/* Title:   SparcRegClassInfo.h    -*- C++ -*-
   Author:  Ruchira Sasanka
   Date:    Aug 20, 01
   Purpose: Contains the description of integer register class of Sparc
*/


#ifndef SPARC_REG_INFO_CLASS_H
#define SPARC_REG_INFO_CLASS_H

#include "llvm/Target/MachineRegInfo.h"
#include "llvm/CodeGen/IGNode.h"

//-----------------------------------------------------------------------------
// Integer Register Class
//-----------------------------------------------------------------------------

// Int register names in same order as enum in class SparcIntRegOrder

static const std::string IntRegNames[] =  {  
    "o0", "o1", "o2", "o3", "o4", "o5",       "o7",
    "l0", "l1", "l2", "l3", "l4", "l5", "l6", "l7",
    "i0", "i1", "i2", "i3", "i4", "i5",  
    "i6", "i7",
    "g0", "g1", "g2", "g3", "g4", "g5",  "g6", "g7", 
    "o6"
}; 



struct SparcIntRegOrder { 
  enum RegsInPrefOrder {   // colors possible for a LR (in preferred order)
     // --- following colors are volatile across function calls
     // %g0 can't be used for coloring - always 0
     o0, o1, o2, o3, o4, o5, o7,  // %o0-%o5, 

     // %o6 is sp, 
     // all %0's can get modified by a call

     // --- following colors are NON-volatile across function calls
     l0, l1, l2, l3, l4, l5, l6, l7,    //  %l0-%l7
     i0, i1, i2, i3, i4, i5,         // %i0-%i5: i's need not be preserved 
      
     // %i6 is the fp - so not allocated
     // %i7 is the ret address by convention - can be used for others

     // max # of colors reg coloring  can allocate (NumOfAvailRegs)

     // --- following colors are not available for allocation within this phase
     // --- but can appear for pre-colored ranges 

     i6, i7, g0,  g1, g2, g3, g4, g5, g6, g7, o6
     
     //*** NOTE: If we decide to use some %g regs, they are volatile
     // (see sparc64ABI)
     // Move the %g regs from the end of the enumeration to just above the
     // enumeration of %o0 (change StartOfAllRegs below)
     // change isRegVloatile method below
     // Also change IntRegNames above.
  };

  // max # of colors reg coloring  can allocate
  static unsigned int const NumOfAvailRegs = i6;

  static unsigned int const StartOfNonVolatileRegs = l0;
  static unsigned int const StartOfAllRegs = o0;
  static unsigned int const NumOfAllRegs = o6 + 1; 


  static const std::string getRegName(unsigned reg) {
    assert( reg < NumOfAllRegs );
    return IntRegNames[reg];
  }

};



struct SparcIntRegClass : public MachineRegClassInfo {
  SparcIntRegClass(unsigned ID) 
    : MachineRegClassInfo(ID, 
			  SparcIntRegOrder::NumOfAvailRegs,
			  SparcIntRegOrder::NumOfAllRegs) {  }

  void colorIGNode(IGNode *Node, bool IsColorUsedArr[]) const;

  inline bool isRegVolatile(int Reg) const {
    return (Reg < (int) SparcIntRegOrder::StartOfNonVolatileRegs); 
  }
};




//-----------------------------------------------------------------------------
// Float Register Class
//-----------------------------------------------------------------------------

static const std::string FloatRegNames[] = 
  {    
    "f0",  "f1",  "f2",  "f3",  "f4",  "f5",  "f6",  "f7",  "f8",  "f9", 
    "f10", "f11", "f12", "f13", "f14", "f15", "f16", "f17", "f18", "f19",
    "f20", "f21", "f22", "f23", "f24", "f25", "f26", "f27", "f28", "f29",
    "f30", "f31", "f32", "f33", "f34", "f35", "f36", "f37", "f38", "f39",
    "f40", "f41", "f42", "f43", "f44", "f45", "f46", "f47", "f48", "f49",
    "f50", "f51", "f52", "f53", "f54", "f55", "f56", "f57", "f58", "f59",
    "f60", "f61", "f62", "f63"
  };


class SparcFloatRegOrder{ 

 public:

  enum RegsInPrefOrder {

    f0, f1, f2, f3, f4, f5, f6, f7, f8, f9, 
    f10, f11, f12, f13, f14, f15, f16, f17, f18, f19,
    f20, f21, f22, f23, f24, f25, f26, f27, f28, f29,
    f30, f31, f32, f33, f34, f35, f36, f37, f38, f39,
    f40, f41, f42, f43, f44, f45, f46, f47, f48, f49,
    f50, f51, f52, f53, f54, f55, f56, f57, f58, f59,
    f60, f61, f62, f63

  };

  // there are 64 regs alltogether but only 32 regs can be allocated at
  // a time.

  static unsigned int const NumOfAvailRegs = 32;
  static unsigned int const NumOfAllRegs = 64;

  static unsigned int const StartOfNonVolatileRegs = f32;
  static unsigned int const StartOfAllRegs = f0;


  static const std::string getRegName(unsigned reg) {
    assert (reg < NumOfAllRegs);
    return FloatRegNames[reg];
  }
};



class SparcFloatRegClass : public MachineRegClassInfo {
  int findFloatColor(const LiveRange *LR, unsigned Start,
		     unsigned End, bool IsColorUsedArr[]) const;
public:
  SparcFloatRegClass(unsigned ID) 
    : MachineRegClassInfo(ID, 
			  SparcFloatRegOrder::NumOfAvailRegs,
			  SparcFloatRegOrder::NumOfAllRegs) {}

  void colorIGNode(IGNode *Node, bool IsColorUsedArr[]) const;

  // according to  Sparc 64 ABI, all %fp regs are volatile
  inline bool isRegVolatile(int Reg) const { return true; }
};




//-----------------------------------------------------------------------------
// Int CC Register Class
// Only one integer cc register is available. However, this register is
// referred to as %xcc when instructions like subcc are executed but 
// referred to as %ccr (i.e., %xcc + %icc") when this register is moved
// into an integer register using RD or WR instrcutions. So, two ids are
// allocated for two names.
//-----------------------------------------------------------------------------


static const std::string IntCCRegNames[] = {    
  "xcc",  "ccr"
};


struct  SparcIntCCRegOrder { 
  enum RegsInPrefOrder {
    xcc, ccr   // only one is available - see the note above
  };

  static const std::string getRegName(unsigned reg) {
    assert(reg < 2);
    return IntCCRegNames[reg];
  }
};



struct SparcIntCCRegClass : public MachineRegClassInfo {
  SparcIntCCRegClass(unsigned ID) 
    : MachineRegClassInfo(ID, 1, 2) {  }
  
  inline void colorIGNode(IGNode *Node, bool IsColorUsedArr[]) const {
    if (IsColorUsedArr[0])
      Node->getParentLR()->markForSpill();
    else
      Node->setColor(0);    // only one int cc reg is available
  }
  
  // according to  Sparc 64 ABI,  %ccr is volatile
  //
  inline bool isRegVolatile(int Reg) const { return true; }
};




//-----------------------------------------------------------------------------
// Float CC Register Class
// Only 4 Float CC registers are available
//-----------------------------------------------------------------------------

static const std::string FloatCCRegNames[] = {    
  "fcc0", "fcc1",  "fcc2",  "fcc3"
};

struct SparcFloatCCRegOrder{ 
  enum RegsInPrefOrder {
    fcc0, fcc1, fcc2, fcc3
  };

  static const std::string getRegName(unsigned reg) {
    assert (reg < 4);
    return FloatCCRegNames[reg];
  }
};

struct SparcFloatCCRegClass : public MachineRegClassInfo {
  SparcFloatCCRegClass(unsigned ID) 
    : MachineRegClassInfo(ID, 4, 4) {  }

  void colorIGNode(IGNode *Node, bool IsColorUsedArr[]) const {
    int c;
    for(c=0; c < 4  && IsColorUsedArr[c] ; ++c) ; // find unused color
    if (c < 4)
      Node->setColor(c);   
    else
      Node->getParentLR()->markForSpill();
  }
  
  // according to  Sparc 64 ABI, all %fp CC regs are volatile
  //
  inline bool isRegVolatile(int Reg) const { return true; }
};

#endif