232 lines
7.8 KiB
C
232 lines
7.8 KiB
C
/*---------------------------------------------------------------------------+
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| load_store.c |
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| $Id: load_store.c,v 1.13 2004-02-11 19:40:25 sshwarts Exp $
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| This file contains most of the code to interpret the FPU instructions |
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| which load and store from user memory. |
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| Copyright (C) 1992,1993,1994,1997 |
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| W. Metzenthen, 22 Parker St, Ormond, Vic 3163, |
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| Australia. E-mail billm@suburbia.net |
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+---------------------------------------------------------------------------*/
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/*---------------------------------------------------------------------------+
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| Note: |
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| The file contains code which accesses user memory. |
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| Emulator static data may change when user memory is accessed, due to |
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| other processes using the emulator while swapping is in progress. |
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+---------------------------------------------------------------------------*/
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#include "fpu_system.h"
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#include "exception.h"
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#include "fpu_emu.h"
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#include "status_w.h"
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#include "control_w.h"
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#define _NONE_ 0 /* st0_ptr etc not needed */
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#define _REG0_ 1 /* Will be storing st(0) */
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#define _PUSH_ 3 /* Need to check for space to push onto stack */
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#define _null_ 4 /* Function illegal or not implemented */
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#define pop_0() { FPU_settag0(TAG_Empty); FPU_tos++; }
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static u_char const type_table[32] = {
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_PUSH_, _PUSH_, _PUSH_, _PUSH_,
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_null_, _null_, _null_, _null_,
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_REG0_, _REG0_, _REG0_, _REG0_,
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_REG0_, _REG0_, _REG0_, _REG0_,
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_NONE_, _null_, _NONE_, _PUSH_,
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_NONE_, _PUSH_, _null_, _PUSH_,
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_NONE_, _null_, _NONE_, _REG0_,
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_NONE_, _REG0_, _NONE_, _REG0_
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};
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int FPU_load_store(u_char type, fpu_addr_modes addr_modes,
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bx_address data_address)
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{
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FPU_REG loaded_data;
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FPU_REG *st0_ptr;
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u_char st0_tag = TAG_Empty; /* This is just to stop a gcc warning. */
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u_char loaded_tag;
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st0_ptr = (FPU_REG*) NULL; /* Initialized just to stop compiler warnings. */
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switch (type_table[type])
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{
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case _NONE_:
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break;
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case _REG0_:
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st0_ptr = &st(0); /* Some of these instructions pop after
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storing */
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st0_tag = FPU_gettag0();
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break;
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case _PUSH_:
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{
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if ( FPU_gettagi(-1) != TAG_Empty )
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{ FPU_stack_overflow(); return 0; }
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FPU_tos--;
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st0_ptr = &st(0);
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}
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break;
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case _null_:
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FPU_illegal();
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return 0;
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#ifdef PARANOID
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default:
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INTERNAL(0x141);
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return 0;
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#endif /* PARANOID */
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}
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switch (type)
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{
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case 000: /* fld m32real */
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clear_C1();
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loaded_tag = FPU_load_single(data_address, &loaded_data);
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if ( (loaded_tag == TAG_Special)
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&& isNaN(&loaded_data)
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&& (real_1op_NaN(&loaded_data) < 0) )
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{
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FPU_tos++;
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break;
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}
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FPU_copy_to_reg0(&loaded_data, loaded_tag);
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break;
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case 001: /* fild m32int */
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clear_C1();
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loaded_tag = FPU_load_int32(data_address, &loaded_data);
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FPU_copy_to_reg0(&loaded_data, loaded_tag);
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break;
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case 002: /* fld m64real */
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clear_C1();
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loaded_tag = FPU_load_double(data_address, &loaded_data);
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if ((loaded_tag == TAG_Special)
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&& isNaN(&loaded_data)
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&& (real_1op_NaN(&loaded_data) < 0))
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{
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FPU_tos++;
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break;
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}
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FPU_copy_to_reg0(&loaded_data, loaded_tag);
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break;
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case 003: /* fild m16int */
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clear_C1();
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loaded_tag = FPU_load_int16(data_address, &loaded_data);
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FPU_copy_to_reg0(&loaded_data, loaded_tag);
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break;
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case 010: /* fst m32real */
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clear_C1();
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FPU_store_single(st0_ptr, st0_tag, data_address);
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break;
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case 011: /* fist m32int */
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clear_C1();
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FPU_store_int32(st0_ptr, st0_tag, data_address);
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break;
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case 012: /* fst m64real */
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clear_C1();
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FPU_store_double(st0_ptr, st0_tag, data_address);
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break;
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case 013: /* fist m16int */
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clear_C1();
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FPU_store_int16(st0_ptr, st0_tag, data_address);
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break;
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case 014: /* fstp m32real */
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clear_C1();
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if ( FPU_store_single(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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case 015: /* fistp m32int */
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clear_C1();
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if ( FPU_store_int32(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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case 016: /* fstp m64real */
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clear_C1();
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if ( FPU_store_double(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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case 017: /* fistp m16int */
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clear_C1();
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if ( FPU_store_int16(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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case 020: /* fldenv m14/28byte */
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fldenv(addr_modes, data_address);
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/* Ensure that the values just loaded are not changed by
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fix-up operations. */
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return 1;
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case 022: /* frstor m94/108byte */
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frstor(addr_modes, data_address);
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/* Ensure that the values just loaded are not changed by
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fix-up operations. */
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return 1;
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case 023: /* fbld m80dec */
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clear_C1();
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loaded_tag = FPU_load_bcd(data_address);
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FPU_settag0(loaded_tag);
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break;
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case 024: /* fldcw */
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FPU_verify_area(VERIFY_READ, data_address, 2);
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FPU_get_user(FPU_control_word, data_address, 2);
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if ( FPU_partial_status & ~FPU_control_word & CW_Exceptions )
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FPU_partial_status |= (SW_Summary | SW_Backward);
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else
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FPU_partial_status &= ~(SW_Summary | SW_Backward);
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#ifdef PECULIAR_486
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FPU_control_word |= 0x40; /* An 80486 appears to always set this bit */
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#endif /* PECULIAR_486 */
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return 1;
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case 025: /* fld m80real */
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clear_C1();
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loaded_tag = FPU_load_extended(data_address, 0);
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FPU_settag0(loaded_tag);
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break;
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case 027: /* fild m64int */
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clear_C1();
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loaded_tag = FPU_load_int64(data_address);
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FPU_settag0(loaded_tag);
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break;
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case 030: /* fstenv m14/28byte */
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fstenv(addr_modes, data_address);
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return 1;
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case 032: /* fsave */
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fsave(addr_modes, data_address);
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return 1;
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case 033: /* fbstp m80dec */
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clear_C1();
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if ( FPU_store_bcd(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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case 034: /* fstcw m16int */
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FPU_verify_area(VERIFY_WRITE,data_address,2);
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FPU_put_user(FPU_control_word, data_address, 2);
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return 1;
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case 035: /* fstp m80real */
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clear_C1();
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if ( FPU_store_extended(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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case 036: /* fstsw m2byte */
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FPU_verify_area(VERIFY_WRITE,data_address,2);
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FPU_put_user(status_word(),data_address, 2);
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return 1;
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case 037: /* fistp m64int */
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clear_C1();
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if ( FPU_store_int64(st0_ptr, st0_tag, data_address) )
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pop_0(); /* pop only if the number was actually stored
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(see the 80486 manual p16-28) */
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break;
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}
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return 0;
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}
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