qemu

fpa11.c (6008B)

---

 /*
     NetWinder Floating Point Emulator
     (c) Rebel.COM, 1998,1999
 
     Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
     the Free Software Foundation; either version 2 of the License, or
     (at your option) any later version.
 
     This program is distributed in the hope that it will be useful,
     but WITHOUT ANY WARRANTY; without even the implied warranty of
     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
     GNU General Public License for more details.
 
     You should have received a copy of the GNU General Public License
     along with this program; if not, see <http://www.gnu.org/licenses/>.
 */
 
 #include "qemu/osdep.h"
 #include "fpa11.h"
 
 #include "fpopcode.h"
 
 //#include "fpmodule.h"
 //#include "fpmodule.inl"
 
 //#include <asm/system.h>
 
 
 FPA11* qemufpa = NULL;
 CPUARMState* user_registers;
 
 /* Reset the FPA11 chip.  Called to initialize and reset the emulator. */
 void resetFPA11(void)
 {
   int i;
   FPA11 *fpa11 = GET_FPA11();
 
   /* initialize the register type array */
   for (i=0;i<=7;i++)
   {
     fpa11->fType[i] = typeNone;
   }
 
   /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
   fpa11->fpsr = FP_EMULATOR | BIT_AC;
 
   /* FPCR: set SB, AB and DA bits, clear all others */
 #ifdef MAINTAIN_FPCR
   fpa11->fpcr = MASK_RESET;
 #endif
 }
 
 void SetRoundingMode(const unsigned int opcode)
 {
     int rounding_mode;
    FPA11 *fpa11 = GET_FPA11();
 
 #ifdef MAINTAIN_FPCR
    fpa11->fpcr &= ~MASK_ROUNDING_MODE;
 #endif
    switch (opcode & MASK_ROUNDING_MODE)
    {
       default:
       case ROUND_TO_NEAREST:
          rounding_mode = float_round_nearest_even;
 #ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_NEAREST;
 #endif
       break;
 
       case ROUND_TO_PLUS_INFINITY:
          rounding_mode = float_round_up;
 #ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_PLUS_INFINITY;
 #endif
       break;
 
       case ROUND_TO_MINUS_INFINITY:
          rounding_mode = float_round_down;
 #ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_MINUS_INFINITY;
 #endif
       break;
 
       case ROUND_TO_ZERO:
          rounding_mode = float_round_to_zero;
 #ifdef MAINTAIN_FPCR
          fpa11->fpcr |= ROUND_TO_ZERO;
 #endif
       break;
   }
    set_float_rounding_mode(rounding_mode, &fpa11->fp_status);
 }
 
 void SetRoundingPrecision(const unsigned int opcode)
 {
     FloatX80RoundPrec rounding_precision;
     FPA11 *fpa11 = GET_FPA11();
 #ifdef MAINTAIN_FPCR
     fpa11->fpcr &= ~MASK_ROUNDING_PRECISION;
 #endif
     switch (opcode & MASK_ROUNDING_PRECISION) {
     case ROUND_SINGLE:
         rounding_precision = floatx80_precision_s;
 #ifdef MAINTAIN_FPCR
         fpa11->fpcr |= ROUND_SINGLE;
 #endif
         break;
 
     case ROUND_DOUBLE:
         rounding_precision = floatx80_precision_d;
 #ifdef MAINTAIN_FPCR
         fpa11->fpcr |= ROUND_DOUBLE;
 #endif
         break;
 
     case ROUND_EXTENDED:
         rounding_precision = floatx80_precision_x;
 #ifdef MAINTAIN_FPCR
         fpa11->fpcr |= ROUND_EXTENDED;
 #endif
         break;
 
     default:
         rounding_precision = floatx80_precision_x;
         break;
     }
     set_floatx80_rounding_precision(rounding_precision, &fpa11->fp_status);
 }
 
 /* Emulate the instruction in the opcode. */
 /* ??? This is not thread safe.  */
 unsigned int EmulateAll(unsigned int opcode, FPA11* qfpa, CPUARMState* qregs)
 {
   unsigned int nRc = 0;
 //  unsigned long flags;
   FPA11 *fpa11;
   unsigned int cp;
 //  save_flags(flags); sti();
 
   /* Check that this is really an FPA11 instruction: the coprocessor
    * field in bits [11:8] must be 1 or 2.
    */
   cp = (opcode >> 8) & 0xf;
   if (cp != 1 && cp != 2) {
     return 0;
   }
 
   qemufpa=qfpa;
   user_registers=qregs;
 
 #if 0
   fprintf(stderr,"emulating FP insn 0x%08x, PC=0x%08x\n",
           opcode, qregs[ARM_REG_PC]);
 #endif
   fpa11 = GET_FPA11();
 
   if (fpa11->initflag == 0)		/* good place for __builtin_expect */
   {
     resetFPA11();
     SetRoundingMode(ROUND_TO_NEAREST);
     SetRoundingPrecision(ROUND_EXTENDED);
     fpa11->initflag = 1;
   }
 
   set_float_exception_flags(0, &fpa11->fp_status);
 
   if (TEST_OPCODE(opcode,MASK_CPRT))
   {
     //fprintf(stderr,"emulating CPRT\n");
     /* Emulate conversion opcodes. */
     /* Emulate register transfer opcodes. */
     /* Emulate comparison opcodes. */
     nRc = EmulateCPRT(opcode);
   }
   else if (TEST_OPCODE(opcode,MASK_CPDO))
   {
     //fprintf(stderr,"emulating CPDO\n");
     /* Emulate monadic arithmetic opcodes. */
     /* Emulate dyadic arithmetic opcodes. */
     nRc = EmulateCPDO(opcode);
   }
   else if (TEST_OPCODE(opcode,MASK_CPDT))
   {
     //fprintf(stderr,"emulating CPDT\n");
     /* Emulate load/store opcodes. */
     /* Emulate load/store multiple opcodes. */
     nRc = EmulateCPDT(opcode);
   }
   else
   {
     /* Invalid instruction detected.  Return FALSE. */
     nRc = 0;
   }
 
 //  restore_flags(flags);
   if(nRc == 1 && get_float_exception_flags(&fpa11->fp_status))
   {
     //printf("fef 0x%x\n",float_exception_flags);
     nRc = -get_float_exception_flags(&fpa11->fp_status);
   }
 
   //printf("returning %d\n",nRc);
   return(nRc);
 }
 
 #if 0
 unsigned int EmulateAll1(unsigned int opcode)
 {
   switch ((opcode >> 24) & 0xf)
   {
      case 0xc:
      case 0xd:
        if ((opcode >> 20) & 0x1)
        {
           switch ((opcode >> 8) & 0xf)
           {
              case 0x1: return PerformLDF(opcode); break;
              case 0x2: return PerformLFM(opcode); break;
              default: return 0;
           }
        }
        else
        {
           switch ((opcode >> 8) & 0xf)
           {
              case 0x1: return PerformSTF(opcode); break;
              case 0x2: return PerformSFM(opcode); break;
              default: return 0;
           }
       }
      break;
 
      case 0xe:
        if (opcode & 0x10)
          return EmulateCPDO(opcode);
        else
          return EmulateCPRT(opcode);
      break;
 
      default: return 0;
   }
 }
 #endif