1 /*
2  * This file is part of the MicroPython project, http://micropython.org/
3  *
4  * These math functions are taken from newlib-nano-2, the newlib/libm/math
5  * directory, available from https://github.com/32bitmicro/newlib-nano-2.
6  *
7  * Appropriate copyright headers are reproduced below.
8  */
9 
10 /* sf_frexp.c -- float version of s_frexp.c.
11  * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
12  */
13 
14 /*
15  * ====================================================
16  * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
17  *
18  * Developed at SunPro, a Sun Microsystems, Inc. business.
19  * Permission to use, copy, modify, and distribute this
20  * software is freely granted, provided that this notice
21  * is preserved.
22  * ====================================================
23  */
24 
25 #include "fdlibm.h"
26 
27 #ifdef __STDC__
28 static const float
29 #else
30 static float
31 #endif
32 two25 =  3.3554432000e+07f; /* 0x4c000000 */
33 
34 #ifdef __STDC__
frexpf(float x,int * eptr)35 	float frexpf(float x, int *eptr)
36 #else
37 	float frexpf(x, eptr)
38 	float x; int *eptr;
39 #endif
40 {
41 	__int32_t hx, ix;
42 	GET_FLOAT_WORD(hx,x);
43 	ix = 0x7fffffff&hx;
44 	*eptr = 0;
45 	if(!FLT_UWORD_IS_FINITE(ix)||FLT_UWORD_IS_ZERO(ix)) return x;	/* 0,inf,nan */
46 	if (FLT_UWORD_IS_SUBNORMAL(ix)) {		/* subnormal */
47 	    x *= two25;
48 	    GET_FLOAT_WORD(hx,x);
49 	    ix = hx&0x7fffffff;
50 	    *eptr = -25;
51 	}
52 	*eptr += (ix>>23)-126;
53 	hx = (hx&0x807fffff)|0x3f000000;
54 	SET_FLOAT_WORD(x,hx);
55 	return x;
56 }
57 
58 #ifdef _DOUBLE_IS_32BITS
59 
60 #ifdef __STDC__
frexp(double x,int * eptr)61 	double frexp(double x, int *eptr)
62 #else
63 	double frexp(x, eptr)
64 	double x; int *eptr;
65 #endif
66 {
67 	return (double) frexpf((float) x, eptr);
68 }
69 
70 #endif /* defined(_DOUBLE_IS_32BITS) */
71