armcommon_iacxl10_2004_3_16.cpp

自己编写的ARM处理器的指令集仿真

#include "armia_IAcxl10_2004_3_16.h"
#include <iostream.h>

void ARMISS_stru::set_decoder_stru(UNL instr)
{
          common_dec   = instr;
          ARM_type0    = instr;
          ARM_type1    = instr;
          ARM_type2    = instr;
          ARM_type3    = instr;
          ARM_type4    = instr;
          ARM_type5    = instr;
          ARM_type6    = instr;
          ARM_type7    = instr;            
          //ins[0]       = instr;
        
}//设置每一个译码结构，当程序进行译码前需要调用此函数以分离出指令中的各位信息；

void ARMISS_stru::Thu_set_decode_stru(UNL instr)
{
          Thu_type1  = instr;
          Thu_type2  = instr;
          Thu_type3  = instr;
          Thu_type4  = instr;
          Thu_type5  = instr;
          Thu_type6  = instr;
          Thu_type7  = instr;
          Thu_type8  = instr;
          Thu_common = instr;
}//set each Thumb decode struct;

void ARMISS_stru::barrel_shifter_imm(int shift_mod, int shiftamount, long shift_oper)
{
         switch(shift_mod)
         {
            case 0:   if( shiftamount == 0 )
                         {
                            shifter.operand   = shift_oper;
                            shifter.carry_out = CPSR.C;
                         }
                      else 
                         {
                            shifter.operand   = shift_oper << shiftamount;
                            shifter.carry_out = shift_oper >> ( 32 - shiftamount );
                         }
                      break;//Logical Shift Left by immediate - LSL;
           case 1:    if ( shiftamount == 0 )
                         {
                            shifter.operand   = 0;
                            shifter.carry_out = shift_oper >> 31;
                         }
                      else 
                         {
                            shifter.operand   = (unsigned long)shift_oper >> shiftamount;
                            shifter.carry_out = shift_oper >> (shiftamount - 1 );
                         }
                      break;//Logical Shift Right by immediate - LSR;
          case 2:     if( shiftamount == 0 )
                        if ( (shift_oper >> 31 ) == 0 )
                         {
                            shifter.operand   = 0;
                            shifter.carry_out = shift_oper >> 31;
                         }
                        else
                         {
                            shifter.operand   = 0xffffffff;
                            shifter.carry_out = shift_oper >> 31;
                         }
                      else
                         {
                            shifter.operand   = shift_oper >> shiftamount; // shao 2004-2-5 (unsigned long)shift_oper >> shiftamount;
                            shifter.carry_out = shift_oper >> (shiftamount - 1);
                         }
                       break;//Airthmetic Shift Right by immediate - ASR;
           case 3:    if( shiftamount == 0 )
                        {
                            shifter.operand   = (shift_oper >> 1 ) || CPSR.C;
                            shifter.carry_out = shift_oper;
                        }
                      else 
                        {
                            long  temp;
                                                     
                            shifter.operand = shift_oper;                       
                            for(int i=0; i<shiftamount;i++)
                              {
                                     temp            = shifter.operand & 0x1;
                                     temp            = temp << 31;
                                     shifter.operand = shifter.operand >> 1;
                                     shifter.operand = (shifter.operand & 0x7fffffff) + temp;
                              }
                          }
                      break;//Rotate right by immediate;
           defaults:  break;
        }
       
}// 完成移位操作，这里移位的位数由指令中的立即数给出；

void ARMISS_stru::barrel_shifter_reg(int mod,long amount,long oper)
{
             switch(mod)
             {
                case 0:   if( amount == 0 )
                           {
                               shifter.operand   = oper;
                               shifter.carry_out = CPSR.C;
                           }
                          else if( amount < 32 )
                           {
                               shifter.operand   = (unsigned long)oper << amount;
                               shifter.carry_out = oper >> (32 - amount);
                           }
                          else if( amount == 32 )
                           {
                               shifter.operand   = 0;
                               shifter.carry_out = oper;
                           }
                          else 
                           {
                               shifter.operand   = 0;
                               shifter.carry_out = 0;
                           }
                          break;//LSL - Logical shift left by register;
                 case 1:  if( amount == 0 )
                           {
                               shifter.operand   = oper;
                               shifter.carry_out = CPSR.C;
                           }
                          else if( amount < 32 )
                           {
                               shifter.operand   = (unsigned long)oper >> amount;
                               shifter.carry_out = oper >> (amount - 1);
                           }
                          else if( amount == 32)
                           {
                               shifter.operand   = 0;
                               shifter.carry_out = oper >> 31;
                           }
                          else 
                           {
                               shifter.operand   = 0;
                               shifter.carry_out = 0;
                           }
                          break;//LSR - Logical Shift Right by register;
               case 2:    if( amount == 0 )
                           {
                                shifter.operand   = oper;
                                shifter.carry_out = CPSR.C;
                           }
                          else if( amount < 32 )
                           {
                                shifter.operand   = oper >> amount;
                                shifter.carry_out = oper >> (amount - 1);
                           }
                          else 
                           {  
                                if( ( oper >> 31 ) == 0 )
                                  {
                                       shifter.operand    = 0;
                                       shifter.carry_out  = 0;
                                  }
                                else 
                                  {
                                       shifter.operand    = 0xffffffff;
                                       shifter.carry_out  = 1;
                                  }
                            }
                           break;//ASL - Arithmatic shift Left by register;
                case 3:   if( amount == 0 )
                           { 
                                       shifter.operand    = oper;
                                       shifter.carry_out  = CPSR.C;
                           }
                          else if( ( amount & 0x1f ) == 0 )
                                {
                                       shifter.operand    = 0;
                                       shifter.carry_out  = oper >> 31;
                                }
                          else 
                                {
                                       long tamount,temp;
                                       
                                       tamount          = ( amount & 0x1f );
                                       shifter.operand  = oper;
                                       for( int i=0; i<tamount; i++)
                                          {
                                             temp             = shifter.operand & 0x1;
                                             temp             = temp << 31;
                                             shifter.operand  = shifter.operand >> 1;
                                             shifter.operand  = (shifter.operand & 0x7fffffff) + temp;
                                          }
                                       shifter.carry_out = oper >> ( tamount - 1 );
                                }
                          break;//循环右移;
                defaults: break;
           
            }  
                         
                                
}//同上，移位位数通过指令中指出的寄存器号中的内容给出；

void ARMISS_stru::barrel_shifter_rotate_imm(int rotate,long imm)
{
         long       temp;
         bit32_stru bit;
        
         shifter.operand  = imm;
         for( int i=0; i<(2*rotate); i++)
          {
            temp             = shifter.operand & 0x1;
            temp             = temp << 31;
            shifter.operand  = shifter.operand >> 1;
            shifter.operand  = (shifter.operand & 0x7fffffff) + temp;
          }
        bit = shifter.operand;
        if( rotate == 0 ) 
            shifter.carry_out = CPSR.C;
        else
            shifter.carry_out = bit[31];
}//立即数的循环移位;

UNL& ARMISS_stru::getreg(int i)
{ 
       switch( CPSR.M )
        {
           case 16: return r_gen[i];//User mode; 
           case 17: if( ( i > 7 ) && ( i < 15 ) )
                          return r_fiq[i];
                    else  
                          return r_gen[i];//Fast interrupt mode;
                    
           case 18: if( ( i == 13 ) || ( i == 14 ) )
                          return r_irq[i - 13];
                    else
                          return r_gen[i];//Normal interrupt mode;
           case 19: if( ( i == 13 ) || ( i == 14 ) )
                          return r_svc[i - 13];
                    else
                          return r_gen[i];//Supervisor mode;
           case 23: if( ( i == 13 ) || ( i == 14 ) )
                          return r_abt[i - 13];
                    else
                          return r_gen[i];//Abort mode;
           case 27: if( ( i == 13 ) || ( i == 14 ) )
                          return r_und[i - 13];
                    else
                          return r_gen[i];//Undeifned abort mode;
           case 31: return r_gen[i];//System mode;
        }
                    
}//函数可以返回对一个寄存器的引用，寄存器可根据当前所处的模式来决定;

UNL ARMISS_stru::getregd(int i)
{
       switch( CPSR.M )
        {
           case 16: return r_gen[i];//User mode;
           case 17: if( ( i > 7 ) && ( i < 15 ) )
                          return r_fiq[i];
                    else  
                          return r_gen[i];//Fast interrrupt mode;
                    
           case 18: if( ( i == 13 ) || ( i == 14 ) )
                          return r_irq[i - 13];
                    else
                          return r_gen[i];//Normal interrrupt mode;
           case 19: if( ( i == 13 ) || ( i == 14 ) )
                          return r_svc[i - 13];
                    else
                          return r_gen[i];//Supervisor mode;
           case 23: if( ( i == 13 ) || ( i == 14 ) )
                          return r_abt[i - 13];
                    else
                          return r_gen[i];//Abort mode;
           case 27: if( ( i == 13 ) || ( i == 14 ) )
                          return r_und[i - 13];
                    else
                          return r_gen[i];//Undefined mode;
           case 31: return r_gen[i];//System mode;
        }
}//返回当前模式下某一个寄存器的值;

int ARMISS_stru::getid()
{
      switch( CPSR.M )
     {
       case 17: return fiq;
       case 18: return irq;
       case 19: return svc;
       case 23: return abt;
       case 27: return und;
       default: return -1;
     }
}//返回当前模式的预定义ID; 

void ARMISS_stru::Addressing_mod1(int flags)
{
    ARM_type0_stru&  tmp0 = ARM_type0;
    ARM_type1_stru&  tmp1 = ARM_type1;
    bit32_stru       bit;
    UNL              shiftm,shiftoper;

    if( tmp0.Rs == PC ) shiftm     = getregd( tmp0.Rs ) + 8;
    else                shiftm     = getregd( tmp0.Rs );
    if( tmp0.Rm == PC ) shiftoper  = getregd( tmp0.Rm ) + 8;
    else                shiftoper  = getregd( tmp0.Rm );

    switch( flags )
  {
    case 0 : bit = tmp1.imm;
             bit.rotate( tmp1.rotate*2 );
             shifter.operand = bit;
             if( tmp1.rotate == 0 )
               shifter.carry_out = CPSR.C;
             else
               shifter.carry_out = bit[31];
             break;
    case 1 : barrel_shifter_reg(tmp0.shift,shiftm,shiftoper);
             break;
    case 2 : barrel_shifter_imm(tmp0.shift,tmp0.shiftm,shiftoper );
             break;
  }
 
}//对应于参考手册中寻址方式1的数据处理指令寻址方式；

UNL ARMISS_stru::Addressing_mod2(int mod)
{
   UNL      addr;
   
   if( mod == 0 )
   {
       ARM_type2_stru&  tmp = ARM_type2;
       UNL              offset_12;
       UNL              trn=(tmp.Rn==PC)?(getregd(tmp.Rn)+8):getregd(tmp.Rn);
       UNL&             rn = getreg( tmp.Rn );

       offset_12        = tmp.imm;
       switch( tmp.P + tmp.W )
      {
        case 0  : addr = trn;
                  if( executable() )
                 {
                     rn = (tmp.U==1)? (rn + offset_12):(rn - offset_12);
                     if( tmp.Rn==PC) 
                         pc_changed = true;
                 }
                  break;
        case 1  : addr = (tmp.U==1)? (trn + offset_12):(trn - offset_12);
                  break;
        case 2  : addr = (tmp.U==1)? (trn + offset_12):(trn - offset_12);
                   if( executable() )
                 {
                     rn = addr;
                     if( tmp.Rn==PC) 
                         pc_changed = true;
                 }
                  break;
      }
                  
    }// immediate;  
   else
      {
        ARM_type3_stru& tmp = ARM_type3;
        UNL             rm  = (tmp.Rm==PC)?(getregd(tmp.Rm)+8):getregd(tmp.Rm);
        UNL            trn  = (tmp.Rn==PC)?(getregd(tmp.Rn)+8):getregd(tmp.Rn);
        UNL&            rn  = getreg( tmp.Rn );
        UNL             index;

        index = addr_mod2_shift(tmp.shift,tmp.shiftm,rm);
         switch( tmp.P + tmp.W )
      {
        case 0  : addr = trn;
                  if( executable() )
                 {
                     rn = (tmp.U==1)? (rn + index):(rn - index);
                     if( tmp.Rn==PC) 
                         pc_changed = true;
                 }
                  break;
        case 1  : addr = (tmp.U==1)? (trn + index):(trn - index);
                  break;
        case 2  : addr = (tmp.U==1)? (trn + index):(trn - index);
                   if( executable() )
                 {
                     rn = addr;
                     if( tmp.Rn==PC ) 
                         pc_changed = true;
                 }
                  break;
      }
   }               
    return addr;
}//Addressing mode 2 - Load and Store Word or Unsigned Byte;    
   

UNL ARMISS_stru::Addressing_mod3()
{
  ARM_type0_stru&    tmp = ARM_type0;
  UNL                addr;
  UNL                offset_8,rm,trn,op;
  UNL&               rn  = getreg( tmp.mul_ext.Rn2 );