/* *  fpu_etc.c * * Implement a few FPU 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_etc.c,v 1.4.2.1 1999/09/05 08:09:40 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>#include <gnu/i386/fpemul/reg_constant.h>static voidfchs(void){	if (NOT_EMPTY_0) {		FPU_st0_ptr->sign ^= SIGN_POS ^ SIGN_NEG;		status_word &= ~SW_C1;	} else		stack_underflow();}static voidfabs(void){	if (FPU_st0_tag ^ TW_Empty) {		FPU_st0_ptr->sign = SIGN_POS;		status_word &= ~SW_C1;	} else		stack_underflow();}static voidftst_(void){	switch (FPU_st0_tag) {		case TW_Zero:		setcc(SW_C3);		break;	case TW_Valid:#ifdef DENORM_OPERAND		if ((FPU_st0_ptr->exp <= EXP_UNDER) && (denormal_operand()))			return;#endif				/* DENORM_OPERAND */		if (FPU_st0_ptr->sign == SIGN_POS)			setcc(0);		else			setcc(SW_C0);		break;	case TW_NaN:		setcc(SW_C0 | SW_C2 | SW_C3);	/* Operand is not comparable */		EXCEPTION(EX_Invalid);		break;	case TW_Infinity:		if (FPU_st0_ptr->sign == SIGN_POS)			setcc(0);		else			setcc(SW_C0);		EXCEPTION(EX_Invalid);		break;	case TW_Empty:		setcc(SW_C0 | SW_C2 | SW_C3);		EXCEPTION(EX_StackUnder);		break;	default:		setcc(SW_C0 | SW_C2 | SW_C3);	/* Operand is not comparable */		EXCEPTION(EX_INTERNAL | 0x14);		break;	}}static voidfxam(void){	int     c = 0;	switch (FPU_st0_tag) {	case TW_Empty:		c = SW_C3 | SW_C0;		break;	case TW_Zero:		c = SW_C3;		break;	case TW_Valid:		/* This will need to be changed if TW_Denormal is ever used. */		if (FPU_st0_ptr->exp <= EXP_UNDER)			c = SW_C2 | SW_C3;	/* Denormal */		else			c = SW_C3;		break;	case TW_NaN:		c = SW_C0;		break;	case TW_Infinity:		c = SW_C2 | SW_C0;		break;	}	if (FPU_st0_ptr->sign == SIGN_NEG)		c |= SW_C1;	setcc(c);}static FUNC fp_etc_table[] = {	fchs, fabs, Un_impl, Un_impl, ftst_, fxam, Un_impl, Un_impl};voidfp_etc(){	(fp_etc_table[FPU_rm]) ();}