5261 libm should stop using synonyms.h
5298 fabs is 0-sized, confuses dis(1) and others
Reviewed by: Josef 'Jeff' Sipek <jeffpc@josefsipek.net>
Approved by: Gordon Ross <gwr@nexenta.com>

   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  * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  23  */
  24 /*
  25  * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  26  * Use is subject to license terms.
  27  */
  28 
  29         .file "isnan.s"
  30 
  31 #include "libm.h"
  32 LIBM_ANSI_PRAGMA_WEAK(isnan,function)
  33         .weak _isnan
  34         .type _isnan,@function
  35 _isnan  = __isnan
  36         .weak _isnand
  37         .type _isnand,@function
  38 _isnand = __isnan
  39         .weak isnand
  40         .type isnand,@function
  41 isnand  = __isnan
  42 #include "libm_synonyms.h"
  43 
  44         ENTRY(isnan)
  45         movl    8(%esp),%eax            / eax <-- hi_32(x)
  46         andl    $0x7fffffff,%eax        / eax <-- hi_32(abs(x))
  47         subl    $0x7ff00000,%eax        / weed out finite values
  48         jae     .nan_or_inf             / no jump if arg. is finite
  49         movl    $0,%eax                 / ansi needs (eax) = 0
  50         ret
  51 .nan_or_inf:
  52         ja      .got_nan                / no jump if arg. may be infinite;
  53                                         / let nan waste time
  54                                         / (eax) = 0 here
  55         testl   $0xffffffff,4(%esp)     / ZF <-- 1 iff lo_frac. = 0
  56                                         /          iff arg. is infinite
  57         jnz     .got_nan                / no jump if arg. is infinite;
  58         ret
  59 .got_nan:
  60         movl    $1,%eax                 / %eax was 0, must be made 1 to
  61                                         / indicate TRUE 
  62         ret
  63         .align  4
  64         SET_SIZE(isnan)
--- EOF ---