/*---------------------------------------------------------------------------+ | load_store.c | | $Id: load_store.c,v 1.12 2003-10-04 12:32:56 sshwarts Exp $ | | | 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 "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); FPU_tos++; } 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_ }; int FPU_load_store(u_char type, fpu_addr_modes addr_modes, bx_address 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 = (FPU_REG*) NULL; /* Initialized just to stop compiler warnings. */ 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; } FPU_tos--; st0_ptr = &st(0); } break; case _null_: FPU_illegal(); return 0; #ifdef PARANOID default: INTERNAL(0x141); return 0; #endif /* PARANOID */ } switch (type) { case 000: /* fld m32real */ clear_C1(); loaded_tag = FPU_load_single(data_address, &loaded_data); if ( (loaded_tag == TAG_Special) && isNaN(&loaded_data) && (real_1op_NaN(&loaded_data) < 0) ) { FPU_tos++; break; } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; case 001: /* fild m32int */ clear_C1(); loaded_tag = FPU_load_int32(data_address, &loaded_data); FPU_copy_to_reg0(&loaded_data, loaded_tag); break; case 002: /* fld m64real */ clear_C1(); loaded_tag = FPU_load_double(data_address, &loaded_data); if ((loaded_tag == TAG_Special) && isNaN(&loaded_data) && (real_1op_NaN(&loaded_data) < 0)) { FPU_tos++; break; } FPU_copy_to_reg0(&loaded_data, loaded_tag); break; case 003: /* fild m16int */ clear_C1(); loaded_tag = FPU_load_int16(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, data_address); break; case 011: /* fist m32int */ clear_C1(); FPU_store_int32(st0_ptr, st0_tag, data_address); break; case 012: /* fst m64real */ clear_C1(); FPU_store_double(st0_ptr, st0_tag, data_address); break; case 013: /* fist m16int */ clear_C1(); FPU_store_int16(st0_ptr, st0_tag, data_address); break; case 014: /* fstp m32real */ clear_C1(); if ( FPU_store_single(st0_ptr, st0_tag, 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, 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, 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, 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, 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, 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(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(FPU_control_word, data_address, 2); RE_ENTRANT_CHECK_ON; if ( FPU_partial_status & ~FPU_control_word & CW_Exceptions ) FPU_partial_status |= (SW_Summary | SW_Backward); else FPU_partial_status &= ~(SW_Summary | SW_Backward); #ifdef PECULIAR_486 FPU_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(data_address, 0); FPU_settag0(loaded_tag); break; case 027: /* fild m64int */ clear_C1(); loaded_tag = FPU_load_int64(data_address); FPU_settag0(loaded_tag); break; case 030: /* fstenv m14/28byte */ fstenv(addr_modes, data_address); return 1; case 032: /* fsave */ fsave(addr_modes, data_address); return 1; case 033: /* fbstp m80dec */ clear_C1(); if ( FPU_store_bcd(st0_ptr, st0_tag, 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(FPU_control_word, data_address, 2); RE_ENTRANT_CHECK_ON; return 1; case 035: /* fstp m80real */ clear_C1(); if ( FPU_store_extended(st0_ptr, st0_tag, 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(),data_address, 2); RE_ENTRANT_CHECK_ON; return 1; case 037: /* fistp m64int */ clear_C1(); if ( FPU_store_int64(st0_ptr, st0_tag, data_address) ) pop_0(); /* pop only if the number was actually stored (see the 80486 manual p16-28) */ break; } return 0; }