LLVM API Documentation

InlineAsm.h

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00001 //===-- llvm/InlineAsm.h - Class to represent inline asm strings-*- C++ -*-===//
00002 //
00003 //                     The LLVM Compiler Infrastructure
00004 //
00005 // This file was developed by Chris Lattner and is distributed under
00006 // the University of Illinois Open Source License. See LICENSE.TXT for details.
00007 //
00008 //===----------------------------------------------------------------------===//
00009 //
00010 // This class represents the inline asm strings, which are Value*'s that are
00011 // used as the callee operand of call instructions.  InlineAsm's are uniqued
00012 // like constants, and created via InlineAsm::get(...).
00013 //
00014 //===----------------------------------------------------------------------===//
00015 
00016 #ifndef LLVM_INLINEASM_H
00017 #define LLVM_INLINEASM_H
00018 
00019 #include "llvm/Value.h"
00020 #include <vector>
00021 
00022 namespace llvm {
00023 
00024 struct AssemblyAnnotationWriter;
00025 class PointerType;
00026 class FunctionType;
00027 class Module;
00028 
00029 class InlineAsm : public Value {
00030   InlineAsm(const InlineAsm &);             // do not implement
00031   void operator=(const InlineAsm&);         // do not implement
00032 
00033   std::string AsmString, Constraints;
00034   bool HasSideEffects;
00035   
00036   InlineAsm(const FunctionType *Ty, const std::string &AsmString,
00037             const std::string &Constraints, bool hasSideEffects);
00038 public:
00039 
00040   /// InlineAsm::get - Return the the specified uniqued inline asm string.
00041   ///
00042   static InlineAsm *get(const FunctionType *Ty, const std::string &AsmString,
00043                         const std::string &Constraints, bool hasSideEffects);
00044   
00045   bool hasSideEffects() const { return HasSideEffects; }
00046   
00047   /// getType - InlineAsm's are always pointers.
00048   ///
00049   const PointerType *getType() const {
00050     return reinterpret_cast<const PointerType*>(Value::getType());
00051   }
00052   
00053   /// getFunctionType - InlineAsm's are always pointers to functions.
00054   ///
00055   const FunctionType *getFunctionType() const;
00056   
00057   const std::string &getAsmString() const { return AsmString; }
00058   const std::string &getConstraintString() const { return Constraints; }
00059 
00060   virtual void print(std::ostream &O) const { print(O, 0); }
00061   void print(std::ostream &OS, AssemblyAnnotationWriter *AAW) const;
00062 
00063   /// Verify - This static method can be used by the parser to check to see if
00064   /// the specified constraint string is legal for the type.  This returns true
00065   /// if legal, false if not.
00066   ///
00067   static bool Verify(const FunctionType *Ty, const std::string &Constraints);
00068 
00069   // Constraint String Parsing 
00070   enum ConstraintPrefix {
00071     isInput,            // 'x'
00072     isOutput,           // '=x'
00073     isClobber           // '~x'
00074   };
00075   
00076   struct ConstraintInfo {
00077     /// Type - The basic type of the constraint: input/output/clobber
00078     ///
00079     ConstraintPrefix Type;
00080     
00081     /// isEarlyClobber - "&": output operand writes result before inputs are all
00082     /// read.  This is only ever set for an output operand.
00083     bool isEarlyClobber; 
00084     
00085     /// isIndirectOutput - If this is true for an output constraint, the address
00086     /// to store the output result is passed as an operand to the call.
00087     bool isIndirectOutput;
00088     
00089     /// hasMatchingInput - This is set to true for an output constraint iff
00090     /// there is an input constraint that is required to match it (e.g. "0").
00091     bool hasMatchingInput;
00092     
00093     /// isCommutative - This is set to true for a constraint that is commutative
00094     /// with the next operand.
00095     bool isCommutative;
00096     
00097     /// Code - The constraint code, either the register name (in braces) or the
00098     /// constraint letter/number.
00099     std::vector<std::string> Codes;
00100     
00101     /// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
00102     /// fields in this structure.  If the constraint string is not understood,
00103     /// return true, otherwise return false.
00104     bool Parse(const std::string &Str, 
00105                std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar);
00106   };
00107   
00108   /// ParseConstraints - Split up the constraint string into the specific
00109   /// constraints and their prefixes.  If this returns an empty vector, and if
00110   /// the constraint string itself isn't empty, there was an error parsing.
00111   static std::vector<ConstraintInfo> 
00112     ParseConstraints(const std::string &ConstraintString);
00113   
00114   /// ParseConstraints - Parse the constraints of this inlineasm object, 
00115   /// returning them the same way that ParseConstraints(str) does.
00116   std::vector<ConstraintInfo> 
00117   ParseConstraints() const {
00118     return ParseConstraints(Constraints);
00119   }
00120   
00121   // Methods for support type inquiry through isa, cast, and dyn_cast:
00122   static inline bool classof(const InlineAsm *) { return true; }
00123   static inline bool classof(const Value *V) {
00124     return V->getValueType() == Value::InlineAsmVal;
00125   }
00126 };
00127 
00128 } // End llvm namespace
00129 
00130 #endif