInt::InstSeq Seq;
2178   RISCVMatInt::generateInstSeq(Value, isRV64(), Seq);
2179 
2180   MCRegister SrcReg = RISCV::X0;
2181   for (RISCVMatInt::Inst &Inst : Seq) {
2182     if (Inst.Opc == RISCV::LUI) {
2183       emitToStreamer(
2184           Out, MCInstBuilder(RISCV::LUI).addReg(DestReg).addImm(Inst.Imm));
2185     } else {
2186       emitToStreamer(
2187           Out, MCInstBuilder(Inst.Opc).addReg(DestReg).addReg(SrcReg).addImm(
2188                    Inst.Imm));
2189     }
2190 
2191     // Only the first instruction has X0 as its source.
2192     SrcReg = DestReg;
2193   }
2194 }
2195 
2196 void RISCVAsmParser::emitAuipcInstPair(MCOperand DestReg, MCOperand TmpReg,
2197                                        const MCExpr *Symbol,
2198                                        RISCVMCExpr::VariantKind VKHi,
2199                                        unsigned SecondOpcode, SMLoc IDLoc,
2200                                        MCStreamer &Out) {
2201   // A pair of instructions for PC-relative addressing; expands to
2202   //   TmpLabel: AUIPC TmpReg, VKHi(symbol)
2203   //             OP DestReg, TmpReg, %pcrel_lo(TmpLabel)
2204   MCContext &Ctx = getContext();
2205 
2206   MCSymbol *TmpLabel = Ctx.createTempSymbol(
2207       "pcrel_hi", /* AlwaysAddSuffix */ true, /* CanBeUnnamed */ false);
2208   Out.emitLabel(TmpLabel);
2209 
2210   const RISCVMCExpr *SymbolHi = RISCVMCExpr::create(Symbol, VKHi, Ctx);
2211   emitToStreamer(
2212       Out, MCInstBuilder(RISCV::AUIPC).addOperand(TmpReg).addExpr(SymbolHi));
2213 
2214   const MCExpr *RefToLinkTmpLabel =
2215       RISCVMCExpr::create(MCSymbolRefExpr::create(TmpLabel, Ctx),
2216                           RISCVMCExpr::VK_RISCV_PCREL_LO, Ctx);
2217 
2218   emitToStreamer(Out, MCInstBuilder(SecondOpcode)
2219                           .addOperand(DestReg)
2220                           .addOperand(TmpReg)
2221                           .addExpr(RefToLinkTmpLabel));
2222 }
2223 
2224 void RISCVAsmParser::emitLoadLocalAddress(MCInst &Inst, SMLoc IDLoc,
2225                                           MCStreamer &Out) {
2226   // The load local address pseudo-instruction "lla" is used in PC-relative
2227   // addressing of local symbols:
2228   //   lla rdest, symbol
2229   // expands to
2230   //   TmpLabel: AUIPC rdest, %pcrel_hi(symbol)
2231   //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
2232   MCOperand DestReg = Inst.getOperand(0);
2233   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2234   emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_PCREL_HI,
2235                     RISCV::ADDI, IDLoc, Out);
2236 }
2237 
2238 void RISCVAsmParser::emitLoadAddress(MCInst &Inst, SMLoc IDLoc,
2239                                      MCStreamer &Out) {
2240   // The load address pseudo-instruction "la" is used in PC-relative and
2241   // GOT-indirect addressing of global symbols:
2242   //   la rdest, symbol
2243   // expands to either (for non-PIC)
2244   //   TmpLabel: AUIPC rdest, %pcrel_hi(symbol)
2245   //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
2246   // or (for PIC)
2247   //   TmpLabel: AUIPC rdest, %got_pcrel_hi(symbol)
2248   //             Lx rdest, %pcrel_lo(TmpLabel)(rdest)
2249   MCOperand DestReg = Inst.getOperand(0);
2250   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2251   unsigned SecondOpcode;
2252   RISCVMCExpr::VariantKind VKHi;
2253   if (ParserOptions.IsPicEnabled) {
2254     SecondOpcode = isRV64() ? RISCV::LD : RISCV::LW;
2255     VKHi = RISCVMCExpr::VK_RISCV_GOT_HI;
2256   } else {
2257     SecondOpcode = RISCV::ADDI;
2258     VKHi = RISCVMCExpr::VK_RISCV_PCREL_HI;
2259   }
2260   emitAuipcInstPair(DestReg, DestReg, Symbol, VKHi, SecondOpcode, IDLoc, Out);
2261 }
2262 
2263 void RISCVAsmParser::emitLoadTLSIEAddress(MCInst &Inst, SMLoc IDLoc,
2264                                           MCStreamer &Out) {
2265   // The load TLS IE address pseudo-instruction "la.tls.ie" is used in
2266   // initial-exec TLS model addressing of global symbols:
2267   //   la.tls.ie rdest, symbol
2268   // expands to
2269   //   TmpLabel: AUIPC rdest, %tls_ie_pcrel_hi(symbol)
2270   //             Lx rdest, %pcrel_lo(TmpLabel)(rdest)
2271   MCOperand DestReg = Inst.getOperand(0);
2272   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2273   unsigned SecondOpcode = isRV64() ? RISCV::LD : RISCV::LW;
2274   emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_TLS_GOT_HI,
2275                     SecondOpcode, IDLoc, Out);
2276 }
2277 
2278 void RISCVAsmParser::emitLoadTLSGDAddress(MCInst &Inst, SMLoc IDLoc,
2279                                           MCStreamer &Out) {
2280   // The load TLS GD address pseudo-instruction "la.tls.gd" is used in
2281   // global-dynamic TLS model addressing of global symbols:
2282   //   la.tls.gd rdest, symbol
2283   // expands to
2284   //   TmpLabel: AUIPC rdest, %tls_gd_pcrel_hi(symbol)
2285   //             ADDI rdest, rdest, %pcrel_lo(TmpLabel)
2286   MCOperand DestReg = Inst.getOperand(0);
2287   const MCExpr *Symbol = Inst.getOperand(1).getExpr();
2288   emitAuipcInstPair(DestReg, DestReg, Symbol, RISCVMCExpr::VK_RISCV_TLS_GD_HI,
2289                     RISCV::ADDI, IDLoc, Out);
2290 }
2291 
2292 void RISCVAsmParser::emitLoadStoreSymbol(MCInst &Inst, unsigned Opcode,
2293                                          SMLoc IDLoc, MCStreamer &Out,
2294                                          bool HasTmpReg) {
2295   // The load/store pseudo-instruction does a pc-relative load with
2296   // a symbol.
2297   //
2298   // The expansion looks like this
2299   //
2300   //   TmpLabel: AUIPC tmp, %pcrel_hi(symbol)
2301   //             [S|L]X    rd, %pcrel_lo(TmpLabel)(tmp)
2302   MCOperand DestReg = Inst.getOperand(0);
2303   unsigned SymbolOpIdx = HasTmpReg ? 2 : 1;
2304   unsigned TmpRegOpIdx = HasTmpReg ? 1 : 0;
2305   MCOperand TmpReg = Inst.getOperand(TmpRegOpIdx);
2306   const MCExpr *Symbol = Inst.getOperand(SymbolOpIdx).getExpr();
2307   emitAuipcInstPair(DestReg, TmpReg, Symbol, RISCVMCExpr::VK_RISCV_PCREL_HI,
2308                     Opcode, IDLoc, Out);
2309 }
2310 
2311 bool RISCVAsmParser::checkPseudoAddTPRel(MCInst &Inst,
2312                                          OperandVector &Operands) {
2313   assert(Inst.getOpcode() == RISCV::PseudoAddTPRel && "Invalid instruction");
2314   assert(Inst.getOperand(2).isReg() && "Unexpected second operand kind");
2315   if (Inst.getOperand(2).getReg() != RISCV::X4) {
2316     SMLoc ErrorLoc = ((RISCVOperand &)*Operands[3]).getStartLoc();
2317     return Error(ErrorLoc, "the second input operand must be tp/x4 when using "
2318                            "%tprel_add modifier");
2319   }
2320 
2321   return false;
2322 }
2323 
2324 std::unique_ptr<RISCVOperand> RISCVAsmParser::defaultMaskRegOp() const {
2325   return RISCVOperand::createReg(RISCV::NoRegister, llvm::SMLoc(),
2326                                  llvm::SMLoc(), isRV64());
2327 }
2328 
2329 bool RISCVAsmParser::validateInstruction(MCInst &Inst,
2330                                          OperandVector &Operands) {
2331   const MCInstrDesc &MCID = MII.get(Inst.getOpcode());
2332   unsigned TargetFlags =
2333       (MCID.TSFlags >> RISCVII::ConstraintOffset) & RISCVII::ConstraintMask;
2334   if (TargetFlags == RISCVII::NoConstraint)
2335     return false;
2336 
2337   unsigned DestReg = Inst.getOperand(0).getReg();
2338   unsigned CheckReg;
2339   // Operands[1] will be the first operand, DestReg.
2340   SMLoc Loc = Operands[1]->getStartLoc();
2341   if (TargetFlags & RISCVII::VS2Constraint) {
2342     CheckReg = Inst.getOperand(1).getReg();
2343     if (DestReg == CheckReg)
2344       return Error(Loc, "The destination vector register group cannot overlap"
2345                         " the source vector register group.");
2346   }
2347   if ((TargetFlags & RISCVII::VS1Constraint) && (Inst.getOperand(2).isReg())) {
2348     CheckReg = Inst.getOperand(2).getReg();
2349     if (DestReg == CheckReg)
2350       return Error(Loc, "The destination vector register group cannot overlap"
2351                         " the source vector register group.");
2352   }
2353   if ((TargetFlags & RISCVII::VMConstraint) && (DestReg == RISCV::V0)) {
2354     // vadc, vsbc are special cases. These instructions have no mask register.
2355     // The destination register could not be V0.
2356     unsigned Opcode = Inst.getOpcode();
2357     if (Opcode == RISCV::VADC_VVM || Opcode == RISCV::VADC_VXM ||
2358         Opcode == RISCV::VADC_VIM || Opcode == RISCV::VSBC_VVM ||
2359         Opcode == RISCV::VSBC_VXM)
2360       return Error(Loc, "The destination vector register group cannot be V0.");
2361 
2362     // Regardless masked or unmasked version, the number of operands is the
2363     // same. For example, "viota.m v0, v2" is "viota.m v0, v2, NoRegister"
2364     // actually. We need to check the last operand to ensure whether it is
2365     // masked or not.
2366     if ((TargetFlags & RISCVII::OneInput) && (Inst.getNumOperands() == 3))
2367       CheckReg = Inst.getOperand(2).getReg();
2368     else if (Inst.getNumOperands() == 4)
2369       CheckReg = Inst.getOperand(3).getReg();
2370     if (DestReg == CheckReg)
2371       return Error(Loc, "The destination vector register group cannot overlap"
2372                         " the mask register.");
2373   }
2374   return false;
2375 }
2376 
2377 bool RISCVAsmParser::processInstruction(MCInst &Inst, SMLoc IDLoc,
2378                                         OperandVector &Operands,
2379                                         MCStreamer &Out) {
2380   Inst.setLoc(IDLoc);
2381 
2382   switch (Inst.getOpcode()) {
2383   default:
2384     break;
2385   case RISCV::PseudoLI: {
2386     MCRegister Reg = Inst.getOperand(0).getReg();
2387     const MCOperand &Op1 = Inst.getOperand(1);
2388     if (Op1.isExpr()) {
2389       // We must have li reg, %lo(sym) or li reg, %pcrel_lo(sym) or similar.
2390       // Just convert to an addi. This allows compatibility with gas.
2391       emitToStreamer(Out, MCInstBuilder(RISCV::ADDI)
2392                               .addReg(Reg)
2393                               .addReg(RISCV::X0)
2394                               .addExpr(Op1.getExpr()));
2395       return false;
2396     }
2397     int64_t Imm = Inst.getOperand(1).getImm();
2398     // On RV32 the immediate here can either be a signed or an unsigned
2399     // 32-bit number. Sign extension has to be performed to ensure that Imm
2400     // represents the expected signed 64-bit number.
2401     if (!isRV64())
2402       Imm = SignExtend64<32>(Imm);
2403     emitLoadImm(Reg, Imm, Out);
2404     return false;
2405   }
2406   case RISCV::PseudoLLA:
2407     emitLoadLocalAddress(Inst, IDLoc, Out);
2408     return false;
2409   case RISCV::PseudoLA:
2410     emitLoadAddress(Inst, IDLoc, Out);
2411     return false;
2412   case RISCV::PseudoLA_TLS_IE:
2413     emitLoadTLSIEAddress(Inst, IDLoc, Out);
2414     return false;
2415   case RISCV::PseudoLA_TLS_GD:
2416     emitLoadTLSGDAddress(Inst, IDLoc, Out);
2417     return false;
2418   case RISCV::PseudoLB:
2419     emitLoadStoreSymbol(Inst, RISCV::LB, IDLoc, Out, /*HasTmpReg=*/false);
2420     return false;
2421   case RISCV::PseudoLBU:
2422     emitLoadStoreSymbol(Inst, RISCV::LBU, IDLoc, Out, /*HasTmpReg=*/false);
2423     return false;
2424   case RISCV::PseudoLH:
2425     emitLoadStoreSymbol(Inst, RISCV::LH, IDLoc, Out, /*HasTmpReg=*/false);
2426     return false;
2427   case RISCV::PseudoLHU:
2428     emitLoadStoreSymbol(Inst, RISCV::LHU, IDLoc, Out, /*HasTmpReg=*/false);
2429     return false;
2430   case RISCV::PseudoLW:
2431     emitLoadStoreSymbol(Inst, RISCV::LW, IDLoc, Out, /*HasTmpReg=*/false);
2432     return false;
2433   case RISCV::PseudoLWU:
2434     emitLoadStoreSymbol(Inst, RISCV::LWU, IDLoc, Out, /*HasTmpReg=*/false);
2435     return false;
2436   case RISCV::PseudoLD:
2437     emitLoadStoreSymbol(Inst, RISCV::LD, IDLoc, Out, /*HasTmpReg=*/false);
2438     return false;
2439   case RISCV::PseudoFLW:
2440     emitLoadStoreSymbol(Inst, RISCV::FLW, IDLoc, Out, /*HasTmpReg=*/true);
2441     return false;
2442   case RISCV::PseudoFLD:
2443     emitLoadStoreSymbol(Inst, RISCV::FLD, IDLoc, Out, /*HasTmpReg=*/true);
2444     return false;
2445   case RISCV::PseudoSB:
2446     emitLoadStoreSymbol(Inst, RISCV::SB, IDLoc, Out, /*HasTmpReg=*/true);
2447     return false;
2448   case RISCV::PseudoSH:
2449     emitLoadStoreSymbol(Inst, RISCV::SH, IDLoc, Out, /*HasTmpReg=*/true);
2450     return false;
2451   case RISCV::PseudoSW:
2452     emitLoadStoreSymbol(Inst, RISCV::SW, IDLoc, Out, /*HasTmpReg=*/true);
2453     return false;
2454   case RISCV::PseudoSD:
2455     emitLoadStoreSymbol(Inst, RISCV::SD, IDLoc, Out, /*HasTmpReg=*/true);
2456     return false;
2457   case RISCV::PseudoFSW:
2458     emitLoadStoreSymbol(Inst, RISCV::FSW, IDLoc, Out, /*HasTmpReg=*/true);
2459     return false;
2460   case RISCV::PseudoFSD:
2461     emitLoadStoreSymbol(Inst, RISCV::FSD, IDLoc, Out, /*HasTmpReg=*/true);
2462     return false;
2463   case RISCV::PseudoAddTPRel:
2464     if (checkPseudoAddTPRel(Inst, Operands))
2465       return true;
2466     break;
2467   }
2468 
2469   emitToStreamer(Out, Inst);
2470   return false;
2471 }
2472 
2473 extern "C" LLVM_EXTERNAL_VISIBILITY void LLVMInitializeRISCVAsmParser() {
2474   RegisterMCAsmParser<RISCVAsmParser> X(getTheRISCV32Target());
2475   RegisterMCAsmParser<RISCVAsmParser> Y(getTheRISCV64Target());
2476 }
2477