0,0 → 1,61 |
/* 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) */ |