Annotation of qemu/linux-user/arm/nwfpe/fpa11.c, revision 1.1

1.1     ! root        1: /*
        !             2:     NetWinder Floating Point Emulator
        !             3:     (c) Rebel.COM, 1998,1999
        !             4: 
        !             5:     Direct questions, comments to Scott Bambrough <[email protected]>
        !             6: 
        !             7:     This program is free software; you can redistribute it and/or modify
        !             8:     it under the terms of the GNU General Public License as published by
        !             9:     the Free Software Foundation; either version 2 of the License, or
        !            10:     (at your option) any later version.
        !            11: 
        !            12:     This program is distributed in the hope that it will be useful,
        !            13:     but WITHOUT ANY WARRANTY; without even the implied warranty of
        !            14:     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
        !            15:     GNU General Public License for more details.
        !            16: 
        !            17:     You should have received a copy of the GNU General Public License
        !            18:     along with this program; if not, write to the Free Software
        !            19:     Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
        !            20: */
        !            21: 
        !            22: #include "fpa11.h"
        !            23: 
        !            24: #include "fpopcode.h"
        !            25: 
        !            26: //#include "fpmodule.h"
        !            27: //#include "fpmodule.inl"
        !            28: 
        !            29: //#include <asm/system.h>
        !            30: 
        !            31: #include <stdio.h>
        !            32: 
        !            33: /* forward declarations */
        !            34: unsigned int EmulateCPDO(const unsigned int);
        !            35: unsigned int EmulateCPDT(const unsigned int);
        !            36: unsigned int EmulateCPRT(const unsigned int);
        !            37: 
        !            38: FPA11* qemufpa=0;
        !            39: CPUARMState* user_registers;
        !            40: 
        !            41: /* Reset the FPA11 chip.  Called to initialize and reset the emulator. */
        !            42: void resetFPA11(void)
        !            43: {
        !            44:   int i;
        !            45:   FPA11 *fpa11 = GET_FPA11();
        !            46: 
        !            47:   /* initialize the register type array */
        !            48:   for (i=0;i<=7;i++)
        !            49:   {
        !            50:     fpa11->fType[i] = typeNone;
        !            51:   }
        !            52: 
        !            53:   /* FPSR: set system id to FP_EMULATOR, set AC, clear all other bits */
        !            54:   fpa11->fpsr = FP_EMULATOR | BIT_AC;
        !            55: 
        !            56:   /* FPCR: set SB, AB and DA bits, clear all others */
        !            57: #ifdef MAINTAIN_FPCR
        !            58:   fpa11->fpcr = MASK_RESET;
        !            59: #endif
        !            60: }
        !            61: 
        !            62: void SetRoundingMode(const unsigned int opcode)
        !            63: {
        !            64:     int rounding_mode;
        !            65:    FPA11 *fpa11 = GET_FPA11();
        !            66: 
        !            67: #ifdef MAINTAIN_FPCR
        !            68:    fpa11->fpcr &= ~MASK_ROUNDING_MODE;
        !            69: #endif
        !            70:    switch (opcode & MASK_ROUNDING_MODE)
        !            71:    {
        !            72:       default:
        !            73:       case ROUND_TO_NEAREST:
        !            74:          rounding_mode = float_round_nearest_even;
        !            75: #ifdef MAINTAIN_FPCR
        !            76:          fpa11->fpcr |= ROUND_TO_NEAREST;
        !            77: #endif
        !            78:       break;
        !            79: 
        !            80:       case ROUND_TO_PLUS_INFINITY:
        !            81:          rounding_mode = float_round_up;
        !            82: #ifdef MAINTAIN_FPCR
        !            83:          fpa11->fpcr |= ROUND_TO_PLUS_INFINITY;
        !            84: #endif
        !            85:       break;
        !            86: 
        !            87:       case ROUND_TO_MINUS_INFINITY:
        !            88:          rounding_mode = float_round_down;
        !            89: #ifdef MAINTAIN_FPCR
        !            90:          fpa11->fpcr |= ROUND_TO_MINUS_INFINITY;
        !            91: #endif
        !            92:       break;
        !            93: 
        !            94:       case ROUND_TO_ZERO:
        !            95:          rounding_mode = float_round_to_zero;
        !            96: #ifdef MAINTAIN_FPCR
        !            97:          fpa11->fpcr |= ROUND_TO_ZERO;
        !            98: #endif
        !            99:       break;
        !           100:   }
        !           101:    set_float_rounding_mode(rounding_mode, &fpa11->fp_status);
        !           102: }
        !           103: 
        !           104: void SetRoundingPrecision(const unsigned int opcode)
        !           105: {
        !           106:     int rounding_precision;
        !           107:    FPA11 *fpa11 = GET_FPA11();
        !           108: #ifdef MAINTAIN_FPCR
        !           109:    fpa11->fpcr &= ~MASK_ROUNDING_PRECISION;
        !           110: #endif
        !           111:    switch (opcode & MASK_ROUNDING_PRECISION)
        !           112:    {
        !           113:       case ROUND_SINGLE:
        !           114:          rounding_precision = 32;
        !           115: #ifdef MAINTAIN_FPCR
        !           116:          fpa11->fpcr |= ROUND_SINGLE;
        !           117: #endif
        !           118:       break;
        !           119: 
        !           120:       case ROUND_DOUBLE:
        !           121:          rounding_precision = 64;
        !           122: #ifdef MAINTAIN_FPCR
        !           123:          fpa11->fpcr |= ROUND_DOUBLE;
        !           124: #endif
        !           125:       break;
        !           126: 
        !           127:       case ROUND_EXTENDED:
        !           128:          rounding_precision = 80;
        !           129: #ifdef MAINTAIN_FPCR
        !           130:          fpa11->fpcr |= ROUND_EXTENDED;
        !           131: #endif
        !           132:       break;
        !           133: 
        !           134:       default: rounding_precision = 80;
        !           135:   }
        !           136:    set_floatx80_rounding_precision(rounding_precision, &fpa11->fp_status);
        !           137: }
        !           138: 
        !           139: /* Emulate the instruction in the opcode. */
        !           140: /* ??? This is not thread safe.  */
        !           141: unsigned int EmulateAll(unsigned int opcode, FPA11* qfpa, CPUARMState* qregs)
        !           142: {
        !           143:   unsigned int nRc = 0;
        !           144: //  unsigned long flags;
        !           145:   FPA11 *fpa11;
        !           146: //  save_flags(flags); sti();
        !           147: 
        !           148:   qemufpa=qfpa;
        !           149:   user_registers=qregs;
        !           150: 
        !           151: #if 0
        !           152:   fprintf(stderr,"emulating FP insn 0x%08x, PC=0x%08x\n",
        !           153:           opcode, qregs[REG_PC]);
        !           154: #endif
        !           155:   fpa11 = GET_FPA11();
        !           156: 
        !           157:   if (fpa11->initflag == 0)            /* good place for __builtin_expect */
        !           158:   {
        !           159:     resetFPA11();
        !           160:     SetRoundingMode(ROUND_TO_NEAREST);
        !           161:     SetRoundingPrecision(ROUND_EXTENDED);
        !           162:     fpa11->initflag = 1;
        !           163:   }
        !           164: 
        !           165:   set_float_exception_flags(0, &fpa11->fp_status);
        !           166: 
        !           167:   if (TEST_OPCODE(opcode,MASK_CPRT))
        !           168:   {
        !           169:     //fprintf(stderr,"emulating CPRT\n");
        !           170:     /* Emulate conversion opcodes. */
        !           171:     /* Emulate register transfer opcodes. */
        !           172:     /* Emulate comparison opcodes. */
        !           173:     nRc = EmulateCPRT(opcode);
        !           174:   }
        !           175:   else if (TEST_OPCODE(opcode,MASK_CPDO))
        !           176:   {
        !           177:     //fprintf(stderr,"emulating CPDO\n");
        !           178:     /* Emulate monadic arithmetic opcodes. */
        !           179:     /* Emulate dyadic arithmetic opcodes. */
        !           180:     nRc = EmulateCPDO(opcode);
        !           181:   }
        !           182:   else if (TEST_OPCODE(opcode,MASK_CPDT))
        !           183:   {
        !           184:     //fprintf(stderr,"emulating CPDT\n");
        !           185:     /* Emulate load/store opcodes. */
        !           186:     /* Emulate load/store multiple opcodes. */
        !           187:     nRc = EmulateCPDT(opcode);
        !           188:   }
        !           189:   else
        !           190:   {
        !           191:     /* Invalid instruction detected.  Return FALSE. */
        !           192:     nRc = 0;
        !           193:   }
        !           194: 
        !           195: //  restore_flags(flags);
        !           196:   if(nRc == 1 && get_float_exception_flags(&fpa11->fp_status))
        !           197:   {
        !           198:     //printf("fef 0x%x\n",float_exception_flags);
        !           199:     nRc=-get_float_exception_flags(&fpa11->fp_status);
        !           200:   }
        !           201: 
        !           202:   //printf("returning %d\n",nRc);
        !           203:   return(nRc);
        !           204: }
        !           205: 
        !           206: #if 0
        !           207: unsigned int EmulateAll1(unsigned int opcode)
        !           208: {
        !           209:   switch ((opcode >> 24) & 0xf)
        !           210:   {
        !           211:      case 0xc:
        !           212:      case 0xd:
        !           213:        if ((opcode >> 20) & 0x1)
        !           214:        {
        !           215:           switch ((opcode >> 8) & 0xf)
        !           216:           {
        !           217:              case 0x1: return PerformLDF(opcode); break;
        !           218:              case 0x2: return PerformLFM(opcode); break;
        !           219:              default: return 0;
        !           220:           }
        !           221:        }
        !           222:        else
        !           223:        {
        !           224:           switch ((opcode >> 8) & 0xf)
        !           225:           {
        !           226:              case 0x1: return PerformSTF(opcode); break;
        !           227:              case 0x2: return PerformSFM(opcode); break;
        !           228:              default: return 0;
        !           229:           }
        !           230:       }
        !           231:      break;
        !           232: 
        !           233:      case 0xe:
        !           234:        if (opcode & 0x10)
        !           235:          return EmulateCPDO(opcode);
        !           236:        else
        !           237:          return EmulateCPRT(opcode);
        !           238:      break;
        !           239: 
        !           240:      default: return 0;
        !           241:   }
        !           242: }
        !           243: #endif

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