root/usr/src/lib/libc/i386/gen/lmul.S
/*
 * 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.
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/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

        .file   "lmul.s"

/ Double long multiply routine.

#include "SYS.h"

        .set    lop,8
        .set    rop,16
        .set    ans,0

        ENTRY(lmul)
        popl    %eax
        xchgl   %eax,0(%esp)

        pushl   %eax

        movl    lop+4(%esp),%eax
        mull    rop(%esp)       / high(lop) * low(rop)
        movl    %eax,%ecx       / partial high(product)

        movl    rop+4(%esp),%eax
        mull    lop(%esp)       / high(rop) * low(lop)
        addl    %eax,%ecx       / partial sum of high(product)

        movl    rop(%esp),%eax
        mull    lop(%esp)       / low(rop) * low(lop)
        addl    %edx,%ecx       / final high(product)

        movl    %eax,%edx
        popl    %eax
        movl    %edx,ans(%eax)
        movl    %ecx,ans+4(%eax)

        ret
        SET_SIZE(lmul)