1 //===-- llvm/InlineAsm.h - Class to represent inline asm strings-*- C++ -*-===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is distributed under the University of Illinois Open Source 6 // License. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 // 10 // This class represents the inline asm strings, which are Value*'s that are 11 // used as the callee operand of call instructions. InlineAsm's are uniqued 12 // like constants, and created via InlineAsm::get(...). 13 // 14 //===----------------------------------------------------------------------===// 15 16 #ifndef LLVM_IR_INLINEASM_H 17 #define LLVM_IR_INLINEASM_H 18 19 #include "llvm/ADT/StringRef.h" 20 #include "llvm/IR/Value.h" 21 #include <vector> 22 23 namespace llvm { 24 25 class PointerType; 26 class FunctionType; 27 class Module; 28 struct InlineAsmKeyType; 29 template<class ValType, class ValRefType, class TypeClass, class ConstantClass, 30 bool HasLargeKey> 31 class ConstantUniqueMap; 32 template<class ConstantClass, class TypeClass, class ValType> 33 struct ConstantCreator; 34 35 class InlineAsm : public Value { 36 public: 37 enum AsmDialect { 38 AD_ATT, 39 AD_Intel 40 }; 41 42 private: 43 friend struct ConstantCreator<InlineAsm, PointerType, InlineAsmKeyType>; 44 friend class ConstantUniqueMap<InlineAsmKeyType, const InlineAsmKeyType&, 45 PointerType, InlineAsm, false>; 46 47 InlineAsm(const InlineAsm &) LLVM_DELETED_FUNCTION; 48 void operator=(const InlineAsm&) LLVM_DELETED_FUNCTION; 49 50 std::string AsmString, Constraints; 51 bool HasSideEffects; 52 bool IsAlignStack; 53 AsmDialect Dialect; 54 55 InlineAsm(PointerType *Ty, const std::string &AsmString, 56 const std::string &Constraints, bool hasSideEffects, 57 bool isAlignStack, AsmDialect asmDialect); 58 virtual ~InlineAsm(); 59 60 /// When the ConstantUniqueMap merges two types and makes two InlineAsms 61 /// identical, it destroys one of them with this method. 62 void destroyConstant(); 63 public: 64 65 /// InlineAsm::get - Return the specified uniqued inline asm string. 66 /// 67 static InlineAsm *get(FunctionType *Ty, StringRef AsmString, 68 StringRef Constraints, bool hasSideEffects, 69 bool isAlignStack = false, 70 AsmDialect asmDialect = AD_ATT); 71 72 bool hasSideEffects() const { return HasSideEffects; } 73 bool isAlignStack() const { return IsAlignStack; } 74 AsmDialect getDialect() const { return Dialect; } 75 76 /// getType - InlineAsm's are always pointers. 77 /// 78 PointerType *getType() const { 79 return reinterpret_cast<PointerType*>(Value::getType()); 80 } 81 82 /// getFunctionType - InlineAsm's are always pointers to functions. 83 /// 84 FunctionType *getFunctionType() const; 85 86 const std::string &getAsmString() const { return AsmString; } 87 const std::string &getConstraintString() const { return Constraints; } 88 89 /// Verify - This static method can be used by the parser to check to see if 90 /// the specified constraint string is legal for the type. This returns true 91 /// if legal, false if not. 92 /// 93 static bool Verify(FunctionType *Ty, StringRef Constraints); 94 95 // Constraint String Parsing 96 enum ConstraintPrefix { 97 isInput, // 'x' 98 isOutput, // '=x' 99 isClobber // '~x' 100 }; 101 102 typedef std::vector<std::string> ConstraintCodeVector; 103 104 struct SubConstraintInfo { 105 /// MatchingInput - If this is not -1, this is an output constraint where an 106 /// input constraint is required to match it (e.g. "0"). The value is the 107 /// constraint number that matches this one (for example, if this is 108 /// constraint #0 and constraint #4 has the value "0", this will be 4). 109 signed char MatchingInput; 110 /// Code - The constraint code, either the register name (in braces) or the 111 /// constraint letter/number. 112 ConstraintCodeVector Codes; 113 /// Default constructor. 114 SubConstraintInfo() : MatchingInput(-1) {} 115 }; 116 117 typedef std::vector<SubConstraintInfo> SubConstraintInfoVector; 118 struct ConstraintInfo; 119 typedef std::vector<ConstraintInfo> ConstraintInfoVector; 120 121 struct ConstraintInfo { 122 /// Type - The basic type of the constraint: input/output/clobber 123 /// 124 ConstraintPrefix Type; 125 126 /// isEarlyClobber - "&": output operand writes result before inputs are all 127 /// read. This is only ever set for an output operand. 128 bool isEarlyClobber; 129 130 /// MatchingInput - If this is not -1, this is an output constraint where an 131 /// input constraint is required to match it (e.g. "0"). The value is the 132 /// constraint number that matches this one (for example, if this is 133 /// constraint #0 and constraint #4 has the value "0", this will be 4). 134 signed char MatchingInput; 135 136 /// hasMatchingInput - Return true if this is an output constraint that has 137 /// a matching input constraint. 138 bool hasMatchingInput() const { return MatchingInput != -1; } 139 140 /// isCommutative - This is set to true for a constraint that is commutative 141 /// with the next operand. 142 bool isCommutative; 143 144 /// isIndirect - True if this operand is an indirect operand. This means 145 /// that the address of the source or destination is present in the call 146 /// instruction, instead of it being returned or passed in explicitly. This 147 /// is represented with a '*' in the asm string. 148 bool isIndirect; 149 150 /// Code - The constraint code, either the register name (in braces) or the 151 /// constraint letter/number. 152 ConstraintCodeVector Codes; 153 154 /// isMultipleAlternative - '|': has multiple-alternative constraints. 155 bool isMultipleAlternative; 156 157 /// multipleAlternatives - If there are multiple alternative constraints, 158 /// this array will contain them. Otherwise it will be empty. 159 SubConstraintInfoVector multipleAlternatives; 160 161 /// The currently selected alternative constraint index. 162 unsigned currentAlternativeIndex; 163 164 ///Default constructor. 165 ConstraintInfo(); 166 167 /// Copy constructor. 168 ConstraintInfo(const ConstraintInfo &other); 169 170 /// Parse - Analyze the specified string (e.g. "=*&{eax}") and fill in the 171 /// fields in this structure. If the constraint string is not understood, 172 /// return true, otherwise return false. 173 bool Parse(StringRef Str, ConstraintInfoVector &ConstraintsSoFar); 174 175 /// selectAlternative - Point this constraint to the alternative constraint 176 /// indicated by the index. 177 void selectAlternative(unsigned index); 178 }; 179 180 /// ParseConstraints - Split up the constraint string into the specific 181 /// constraints and their prefixes. If this returns an empty vector, and if 182 /// the constraint string itself isn't empty, there was an error parsing. 183 static ConstraintInfoVector ParseConstraints(StringRef ConstraintString); 184 185 /// ParseConstraints - Parse the constraints of this inlineasm object, 186 /// returning them the same way that ParseConstraints(str) does. 187 ConstraintInfoVector ParseConstraints() const { 188 return ParseConstraints(Constraints); 189 } 190 191 // Methods for support type inquiry through isa, cast, and dyn_cast: 192 static inline bool classof(const Value *V) { 193 return V->getValueID() == Value::InlineAsmVal; 194 } 195 196 197 // These are helper methods for dealing with flags in the INLINEASM SDNode 198 // in the backend. 199 200 enum { 201 // Fixed operands on an INLINEASM SDNode. 202 Op_InputChain = 0, 203 Op_AsmString = 1, 204 Op_MDNode = 2, 205 Op_ExtraInfo = 3, // HasSideEffects, IsAlignStack, AsmDialect. 206 Op_FirstOperand = 4, 207 208 // Fixed operands on an INLINEASM MachineInstr. 209 MIOp_AsmString = 0, 210 MIOp_ExtraInfo = 1, // HasSideEffects, IsAlignStack, AsmDialect. 211 MIOp_FirstOperand = 2, 212 213 // Interpretation of the MIOp_ExtraInfo bit field. 214 Extra_HasSideEffects = 1, 215 Extra_IsAlignStack = 2, 216 Extra_AsmDialect = 4, 217 Extra_MayLoad = 8, 218 Extra_MayStore = 16, 219 220 // Inline asm operands map to multiple SDNode / MachineInstr operands. 221 // The first operand is an immediate describing the asm operand, the low 222 // bits is the kind: 223 Kind_RegUse = 1, // Input register, "r". 224 Kind_RegDef = 2, // Output register, "=r". 225 Kind_RegDefEarlyClobber = 3, // Early-clobber output register, "=&r". 226 Kind_Clobber = 4, // Clobbered register, "~r". 227 Kind_Imm = 5, // Immediate. 228 Kind_Mem = 6, // Memory operand, "m". 229 230 Flag_MatchingOperand = 0x80000000 231 }; 232 233 static unsigned getFlagWord(unsigned Kind, unsigned NumOps) { 234 assert(((NumOps << 3) & ~0xffff) == 0 && "Too many inline asm operands!"); 235 assert(Kind >= Kind_RegUse && Kind <= Kind_Mem && "Invalid Kind"); 236 return Kind | (NumOps << 3); 237 } 238 239 /// getFlagWordForMatchingOp - Augment an existing flag word returned by 240 /// getFlagWord with information indicating that this input operand is tied 241 /// to a previous output operand. 242 static unsigned getFlagWordForMatchingOp(unsigned InputFlag, 243 unsigned MatchedOperandNo) { 244 assert(MatchedOperandNo <= 0x7fff && "Too big matched operand"); 245 assert((InputFlag & ~0xffff) == 0 && "High bits already contain data"); 246 return InputFlag | Flag_MatchingOperand | (MatchedOperandNo << 16); 247 } 248 249 /// getFlagWordForRegClass - Augment an existing flag word returned by 250 /// getFlagWord with the required register class for the following register 251 /// operands. 252 /// A tied use operand cannot have a register class, use the register class 253 /// from the def operand instead. 254 static unsigned getFlagWordForRegClass(unsigned InputFlag, unsigned RC) { 255 // Store RC + 1, reserve the value 0 to mean 'no register class'. 256 ++RC; 257 assert(RC <= 0x7fff && "Too large register class ID"); 258 assert((InputFlag & ~0xffff) == 0 && "High bits already contain data"); 259 return InputFlag | (RC << 16); 260 } 261 262 static unsigned getKind(unsigned Flags) { 263 return Flags & 7; 264 } 265 266 static bool isRegDefKind(unsigned Flag){ return getKind(Flag) == Kind_RegDef;} 267 static bool isImmKind(unsigned Flag) { return getKind(Flag) == Kind_Imm; } 268 static bool isMemKind(unsigned Flag) { return getKind(Flag) == Kind_Mem; } 269 static bool isRegDefEarlyClobberKind(unsigned Flag) { 270 return getKind(Flag) == Kind_RegDefEarlyClobber; 271 } 272 static bool isClobberKind(unsigned Flag) { 273 return getKind(Flag) == Kind_Clobber; 274 } 275 276 /// getNumOperandRegisters - Extract the number of registers field from the 277 /// inline asm operand flag. 278 static unsigned getNumOperandRegisters(unsigned Flag) { 279 return (Flag & 0xffff) >> 3; 280 } 281 282 /// isUseOperandTiedToDef - Return true if the flag of the inline asm 283 /// operand indicates it is an use operand that's matched to a def operand. 284 static bool isUseOperandTiedToDef(unsigned Flag, unsigned &Idx) { 285 if ((Flag & Flag_MatchingOperand) == 0) 286 return false; 287 Idx = (Flag & ~Flag_MatchingOperand) >> 16; 288 return true; 289 } 290 291 /// hasRegClassConstraint - Returns true if the flag contains a register 292 /// class constraint. Sets RC to the register class ID. 293 static bool hasRegClassConstraint(unsigned Flag, unsigned &RC) { 294 if (Flag & Flag_MatchingOperand) 295 return false; 296 unsigned High = Flag >> 16; 297 // getFlagWordForRegClass() uses 0 to mean no register class, and otherwise 298 // stores RC + 1. 299 if (!High) 300 return false; 301 RC = High - 1; 302 return true; 303 } 304 305 }; 306 307 } // End llvm namespace 308 309 #endif 310
