utils/TableGen/CodeGenRegisters.h

   1 //===- CodeGenRegisters.h - Register and RegisterClass Info -----*- 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 file defines structures to encapsulate information gleaned from the
  11 // target register and register class definitions.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #ifndef CODEGEN_REGISTERS_H
  16 #define CODEGEN_REGISTERS_H
  17
  18 #include "llvm/CodeGen/ValueTypes.h"
  19 #include "llvm/ADT/DenseMap.h"
  20 #include <string>
  21 #include <vector>
  22 #include <set>
  23 #include <cstdlib>
  24
  25 namespace llvm {
  26   class Record;
  27
  28   /// CodeGenRegister - Represents a register definition.
  29   struct CodeGenRegister {
  30     Record *TheDef;
  31     const std::string &getName() const;
  32     unsigned EnumValue;
  33     unsigned CostPerUse;
  34     CodeGenRegister(Record *R);
  35   };
  36
  37
  38   struct CodeGenRegisterClass {
  39     Record *TheDef;
  40     std::string Namespace;
  41     std::vector<Record*> Elements;
  42     std::vector<MVT::SimpleValueType> VTs;
  43     unsigned SpillSize;
  44     unsigned SpillAlignment;
  45     int CopyCost;
  46     bool Allocatable;
  47     // Map SubRegIndex -> RegisterClass
  48     DenseMap<Record*,Record*> SubRegClasses;
  49     std::string MethodProtos, MethodBodies;
  50
  51     const std::string &getName() const;
  52     const std::vector<MVT::SimpleValueType> &getValueTypes() const {return VTs;}
  53     unsigned getNumValueTypes() const { return VTs.size(); }
  54
  55     MVT::SimpleValueType getValueTypeNum(unsigned VTNum) const {
  56       if (VTNum < VTs.size())
  57         return VTs[VTNum];
  58       assert(0 && "VTNum greater than number of ValueTypes in RegClass!");
  59       abort();
  60     }
  61
  62     bool containsRegister(Record *R) const {
  63       for (unsigned i = 0, e = Elements.size(); i != e; ++i)
  64         if (Elements[i] == R) return true;
  65       return false;
  66     }
  67
  68     // Returns true if RC is a strict subclass.
  69     // RC is a sub-class of this class if it is a valid replacement for any
  70     // instruction operand where a register of this classis required. It must
  71     // satisfy these conditions:
  72     //
  73     // 1. All RC registers are also in this.
  74     // 2. The RC spill size must not be smaller than our spill size.
  75     // 3. RC spill alignment must be compatible with ours.
  76     //
  77     bool hasSubClass(const CodeGenRegisterClass *RC) const {
  78
  79       if (RC->Elements.size() > Elements.size() ||
  80           (SpillAlignment && RC->SpillAlignment % SpillAlignment) ||
  81           SpillSize > RC->SpillSize)
  82         return false;
  83
  84       std::set<Record*> RegSet;
  85       for (unsigned i = 0, e = Elements.size(); i != e; ++i) {
  86         Record *Reg = Elements[i];
  87         RegSet.insert(Reg);
  88       }
  89
  90       for (unsigned i = 0, e = RC->Elements.size(); i != e; ++i) {
  91         Record *Reg = RC->Elements[i];
  92         if (!RegSet.count(Reg))
  93           return false;
  94       }
  95
  96       return true;
  97     }
  98
  99     CodeGenRegisterClass(Record *R);
 100   };
 101 }
 102
 103 #endif