/*---------------------------------------------------------------------------+
| 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;
}
