sysdeps/m68k/fpu/s_ilogb.c

   1 /* Copyright (C) 1996, 1997, 1999 Free Software Foundation, Inc.
   2    This file is part of the GNU C Library.
   3
   4    The GNU C Library is free software; you can redistribute it and/or
   5    modify it under the terms of the GNU Lesser General Public
   6    License as published by the Free Software Foundation; either
   7    version 2.1 of the License, or (at your option) any later version.
   8
   9    The GNU C Library is distributed in the hope that it will be useful,
  10    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12    Lesser General Public License for more details.
  13
  14    You should have received a copy of the GNU Lesser General Public
  15    License along with the GNU C Library; if not, write to the Free
  16    Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
  17    02111-1307 USA.  */
  18
  19 #include <math.h>
  20 #include "mathimpl.h"
  21
  22 #ifndef SUFF
  23 #define SUFF
  24 #endif
  25 #ifndef float_type
  26 #define float_type double
  27 #endif
  28
  29 #define CONCATX(a,b) __CONCAT(a,b)
  30 #define s(name) CONCATX(name,SUFF)
  31 #define m81(func) __m81_u(s(func))
  32
  33 int
  34 s(__ilogb) (float_type x)
  35 {
  36   float_type result;
  37   unsigned long x_cond;
  38
  39   x_cond = __m81_test (x);
  40   /* We must return consistent values for zero and NaN.  */
  41   if (x_cond & __M81_COND_ZERO)
  42     return FP_ILOGB0;
  43   if (x_cond & (__M81_COND_NAN | __M81_COND_INF))
  44     return FP_ILOGBNAN;
  45
  46   __asm ("fgetexp%.x %1, %0" : "=f" (result) : "f" (x));
  47   return (int) result;
  48 }
  49
  50 #define weak_aliasx(a,b) weak_alias(a,b)
  51 weak_aliasx (s(__ilogb), s(ilogb))