.file	"reg_div.S"/* *  reg_div.S * * Divide one FPU_REG by another and put the result in a destination FPU_REG. * * Call from C as: *   void reg_div(FPU_REG *a, FPU_REG *b, FPU_REG *dest, * * * 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/reg_div.s,v 1.4.2.1 1999/09/05 08:09:52 peter Exp $ * */#include <gnu/i386/fpemul/exception.h>#include <gnu/i386/fpemul/fpu_asm.h>#include <gnu/i386/fpemul/control_w.h>.text	.align 2.globl	_reg_div_reg_div:	pushl	%ebp	movl	%esp,%ebp	pushl	%esi	pushl	%edi	pushl	%ebx	movl	PARAM1,%esi	movl	PARAM2,%ebx	movl	PARAM3,%edi	movb	TAG(%esi),%al	orb	TAG(%ebx),%al	jne	L_div_special		/* Not (both numbers TW_Valid) */#ifdef DENORM_OPERAND/* Check for denormals */	cmpl	EXP_UNDER,EXP(%esi)	jg	xL_arg1_not_denormal	call	_denormal_operand	orl	%eax,%eax	jnz	FPU_Arith_exitxL_arg1_not_denormal:	cmpl	EXP_UNDER,EXP(%ebx)	jg	xL_arg2_not_denormal	call	_denormal_operand	orl	%eax,%eax	jnz	FPU_Arith_exitxL_arg2_not_denormal:#endif DENORM_OPERAND/* Both arguments are TW_Valid */	movb	TW_Valid,TAG(%edi)	movb	SIGN(%esi),%cl	cmpb	%cl,SIGN(%ebx)	setne	(%edi)	   /* Set the sign, requires SIGN_NEG=1, SIGN_POS=0 */	movl	EXP(%esi),%edx	movl	EXP(%ebx),%eax	subl	%eax,%edx	addl	EXP_BIAS,%edx	movl	%edx,EXP(%edi)	jmp	_divide_kernel/*-----------------------------------------------------------------------*/L_div_special:	cmpb	TW_NaN,TAG(%esi)	/* A NaN with anything to give NaN */	je	L_arg1_NaN	cmpb	TW_NaN,TAG(%ebx)	/* A NaN with anything to give NaN */	jne	L_no_NaN_arg/*  Operations on NaNs */L_arg1_NaN:L_arg2_NaN:	pushl	%edi			/* Destination */	pushl	%ebx	pushl	%esi	call	_real_2op_NaN	jmp	LDiv_exit/* Invalid operations */L_zero_zero:L_inf_inf:	pushl	%edi			/* Destination */	call	_arith_invalid		/* 0/0 or Infinity/Infinity */	jmp	LDiv_exitL_no_NaN_arg:	cmpb	TW_Infinity,TAG(%esi)	jne	L_arg1_not_inf	cmpb	TW_Infinity,TAG(%ebx)	je	L_inf_inf		/* invalid operation */	cmpb	TW_Valid,TAG(%ebx)	je	L_inf_valid#ifdef PARANOID	/* arg2 must be zero or valid */	cmpb	TW_Zero,TAG(%ebx)	ja	L_unknown_tags#endif PARANOID	/* Note that p16-9 says that infinity/0 returns infinity */	jmp	L_copy_arg1		/* Answer is Inf */L_inf_valid:#ifdef DENORM_OPERAND	cmpl	EXP_UNDER,EXP(%ebx)	jg	L_copy_arg1		/* Answer is Inf */	call	_denormal_operand	orl	%eax,%eax	jnz	FPU_Arith_exit#endif DENORM_OPERAND	jmp	L_copy_arg1		/* Answer is Inf */L_arg1_not_inf:	cmpb	TW_Zero,TAG(%ebx)	/* Priority to div-by-zero error */	jne	L_arg2_not_zero	cmpb	TW_Zero,TAG(%esi)	je	L_zero_zero		/* invalid operation */#ifdef PARANOID	/* arg1 must be valid */	cmpb	TW_Valid,TAG(%esi)	ja	L_unknown_tags#endif PARANOID/* Division by zero error */	pushl	%edi			/* destination */	movb	SIGN(%esi),%al	xorb	SIGN(%ebx),%al	pushl	%eax			/* lower 8 bits have the sign */	call	_divide_by_zero	jmp	LDiv_exitL_arg2_not_zero:	cmpb	TW_Infinity,TAG(%ebx)	jne	L_arg2_not_inf#ifdef DENORM_OPERAND	cmpb	TW_Valid,TAG(%esi)	jne	L_return_zero	cmpl	EXP_UNDER,EXP(%esi)	jg	L_return_zero		/* Answer is zero */	call	_denormal_operand	orl	%eax,%eax	jnz	FPU_Arith_exit#endif DENORM_OPERAND	jmp	L_return_zero		/* Answer is zero */L_arg2_not_inf:#ifdef PARANOID	cmpb	TW_Zero,TAG(%esi)	jne	L_unknown_tags#endif PARANOID	/* arg1 is zero, arg2 is not Infinity or a NaN */#ifdef DENORM_OPERAND	cmpl	EXP_UNDER,EXP(%ebx)	jg	L_copy_arg1		/* Answer is zero */	call	_denormal_operand	orl	%eax,%eax	jnz	FPU_Arith_exit#endif DENORM_OPERANDL_copy_arg1:	movb	TAG(%esi),%ax	movb	%ax,TAG(%edi)	movl	EXP(%esi),%eax	movl	%eax,EXP(%edi)	movl	SIGL(%esi),%eax	movl	%eax,SIGL(%edi)	movl	SIGH(%esi),%eax	movl	%eax,SIGH(%edi)	movb	SIGN(%esi),%cl	cmpb	%cl,SIGN(%ebx)	jne	LDiv_negative_result	movb	SIGN_POS,SIGN(%edi)	jmp	LDiv_exitLDiv_set_result_sign:	movb	SIGN(%esi),%cl	cmpb	%cl,SIGN(%edi)	jne	LDiv_negative_result	movb	SIGN_POS,SIGN(%ebx)	jmp	LDiv_exitLDiv_negative_result:	movb	SIGN_NEG,SIGN(%edi)LDiv_exit:	leal	-12(%ebp),%esp	popl	%ebx	popl	%edi	popl	%esi	leave	retL_return_zero:	movb	TW_Zero,TAG(%edi)	jmp	LDiv_set_result_sign#ifdef PARANOIDL_unknown_tags:	push	EX_INTERNAL | 0x208	call	EXCEPTION	/* Generate a NaN for unknown tags */	movl	_CONST_QNaN,%eax	movl	%eax,(%edi)	movl	_CONST_QNaN+4,%eax	movl	%eax,SIGL(%edi)	movl	_CONST_QNaN+8,%eax	movl	%eax,SIGH(%edi)	jmp	LDiv_exit#endif PARANOID