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/*---------------------------------------------------------------------------+

 |  load_store.c                                                             |

 |                                                                           |

 | This file contains most of the code to interpret the FPU instructions     |

 | which load and store from user memory.                                    |

 |                                                                           |

 | Copyright (C) 1992,1993,1994                                              |

 |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |

 |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |

 |                                                                           |

 |                                                                           |

 +---------------------------------------------------------------------------*/

/*---------------------------------------------------------------------------+

 | Note:                                                                     |

 |    The file contains code which accesses user memory.                     |

 |    Emulator static data may change when user memory is accessed, due to   |

 |    other processes using the emulator while swapping is in progress.      |

 +---------------------------------------------------------------------------*/

#include <asm/segment.h>

#include "fpu_system.h"

#include "exception.h"

#include "fpu_emu.h"

#include "status_w.h"

#include "control_w.h"

#define _NONE_ 0   /* st0_ptr etc not needed */

#define _REG0_ 1   /* Will be storing st(0) */

#define _PUSH_ 3   /* Need to check for space to push onto stack */

#define _null_ 4   /* Function illegal or not implemented */

#define pop_0() { st0_ptr->tag = TW_Empty; top++; }

static unsigned char const type_table[32] = {

  _PUSH_, _PUSH_, _PUSH_, _PUSH_,

  _null_, _null_, _null_, _null_,

  _REG0_, _REG0_, _REG0_, _REG0_,

  _REG0_, _REG0_, _REG0_, _REG0_,

  _NONE_, _null_, _NONE_, _PUSH_,

  _NONE_, _PUSH_, _null_, _PUSH_,

  _NONE_, _null_, _NONE_, _REG0_,

  _NONE_, _REG0_, _NONE_, _REG0_

  };

unsigned char const data_sizes_16[32] = {

  4,  4,  8,  2,  0,  0,  0,  0,

  4,  4,  8,  2,  4,  4,  8,  2,

  14, 0, 94, 10,  2, 10,  0,  8,

  14, 0, 94, 10,  2, 10,  2,  8

};

unsigned char const data_sizes_32[32] = {

  4,  4,  8,  2,  0,  0,  0,  0,

  4,  4,  8,  2,  4,  4,  8,  2,

  28, 0,108, 10,  2, 10,  0,  8,

  28, 0,108, 10,  2, 10,  2,  8

};

int load_store_instr(unsigned char type, fpu_addr_modes addr_modes,

                     void *data_address)

{

  FPU_REG loaded_data;

  FPU_REG *st0_ptr;

  st0_ptr = NULL;    /* Initialized just to stop compiler warnings. */

  if ( addr_modes.default_mode & PROTECTED )

    {

      if ( addr_modes.default_mode == SEG32 )

        {

          if ( access_limit < data_sizes_32[type] )

            math_abort(FPU_info,SIGSEGV);

        }

      else if ( addr_modes.default_mode == PM16 )

        {

          if ( access_limit < data_sizes_16[type] )

            math_abort(FPU_info,SIGSEGV);

        }

#ifdef PARANOID

      else

        EXCEPTION(EX_INTERNAL|0x140);

#endif PARANOID

    }

  switch ( type_table[type] )

    {

    case _NONE_:

      break;

    case _REG0_:

      st0_ptr = &st(0);       /* Some of these instructions pop after

                                 storing */

      break;

    case _PUSH_:

      {

        st0_ptr = &st(-1);

        if ( st0_ptr->tag != TW_Empty )

          { stack_overflow(); return 0; }

        top--;

      }

      break;

    case _null_:

      FPU_illegal();

      return 0;

#ifdef PARANOID

    default:

      EXCEPTION(EX_INTERNAL|0x141);

      return 0;

#endif PARANOID

    }

  switch ( type )

    {

    case 000:       /* fld m32real */

      clear_C1();

      reg_load_single((float *)data_address, &loaded_data);

      if ( (loaded_data.tag == TW_NaN) &&

          real_2op_NaN(&loaded_data, &loaded_data, &loaded_data) )

        {

          top++;

          break;

        }

      reg_move(&loaded_data, st0_ptr);

      break;

    case 001:      /* fild m32int */

      clear_C1();

      reg_load_int32((long *)data_address, st0_ptr);

      break;

    case 002:      /* fld m64real */

      clear_C1();

      reg_load_double((double *)data_address, &loaded_data);

      if ( (loaded_data.tag == TW_NaN) &&

          real_2op_NaN(&loaded_data, &loaded_data, &loaded_data) )

        {

          top++;

          break;

        }

      reg_move(&loaded_data, st0_ptr);

      break;

    case 003:      /* fild m16int */

      clear_C1();

      reg_load_int16((short *)data_address, st0_ptr);

      break;

    case 010:      /* fst m32real */

      clear_C1();

      reg_store_single((float *)data_address, st0_ptr);

      break;

    case 011:      /* fist m32int */

      clear_C1();

      reg_store_int32((long *)data_address, st0_ptr);

      break;

    case 012:     /* fst m64real */

      clear_C1();

      reg_store_double((double *)data_address, st0_ptr);

      break;

    case 013:     /* fist m16int */

      clear_C1();

      reg_store_int16((short *)data_address, st0_ptr);

      break;

    case 014:     /* fstp m32real */

      clear_C1();

      if ( reg_store_single((float *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    case 015:     /* fistp m32int */

      clear_C1();

      if ( reg_store_int32((long *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    case 016:     /* fstp m64real */

      clear_C1();

      if ( reg_store_double((double *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    case 017:     /* fistp m16int */

      clear_C1();

      if ( reg_store_int16((short *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    case 020:     /* fldenv  m14/28byte */

      fldenv(addr_modes, (char *)data_address);

      /* Ensure that the values just loaded are not changed by

         fix-up operations. */

      return 1;

    case 022:     /* frstor m94/108byte */

      frstor(addr_modes, (char *)data_address);

      /* Ensure that the values just loaded are not changed by

         fix-up operations. */

      return 1;

    case 023:     /* fbld m80dec */

      clear_C1();

      reg_load_bcd((char *)data_address, st0_ptr);

      break;

    case 024:     /* fldcw */

      RE_ENTRANT_CHECK_OFF;

      FPU_verify_area(VERIFY_READ, data_address, 2);

      control_word = get_fs_word((unsigned short *) data_address);

      RE_ENTRANT_CHECK_ON;

      if ( partial_status & ~control_word & CW_Exceptions )

        partial_status |= (SW_Summary | SW_Backward);

      else

        partial_status &= ~(SW_Summary | SW_Backward);

#ifdef PECULIAR_486

      control_word |= 0x40;  /* An 80486 appears to always set this bit */

#endif PECULIAR_486

      return 1;

    case 025:      /* fld m80real */

      clear_C1();

      reg_load_extended((long double *)data_address, st0_ptr);

      break;

    case 027:      /* fild m64int */

      clear_C1();

      reg_load_int64((long long *)data_address, st0_ptr);

      break;

    case 030:     /* fstenv  m14/28byte */

      fstenv(addr_modes, (char *)data_address);

      return 1;

    case 032:      /* fsave */

      fsave(addr_modes, (char *)data_address);

      return 1;

    case 033:      /* fbstp m80dec */

      clear_C1();

      if ( reg_store_bcd((char *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    case 034:      /* fstcw m16int */

      RE_ENTRANT_CHECK_OFF;

      FPU_verify_area(VERIFY_WRITE,data_address,2);

      put_fs_word(control_word, (short *) data_address);

      RE_ENTRANT_CHECK_ON;

      return 1;

    case 035:      /* fstp m80real */

      clear_C1();

      if ( reg_store_extended((long double *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    case 036:      /* fstsw m2byte */

      RE_ENTRANT_CHECK_OFF;

      FPU_verify_area(VERIFY_WRITE,data_address,2);

      put_fs_word(status_word(),(short *) data_address);

      RE_ENTRANT_CHECK_ON;

      return 1;

    case 037:      /* fistp m64int */

      clear_C1();

      if ( reg_store_int64((long long *)data_address, st0_ptr) )

        pop_0();  /* pop only if the number was actually stored

                     (see the 80486 manual p16-28) */

      break;

    }

  return 0;

}