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comparison packages/language/c/libm/current/src/float/portable-api/sf_frexp.c @ 3337:77f9d3253c3e

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Add: Complex number header and library (single and double precision floating point), port from Newlib. Add: Single precision floating point library, port from Newlib. [ Bugzilla 1001539 ]
author vae
date Sun, 25 Aug 2013 14:38:57 +0000
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3336:8ecac279f33c 3337:77f9d3253c3e
1 //===========================================================================
2 //
3 // sf_frexp.c
4 //
5 // Part of the standard mathematical function library
6 //
7 //===========================================================================
8 // ####ECOSGPLCOPYRIGHTBEGIN####
9 // -------------------------------------------
10 // This file is part of eCos, the Embedded Configurable Operating System.
11 // Copyright (C) 2012 Free Software Foundation, Inc.
12 //
13 // eCos is free software; you can redistribute it and/or modify it under
14 // the terms of the GNU General Public License as published by the Free
15 // Software Foundation; either version 2 or (at your option) any later
16 // version.
17 //
18 // eCos is distributed in the hope that it will be useful, but WITHOUT
19 // ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
20 // FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
21 // for more details.
22 //
23 // You should have received a copy of the GNU General Public License
24 // along with eCos; if not, write to the Free Software Foundation, Inc.,
25 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
26 //
27 // As a special exception, if other files instantiate templates or use
28 // macros or inline functions from this file, or you compile this file
29 // and link it with other works to produce a work based on this file,
30 // this file does not by itself cause the resulting work to be covered by
31 // the GNU General Public License. However the source code for this file
32 // must still be made available in accordance with section (3) of the GNU
33 // General Public License v2.
34 //
35 // This exception does not invalidate any other reasons why a work based
36 // on this file might be covered by the GNU General Public License.
37 // -------------------------------------------
38 // ####ECOSGPLCOPYRIGHTEND####
39 //===========================================================================
40 //#####DESCRIPTIONBEGIN####
41 //
42 // Author(s):
43 // Contributors: visar, ilijak
44 // Date: 2012-03-08
45 // Purpose:
46 // Description:
47 // Usage:
48 //
49 //####DESCRIPTIONEND####
50 //
51 //===========================================================================
52
53 // CONFIGURATION
54
55 #include <pkgconf/libm.h> // Configuration header
56
57 // Include the Math library?
58 #ifdef CYGPKG_LIBM
59
60 // Derived from code with the following copyright
61
62 /* sf_frexp.c -- float version of s_frexp.c.
63 * Conversion to float by Ian Lance Taylor, Cygnus Support, ian@cygnus.com.
64 */
65
66 /*
67 * ====================================================
68 * Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
69 *
70 * Developed at SunPro, a Sun Microsystems, Inc. business.
71 * Permission to use, copy, modify, and distribute this
72 * software is freely granted, provided that this notice
73 * is preserved.
74 * ====================================================
75 */
76
77
78 #include "mathincl/fdlibm.h"
79
80 #ifdef __STDC__
81 static const float
82 #else
83 static float
84 #endif
85 two25 = 3.3554432000e+07; /* 0x4c000000 */
86
87 #ifdef __STDC__
88 float frexpf(float x, int *eptr)
89 #else
90 float frexpf(x, eptr)
91 float x; int *eptr;
92 #endif
93 {
94 __int32_t hx, ix;
95 hx = CYG_LIBM_WORD(x);
96 ix = 0x7fffffff&hx;
97 *eptr = 0;
98 if(!FLT_UWORD_IS_FINITE(ix)||FLT_UWORD_IS_ZERO(ix)) return x; /* 0,inf,nan */
99 if (FLT_UWORD_IS_SUBNORMAL(ix)) { /* subnormal */
100 x *= two25;
101 hx = CYG_LIBM_WORD(x);
102 ix = hx&0x7fffffff;
103 *eptr = -25;
104 }
105 *eptr += (ix>>23)-126;
106 hx = (hx&0x807fffff)|0x3f000000;
107 SET_FLOAT_WORD(x,hx);
108 return x;
109 }
110
111 #endif // ifdef CYGPKG_LIBM
112
113 // EOF sf_frexp.c