usr/src/lib/libc/i386/gen/lmul.s

   1 /*
   2  * CDDL HEADER START
   3  *
   4  * The contents of this file are subject to the terms of the
   5  * Common Development and Distribution License (the "License").
   6  * You may not use this file except in compliance with the License.
   7  *
   8  * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9  * or http://www.opensolaris.org/os/licensing.
  10  * See the License for the specific language governing permissions
  11  * and limitations under the License.
  12  *
  13  * When distributing Covered Code, include this CDDL HEADER in each
  14  * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15  * If applicable, add the following below this CDDL HEADER, with the
  16  * fields enclosed by brackets "[]" replaced with your own identifying
  17  * information: Portions Copyright [yyyy] [name of copyright owner]
  18  *
  19  * CDDL HEADER END
  20  */
  21
  22 /*
  23  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  24  * Use is subject to license terms.
  25  */
  26
  27         .file   "lmul.s"
  28
  29 / Double long multiply routine.
  30
  31 #include "SYS.h"
  32
  33         .set    lop,8
  34         .set    rop,16
  35         .set    ans,0
  36
  37         ENTRY(lmul)
  38         popl    %eax
  39         xchgl   %eax,0(%esp)
  40
  41         pushl   %eax
  42
  43         movl    lop+4(%esp),%eax
  44         mull    rop(%esp)       / high(lop) * low(rop)
  45         movl    %eax,%ecx       / partial high(product)
  46
  47         movl    rop+4(%esp),%eax
  48         mull    lop(%esp)       / high(rop) * low(lop)
  49         addl    %eax,%ecx       / partial sum of high(product)
  50
  51         movl    rop(%esp),%eax
  52         mull    lop(%esp)       / low(rop) * low(lop)
  53         addl    %edx,%ecx       / final high(product)
  54
  55         movl    %eax,%edx
  56         popl    %eax
  57         movl    %edx,ans(%eax)
  58         movl    %ecx,ans+4(%eax)
  59
  60         ret
  61         SET_SIZE(lmul)