usr/src/lib/libc/i386/gen/lshiftl.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   "lshiftl.s"
  28
  29 / Shift a double long value.
  30
  31 #include "SYS.h"
  32
  33         .set    arg,8
  34         .set    cnt,16
  35         .set    ans,0
  36
  37         ENTRY(lshiftl)
  38         popl    %eax
  39         xchgl   %eax,0(%esp)
  40
  41         pushl   %eax
  42         movl    arg(%esp),%eax
  43         movl    arg+4(%esp),%edx
  44         movl    cnt(%esp),%ecx
  45         orl     %ecx,%ecx
  46         jz      .lshiftld
  47         jns     .lshiftlp
  48
  49 / We are doing a negative (right) shift
  50
  51         negl    %ecx
  52
  53 .lshiftln:
  54         sarl    $1,%edx
  55         rcrl    $1,%eax
  56         loop    .lshiftln
  57         jmp     .lshiftld
  58
  59 / We are doing a positive (left) shift
  60
  61 .lshiftlp:
  62         shll    $1,%eax
  63         rcll    $1,%edx
  64         loop    .lshiftlp
  65
  66 / We are done.
  67
  68 .lshiftld:
  69         movl    %eax,%ecx
  70         popl    %eax
  71         movl    %ecx,ans(%eax)
  72         movl    %edx,ans+4(%eax)
  73
  74         ret
  75         SET_SIZE(lshiftl)