newlib/libm/common/sf_lround.c

   1 /*
   2  * ====================================================
   3  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
   4  *
   5  * Developed at SunPro, a Sun Microsystems, Inc. business.
   6  * Permission to use, copy, modify, and distribute this
   7  * software is freely granted, provided that this notice
   8  * is preserved.
   9  * ====================================================
  10  */
  11
  12 #include "fdlibm.h"
  13
  14 #ifdef __STDC__
  15         long int lroundf(float x)
  16 #else
  17         long int lroundf(x)
  18         float x;
  19 #endif
  20 {
  21   __int32_t exponent_less_127;
  22   __uint32_t w;
  23   long int result;
  24   __int32_t sign;
  25
  26   GET_FLOAT_WORD (w, x);
  27   exponent_less_127 = ((w & 0x7f800000) >> 23) - 127;
  28   sign = (w & 0x80000000) != 0 ? -1 : 1;
  29   w &= 0x7fffff;
  30   w |= 0x800000;
  31
  32   if (exponent_less_127 < (int)((8 * sizeof (long int)) - 1))
  33     {
  34       if (exponent_less_127 < 0)
  35         return exponent_less_127 < -1 ? 0 : sign;
  36       else if (exponent_less_127 >= 23)
  37         result = (long int) w << (exponent_less_127 - 23);
  38       else
  39         {
  40           w += 0x400000 >> exponent_less_127;
  41           result = w >> (23 - exponent_less_127);
  42         }
  43     }
  44   else
  45       return (long int) x;
  46
  47   return sign * result;
  48 }
  49
  50 #ifdef _DOUBLE_IS_32BITS
  51
  52 #ifdef __STDC__
  53         long int lround(double x)
  54 #else
  55         long int lround(x)
  56         double x;
  57 #endif
  58 {
  59         return lroundf((float) x);
  60 }
  61
  62 #endif /* defined(_DOUBLE_IS_32BITS) */