/*
 * 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)