5261 libm should stop using synonyms.h

          --- old/usr/src/lib/libm/common/C/ilogb.c
          +++ new/usr/src/lib/libm/common/C/ilogb.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 ilogb = __ilogb
       30 +#pragma weak __ilogb = ilogb
  31   31  
  32   32  #include "libm.h"
  33   33  #include "xpg6.h"       /* __xpg6 */
  34   34  
  35   35  #if defined(__x86)
  36   36  static const double two52 = 4503599627370496.0;
  37   37  #else
  38   38  /*
  39   39   * v: high part of a non-zero subnormal |x|; w: low part of |x|
  40   40   */

  41   41  static int
  42   42  ilogb_subnormal(unsigned v, unsigned w) {
  43   43          int r = -1022 - 52;
  44   44  
  45   45          if (v)
  46   46                  r += 32;
  47   47          else
  48   48                  v = w;
  49   49          if (v & 0xffff0000)
  50   50                  r += 16, v >>= 16;
  51   51          if (v & 0xff00)
  52   52                  r += 8, v >>= 8;
  53   53          if (v & 0xf0)
  54   54                  r += 4, v >>= 4;
  55   55          v <<= 1;
  56   56          return (r + ((0xffffaa50 >> v) & 0x3));
  57   57  }
  58   58  #endif  /* defined(__x86) */
  59   59  
  60   60  static int
  61   61  raise_invalid(int v) {  /* SUSv3 requires ilogb(0,+/-Inf,NaN) raise invalid */
  62   62  #ifndef lint
  63   63          if ((__xpg6 & _C99SUSv3_ilogb_0InfNaN_raises_invalid) != 0) {
  64   64                  static const double zero = 0.0;
  65   65                  volatile double dummy;
  66   66  
  67   67                  dummy = zero / zero;
  68   68          }
  69   69  #endif
  70   70          return (v);
  71   71  }
  72   72  
  73   73  int
  74   74  ilogb(double x) {
  75   75          int *px = (int *) &x, k = px[HIWORD] & ~0x80000000;
  76   76  
  77   77          if (k < 0x00100000) {
  78   78                  if ((px[LOWORD] | k) == 0)
  79   79                          return (raise_invalid(0x80000001));
  80   80                  else {
  81   81  #if defined(__x86)
  82   82                          x *= two52;
  83   83                          return (((px[HIWORD] & 0x7ff00000) >> 20) - 1075);
  84   84  #else
  85   85                          return (ilogb_subnormal(k, px[LOWORD]));
  86   86  #endif
  87   87                  }
  88   88          } else if (k < 0x7ff00000)
  89   89                  return ((k >> 20) - 1023);
  90   90          else
  91   91                  return (raise_invalid(0x7fffffff));
  92   92  }

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