/* * 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 * All rights reserved. * * This copyright notice covers the redistribution and use of the * FPU emulator developed by W. Metzenthen. It covers only its use * in the 386BSD, FreeBSD and NetBSD operating systems. Any other * use is not permitted under this copyright. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must include information specifying * that source code for the emulator is freely available and include * either: * a) an offer to provide the source code for a nominal distribution * fee, or * b) list at least two alternative methods whereby the source * can be obtained, e.g. a publically accessible bulletin board * and an anonymous ftp site from which the software can be * downloaded. * 3. All advertising materials specifically mentioning features or use of * this emulator must acknowledge that it was developed by W. Metzenthen. * 4. The name of W. Metzenthen may not be used to endorse or promote * products derived from this software without specific prior written * permission. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL * W. METZENTHEN BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. * * * The purpose of this copyright, based upon the Berkeley copyright, is to * ensure that the covered software remains freely available to everyone. * * The software (with necessary differences) is also available, but under * the terms of the GNU copyleft, for the Linux operating system and for * the djgpp ms-dos extender. * * W. Metzenthen June 1994. * * * $FreeBSD: src/sys/gnu/i386/fpemul/load_store.c,v 1.13 1999/08/28 00:42:52 peter Exp $ * $DragonFly: src/sys/i386/gnu/fpemul/Attic/load_store.c,v 1.2 2003/06/17 04:28:34 dillon Exp $ * */ /*---------------------------------------------------------------------------+ | 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 #include #include #include #include #include #include #define _NONE_ 0 /* FPU_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() { pop_ptr->tag = TW_Empty; top++; } static unsigned char 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_ }; void load_store_instr(char type) { FPU_REG *pop_ptr; /* We need a version of FPU_st0_ptr which * won't change. */ pop_ptr = NULL; /* Initialized just to stop compiler warnings. */ switch (type_table[(int) (unsigned) type]) { case _NONE_: break; case _REG0_: pop_ptr = &st(0); /* Some of these instructions pop * after storing */ FPU_st0_ptr = pop_ptr; /* Set the global variables. */ FPU_st0_tag = FPU_st0_ptr->tag; break; case _PUSH_: { pop_ptr = &st(-1); if (pop_ptr->tag != TW_Empty) { stack_overflow(); return; } top--; } break; case _null_: Un_impl(); return; #ifdef PARANOID default: return EXCEPTION(EX_INTERNAL); #endif /* PARANOID */ } switch (type) { case 000: /* fld m32real */ reg_load_single(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 001: /* fild m32int */ reg_load_int32(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 002: /* fld m64real */ reg_load_double(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 003: /* fild m16int */ reg_load_int16(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 010: /* fst m32real */ reg_store_single(); break; case 011: /* fist m32int */ reg_store_int32(); break; case 012: /* fst m64real */ reg_store_double(); break; case 013: /* fist m16int */ reg_store_int16(); break; case 014: /* fstp m32real */ if (reg_store_single()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; case 015: /* fistp m32int */ if (reg_store_int32()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; case 016: /* fstp m64real */ if (reg_store_double()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; case 017: /* fistp m16int */ if (reg_store_int16()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; case 020: /* fldenv m14/28byte */ fldenv(); break; case 022: /* frstor m94/108byte */ frstor(); break; case 023: /* fbld m80dec */ reg_load_bcd(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 024: /* fldcw */ REENTRANT_CHECK(OFF); control_word = fusword((unsigned short *) FPU_data_address); REENTRANT_CHECK(ON); #ifdef NO_UNDERFLOW_TRAP if (!(control_word & EX_Underflow)) { control_word |= EX_Underflow; } #endif /* We want no net effect: */ FPU_data_address = (void *) (intptr_t) data_operand_offset; FPU_entry_eip = ip_offset; /* We want no net effect */ break; case 025: /* fld m80real */ reg_load_extended(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 027: /* fild m64int */ reg_load_int64(); setcc(0); /* Clear the SW_C1 bit, "other bits undefined" */ reg_move(&FPU_loaded_data, pop_ptr); break; case 030: /* fstenv m14/28byte */ fstenv(); /* We want no net effect: */ FPU_data_address = (void *) (intptr_t) data_operand_offset; FPU_entry_eip = ip_offset; /* We want no net effect */ break; case 032: /* fsave */ fsave(); /* We want no net effect: */ FPU_data_address = (void *) (intptr_t) data_operand_offset; FPU_entry_eip = ip_offset; /* We want no net effect */ break; case 033: /* fbstp m80dec */ if (reg_store_bcd()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; case 034: /* fstcw m16int */ REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, FPU_data_address, 2);*/ susword( (short *) FPU_data_address,control_word); REENTRANT_CHECK(ON); /* We want no net effect: */ FPU_data_address = (void *) (intptr_t ) data_operand_offset; FPU_entry_eip = ip_offset; /* We want no net effect */ break; case 035: /* fstp m80real */ if (reg_store_extended()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; case 036: /* fstsw m2byte */ status_word &= ~SW_Top; status_word |= (top & 7) << SW_Top_Shift; REENTRANT_CHECK(OFF); /* verify_area(VERIFY_WRITE, FPU_data_address, 2);*/ susword( (short *) FPU_data_address,status_word); REENTRANT_CHECK(ON); /* We want no net effect: */ FPU_data_address = (void *) (intptr_t) data_operand_offset; FPU_entry_eip = ip_offset; /* We want no net effect */ break; case 037: /* fistp m64int */ if (reg_store_int64()) pop_0();/* pop only if the number was actually stored * (see the 80486 manual p16-28) */ break; } }