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/asinh.c
          +++ new/usr/src/lib/libm/common/C/asinh.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  /*
  23   23   * Copyright 2011 Nexenta Systems, Inc.  All rights reserved.
  24   24   */
  25   25  /*
  26   26   * Copyright 2006 Sun Microsystems, Inc.  All rights reserved.
  27   27   * Use is subject to license terms.
  28   28   */
  29   29  
  30      -#pragma weak asinh = __asinh
       30 +#pragma weak __asinh = asinh
  31   31  
  32   32  /* INDENT OFF */
  33   33  /*
  34   34   * asinh(x)
  35   35   * Method :
  36   36   *      Based on
  37   37   *              asinh(x) = sign(x) * log [ |x| + sqrt(x*x+1) ]
  38   38   *      we have
  39   39   *      asinh(x) := x  if  1+x*x == 1,
  40   40   *               := sign(x)*(log(x)+ln2)) for large |x|, else
  41   41   *               := sign(x)*log(2|x|+1/(|x|+sqrt(x*x+1))) if|x| > 2, else
  42   42   *               := sign(x)*log1p(|x|+x^2/(1+sqrt(1+x^2)))
  43   43   */
  44   44  /* INDENT ON */
  45   45  
  46      -#include "libm_synonyms.h"      /* __asinh */
  47   46  #include "libm_macros.h"
  48   47  #include <math.h>
  49   48  
  50   49  static const double xxx[] = {
  51   50  /* one */       1.00000000000000000000e+00,     /* 3FF00000, 00000000 */
  52   51  /* ln2 */       6.93147180559945286227e-01,     /* 3FE62E42, FEFA39EF */
  53   52  /* huge */      1.00000000000000000000e+300
  54   53  };
  55   54  #define one     xxx[0]
  56   55  #define ln2     xxx[1]

  57   56  #define huge    xxx[2]
  58   57  
  59   58  double
  60   59  asinh(double x) {
  61   60          double t, w;
  62   61          int hx, ix;
  63   62  
  64   63          hx = ((int *) &x)[HIWORD];
  65   64          ix = hx & 0x7fffffff;
  66   65          if (ix >= 0x7ff00000)
  67   66  #if defined(FPADD_TRAPS_INCOMPLETE_ON_NAN)
  68   67                  return (ix >= 0x7ff80000 ? x : x + x);
  69   68                  /* assumes sparc-like QNaN */
  70   69  #else
  71   70                  return (x + x); /* x is inf or NaN */
  72   71  #endif
  73   72          if (ix < 0x3e300000) {  /* |x|<2**-28 */
  74   73                  if (huge + x > one)
  75   74                          return (x);     /* return x inexact except 0 */
  76   75          }
  77   76          if (ix > 0x41b00000) {  /* |x| > 2**28 */
  78   77                  w = log(fabs(x)) + ln2;
  79   78          } else if (ix > 0x40000000) {
  80   79                  /* 2**28 > |x| > 2.0 */
  81   80                  t = fabs(x);
  82   81                  w = log(2.0 * t + one / (sqrt(x * x + one) + t));
  83   82          } else {
  84   83                  /* 2.0 > |x| > 2**-28 */
  85   84                  t = x * x;
  86   85                  w = log1p(fabs(x) + t / (one + sqrt(one + t)));
  87   86          }
  88   87          return (hx > 0 ? w : -w);
  89   88  }

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