Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /* sf_frexp.c -- float version of s_frexp.c.
  2.  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
  3.  */
  4.  
  5. /*
  6.  * ====================================================
  7.  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
  8.  *
  9.  * Developed at SunPro, a Sun Microsystems, Inc. business.
  10.  * Permission to use, copy, modify, and distribute this
  11.  * software is freely granted, provided that this notice
  12.  * is preserved.
  13.  * ====================================================
  14.  */
  15.  
  16. #include "fdlibm.h"
  17.  
  18. #ifdef __STDC__
  19. static const float
  20. #else
  21. static float
  22. #endif
  23. two25 =  3.3554432000e+07; /* 0x4c000000 */
  24.  
  25. #ifdef __STDC__
  26.         float frexpf(float x, int *eptr)
  27. #else
  28.         float frexpf(x, eptr)
  29.         float x; int *eptr;
  30. #endif
  31. {
  32.         __int32_t hx, ix;
  33.         GET_FLOAT_WORD(hx,x);
  34.         ix = 0x7fffffff&hx;
  35.         *eptr = 0;
  36.         if(!FLT_UWORD_IS_FINITE(ix)||FLT_UWORD_IS_ZERO(ix)) return x;   /* 0,inf,nan */
  37.         if (FLT_UWORD_IS_SUBNORMAL(ix)) {               /* subnormal */
  38.             x *= two25;
  39.             GET_FLOAT_WORD(hx,x);
  40.             ix = hx&0x7fffffff;
  41.             *eptr = -25;
  42.         }
  43.         *eptr += (ix>>23)-126;
  44.         hx = (hx&0x807fffff)|0x3f000000;
  45.         SET_FLOAT_WORD(x,hx);
  46.         return x;
  47. }
  48.  
  49. #ifdef _DOUBLE_IS_32BITS
  50.  
  51. #ifdef __STDC__
  52.         double frexp(double x, int *eptr)
  53. #else
  54.         double frexp(x, eptr)
  55.         double x; int *eptr;
  56. #endif
  57. {
  58.         return (double) frexpf((float) x, eptr);
  59. }
  60.  
  61. #endif /* defined(_DOUBLE_IS_32BITS) */
  62.