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>

          --- old/usr/src/lib/libm/common/C/scalb.c
          +++ new/usr/src/lib/libm/common/C/scalb.c

   1    1  /*
   2    2   * CDDL HEADER START
   3    3   *
   4    4   * The contents of this file are subject to the terms of the
   5    5   * Common Development and Distribution License (the "License").
   6    6   * You may not use this file except in compliance with the License.
   7    7   *
   8    8   * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
   9    9   * or http://www.opensolaris.org/os/licensing.
  10   10   * See the License for the specific language governing permissions
  11   11   * and limitations under the License.
  12   12   *
  13   13   * When distributing Covered Code, include this CDDL HEADER in each
  14   14   * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
  15   15   * If applicable, add the following below this CDDL HEADER, with the
  16   16   * fields enclosed by brackets "[]" replaced with your own identifying
  17   17   * information: Portions Copyright [yyyy] [name of copyright owner]
  18   18   *

  19   19   * CDDL HEADER END
  20   20   */
  21   21  /*
  22   22   * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  23   23   */
  24   24  /*
  25   25   * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  26   26   * Use is subject to license terms.
  27   27   */
  28   28  
  29      -#pragma weak scalb = __scalb
  30      -#pragma weak _scalb = __scalb
       29 +#pragma weak __scalb = scalb
       30 +#pragma weak _scalb = scalb
  31   31  
  32   32  #include "libm.h"
  33   33  
  34   34  double
  35   35  scalb(double x, double fn) {
  36   36          int     hn, in, n;
  37   37          double  z;
  38   38  
  39   39          if (isnan(x) || isnan(fn))
  40   40                  return (x * fn);

  41   41  
  42   42          in = ((int *)&fn)[HIWORD];
  43   43          hn = in & ~0x80000000;
  44   44          if (hn == 0x7ff00000)   /* fn is inf */
  45   45                  return (_SVID_libm_err(x, fn, 47));
  46   46  
  47   47          /* see if fn is an integer without raising inexact */
  48   48          if (hn >= 0x43300000) {
  49   49                  /* |fn| >= 2^52, so it must be an integer */
  50   50                  n = (in < 0)? -65000 : 65000;
  51   51          } else if (hn < 0x3ff00000) {
  52   52                  /* |fn| < 1, so it must be zero or non-integer */
  53   53                  return ((fn == 0.0)? x : (x - x) / (x - x));
  54   54          } else if (hn < 0x41400000) {
  55   55                  /* |fn| < 2^21 */
  56   56                  if ((hn & ((1 << (0x413 - (hn >> 20))) - 1))
  57   57                      | ((int *)&fn)[LOWORD])
  58   58                          return ((x - x) / (x - x));
  59   59                  n = (int)fn;
  60   60          } else {
  61   61                  if (((int *)&fn)[LOWORD] & ((1 << (0x433 - (hn >> 20))) - 1))
  62   62                          return ((x - x) / (x - x));
  63   63                  n = (in < 0)? -65000 : 65000;
  64   64          }
  65   65          z = scalbn(x, n);
  66   66          if (z != x) {
  67   67                  if (z == 0.0)
  68   68                          return (_SVID_libm_err(x, fn, 33));
  69   69                  if (!finite(z))
  70   70                          return (_SVID_libm_err(x, fn, 32));
  71   71          }
  72   72          return (z);
  73   73  }

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