kernel/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    W. Metzenthen, 22 Parker St, Ormond, Vic 3163,      |
   8  |                       Australia.  E-mail apm233m@vaxc.cc.monash.edu.au    |
   9  |                                                                           |
  10  |                                                                           |
  11  +---------------------------------------------------------------------------*/
  12 
  13 /*---------------------------------------------------------------------------+
  14  | Note:                                                                     |
  15  |    The file contains code which accesses user memory.                     |
  16  |    Emulator static data may change when user memory is accessed, due to   |
  17  |    other processes using the emulator while swapping is in progress.      |
  18  +---------------------------------------------------------------------------*/
  19 
  20 #include <asm/segment.h>
  21 
  22 #include "fpu_system.h"
  23 #include "exception.h"
  24 #include "fpu_emu.h"
  25 #include "status_w.h"
  26 
  27 
  28 #define _NONE_ 0   /* FPU_st0_ptr etc not needed */
  29 #define _REG0_ 1   /* Will be storing st(0) */
  30 #define _PUSH_ 3   /* Need to check for space to push onto stack */
  31 #define _null_ 4   /* Function illegal or not implemented */
  32 
  33 #define pop_0() { pop_ptr->tag = TW_Empty; top++; }
  34 
  35 
  36 static unsigned char type_table[32] = {
  37   _PUSH_, _PUSH_, _PUSH_, _PUSH_,
  38   _null_, _null_, _null_, _null_,
  39   _REG0_, _REG0_, _REG0_, _REG0_,
  40   _REG0_, _REG0_, _REG0_, _REG0_,
  41   _NONE_, _null_, _NONE_, _PUSH_,
  42   _NONE_, _PUSH_, _null_, _PUSH_,
  43   _NONE_, _null_, _NONE_, _REG0_,
  44   _NONE_, _REG0_, _NONE_, _REG0_
  45   };
  46 
  47 void load_store_instr(char type)
     /*  */
  48 {
  49   FPU_REG *pop_ptr;  /* We need a version of FPU_st0_ptr which won't change. */
  50 
  51   pop_ptr = NULL;    /* Initialized just to stop compiler warnings. */
  52   switch ( type_table[(int) (unsigned) type] )
  53     {
  54     case _NONE_:
  55       break;
  56     case _REG0_:
  57       pop_ptr = &st(0);       /* Some of these instructions pop after
  58                                  storing */
  59 
  60       FPU_st0_ptr = pop_ptr;      /* Set the global variables. */
  61       FPU_st0_tag = FPU_st0_ptr->tag;
  62       break;
  63     case _PUSH_:
  64       {
  65         pop_ptr = &st(-1);
  66         if ( pop_ptr->tag != TW_Empty )
  67           { stack_overflow(); return; }
  68         top--;
  69       }
  70       break;
  71     case _null_:
  72       return Un_impl();
  73 #ifdef PARANOID
  74     default:
  75       return EXCEPTION(EX_INTERNAL);
  76 #endif PARANOID
  77     }
  78 
  79 switch ( type )
  80   {
  81   case 000:       /* fld m32real */
  82     reg_load_single();
  83     reg_move(&FPU_loaded_data, pop_ptr);
  84     break;
  85   case 001:      /* fild m32int */
  86     reg_load_int32();
  87     reg_move(&FPU_loaded_data, pop_ptr);
  88     break;
  89   case 002:      /* fld m64real */
  90     reg_load_double();
  91     reg_move(&FPU_loaded_data, pop_ptr);
  92     break;
  93   case 003:      /* fild m16int */
  94     reg_load_int16();
  95     reg_move(&FPU_loaded_data, pop_ptr);
  96     break;
  97   case 010:      /* fst m32real */
  98     reg_store_single();
  99     break;
 100   case 011:      /* fist m32int */
 101     reg_store_int32();
 102     break;
 103   case 012:     /* fst m64real */
 104     reg_store_double();
 105     break;
 106   case 013:     /* fist m16int */
 107     reg_store_int16();
 108     break;
 109   case 014:     /* fstp m32real */
 110     if ( reg_store_single() )
 111       pop_0();  /* pop only if the number was actually stored
 112                  (see the 80486 manual p16-28) */
 113     break;
 114   case 015:     /* fistp m32int */
 115     if ( reg_store_int32() )
 116       pop_0();  /* pop only if the number was actually stored
 117                  (see the 80486 manual p16-28) */
 118     break;
 119   case 016:     /* fstp m64real */
 120     if ( reg_store_double() )
 121       pop_0();  /* pop only if the number was actually stored
 122                  (see the 80486 manual p16-28) */
 123     break;
 124   case 017:     /* fistp m16int */
 125     if ( reg_store_int16() )
 126       pop_0();  /* pop only if the number was actually stored
 127                  (see the 80486 manual p16-28) */
 128     break;
 129   case 020:     /* fldenv  m14/28byte */
 130     fldenv();
 131     break;
 132   case 022:     /* frstor m94/108byte */
 133     frstor();
 134     break;
 135   case 023:     /* fbld m80dec */
 136     reg_load_bcd();
 137     reg_move(&FPU_loaded_data, pop_ptr);
 138     break;
 139   case 024:     /* fldcw */
 140     RE_ENTRANT_CHECK_OFF
 141     control_word = get_fs_word((unsigned short *) FPU_data_address);
 142     RE_ENTRANT_CHECK_ON
 143 #ifdef NO_UNDERFLOW_TRAP
 144     if ( !(control_word & EX_Underflow) )
 145       {
 146         control_word |= EX_Underflow;
 147       }
 148 #endif
 149     FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
 150     FPU_entry_eip = ip_offset;               /* We want no net effect */
 151     break;
 152   case 025:      /* fld m80real */
 153     reg_load_extended();
 154     reg_move(&FPU_loaded_data, pop_ptr);
 155     break;
 156   case 027:      /* fild m64int */
 157     reg_load_int64();
 158     reg_move(&FPU_loaded_data, pop_ptr);
 159     break;
 160   case 030:     /* fstenv  m14/28byte */
 161     fstenv();
 162     FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
 163     FPU_entry_eip = ip_offset;               /* We want no net effect */
 164     break;
 165   case 032:      /* fsave */
 166     fsave();
 167     FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
 168     FPU_entry_eip = ip_offset;               /* We want no net effect */
 169     break;
 170   case 033:      /* fbstp m80dec */
 171     if ( reg_store_bcd() )
 172       pop_0();  /* pop only if the number was actually stored
 173                  (see the 80486 manual p16-28) */
 174     break;
 175   case 034:      /* fstcw m16int */
 176     RE_ENTRANT_CHECK_OFF
 177     verify_area(FPU_data_address,2);
 178     put_fs_word(control_word, (short *) FPU_data_address);
 179     RE_ENTRANT_CHECK_ON
 180     FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
 181     FPU_entry_eip = ip_offset;               /* We want no net effect */
 182     break;
 183   case 035:      /* fstp m80real */
 184     if ( reg_store_extended() )
 185       pop_0();  /* pop only if the number was actually stored
 186                  (see the 80486 manual p16-28) */
 187     break;
 188   case 036:      /* fstsw m2byte */
 189     status_word &= ~SW_TOP;
 190     status_word |= (top&7) << SW_TOPS;
 191     RE_ENTRANT_CHECK_OFF
 192     verify_area(FPU_data_address,2);
 193     put_fs_word(status_word,(short *) FPU_data_address);
 194     RE_ENTRANT_CHECK_ON
 195     FPU_data_address = (void *)data_operand_offset; /* We want no net effect */
 196     FPU_entry_eip = ip_offset;               /* We want no net effect */
 197     break;
 198   case 037:      /* fistp m64int */
 199     if ( reg_store_int64() )
 200       pop_0();  /* pop only if the number was actually stored
 201                  (see the 80486 manual p16-28) */
 202     break;
 203   }
 204 }
/* */
root/kernel/FPU-emu/load_store.c

DEFINITIONS
