usr/src/lib/libc/i386/gen/wslen.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   "wslen.s"
  28
  29 /*
  30  * Wide character wcslen() implementation
  31  *
  32  * size_t
  33  * wcslen(const wchar_t *s)
  34  *{
  35  *      const wchar_t *s0 = s + 1;
  36  *      while (*s++)
  37  *              ;
  38  *      return (s - s0);
  39  *}
  40  */
  41
  42 #include "SYS.h"
  43
  44         ANSI_PRAGMA_WEAK(wcslen,function)
  45         ANSI_PRAGMA_WEAK(wslen,function)
  46
  47         ENTRY(wcslen)
  48         movl    4(%esp),%edx
  49         xorl    %eax,%eax
  50
  51         .align  8
  52 .loop:
  53         cmpl    $0,(%edx)
  54         je      .out0
  55         cmpl    $0,4(%edx)
  56         je      .out1
  57         cmpl    $0,8(%edx)
  58         je      .out2
  59         cmpl    $0,12(%edx)
  60         je      .out3
  61         addl    $4,%eax
  62         addl    $16,%edx
  63         jmp     .loop
  64
  65         .align  4
  66 .out1:
  67         incl    %eax
  68 .out0:
  69         ret
  70
  71         .align  4
  72 .out2:
  73         add     $2,%eax
  74         ret
  75
  76         .align  4
  77 .out3:
  78         add     $3, %eax
  79         ret
  80         SET_SIZE(wcslen)
  81
  82         ENTRY(wslen)
  83         _prologue_
  84         movl    _esp_(8),%eax
  85         movl    _esp_(4),%edx
  86         pushl   %eax
  87         pushl   %edx
  88         call    _fref_(wcslen)
  89         addl    $8,%esp
  90         _epilogue_
  91         ret
  92         SET_SIZE(wslen)