/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

	.file	"_xtoull.s"

#include <SYS.h>

	.set	cw,0
	.set	cw_old,2
	.set	two_words,4
	.set	four_words,8
	.text
	.align	4
two_to_63: .long	0x5f000000

	ENTRY(__xtoull)	// 387-stack to unsigned long long
	subl	$12,%esp
	fstcw	cw_old(%esp)
	movw	cw_old(%esp),%ax
	movw	%ax,%cx
	andw	$0x0c00,%cx		// save RC
	orw	$0x0c00,%ax
	movw	%ax,cw(%esp)
	fldcw	cw(%esp)
	_prologue_
	fcoms	_sref_(two_to_63)	// compare st to 2**63
	_epilogue_
	fstsw	%ax			// store status in %ax
					// use fstsw for correct trap handling
	sahf				// load AH into flags
	jb	.donotsub		// jump if st < 2**63 or is NaN
	_prologue_
	fsubs	_sref_(two_to_63)	// subtract 2**63
	_epilogue_
.donotsub:
	fistpll	two_words(%esp)
	fwait				// in case fistpll causes exception
	movl	four_words(%esp),%edx
	jb	.donotadd		// flags did not change
	add	$0x80000000,%edx	// add back 2**63
.donotadd:
	fstcw	cw(%esp)		// fetch CW in case masks changed value
	movw	cw(%esp),%ax
	andw	$0xf3ff,%ax
	orw	%cx,%ax			// restore RC
	movw	%ax,cw(%esp)
	fldcw	cw(%esp)
	movl	two_words(%esp),%eax
	addl	$12,%esp
	ret
	SET_SIZE(__xtoull)