newlib/libm/common/sf_llround.c

   1 /* lroundf adapted to be llroundf for Newlib, 2009 by Craig Howland.  */
   2 /*
   3  * ====================================================
   4  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   5  *
   6  * Developed at SunPro, a Sun Microsystems, Inc. business.
   7  * Permission to use, copy, modify, and distribute this
   8  * software is freely granted, provided that this notice
   9  * is preserved.
  10  * ====================================================
  11  */
  12
  13 #include "fdlibm.h"
  14
  15 long long int
  16 llroundf(float x)
  17 {
  18   __int32_t exponent_less_127;
  19   __uint32_t w;
  20   long long int result;
  21   __int32_t sign;
  22
  23   GET_FLOAT_WORD (w, x);
  24   exponent_less_127 = ((w & 0x7f800000) >> 23) - 127;
  25   sign = (w & 0x80000000) != 0 ? -1 : 1;
  26   w &= 0x7fffff;
  27   w |= 0x800000;
  28
  29   if (exponent_less_127 < (int)((8 * sizeof (long long int)) - 1))
  30     {
  31       if (exponent_less_127 < 0)
  32         return exponent_less_127 < -1 ? 0 : sign;
  33       else if (exponent_less_127 >= 23)
  34         result = (long long int) w << (exponent_less_127 - 23);
  35       else
  36         {
  37           w += 0x400000 >> exponent_less_127;
  38           result = w >> (23 - exponent_less_127);
  39         }
  40     }
  41   else
  42       return (long long int) x;
  43
  44   return sign * result;
  45 }
  46
  47 #ifdef _DOUBLE_IS_32BITS
  48
  49 long long int
  50 llround(double x)
  51 {
  52         return llroundf((float) x);
  53 }
  54
  55 #endif /* defined(_DOUBLE_IS_32BITS) */