1 //===-- llvm/InlineAsm.h - Class to represent inline asm strings-*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
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(...).
14 //===----------------------------------------------------------------------===//
16 #ifndef LLVM_INLINEASM_H
17 #define LLVM_INLINEASM_H
19 #include "llvm/Value.h"
28 class InlineAsm : public Value {
29 InlineAsm(const InlineAsm &); // do not implement
30 void operator=(const InlineAsm&); // do not implement
32 std::string AsmString, Constraints;
36 InlineAsm(const FunctionType *Ty, StringRef AsmString,
37 StringRef Constraints, bool hasSideEffects,
38 bool isAlignStack = false);
42 /// InlineAsm::get - Return the specified uniqued inline asm string.
44 static InlineAsm *get(const FunctionType *Ty, StringRef AsmString,
45 StringRef Constraints, bool hasSideEffects,
46 bool isAlignStack = false);
48 bool hasSideEffects() const { return HasSideEffects; }
49 bool isAlignStack() const { return IsAlignStack; }
51 /// getType - InlineAsm's are always pointers.
53 const PointerType *getType() const {
54 return reinterpret_cast<const PointerType*>(Value::getType());
57 /// getFunctionType - InlineAsm's are always pointers to functions.
59 const FunctionType *getFunctionType() const;
61 const std::string &getAsmString() const { return AsmString; }
62 const std::string &getConstraintString() const { return Constraints; }
64 /// Verify - This static method can be used by the parser to check to see if
65 /// the specified constraint string is legal for the type. This returns true
66 /// if legal, false if not.
68 static bool Verify(const FunctionType *Ty, StringRef Constraints);
70 // Constraint String Parsing
71 enum ConstraintPrefix {
77 struct ConstraintInfo {
78 /// Type - The basic type of the constraint: input/output/clobber
80 ConstraintPrefix Type;
82 /// isEarlyClobber - "&": output operand writes result before inputs are all
83 /// read. This is only ever set for an output operand.
86 /// MatchingInput - If this is not -1, this is an output constraint where an
87 /// input constraint is required to match it (e.g. "0"). The value is the
88 /// constraint number that matches this one (for example, if this is
89 /// constraint #0 and constraint #4 has the value "0", this will be 4).
90 signed char MatchingInput;
92 /// hasMatchingInput - Return true if this is an output constraint that has
93 /// a matching input constraint.
94 bool hasMatchingInput() const { return MatchingInput != -1; }
96 /// isCommutative - This is set to true for a constraint that is commutative
97 /// with the next operand.
100 /// isIndirect - True if this operand is an indirect operand. This means
101 /// that the address of the source or destination is present in the call
102 /// instruction, instead of it being returned or passed in explicitly. This
103 /// is represented with a '*' in the asm string.
106 /// Code - The constraint code, either the register name (in braces) or the
107 /// constraint letter/number.
108 std::vector<std::string> Codes;
110 /// Parse - Analyze the specified string (e.g. "=*&{eax}") and fill in the
111 /// fields in this structure. If the constraint string is not understood,
112 /// return true, otherwise return false.
113 bool Parse(StringRef Str,
114 std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar);
117 /// ParseConstraints - Split up the constraint string into the specific
118 /// constraints and their prefixes. If this returns an empty vector, and if
119 /// the constraint string itself isn't empty, there was an error parsing.
120 static std::vector<ConstraintInfo>
121 ParseConstraints(StringRef ConstraintString);
123 /// ParseConstraints - Parse the constraints of this inlineasm object,
124 /// returning them the same way that ParseConstraints(str) does.
125 std::vector<ConstraintInfo>
126 ParseConstraints() const {
127 return ParseConstraints(Constraints);
130 // Methods for support type inquiry through isa, cast, and dyn_cast:
131 static inline bool classof(const InlineAsm *) { return true; }
132 static inline bool classof(const Value *V) {
133 return V->getValueID() == Value::InlineAsmVal;
136 /// getNumOperandRegisters - Extract the number of registers field from the
137 /// inline asm operand flag.
138 static unsigned getNumOperandRegisters(unsigned Flag) {
139 return (Flag & 0xffff) >> 3;
142 /// isUseOperandTiedToDef - Return true if the flag of the inline asm
143 /// operand indicates it is an use operand that's matched to a def operand.
144 static bool isUseOperandTiedToDef(unsigned Flag, unsigned &Idx) {
145 if ((Flag & 0x80000000) == 0)
147 Idx = (Flag & ~0x80000000) >> 16;
154 } // End llvm namespace