drivers/FPU-emu/load

/* */
This source file includes following definitions.
load_store_instr
   1 /*---------------------------------------------------------------------------+
   2  |  load_store.c                                                             |
   3  |                                                                           |
   4  | This file contains most of the code to interpret the FPU instructions     |
   5  | which load and store from user memory.                                    |
   6  |                                                                           |
   7  | Copyright (C) 1992,1993                                                   |
   8  |                       W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
   9  |                       Australia.  E-mail   billm@vaxc.cc.monash.edu.au    |
  10  |                                                                           |
  11  |                                                                           |
  12  +---------------------------------------------------------------------------*/
  13 
  14 /*---------------------------------------------------------------------------+
  15  | Note:                                                                     |
  16  |    The file contains code which accesses user memory.                     |
  17  |    Emulator static data may change when user memory is accessed, due to   |
  18  |    other processes using the emulator while swapping is in progress.      |
  19  +---------------------------------------------------------------------------*/
  20 
  21 #include <asm/segment.h>
  22 
  23 #include "fpu_system.h"
  24 #include "exception.h"
  25 #include "fpu_emu.h"
  26 #include "status_w.h"
  27 #include "control_w.h"
  28 
  29 
  30 #define _NONE_ 0   /* FPU_st0_ptr etc not needed */
  31 #define _REG0_ 1   /* Will be storing st(0) */
  32 #define _PUSH_ 3   /* Need to check for space to push onto stack */
  33 #define _null_ 4   /* Function illegal or not implemented */
  34 
  35 #define pop_0() { pop_ptr->tag = TW_Empty; top++; }
  36 
  37 
  38 static unsigned char const type_table[32] = {
  39   _PUSH_, _PUSH_, _PUSH_, _PUSH_,
  40   _null_, _null_, _null_, _null_,
  41   _REG0_, _REG0_, _REG0_, _REG0_,
  42   _REG0_, _REG0_, _REG0_, _REG0_,
  43   _NONE_, _null_, _NONE_, _PUSH_,
  44   _NONE_, _PUSH_, _null_, _PUSH_,
  45   _NONE_, _null_, _NONE_, _REG0_,
  46   _NONE_, _REG0_, _NONE_, _REG0_
  47   };
  48 
  49 void load_store_instr(char type)
     /*  */
  50 {
  51   FPU_REG *pop_ptr;  /* We need a version of FPU_st0_ptr which won't
  52                         change if the emulator is re-entered. */
  53 
  54   pop_ptr = NULL;    /* Initialized just to stop compiler warnings. */
  55   switch ( type_table[(int) (unsigned) type] )
  56     {
  57     case _NONE_:
  58       break;
  59     case _REG0_:
  60       pop_ptr = &st(0);       /* Some of these instructions pop after
  61                                  storing */
  62 
  63       FPU_st0_ptr = pop_ptr;      /* Set the global variables. */
  64       FPU_st0_tag = FPU_st0_ptr->tag;
  65       break;
  66     case _PUSH_:
  67       {
  68         pop_ptr = &st(-1);
  69         if ( pop_ptr->tag != TW_Empty )
  70           { stack_overflow(); return; }
  71         top--;
  72       }
  73       break;
  74     case _null_:
  75       Un_impl();
  76       return;
  77 #ifdef PARANOID
  78     default:
  79       EXCEPTION(EX_INTERNAL);
  80       return;
  81 #endif PARANOID
  82     }
  83 
  84 switch ( type )
  85   {
  86   case 000:       /* fld m32real */
  87     clear_C1();
  88     reg_load_single();
  89     if ( (FPU_loaded_data.tag == TW_NaN) &&
  90         real_2op_NaN(&FPU_loaded_data, &FPU_loaded_data, &FPU_loaded_data) )
  91       {
  92         top++;
  93         break;
  94       }
  95     reg_move(&FPU_loaded_data, pop_ptr);
  96     break;
  97   case 001:      /* fild m32int */
  98     clear_C1();
  99     reg_load_int32();
 100     reg_move(&FPU_loaded_data, pop_ptr);
 101     break;
 102   case 002:      /* fld m64real */
 103     clear_C1();
 104     reg_load_double();
 105     if ( (FPU_loaded_data.tag == TW_NaN) &&
 106         real_2op_NaN(&FPU_loaded_data, &FPU_loaded_data, &FPU_loaded_data) )
 107       {
 108         top++;
 109         break;
 110       }
 111     reg_move(&FPU_loaded_data, pop_ptr);
 112     break;
 113   case 003:      /* fild m16int */
 114     clear_C1();
 115     reg_load_int16();
 116     reg_move(&FPU_loaded_data, pop_ptr);
 117     break;
 118   case 010:      /* fst m32real */
 119     clear_C1();
 120     reg_store_single();
 121     break;
 122   case 011:      /* fist m32int */
 123     clear_C1();
 124     reg_store_int32();
 125     break;
 126   case 012:     /* fst m64real */
 127     clear_C1();
 128     reg_store_double();
 129     break;
 130   case 013:     /* fist m16int */
 131     clear_C1();
 132     reg_store_int16();
 133     break;
 134   case 014:     /* fstp m32real */
 135     clear_C1();
 136     if ( reg_store_single() )
 137       pop_0();  /* pop only if the number was actually stored
 138                  (see the 80486 manual p16-28) */
 139     break;
 140   case 015:     /* fistp m32int */
 141     clear_C1();
 142     if ( reg_store_int32() )
 143       pop_0();  /* pop only if the number was actually stored
 144                  (see the 80486 manual p16-28) */
 145     break;
 146   case 016:     /* fstp m64real */
 147     clear_C1();
 148     if ( reg_store_double() )
 149       pop_0();  /* pop only if the number was actually stored
 150                  (see the 80486 manual p16-28) */
 151     break;
 152   case 017:     /* fistp m16int */
 153     clear_C1();
 154     if ( reg_store_int16() )
 155       pop_0();  /* pop only if the number was actually stored
 156                  (see the 80486 manual p16-28) */
 157     break;
 158   case 020:     /* fldenv  m14/28byte */
 159     fldenv();
 160     break;
 161   case 022:     /* frstor m94/108byte */
 162     frstor();
 163     break;
 164   case 023:     /* fbld m80dec */
 165     clear_C1();
 166     reg_load_bcd();
 167     reg_move(&FPU_loaded_data, pop_ptr);
 168     break;
 169   case 024:     /* fldcw */
 170     RE_ENTRANT_CHECK_OFF;
 171     control_word = get_fs_word((unsigned short *) FPU_data_address);
 172     RE_ENTRANT_CHECK_ON;
 173     if ( partial_status & ~control_word & CW_Exceptions )
 174       partial_status |= (SW_Summary | SW_Backward);
 175     else
 176       partial_status &= ~(SW_Summary | SW_Backward);
 177 #ifdef PECULIAR_486
 178     control_word |= 0x40;  /* An 80486 appears to always set this bit */
 179 #endif PECULIAR_486
 180     NO_NET_DATA_EFFECT;
 181     NO_NET_INSTR_EFFECT;
 182     break;
 183   case 025:      /* fld m80real */
 184     clear_C1();
 185     reg_load_extended();
 186     reg_move(&FPU_loaded_data, pop_ptr);
 187     break;
 188   case 027:      /* fild m64int */
 189     clear_C1();
 190     reg_load_int64();
 191     reg_move(&FPU_loaded_data, pop_ptr);
 192     break;
 193   case 030:     /* fstenv  m14/28byte */
 194     fstenv();
 195     NO_NET_DATA_EFFECT;
 196     break;
 197   case 032:      /* fsave */
 198     fsave();
 199     NO_NET_DATA_EFFECT;
 200     break;
 201   case 033:      /* fbstp m80dec */
 202     clear_C1();
 203     if ( reg_store_bcd() )
 204       pop_0();  /* pop only if the number was actually stored
 205                  (see the 80486 manual p16-28) */
 206     break;
 207   case 034:      /* fstcw m16int */
 208     RE_ENTRANT_CHECK_OFF;
 209     verify_area(VERIFY_WRITE,FPU_data_address,2);
 210     put_fs_word(control_word, (short *) FPU_data_address);
 211     RE_ENTRANT_CHECK_ON;
 212     NO_NET_DATA_EFFECT;
 213     NO_NET_INSTR_EFFECT;
 214     break;
 215   case 035:      /* fstp m80real */
 216     clear_C1();
 217     if ( reg_store_extended() )
 218       pop_0();  /* pop only if the number was actually stored
 219                  (see the 80486 manual p16-28) */
 220     break;
 221   case 036:      /* fstsw m2byte */
 222     RE_ENTRANT_CHECK_OFF;
 223     verify_area(VERIFY_WRITE,FPU_data_address,2);
 224     put_fs_word(status_word(),(short *) FPU_data_address);
 225     RE_ENTRANT_CHECK_ON;
 226     NO_NET_DATA_EFFECT;
 227     NO_NET_INSTR_EFFECT;
 228     break;
 229   case 037:      /* fistp m64int */
 230     clear_C1();
 231     if ( reg_store_int64() )
 232       pop_0();  /* pop only if the number was actually stored
 233                  (see the 80486 manual p16-28) */
 234     break;
 235   }
 236 }
/* */
root/drivers/FPU-emu/load_store.c

DEFINITIONS
