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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) 1992,1993,1994,1997 |
| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
| Australia. E-mail billm@suburbia.net |
| |
| |
+---------------------------------------------------------------------------*/
/*---------------------------------------------------------------------------+
| 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/uaccess.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() { FPU_settag0(TAG_Empty); top++; }
static u_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_
};
u_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
};
u_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 FPU_load_store(u_char type, fpu_addr_modes addr_modes,
void *data_address)
{
FPU_REG loaded_data;
FPU_REG *st0_ptr;
u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */
u_char loaded_tag;
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 */
st0_tag = FPU_gettag0();
break;
case _PUSH_:
{
if ( FPU_gettagi(-1) != TAG_Empty )
{ FPU_stack_overflow(); return 0; }
top--;
st0_ptr = &st(0);
}
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();
loaded_tag = FPU_load_single((float *)data_address, &loaded_data);
if ( (loaded_tag == TAG_Special)
&& isNaN(&loaded_data)
&& (real_1op_NaN(&loaded_data) < 0) )
{
top++;
break;
}
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 001: /* fild m32int */
clear_C1();
loaded_tag = FPU_load_int32((long *)data_address, &loaded_data);
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 002: /* fld m64real */
clear_C1();
loaded_tag = FPU_load_double((double *)data_address, &loaded_data);
if ( (loaded_tag == TAG_Special)
&& isNaN(&loaded_data)
&& (real_1op_NaN(&loaded_data) < 0) )
{
top++;
break;
}
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 003: /* fild m16int */
clear_C1();
loaded_tag = FPU_load_int16((short *)data_address, &loaded_data);
FPU_copy_to_reg0(&loaded_data, loaded_tag);
break;
case 010: /* fst m32real */
clear_C1();
FPU_store_single(st0_ptr, st0_tag, (float *)data_address);
break;
case 011: /* fist m32int */
clear_C1();
FPU_store_int32(st0_ptr, st0_tag, (long *)data_address);
break;
case 012: /* fst m64real */
clear_C1();
FPU_store_double(st0_ptr, st0_tag, (double *)data_address);
break;
case 013: /* fist m16int */
clear_C1();
FPU_store_int16(st0_ptr, st0_tag, (short *)data_address);
break;
case 014: /* fstp m32real */
clear_C1();
if ( FPU_store_single(st0_ptr, st0_tag, (float *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 015: /* fistp m32int */
clear_C1();
if ( FPU_store_int32(st0_ptr, st0_tag, (long *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 016: /* fstp m64real */
clear_C1();
if ( FPU_store_double(st0_ptr, st0_tag, (double *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
case 017: /* fistp m16int */
clear_C1();
if ( FPU_store_int16(st0_ptr, st0_tag, (short *)data_address) )
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, (u_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, (u_char *)data_address);
/* Ensure that the values just loaded are not changed by
fix-up operations. */
return 1;
case 023: /* fbld m80dec */
clear_C1();
loaded_tag = FPU_load_bcd((u_char *)data_address);
FPU_settag0(loaded_tag);
break;
case 024: /* fldcw */
RE_ENTRANT_CHECK_OFF;
FPU_verify_area(VERIFY_READ, data_address, 2);
FPU_get_user(control_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();
loaded_tag = FPU_load_extended((long double *)data_address, 0);
FPU_settag0(loaded_tag);
break;
case 027: /* fild m64int */
clear_C1();
loaded_tag = FPU_load_int64((long long *)data_address);
FPU_settag0(loaded_tag);
break;
case 030: /* fstenv m14/28byte */
fstenv(addr_modes, (u_char *)data_address);
return 1;
case 032: /* fsave */
fsave(addr_modes, (u_char *)data_address);
return 1;
case 033: /* fbstp m80dec */
clear_C1();
if ( FPU_store_bcd(st0_ptr, st0_tag, (u_char *)data_address) )
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);
FPU_put_user(control_word, (unsigned short *) data_address);
RE_ENTRANT_CHECK_ON;
return 1;
case 035: /* fstp m80real */
clear_C1();
if ( FPU_store_extended(st0_ptr, st0_tag, (long double *)data_address) )
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);
FPU_put_user(status_word(),(unsigned short *) data_address);
RE_ENTRANT_CHECK_ON;
return 1;
case 037: /* fistp m64int */
clear_C1();
if ( FPU_store_int64(st0_ptr, st0_tag, (long long *)data_address) )
pop_0(); /* pop only if the number was actually stored
(see the 80486 manual p16-28) */
break;
}
return 0;
}
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