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/nextafter.c
          +++ new/usr/src/lib/libm/common/C/nextafter.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 nextafter = __nextafter
  30      -#pragma weak _nextafter = __nextafter
       29 +#pragma weak __nextafter = nextafter
       30 +#pragma weak _nextafter = nextafter
  31   31  
  32   32  #include "libm.h"
  33   33  #include <float.h>              /* DBL_MIN */
  34   34  
  35   35  double
  36   36  nextafter(double x, double y) {
  37   37          int             hx, hy, k;
  38   38          double          ans;
  39   39          unsigned        lx;
  40   40          volatile double dummy;

  41   41  
  42   42          hx = ((int *)&x)[HIWORD];
  43   43          lx = ((int *)&x)[LOWORD];
  44   44          hy = ((int *)&y)[HIWORD];
  45   45          k = (hx & ~0x80000000) | lx;
  46   46  
  47   47          if (x == y)
  48   48                  return (y);             /* C99 requirement */
  49   49          if (x != x || y != y)
  50   50                  return (x * y);
  51   51          if (k == 0) {                   /* x = 0 */
  52   52                  k = hy & 0x80000000;
  53   53                  ((int *)&ans)[HIWORD] = k;
  54   54                  ((int *)&ans)[LOWORD] = 1;
  55   55          } else if (hx >= 0) {
  56   56                  if (x > y) {
  57   57                          ((int *)&ans)[LOWORD] = lx - 1;
  58   58                          k = (lx == 0)? hx - 1 : hx;
  59   59                          ((int *)&ans)[HIWORD] = k;
  60   60                  } else {
  61   61                          ((int *)&ans)[LOWORD] = lx + 1;
  62   62                          k  = (lx == 0xffffffff)? hx + 1 : hx;
  63   63                          ((int *)&ans)[HIWORD] = k;
  64   64                  }
  65   65          } else {
  66   66                  if (x < y) {
  67   67                          ((int *)&ans)[LOWORD] = lx - 1;
  68   68                          k = (lx == 0)? hx - 1 : hx;
  69   69                          ((int *)&ans)[HIWORD] = k;
  70   70                  } else {
  71   71                          ((int *)&ans)[LOWORD] = lx + 1;
  72   72                          k  = (lx == 0xffffffff)? hx + 1 : hx;
  73   73                          ((int *)&ans)[HIWORD] = k;
  74   74                  }
  75   75          }
  76   76          k = (k >> 20) & 0x7ff;
  77   77          if (k == 0x7ff) {
  78   78                  /* overflow */
  79   79                  return (_SVID_libm_err(x, y, 46));
  80   80  #if !defined(__lint)
  81   81          } else if (k == 0) {
  82   82                  /* underflow */
  83   83                  dummy = DBL_MIN * copysign(DBL_MIN, x);
  84   84  #endif
  85   85          }
  86   86          return (ans);
  87   87  }

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