toolchain/gcc/newlib/libm/common/sf_modf.c

   1 /* sf_modf.c -- float version of s_modf.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 one = 1.0;
  20 #else
  21 static float one = 1.0;
  22 #endif
  23
  24 #ifdef __STDC__
  25         float modff(float x, float *iptr)
  26 #else
  27         float modff(x, iptr)
  28         float x,*iptr;
  29 #endif
  30 {
  31         __int32_t i0,j0;
  32         __uint32_t i;
  33         GET_FLOAT_WORD(i0,x);
  34         j0 = ((i0>>23)&0xff)-0x7f;      /* exponent of x */
  35         if(j0<23) {                     /* integer part in x */
  36             if(j0<0) {                  /* |x|<1 */
  37                 SET_FLOAT_WORD(*iptr,i0&0x80000000);    /* *iptr = +-0 */
  38                 return x;
  39             } else {
  40                 i = (0x007fffff)>>j0;
  41                 if((i0&i)==0) {                 /* x is integral */
  42                     __uint32_t ix;
  43                     *iptr = x;
  44                     GET_FLOAT_WORD(ix,x);
  45                     SET_FLOAT_WORD(x,ix&0x80000000);    /* return +-0 */
  46                     return x;
  47                 } else {
  48                     SET_FLOAT_WORD(*iptr,i0&(~i));
  49                     return x - *iptr;
  50                 }
  51             }
  52         } else {                        /* no fraction part */
  53             __uint32_t ix;
  54             *iptr = x*one;
  55             GET_FLOAT_WORD(ix,x);
  56             SET_FLOAT_WORD(x,ix&0x80000000);    /* return +-0 */
  57             return x;
  58         }
  59 }
  60
  61 #ifdef _DOUBLE_IS_32BITS
  62
  63 #ifdef __STDC__
  64         double modf(double x, double *iptr)
  65 #else
  66         double modf(x, iptr)
  67         double x,*iptr;
  68 #endif
  69 {
  70         return (double) modff((float) x, (float *) iptr);
  71 }
  72
  73 #endif /* defined(_DOUBLE_IS_32BITS) */