2015-01-22 08:48:29 -05:00
|
|
|
/*
|
2017-06-30 03:22:17 -04:00
|
|
|
* This file is part of the MicroPython project, http://micropython.org/
|
2015-01-22 08:48:29 -05:00
|
|
|
*
|
|
|
|
|
* These math functions are taken from newlib-nano-2, the newlib/libm/math
|
|
|
|
|
* directory, available from https://github.com/32bitmicro/newlib-nano-2.
|
|
|
|
|
*
|
|
|
|
|
* Appropriate copyright headers are reproduced below.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/* sf_frexp.c -- float version of s_frexp.c.
|
|
|
|
|
* Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
/*
|
|
|
|
|
* ====================================================
|
|
|
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
|
|
|
*
|
|
|
|
|
* Developed at SunPro, a Sun Microsystems, Inc. business.
|
|
|
|
|
* Permission to use, copy, modify, and distribute this
|
|
|
|
|
* software is freely granted, provided that this notice
|
|
|
|
|
* is preserved.
|
|
|
|
|
* ====================================================
|
|
|
|
|
*/
|
|
|
|
|
|
|
|
|
|
#include "fdlibm.h"
|
|
|
|
|
|
|
|
|
|
#ifdef __STDC__
|
|
|
|
|
static const float
|
|
|
|
|
#else
|
|
|
|
|
static float
|
|
|
|
|
#endif
|
|
|
|
|
two25 = 3.3554432000e+07; /* 0x4c000000 */
|
|
|
|
|
|
|
|
|
|
#ifdef __STDC__
|
|
|
|
|
float frexpf(float x, int *eptr)
|
|
|
|
|
#else
|
|
|
|
|
float frexpf(x, eptr)
|
|
|
|
|
float x; int *eptr;
|
|
|
|
|
#endif
|
|
|
|
|
{
|
|
|
|
|
__int32_t hx, ix;
|
|
|
|
|
GET_FLOAT_WORD(hx,x);
|
|
|
|
|
ix = 0x7fffffff&hx;
|
|
|
|
|
*eptr = 0;
|
|
|
|
|
if(!FLT_UWORD_IS_FINITE(ix)||FLT_UWORD_IS_ZERO(ix)) return x; /* 0,inf,nan */
|
|
|
|
|
if (FLT_UWORD_IS_SUBNORMAL(ix)) { /* subnormal */
|
|
|
|
|
x *= two25;
|
|
|
|
|
GET_FLOAT_WORD(hx,x);
|
|
|
|
|
ix = hx&0x7fffffff;
|
|
|
|
|
*eptr = -25;
|
|
|
|
|
}
|
|
|
|
|
*eptr += (ix>>23)-126;
|
|
|
|
|
hx = (hx&0x807fffff)|0x3f000000;
|
|
|
|
|
SET_FLOAT_WORD(x,hx);
|
|
|
|
|
return x;
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#ifdef _DOUBLE_IS_32BITS
|
|
|
|
|
|
|
|
|
|
#ifdef __STDC__
|
|
|
|
|
double frexp(double x, int *eptr)
|
|
|
|
|
#else
|
|
|
|
|
double frexp(x, eptr)
|
|
|
|
|
double x; int *eptr;
|
|
|
|
|
#endif
|
|
|
|
|
{
|
|
|
|
|
return (double) frexpf((float) x, eptr);
|
|
|
|
|
}
|
|
|
|
|
|
|
|
|
|
#endif /* defined(_DOUBLE_IS_32BITS) */
|
