1 //===- MCInstPrinter.cpp - Convert an MCInst to target assembly syntax ----===// 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 "llvm/MC/MCInstPrinter.h" 10 #include "llvm/ADT/ArrayRef.h" 11 #include "llvm/ADT/StringRef.h" 12 #include "llvm/MC/MCAsmInfo.h" 13 #include "llvm/MC/MCInst.h" 14 #include "llvm/MC/MCInstrInfo.h" 15 #include "llvm/MC/MCRegisterInfo.h" 16 #include "llvm/MC/MCSubtargetInfo.h" 17 #include "llvm/Support/ErrorHandling.h" 18 #include "llvm/Support/Format.h" 19 #include "llvm/Support/raw_ostream.h" 20 #include <cinttypes> 21 #include <cstdint> 22 23 using namespace llvm; 24 25 void llvm::dumpBytes(ArrayRef<uint8_t> bytes, raw_ostream &OS) { 26 static const char hex_rep[] = "0123456789abcdef"; 27 bool First = true; 28 for (char i: bytes) { 29 if (First) 30 First = false; 31 else 32 OS << ' '; 33 OS << hex_rep[(i & 0xF0) >> 4]; 34 OS << hex_rep[i & 0xF]; 35 } 36 } 37 38 MCInstPrinter::~MCInstPrinter() = default; 39 40 /// getOpcodeName - Return the name of the specified opcode enum (e.g. 41 /// "MOV32ri") or empty if we can't resolve it. 42 StringRef MCInstPrinter::getOpcodeName(unsigned Opcode) const { 43 return MII.getName(Opcode); 44 } 45 46 void MCInstPrinter::printRegName(raw_ostream &OS, unsigned RegNo) const { 47 llvm_unreachable("Target should implement this"); 48 } 49 50 void MCInstPrinter::printAnnotation(raw_ostream &OS, StringRef Annot) { 51 if (!Annot.empty()) { 52 if (CommentStream) { 53 (*CommentStream) << Annot; 54 // By definition (see MCInstPrinter.h), CommentStream must end with 55 // a newline after each comment. 56 if (Annot.back() != '\n') 57 (*CommentStream) << '\n'; 58 } else 59 OS << " " << MAI.getCommentString() << " " << Annot; 60 } 61 } 62 63 static bool matchAliasCondition(const MCInst &MI, const MCSubtargetInfo *STI, 64 const MCRegisterInfo &MRI, unsigned &OpIdx, 65 const AliasMatchingData &M, 66 const AliasPatternCond &C, 67 bool &OrPredicateResult) { 68 // Feature tests are special, they don't consume operands. 69 if (C.Kind == AliasPatternCond::K_Feature) 70 return STI->getFeatureBits().test(C.Value); 71 if (C.Kind == AliasPatternCond::K_NegFeature) 72 return !STI->getFeatureBits().test(C.Value); 73 // For feature tests where just one feature is required in a list, set the 74 // predicate result bit to whether the expression will return true, and only 75 // return the real result at the end of list marker. 76 if (C.Kind == AliasPatternCond::K_OrFeature) { 77 OrPredicateResult |= STI->getFeatureBits().test(C.Value); 78 return true; 79 } 80 if (C.Kind == AliasPatternCond::K_OrNegFeature) { 81 OrPredicateResult |= !(STI->getFeatureBits().test(C.Value)); 82 return true; 83 } 84 if (C.Kind == AliasPatternCond::K_EndOrFeatures) { 85 bool Res = OrPredicateResult; 86 OrPredicateResult = false; 87 return Res; 88 } 89 90 // Get and consume an operand. 91 const MCOperand &Opnd = MI.getOperand(OpIdx); 92 ++OpIdx; 93 94 // Check the specific condition for the operand. 95 switch (C.Kind) { 96 case AliasPatternCond::K_Imm: 97 // Operand must be a specific immediate. 98 return Opnd.isImm() && Opnd.getImm() == int32_t(C.Value); 99 case AliasPatternCond::K_Reg: 100 // Operand must be a specific register. 101 return Opnd.isReg() && Opnd.getReg() == C.Value; 102 case AliasPatternCond::K_TiedReg: 103 // Operand must match the register of another operand. 104 return Opnd.isReg() && Opnd.getReg() == MI.getOperand(C.Value).getReg(); 105 case AliasPatternCond::K_RegClass: 106 // Operand must be a register in this class. Value is a register class id. 107 return Opnd.isReg() && MRI.getRegClass(C.Value).contains(Opnd.getReg()); 108 case AliasPatternCond::K_Custom: 109 // Operand must match some custom criteria. 110 return M.ValidateMCOperand(Opnd, *STI, C.Value); 111 case AliasPatternCond::K_Ignore: 112 // Operand can be anything. 113 return true; 114 case AliasPatternCond::K_Feature: 115 case AliasPatternCond::K_NegFeature: 116 case AliasPatternCond::K_OrFeature: 117 case AliasPatternCond::K_OrNegFeature: 118 case AliasPatternCond::K_EndOrFeatures: 119 llvm_unreachable("handled earlier"); 120 } 121 llvm_unreachable("invalid kind"); 122 } 123 124 const char *MCInstPrinter::matchAliasPatterns(const MCInst *MI, 125 const MCSubtargetInfo *STI, 126 const AliasMatchingData &M) { 127 // Binary search by opcode. Return false if there are no aliases for this 128 // opcode. 129 auto It = lower_bound(M.OpToPatterns, MI->getOpcode(), 130 [](const PatternsForOpcode &L, unsigned Opcode) { 131 return L.Opcode < Opcode; 132 }); 133 if (It == M.OpToPatterns.end() || It->Opcode != MI->getOpcode()) 134 return nullptr; 135 136 // Try all patterns for this opcode. 137 uint32_t AsmStrOffset = ~0U; 138 ArrayRef<AliasPattern> Patterns = 139 M.Patterns.slice(It->PatternStart, It->NumPatterns); 140 for (const AliasPattern &P : Patterns) { 141 // Check operand count first. 142 if (MI->getNumOperands() != P.NumOperands) 143 return nullptr; 144 145 // Test all conditions for this pattern. 146 ArrayRef<AliasPatternCond> Conds = 147 M.PatternConds.slice(P.AliasCondStart, P.NumConds); 148 unsigned OpIdx = 0; 149 bool OrPredicateResult = false; 150 if (llvm::all_of(Conds, [&](const AliasPatternCond &C) { 151 return matchAliasCondition(*MI, STI, MRI, OpIdx, M, C, 152 OrPredicateResult); 153 })) { 154 // If all conditions matched, use this asm string. 155 AsmStrOffset = P.AsmStrOffset; 156 break; 157 } 158 } 159 160 // If no alias matched, don't print an alias. 161 if (AsmStrOffset == ~0U) 162 return nullptr; 163 164 // Go to offset AsmStrOffset and use the null terminated string there. The 165 // offset should point to the beginning of an alias string, so it should 166 // either be zero or be preceded by a null byte. 167 assert(AsmStrOffset < M.AsmStrings.size() && 168 (AsmStrOffset == 0 || M.AsmStrings[AsmStrOffset - 1] == '\0') && 169 "bad asm string offset"); 170 return M.AsmStrings.data() + AsmStrOffset; 171 } 172 173 /// Utility functions to make adding mark ups simpler. 174 StringRef MCInstPrinter::markup(StringRef s) const { 175 if (getUseMarkup()) 176 return s; 177 else 178 return ""; 179 } 180 181 // For asm-style hex (e.g. 0ffh) the first digit always has to be a number. 182 static bool needsLeadingZero(uint64_t Value) 183 { 184 while (Value) 185 { 186 uint64_t digit = (Value >> 60) & 0xf; 187 if (digit != 0) 188 return (digit >= 0xa); 189 Value <<= 4; 190 } 191 return false; 192 } 193 194 format_object<int64_t> MCInstPrinter::formatDec(int64_t Value) const { 195 return format("%" PRId64, Value); 196 } 197 198 format_object<int64_t> MCInstPrinter::formatHex(int64_t Value) const { 199 switch (PrintHexStyle) { 200 case HexStyle::C: 201 if (Value < 0) { 202 if (Value == std::numeric_limits<int64_t>::min()) 203 return format<int64_t>("-0x8000000000000000", Value); 204 return format("-0x%" PRIx64, -Value); 205 } 206 return format("0x%" PRIx64, Value); 207 case HexStyle::Asm: 208 if (Value < 0) { 209 if (Value == std::numeric_limits<int64_t>::min()) 210 return format<int64_t>("-8000000000000000h", Value); 211 if (needsLeadingZero(-(uint64_t)(Value))) 212 return format("-0%" PRIx64 "h", -Value); 213 return format("-%" PRIx64 "h", -Value); 214 } 215 if (needsLeadingZero((uint64_t)(Value))) 216 return format("0%" PRIx64 "h", Value); 217 return format("%" PRIx64 "h", Value); 218 } 219 llvm_unreachable("unsupported print style"); 220 } 221 222 format_object<uint64_t> MCInstPrinter::formatHex(uint64_t Value) const { 223 switch(PrintHexStyle) { 224 case HexStyle::C: 225 return format("0x%" PRIx64, Value); 226 case HexStyle::Asm: 227 if (needsLeadingZero(Value)) 228 return format("0%" PRIx64 "h", Value); 229 else 230 return format("%" PRIx64 "h", Value); 231 } 232 llvm_unreachable("unsupported print style"); 233 } 234