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/* @(#)w_exp.c 5.1 93/09/24 */
/*
 * ====================================================
 * 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.
 * ====================================================
 */
 
/*
FUNCTION
        <<exp>>, <<expf>>---exponential
INDEX
        exp
INDEX
        expf
 
ANSI_SYNOPSIS
        #include <math.h>
        double exp(double <[x]>);
        float expf(float <[x]>);
 
TRAD_SYNOPSIS
        #include <math.h>
        double exp(<[x]>);
        double <[x]>;
 
        float expf(<[x]>);
        float <[x]>;
 
DESCRIPTION
        <<exp>> and <<expf>> calculate the exponential of <[x]>, that is,
        @ifnottex
        e raised to the power <[x]> (where e
        @end ifnottex
        @tex
        $e^x$ (where $e$
        @end tex
        is the base of the natural system of logarithms, approximately 2.71828).
 
        You can use the (non-ANSI) function <<matherr>> to specify
        error handling for these functions.
 
RETURNS
        On success, <<exp>> and <<expf>> return the calculated value.
        If the result underflows, the returned value is <<0>>.  If the
        result overflows, the returned value is <<HUGE_VAL>>.  In
        either case, <<errno>> is set to <<ERANGE>>.
 
PORTABILITY
        <<exp>> is ANSI C.  <<expf>> is an extension.
 
*/
 
/*
 * wrapper exp(x)
 */
 
#include "fdlibm.h"
#include <errno.h>
 
#ifndef _DOUBLE_IS_32BITS
 
#ifdef __STDC__
static const double
#else
static double
#endif
o_threshold=  7.09782712893383973096e+02,  /* 0x40862E42, 0xFEFA39EF */
u_threshold= -7.45133219101941108420e+02;  /* 0xc0874910, 0xD52D3051 */
 
#ifdef __STDC__
        double exp(double x)            /* wrapper exp */
#else
        double exp(x)                   /* wrapper exp */
        double x;
#endif
{
#ifdef _IEEE_LIBM
        return __ieee754_exp(x);
#else
        double z;
        struct exception exc;
        z = __ieee754_exp(x);
        if(_LIB_VERSION == _IEEE_) return z;
        if(finite(x)) {
            if(x>o_threshold) {
                /* exp(finite) overflow */
#ifndef HUGE_VAL
#define HUGE_VAL inf
                double inf = 0.0;
 
                SET_HIGH_WORD(inf,0x7ff00000);  /* set inf to infinite */
#endif
                exc.type = OVERFLOW;
                exc.name = "exp";
                exc.err = 0;
                exc.arg1 = exc.arg2 = x;
                if (_LIB_VERSION == _SVID_)
                  exc.retval = HUGE;
                else
                  exc.retval = HUGE_VAL;
                if (_LIB_VERSION == _POSIX_)
                  errno = ERANGE;
                else if (!matherr(&exc)) {
                        errno = ERANGE;
                }
                if (exc.err != 0)
                   errno = exc.err;
                return exc.retval;
            } else if(x<u_threshold) {
                /* exp(finite) underflow */
                exc.type = UNDERFLOW;
                exc.name = "exp";
                exc.err = 0;
                exc.arg1 = exc.arg2 = x;
                exc.retval = 0.0;
                if (_LIB_VERSION == _POSIX_)
                  errno = ERANGE;
                else if (!matherr(&exc)) {
                        errno = ERANGE;
                }
                if (exc.err != 0)
                   errno = exc.err;
                return exc.retval;
            }
        }
        return z;
#endif
}
 
#endif /* defined(_DOUBLE_IS_32BITS) */

Line No.	Rev	Author	Line
1	207	jeremybenn
2			`/* @(#)w_exp.c 5.1 93/09/24 */`
3			`/*`
4			`* ====================================================`
5			`* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.`
6			`*`
7			`* Developed at SunPro, a Sun Microsystems, Inc. business.`
8			`* Permission to use, copy, modify, and distribute this`
9			`* software is freely granted, provided that this notice`
10			`* is preserved.`
11			`* ====================================================`
12			`*/`
13
14			`/*`
15			`FUNCTION`
16			`<<exp>>, <<expf>>---exponential`
17			`INDEX`
18			`exp`
19			`INDEX`
20			`expf`
21
22			`ANSI_SYNOPSIS`
23			`#include <math.h>`
24			`double exp(double <[x]>);`
25			`float expf(float <[x]>);`
26
27			`TRAD_SYNOPSIS`
28			`#include <math.h>`
29			`double exp(<[x]>);`
30			`double <[x]>;`
31
32			`float expf(<[x]>);`
33			`float <[x]>;`
34
35			`DESCRIPTION`
36			`<<exp>> and <<expf>> calculate the exponential of <[x]>, that is,`
37			`@ifnottex`
38			`e raised to the power <[x]> (where e`
39			`@end ifnottex`
40			`@tex`
41			`$e^x$ (where $e$`
42			`@end tex`
43			`is the base of the natural system of logarithms, approximately 2.71828).`
44
45			`You can use the (non-ANSI) function <<matherr>> to specify`
46			`error handling for these functions.`
47
48			`RETURNS`
49			`On success, <<exp>> and <<expf>> return the calculated value.`
50			`If the result underflows, the returned value is <<0>>. If the`
51			`result overflows, the returned value is <<HUGE_VAL>>. In`
52			`either case, <<errno>> is set to <<ERANGE>>.`
53
54			`PORTABILITY`
55			`<<exp>> is ANSI C. <<expf>> is an extension.`
56
57			`*/`
58
59			`/*`
60			`* wrapper exp(x)`
61			`*/`
62
63			`#include "fdlibm.h"`
64			`#include <errno.h>`
65
66			`#ifndef _DOUBLE_IS_32BITS`
67
68			`#ifdef __STDC__`
69			`static const double`
70			`#else`
71			`static double`
72			`#endif`
73			`o_threshold= 7.09782712893383973096e+02, /* 0x40862E42, 0xFEFA39EF */`
74			`u_threshold= -7.45133219101941108420e+02; /* 0xc0874910, 0xD52D3051 */`
75
76			`#ifdef __STDC__`
77			`double exp(double x) /* wrapper exp */`
78			`#else`
79			`double exp(x) /* wrapper exp */`
80			`double x;`
81			`#endif`
82			`{`
83			`#ifdef _IEEE_LIBM`
84			`return __ieee754_exp(x);`
85			`#else`
86			`double z;`
87			`struct exception exc;`
88			`z = __ieee754_exp(x);`
89			`if(_LIB_VERSION == _IEEE_) return z;`
90			`if(finite(x)) {`
91			`if(x>o_threshold) {`
92			`/* exp(finite) overflow */`
93			`#ifndef HUGE_VAL`
94			`#define HUGE_VAL inf`
95			`double inf = 0.0;`
96
97			`SET_HIGH_WORD(inf,0x7ff00000); /* set inf to infinite */`
98			`#endif`
99			`exc.type = OVERFLOW;`
100			`exc.name = "exp";`
101			`exc.err = 0;`
102			`exc.arg1 = exc.arg2 = x;`
103			`if (_LIB_VERSION == _SVID_)`
104			`exc.retval = HUGE;`
105			`else`
106			`exc.retval = HUGE_VAL;`
107			`if (_LIB_VERSION == _POSIX_)`
108			`errno = ERANGE;`
109			`else if (!matherr(&exc)) {`
110			`errno = ERANGE;`
111			`}`
112			`if (exc.err != 0)`
113			`errno = exc.err;`
114			`return exc.retval;`
115			`} else if(x<u_threshold) {`
116			`/* exp(finite) underflow */`
117			`exc.type = UNDERFLOW;`
118			`exc.name = "exp";`
119			`exc.err = 0;`
120			`exc.arg1 = exc.arg2 = x;`
121			`exc.retval = 0.0;`
122			`if (_LIB_VERSION == _POSIX_)`
123			`errno = ERANGE;`
124			`else if (!matherr(&exc)) {`
125			`errno = ERANGE;`
126			`}`
127			`if (exc.err != 0)`
128			`errno = exc.err;`
129			`return exc.retval;`
130			`}`
131			`}`
132			`return z;`
133			`#endif`
134			`}`
135
136			`#endif /* defined(_DOUBLE_IS_32BITS) */`

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[/] [openrisc/] [trunk/] [gnu-stable/] [newlib-1.18.0/] [newlib/] [libm/] [math/] [w_exp.c] - Blame information for rev 862