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