/* *  fpu_aux.c * * Code to implement some of the FPU auxiliary instructions. * * * 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/fpu_aux.c,v 1.5.2.1 1999/09/05 08:09:37 peter Exp $ * */#include <sys/param.h>#include <sys/proc.h>#include <machine/cpu.h>#include <machine/pcb.h>#include <gnu/i386/fpemul/fpu_emu.h>#include <gnu/i386/fpemul/fpu_system.h>#include <gnu/i386/fpemul/exception.h>#include <gnu/i386/fpemul/status_w.h>static voidfclex(void){	status_word &= ~(SW_Backward | SW_Summary | SW_Stack_Fault | SW_Precision |	    SW_Underflow | SW_Overflow | SW_Zero_Div | SW_Denorm_Op |	    SW_Invalid);	FPU_entry_eip = ip_offset;	/* We want no net effect */}/* Needs to be externally visible */voidfinit(){	int     r;	control_word = 0x037f;	status_word = 0;	top = 0;		/* We don't keep top in the status word				 * internally. */	for (r = 0; r < 8; r++) {		regs[r].tag = TW_Empty;	}	FPU_entry_eip = ip_offset = 0;}static FUNC finit_table[] = {	Un_impl, Un_impl, fclex, finit, Un_impl, Un_impl, Un_impl, Un_impl};voidfinit_(){	(finit_table[FPU_rm]) ();}static voidfstsw_ax(void){	status_word &= ~SW_Top;	status_word |= (top & 7) << SW_Top_Shift;	*(short *) &FPU_EAX = status_word;}static FUNC fstsw_table[] = {	fstsw_ax, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl};voidfstsw_(){	(fstsw_table[FPU_rm]) ();}static voidfnop(void){}static FUNC    fp_nop_table[] = {	fnop, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl, Un_impl};voidfp_nop(){	(fp_nop_table[FPU_rm]) ();}voidfld_i_(){	FPU_REG *st_new_ptr;	if (STACK_OVERFLOW) {		stack_overflow();		return;	}	/* fld st(i) */	if (NOT_EMPTY(FPU_rm)) {		reg_move(&st(FPU_rm), st_new_ptr);		push();	} else {		if (control_word & EX_Invalid) {			/* The masked response */			push();			stack_underflow();		} else			EXCEPTION(EX_StackUnder);	}}voidfxch_i(){	/* fxch st(i) */	FPU_REG t;	register FPU_REG *sti_ptr = &st(FPU_rm);	if (FPU_st0_tag == TW_Empty) {		if (sti_ptr->tag == TW_Empty) {			stack_underflow();			stack_underflow_i(FPU_rm);			return;		}		reg_move(sti_ptr, FPU_st0_ptr);		stack_underflow_i(FPU_rm);		return;	}	if (sti_ptr->tag == TW_Empty) {		reg_move(FPU_st0_ptr, sti_ptr);		stack_underflow();		return;	}	reg_move(FPU_st0_ptr, &t);	reg_move(sti_ptr, FPU_st0_ptr);	reg_move(&t, sti_ptr);}voidffree_(){	/* ffree st(i) */	st(FPU_rm).tag = TW_Empty;}voidffreep(){	/* ffree st(i) + pop - unofficial code */	st(FPU_rm).tag = TW_Empty;	pop();}voidfst_i_(){	/* fst st(i) */	reg_move(FPU_st0_ptr, &st(FPU_rm));}voidfstp_i(){	/* fstp st(i) */	reg_move(FPU_st0_ptr, &st(FPU_rm));	pop();}