llvm/lib/Target/Sparc/SparcRegInfo.cpp

#include "llvm/Target/Sparc.h"
#include "SparcInternals.h"
#include "llvm/Method.h"
#include "llvm/iTerminators.h"
#include "llvm/iOther.h"
#include "llvm/CodeGen/InstrScheduling.h"
#include "llvm/CodeGen/InstrSelection.h"

#include "llvm/Analysis/LiveVar/MethodLiveVarInfo.h"
#include "llvm/CodeGen/PhyRegAlloc.h"




//---------------------------------------------------------------------------
// UltraSparcRegInfo
//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
// Suggests a register for the ret address in the RET machine instruction
//---------------------------------------------------------------------------
void UltraSparcRegInfo::suggestReg4RetAddr(const MachineInstr * RetMI, 
					   LiveRangeInfo& LRI) const {

  assert( (RetMI->getNumOperands() == 2) && "RETURN must have 2 operands");
  MachineOperand & MO  = ( MachineOperand &) RetMI->getOperand(0);

  MO.setRegForValue( getUnifiedRegNum( IntRegClassID, SparcIntRegOrder::i7) );


  // TODO (Optimize): 
  //Instead of setting the color, we can suggest one. In that case,
  // we have to test later whether it received the suggested color.
  // In that case, a LR has to be created at the start of method.
  // It has to be done as follows (remove the setRegVal above):

  /*
  const Value *RetAddrVal = MO.getVRegValue();

  assert( RetAddrVal && "LR for ret address must be created at start");

  LiveRange * RetAddrLR = LRI.getLiveRangeForValue( RetAddrVal);  
  RetAddrLR->setSuggestedColor(getUnifiedRegNum( IntRegClassID, 
  SparcIntRegOrdr::i7) );
  */


}


//---------------------------------------------------------------------------
// Suggests a register for the ret address in the JMPL/CALL machine instr
//---------------------------------------------------------------------------
void UltraSparcRegInfo::suggestReg4CallAddr(const MachineInstr * CallMI) const
{

  assert( (CallMI->getNumOperands() == 3) && "JMPL must have 3 operands");

  // directly set color since the LR of ret address (if there were one) 
  // will not extend after the call instr

  MachineOperand & MO  = ( MachineOperand &) CallMI->getOperand(2);
  MO.setRegForValue( getUnifiedRegNum( IntRegClassID,SparcIntRegOrder::o7) );

}




//---------------------------------------------------------------------------
//  This method will suggest colors to incoming args to a method. 
//  If the arg is passed on stack due to the lack of regs, NOTHING will be
//  done - it will be colored (or spilled) as a normal value.
//---------------------------------------------------------------------------

void UltraSparcRegInfo::suggestRegs4MethodArgs(const Method *const Meth, 
					       LiveRangeInfo& LRI) const 
{

                                                 // get the argument list
  const Method::ArgumentListType& ArgList = Meth->getArgumentList();           
                                                 // get an iterator to arg list
  Method::ArgumentListType::const_iterator ArgIt = ArgList.begin(); 

  // for each argument
  for( unsigned argNo=0; ArgIt != ArgList.end() ; ++ArgIt, ++argNo) {    

    // get the LR of arg
    LiveRange *const LR = LRI.getLiveRangeForValue((const Value *) *ArgIt); 
    assert( LR && "No live range found for method arg");

    unsigned RegType = getRegType( LR );


    // if the arg is in int class - allocate a reg for an int arg
    if( RegType == IntRegType ) {

      if( argNo < NumOfIntArgRegs) {
	LR->setSuggestedColor( SparcIntRegOrder::i0 + argNo );

      }
  
      else {
	// Do NOTHING as this will be colored as a normal value.
	if (DEBUG_RA) cerr << " Int Regr not suggested for method arg\n";
      }
     
    }
    else if( RegType==FPSingleRegType && (argNo*2+1) < NumOfFloatArgRegs) 
      LR->setSuggestedColor( SparcFloatRegOrder::f0 + (argNo * 2 + 1) );
    
 
    else if( RegType == FPDoubleRegType && (argNo*2) < NumOfFloatArgRegs) 
      LR->setSuggestedColor( SparcFloatRegOrder::f0 + (argNo * 2) ); 
    

  }
  
}

//---------------------------------------------------------------------------
// 
//---------------------------------------------------------------------------

void UltraSparcRegInfo::colorMethodArgs(const Method *const Meth, 
					LiveRangeInfo& LRI,
					AddedInstrns *const FirstAI) const {

                                                 // get the argument list
  const Method::ArgumentListType& ArgList = Meth->getArgumentList();           
                                                 // get an iterator to arg list
  Method::ArgumentListType::const_iterator ArgIt = ArgList.begin(); 

  MachineInstr *AdMI;


  // for each argument
  for( unsigned argNo=0; ArgIt != ArgList.end() ; ++ArgIt, ++argNo) {    

    // get the LR of arg
    LiveRange *const LR = LRI.getLiveRangeForValue((const Value *) *ArgIt); 
    assert( LR && "No live range found for method arg");


    // if the LR received the suggested color, NOTHING to be done
    if( LR->hasSuggestedColor() && LR->hasColor() )
      if( LR->getSuggestedColor() == LR->getColor() )
	continue;

    // We are here because the LR did not have a suggested 
    // color or did not receive the suggested color. Now handle
    // individual cases.


    unsigned RegType = getRegType( LR );
    unsigned RegClassID = (LR->getRegClass())->getID();


    // find whether this argument is coming in a register (if not, on stack)

    bool isArgInReg = false;
    unsigned UniArgReg = InvalidRegNum;

    if( (RegType== IntRegType && argNo <  NumOfIntArgRegs)) {
      isArgInReg = true;
      UniArgReg = getUnifiedRegNum( RegClassID, SparcIntRegOrder::o0 + argNo );
    }
    else if(RegType == FPSingleRegType && argNo < NumOfFloatArgRegs)  { 
      isArgInReg = true;
      UniArgReg = getUnifiedRegNum( RegClassID, 
				    SparcFloatRegOrder::f0 + argNo*2 + 1 ) ;
    }
    else if(RegType == FPDoubleRegType && argNo < NumOfFloatArgRegs)  { 
      isArgInReg = true;
      UniArgReg = getUnifiedRegNum(RegClassID, SparcFloatRegOrder::f0+argNo*2);
    }

    
    if( LR->hasColor() ) {

      // We are here because the LR did not have a suggested 
      // color or did not receive the suggested color but LR got a register.
      // Now we have to copy %ix reg (or stack pos of arg) 
      // to the register it was colored with.

      unsigned UniLRReg = getUnifiedRegNum(  RegClassID, LR->getColor() );
       
      // if the arg is coming in a register and goes into a register
      if( isArgInReg ) 
	AdMI = cpReg2RegMI(UniArgReg, UniLRReg, RegType );

      else 
	assert(0 && "TODO: Color an Incoming arg on stack");

      // Now add the instruction
      FirstAI->InstrnsBefore.push_back( AdMI );

    }

    else {                                // LR is not colored (i.e., spilled)
      
      assert(0 && "TODO: Color a spilled arg ");
      
    }


  }  // for each incoming argument

}




//---------------------------------------------------------------------------
// This method is called before graph coloring to suggest colors to the
// outgoing call args and the return value of the call.
//---------------------------------------------------------------------------
void UltraSparcRegInfo::suggestRegs4CallArgs(const MachineInstr *const CallMI, 
					     LiveRangeInfo& LRI,
					     vector<RegClass *> RCList) const {

  assert ( (UltraSparcInfo->getInstrInfo()).isCall(CallMI->getOpCode()) );

  suggestReg4CallAddr(CallMI);


  // First color the return value of the call instruction. The return value
  // will be in %o0 if the value is an integer type, or in %f0 if the 
  // value is a float type.

  // the return value cannot have a LR in machine instruction since it is
  // only defined by the call instruction

  // if type is not void,  create a new live range and set its 
  // register class and add to LRI

  unsigned NumOfImpRefs =  CallMI->getNumImplicitRefs();
  unsigned NumOfCallArgs = NumOfImpRefs;  // assume all implicits are args

  if(  NumOfImpRefs > 0 ) {

    // The last implicit operand is the return value of a call
    if(  CallMI->implicitRefIsDefined(NumOfImpRefs-1) ) {

      const Value *RetVal = CallMI->getImplicitRef(NumOfImpRefs-1); 

      assert( (! LRI.getLiveRangeForValue( RetVal ) ) && 
	      "LR for ret Value of call already definded!");


      // create a new LR for the return value

      LiveRange * RetValLR = new LiveRange();  
      RetValLR->add( RetVal );
      unsigned RegClassID = getRegClassIDOfValue( RetVal );
      RetValLR->setRegClass( RCList[RegClassID] );
      LRI.addLRToMap( RetVal, RetValLR);

      // now suggest a register depending on the register class of ret arg

      if( RegClassID == IntRegClassID ) 
	RetValLR->setSuggestedColor(SparcIntRegOrder::o0);
      else if (RegClassID == FloatRegClassID ) 
	RetValLR->setSuggestedColor(SparcFloatRegOrder::f0 );
      else assert( 0 && "Unknown reg class for return value of call\n");

      // the last imp ref is the def, so one less arg
      NumOfCallArgs--; 

    }

  }

  // Now suggest colors for arguments (operands) of the call instruction.
  // Colors are suggested only if the arg number is smaller than the
  // the number of registers allocated for argument passing.

  
  // go thru call args - implicit operands of the call MI
  for(unsigned argNo=0, i=0; i < NumOfCallArgs; ++i, ++argNo ) {

    const Value *CallArg = CallMI->getImplicitRef(i);
    
    // get the LR of call operand (parameter)
    LiveRange *const LR = LRI.getLiveRangeForValue(CallArg); 

    // not possible to have a null LR since all args (even consts)  
    // must be defined before
    if( !LR ) {          
      if( DEBUG_RA) {
	cerr << " ERROR: In call instr, no LR for arg:  " ;
	printValue(CallArg); cerr << endl;
      }
      assert(0 && "NO LR for call arg");  
      // continue;
    }
    
    unsigned RegType = getRegType( LR );

    // if the arg is in int class - allocate a reg for an int arg
    if( RegType == IntRegType ) {

      if( argNo < NumOfIntArgRegs) 
	LR->setSuggestedColor( SparcIntRegOrder::o0 + argNo );

      else if (DEBUG_RA) 
	// Do NOTHING as this will be colored as a normal value.
	cerr << " Regr not suggested for int call arg" << endl;
      
    }
    else if( RegType == FPSingleRegType &&  (argNo*2 +1)< NumOfFloatArgRegs) 
      LR->setSuggestedColor( SparcFloatRegOrder::f0 + (argNo * 2 + 1) );
    
 
    else if( RegType == FPDoubleRegType && (argNo*2) < NumOfFloatArgRegs) 
      LR->setSuggestedColor( SparcFloatRegOrder::f0 + (argNo * 2) ); 
    

  } // for all call arguments

}


//---------------------------------------------------------------------------
// After graph coloring, we have call this method to see whehter the return
// value and the call args received the correct colors. If not, we have
// to instert copy instructions.
//---------------------------------------------------------------------------


void UltraSparcRegInfo::colorCallArgs(const MachineInstr *const CallMI,
				      LiveRangeInfo& LRI,
				      AddedInstrns *const CallAI) const {


  assert ( (UltraSparcInfo->getInstrInfo()).isCall(CallMI->getOpCode()) );

  // First color the return value of the call.
  // If there is a LR for the return value, it means this
  // method returns a value
  
  MachineInstr *AdMI;

  unsigned NumOfImpRefs =  CallMI->getNumImplicitRefs();
  unsigned NumOfCallArgs = NumOfImpRefs;  // assume all implicits are args

  if(  NumOfImpRefs > 0 ) {

    // The last implicit operand is the return value of a call
    if(  CallMI->implicitRefIsDefined(NumOfImpRefs-1) ) {

      // one less call arg since last implicit ref is the return value
      NumOfCallArgs--;

      // find the return value and its LR
      const Value *RetVal = CallMI->getImplicitRef(NumOfImpRefs-1); 
      LiveRange * RetValLR = LRI.getLiveRangeForValue( RetVal );

      if( !RetValLR ) {
	cerr << "\nNo LR for:";
	printValue( RetVal );
	cerr << endl;
	assert( RetValLR && "ERR:No LR for non-void return value");
	//return;
      }

      bool recvSugColor = false;

      if( RetValLR->hasSuggestedColor() && RetValLR->hasColor() )
	if( RetValLR->getSuggestedColor() == RetValLR->getColor())
	  recvSugColor = true;

      // if we didn't receive the suggested color for some reason, 
      // put copy instruction

      if( !recvSugColor ) {

	if( RetValLR->hasColor() ) {

	  unsigned RegType = getRegType( RetValLR );
	  unsigned RegClassID = (RetValLR->getRegClass())->getID();

	  unsigned 
	    UniRetLRReg=getUnifiedRegNum(RegClassID,RetValLR->getColor());
	  unsigned UniRetReg = InvalidRegNum;

	  // find where we receive the return value depending on
	  // register class
	    
	  if(RegClassID == IntRegClassID)
	    UniRetReg = getUnifiedRegNum( RegClassID, SparcIntRegOrder::o0);
	  else if(RegClassID == FloatRegClassID)
	    UniRetReg = getUnifiedRegNum( RegClassID, SparcFloatRegOrder::f0);


	  AdMI = cpReg2RegMI(UniRetLRReg, UniRetReg, RegType ); 	
	  CallAI->InstrnsAfter.push_back( AdMI );
      
	
	} // if LR has color
	else {
	
	  assert(0 && "LR of return value is splilled");
	}
      

      } // the LR didn't receive the suggested color  
    
    } // if there a return value

  } // if there is an implicit arg for a return value
  


  // Now color all args of the call instruction


  for(unsigned argNo=0, i=0; i < NumOfCallArgs; ++i, ++argNo ) {

    const Value *CallArg = CallMI->getImplicitRef(i);

    // get the LR of call operand (parameter)
    LiveRange *const LR = LRI.getLiveRangeForValue(CallArg); 

    unsigned RegType = getRegType( CallArg );
    unsigned RegClassID =  getRegClassIDOfValue( CallArg);
    
    // find whether this argument is coming in a register (if not, on stack)

    bool isArgInReg = false;
    unsigned UniArgReg = InvalidRegNum;

    if( (RegType== IntRegType && argNo <  NumOfIntArgRegs)) {
      isArgInReg = true;
      UniArgReg = getUnifiedRegNum(RegClassID, SparcIntRegOrder::o0 + argNo );
    }
    else if(RegType == FPSingleRegType && argNo < NumOfFloatArgRegs)  { 
      isArgInReg = true;
      UniArgReg = getUnifiedRegNum(RegClassID, 
				   SparcFloatRegOrder::f0 + (argNo*2 + 1) );
    }
    else if(RegType == FPDoubleRegType && argNo < NumOfFloatArgRegs)  { 
      isArgInReg = true;
      UniArgReg = getUnifiedRegNum(RegClassID, SparcFloatRegOrder::f0+argNo*2);
    }


    // not possible to have a null LR since all args (even consts)  
    // must be defined before
    if( !LR ) {          
      if( DEBUG_RA) {
	cerr << " ERROR: In call instr, no LR for arg:  " ;
	printValue(CallArg); cerr << endl;
      }
      assert(0 && "NO LR for call arg");  
      // continue;
    }


    // if the LR received the suggested color, NOTHING to do

    if( LR->hasSuggestedColor() && LR->hasColor() )
      if( LR->getSuggestedColor() == LR->getColor() )
	continue;
	
    
    if( LR->hasColor() ) {

      // We are here because though the LR is allocated a register, it
      // was not allocated the suggested register. So, we have to copy %ix reg 
      // (or stack pos of arg) to the register it was colored with


      unsigned UniLRReg = getUnifiedRegNum( RegClassID,  LR->getColor() );

      if( isArgInReg ) 
	AdMI = cpReg2RegMI(UniLRReg, UniArgReg, RegType );

      else 
	assert(0 && "TODO: Push an outgoing arg on stack");

      // Now add the instruction
      CallAI->InstrnsBefore.push_back( AdMI );

    }

    else {                                // LR is not colored (i.e., spilled)
      
      assert(0 && "TODO: Copy a spilled call arg to an output reg ");
      
    }

  }  // for each parameter in call instruction

}

//---------------------------------------------------------------------------
// This method is called for an LLVM return instruction to identify which
// values will be returned from this method and to suggest colors.
//---------------------------------------------------------------------------
void UltraSparcRegInfo::suggestReg4RetValue(const MachineInstr *const RetMI, 
					     LiveRangeInfo& LRI) const {

  assert( (UltraSparcInfo->getInstrInfo()).isReturn( RetMI->getOpCode() ) );

  
  suggestReg4RetAddr(RetMI, LRI);

  // if there is an implicit ref, that has to be the ret value
  if(  RetMI->getNumImplicitRefs() > 0 ) {

    // The first implicit operand is the return value of a return instr
    const Value *RetVal =  RetMI->getImplicitRef(0);

    MachineInstr *AdMI;
    LiveRange *const LR = LRI.getLiveRangeForValue( RetVal ); 

    if( !LR ) {
     cerr << "\nNo LR for:";
     printValue( RetVal );
     cerr << endl;
     assert( LR && "No LR for return value of non-void method");
     //return;
   }

    unsigned RegClassID = (LR->getRegClass())->getID();
      
    if( RegClassID == IntRegClassID ) 
      LR->setSuggestedColor(SparcIntRegOrder::i0);
    
    else if ( RegClassID == FloatRegClassID ) 
      LR->setSuggestedColor(SparcFloatRegOrder::f0);
      
  }

}

//---------------------------------------------------------------------------

//---------------------------------------------------------------------------
void UltraSparcRegInfo::colorRetValue(const  MachineInstr *const RetMI, 
				      LiveRangeInfo& LRI,
				      AddedInstrns *const RetAI) const {

  assert( (UltraSparcInfo->getInstrInfo()).isReturn( RetMI->getOpCode() ) );

  // if there is an implicit ref, that has to be the ret value
  if(  RetMI->getNumImplicitRefs() > 0 ) {

    // The first implicit operand is the return value of a return instr
    const Value *RetVal =  RetMI->getImplicitRef(0);

    MachineInstr *AdMI;
    LiveRange *const LR = LRI.getLiveRangeForValue( RetVal ); 

    if( ! LR ) {
	cerr << "\nNo LR for:";
	printValue( RetVal );
	cerr << endl;
	// assert( LR && "No LR for return value of non-void method");
	return;
   }

    unsigned RegClassID =  getRegClassIDOfValue(RetVal);
    unsigned RegType = getRegType( RetVal );
    unsigned UniRetReg = InvalidRegNum;
    
    if(RegClassID == IntRegClassID)
      UniRetReg = getUnifiedRegNum( RegClassID, SparcIntRegOrder::i0 );
    else if(RegClassID == FloatRegClassID)
      UniRetReg = getUnifiedRegNum( RegClassID, SparcFloatRegOrder::f0);
     


    // if the LR received the suggested color, NOTHING to do

    if( LR->hasSuggestedColor() && LR->hasColor() )
      if( LR->getSuggestedColor() == LR->getColor() )
	return;

    if( LR->hasColor() ) {

      // We are here because the LR was allocted a regiter, but NOT
      // the correct register.

      // copy the LR of retun value to i0 or f0

      unsigned UniLRReg =getUnifiedRegNum( RegClassID, LR->getColor());

      if(RegClassID == IntRegClassID)
	UniRetReg = getUnifiedRegNum( RegClassID, SparcIntRegOrder::i0);
      else if(RegClassID == FloatRegClassID)
	UniRetReg = getUnifiedRegNum( RegClassID, SparcFloatRegOrder::f0);
      
      AdMI = cpReg2RegMI( UniLRReg, UniRetReg, RegType); 

    }
    else 
      assert(0 && "TODO: Copy the return value from stack\n");

  } // if there is a return value

}


//---------------------------------------------------------------------------
// Copy from a register to register. Register number must be the unified
// register number
//---------------------------------------------------------------------------


MachineInstr * UltraSparcRegInfo::cpReg2RegMI(const unsigned SrcReg, 
					      const unsigned DestReg,
					      const int RegType) const {

  assert( (SrcReg != InvalidRegNum) && (DestReg != InvalidRegNum) &&
	  "Invalid Register");
  
  MachineInstr * MI = NULL;

  switch( RegType ) {
    
  case IntRegType:
    MI = new MachineInstr(ADD, 3);
    MI->SetMachineOperand(0, SrcReg, false);
    MI->SetMachineOperand(1, SparcIntRegOrder::g0, false);
    MI->SetMachineOperand(2, DestReg, true);
    break;

  case FPSingleRegType:
    MI = new MachineInstr(FMOVS, 2);
    MI->SetMachineOperand(0, SrcReg, false);
    MI->SetMachineOperand(1, DestReg, true);
    break;

  case FPDoubleRegType:
    MI = new MachineInstr(FMOVD, 2);
    MI->SetMachineOperand(0, SrcReg, false);    
    MI->SetMachineOperand(1, DestReg, true);
    break;

  default:
    assert(0 && "Unknow RegType");
  }

  return MI;
}




//---------------------------------------------------------------------------
// Only  constant/label values are accepted.
// ***This code is temporary ***
//---------------------------------------------------------------------------


MachineInstr * UltraSparcRegInfo::cpValue2RegMI(Value * Val, 
						const unsigned DestReg,
						const int RegType) const {

  assert( (DestReg != InvalidRegNum) && "Invalid Register");

  /*
  unsigned MReg;
  int64_t Imm;

  MachineOperand::MachineOperandType MOTypeInt = 
    ChooseRegOrImmed(Val, ADD,  *UltraSparcInfo, true, MReg, Imm);
  */

  MachineOperand::MachineOperandType MOType;

  switch( Val->getValueType() ) {

  case Value::ConstantVal: 
  case Value::GlobalVariableVal:
    MOType = MachineOperand:: MO_UnextendedImmed;  // TODO**** correct???
    break;

  case Value::BasicBlockVal:
  case Value::MethodVal:
    MOType = MachineOperand::MO_PCRelativeDisp;
    break;

  default:
    cerr << "Value Type: " << Val->getValueType() << endl;
    assert(0 && "Unknown val type - Only constants/globals/labels are valid");
  }



  MachineInstr * MI = NULL;

  switch( RegType ) {
    
  case IntRegType:
    MI = new MachineInstr(ADD);
    MI->SetMachineOperand(0, MOType, Val, false);
    MI->SetMachineOperand(1, SparcIntRegOrder::g0, false);
    MI->SetMachineOperand(2, DestReg, true);
    break;

  case FPSingleRegType:
    assert(0 && "FP const move not yet implemented");
    MI = new MachineInstr(FMOVS);
    MI->SetMachineOperand(0, MachineOperand::MO_SignExtendedImmed, Val, false);
    MI->SetMachineOperand(1, DestReg, true);
    break;

  case FPDoubleRegType:    
    assert(0 && "FP const move not yet implemented");
    MI = new MachineInstr(FMOVD);
    MI->SetMachineOperand(0, MachineOperand::MO_SignExtendedImmed, Val, false);
    MI->SetMachineOperand(1, DestReg, true);
    break;

  default:
    assert(0 && "Unknow RegType");
  }

  return MI;
}







//---------------------------------------------------------------------------
// Print the register assigned to a LR
//---------------------------------------------------------------------------

void UltraSparcRegInfo::printReg(const LiveRange *const LR) {

  unsigned RegClassID = (LR->getRegClass())->getID();

  cerr << " *Node " << (LR->getUserIGNode())->getIndex();

  if( ! LR->hasColor() ) {
    cerr << " - could not find a color" << endl;
    return;
  }
  
  // if a color is found

  cerr << " colored with color "<< LR->getColor();

  if( RegClassID == IntRegClassID ) {

    cerr<< " [" << SparcIntRegOrder::getRegName(LR->getColor()) ;
    cerr << "]" << endl;
  }
  else if ( RegClassID == FloatRegClassID) {
    cerr << "[" << SparcFloatRegOrder::getRegName(LR->getColor());
    if( LR->getTypeID() == Type::DoubleTyID )
      cerr << "+" << SparcFloatRegOrder::getRegName(LR->getColor()+1);
    cerr << "]" << endl;
  }
}