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[/] [or1k/] [trunk/] [linux/] [uClibc/] [libm/] [s_modf.c] - Blame information for rev 1771

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/* @(#)s_modf.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.
 * ====================================================
 */
 
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: s_modf.c,v 1.8 1995/05/10 20:47:55 jtc Exp $";
#endif
 
/*
 * modf(double x, double *iptr)
 * return fraction part of x, and return x's integral part in *iptr.
 * Method:
 *      Bit twiddling.
 *
 * Exception:
 *      No exception.
 */
 
#include "math.h"
#include "math_private.h"
 
#ifdef __STDC__
static const double one = 1.0;
#else
static double one = 1.0;
#endif
 
#ifdef __STDC__
        double modf(double x, double *iptr)
#else
        double modf(x, iptr)
        double x,*iptr;
#endif
{
        int32_t i0,i1,j0;
        u_int32_t i;
        EXTRACT_WORDS(i0,i1,x);
        j0 = ((i0>>20)&0x7ff)-0x3ff;    /* exponent of x */
        if(j0<20) {                     /* integer part in high x */
            if(j0<0) {                   /* |x|<1 */
                INSERT_WORDS(*iptr,i0&0x80000000,0);     /* *iptr = +-0 */
                return x;
            } else {
                i = (0x000fffff)>>j0;
                if(((i0&i)|i1)==0) {             /* x is integral */
                    u_int32_t high;
                    *iptr = x;
                    GET_HIGH_WORD(high,x);
                    INSERT_WORDS(x,high&0x80000000,0);   /* return +-0 */
                    return x;
                } else {
                    INSERT_WORDS(*iptr,i0&(~i),0);
                    return x - *iptr;
                }
            }
        } else if (j0>51) {             /* no fraction part */
            u_int32_t high;
            *iptr = x*one;
            GET_HIGH_WORD(high,x);
            INSERT_WORDS(x,high&0x80000000,0);   /* return +-0 */
            return x;
        } else {                        /* fraction part in low x */
            i = ((u_int32_t)(0xffffffff))>>(j0-20);
            if((i1&i)==0) {              /* x is integral */
                u_int32_t high;
                *iptr = x;
                GET_HIGH_WORD(high,x);
                INSERT_WORDS(x,high&0x80000000,0);       /* return +-0 */
                return x;
            } else {
                INSERT_WORDS(*iptr,i0,i1&(~i));
                return x - *iptr;
            }
        }
}

Line No.	Rev	Author	Line
1	1325	phoenix	`/* @(#)s_modf.c 5.1 93/09/24 */`
2			`/*`
3			`* ====================================================`
4			`* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.`
5			`*`
6			`* Developed at SunPro, a Sun Microsystems, Inc. business.`
7			`* Permission to use, copy, modify, and distribute this`
8			`* software is freely granted, provided that this notice`
9			`* is preserved.`
10			`* ====================================================`
11			`*/`
12
13			`#if defined(LIBM_SCCS) && !defined(lint)`
14			`static char rcsid[] = "$NetBSD: s_modf.c,v 1.8 1995/05/10 20:47:55 jtc Exp $";`
15			`#endif`
16
17			`/*`
18			`* modf(double x, double *iptr)`
19			`* return fraction part of x, and return x's integral part in *iptr.`
20			`* Method:`
21			`* Bit twiddling.`
22			`*`
23			`* Exception:`
24			`* No exception.`
25			`*/`
26
27			`#include "math.h"`
28			`#include "math_private.h"`
29
30			`#ifdef __STDC__`
31			`static const double one = 1.0;`
32			`#else`
33			`static double one = 1.0;`
34			`#endif`
35
36			`#ifdef __STDC__`
37			`double modf(double x, double *iptr)`
38			`#else`
39			`double modf(x, iptr)`
40			`double x,*iptr;`
41			`#endif`
42			`{`
43			`int32_t i0,i1,j0;`
44			`u_int32_t i;`
45			`EXTRACT_WORDS(i0,i1,x);`
46			`j0 = ((i0>>20)&0x7ff)-0x3ff; /* exponent of x */`
47			`if(j0<20) { /* integer part in high x */`
48			`if(j0<0) { /* \|x\|<1 */`
49			`INSERT_WORDS(iptr,i0&0x80000000,0); / iptr = +-0 /`
50			`return x;`
51			`} else {`
52			`i = (0x000fffff)>>j0;`
53			`if(((i0&i)\|i1)==0) { /* x is integral */`
54			`u_int32_t high;`
55			`*iptr = x;`
56			`GET_HIGH_WORD(high,x);`
57			`INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */`
58			`return x;`
59			`} else {`
60			`INSERT_WORDS(*iptr,i0&(~i),0);`
61			`return x - *iptr;`
62			`}`
63			`}`
64			`} else if (j0>51) { /* no fraction part */`
65			`u_int32_t high;`
66			`iptr = xone;`
67			`GET_HIGH_WORD(high,x);`
68			`INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */`
69			`return x;`
70			`} else { /* fraction part in low x */`
71			`i = ((u_int32_t)(0xffffffff))>>(j0-20);`
72			`if((i1&i)==0) { /* x is integral */`
73			`u_int32_t high;`
74			`*iptr = x;`
75			`GET_HIGH_WORD(high,x);`
76			`INSERT_WORDS(x,high&0x80000000,0); /* return +-0 */`
77			`return x;`
78			`} else {`
79			`INSERT_WORDS(*iptr,i0,i1&(~i));`
80			`return x - *iptr;`
81			`}`
82			`}`
83			`}`

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[/] [or1k/] [trunk/] [linux/] [uClibc/] [libm/] [s_modf.c] - Blame information for rev 1771