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[/] [or1k/] [trunk/] [newlib/] [newlib/] [libm/] [math/] [s_ceil.c] - Blame information for rev 1774

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/* @(#)s_ceil.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.
 * ====================================================
 */
 
/*
 * ceil(x)
 * Return x rounded toward -inf to integral value
 * Method:
 *      Bit twiddling.
 * Exception:
 *      Inexact flag raised if x not equal to ceil(x).
 */
 
#include "fdlibm.h"
 
#ifndef _DOUBLE_IS_32BITS
 
#ifdef __STDC__
static const double huge = 1.0e300;
#else
static double huge = 1.0e300;
#endif
 
#ifdef __STDC__
        double ceil(double x)
#else
        double ceil(x)
        double x;
#endif
{
        __int32_t i0,i1,j0;
        __uint32_t i,j;
        EXTRACT_WORDS(i0,i1,x);
        j0 = ((i0>>20)&0x7ff)-0x3ff;
        if(j0<20) {
            if(j0<0) {   /* raise inexact if x != 0 */
                if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
                    if(i0<0) {i0=0x80000000;i1=0;}
                    else if((i0|i1)!=0) { i0=0x3ff00000;i1=0;}
                }
            } else {
                i = (0x000fffff)>>j0;
                if(((i0&i)|i1)==0) return x; /* x is integral */
                if(huge+x>0.0) {        /* raise inexact flag */
                    if(i0>0) i0 += (0x00100000)>>j0;
                    i0 &= (~i); i1=0;
                }
            }
        } else if (j0>51) {
            if(j0==0x400) return x+x;   /* inf or NaN */
            else return x;              /* x is integral */
        } else {
            i = ((__uint32_t)(0xffffffff))>>(j0-20);
            if((i1&i)==0) return x;      /* x is integral */
            if(huge+x>0.0) {            /* raise inexact flag */
                if(i0>0) {
                    if(j0==20) i0+=1;
                    else {
                        j = i1 + (1<<(52-j0));
                        if(j<i1) i0+=1; /* got a carry */
                        i1 = j;
                    }
                }
                i1 &= (~i);
            }
        }
        INSERT_WORDS(x,i0,i1);
        return x;
}
 
#endif /* _DOUBLE_IS_32BITS */

Line No.	Rev	Author	Line
1	39	lampret
2			`/* @(#)s_ceil.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			`* ceil(x)`
16			`* Return x rounded toward -inf to integral value`
17			`* Method:`
18			`* Bit twiddling.`
19			`* Exception:`
20			`* Inexact flag raised if x not equal to ceil(x).`
21			`*/`
22
23			`#include "fdlibm.h"`
24
25			`#ifndef _DOUBLE_IS_32BITS`
26
27			`#ifdef __STDC__`
28			`static const double huge = 1.0e300;`
29			`#else`
30			`static double huge = 1.0e300;`
31			`#endif`
32
33			`#ifdef __STDC__`
34			`double ceil(double x)`
35			`#else`
36			`double ceil(x)`
37			`double x;`
38			`#endif`
39			`{`
40			`__int32_t i0,i1,j0;`
41			`__uint32_t i,j;`
42			`EXTRACT_WORDS(i0,i1,x);`
43			`j0 = ((i0>>20)&0x7ff)-0x3ff;`
44			`if(j0<20) {`
45			`if(j0<0) { /* raise inexact if x != 0 */`
46			`if(huge+x>0.0) {/* return 0sign(x) if \|x\|<1 /`
47			`if(i0<0) {i0=0x80000000;i1=0;}`
48			`else if((i0\|i1)!=0) { i0=0x3ff00000;i1=0;}`
49			`}`
50			`} else {`
51			`i = (0x000fffff)>>j0;`
52			`if(((i0&i)\|i1)==0) return x; /* x is integral */`
53			`if(huge+x>0.0) { /* raise inexact flag */`
54			`if(i0>0) i0 += (0x00100000)>>j0;`
55			`i0 &= (~i); i1=0;`
56			`}`
57			`}`
58			`} else if (j0>51) {`
59			`if(j0==0x400) return x+x; /* inf or NaN */`
60			`else return x; /* x is integral */`
61			`} else {`
62			`i = ((__uint32_t)(0xffffffff))>>(j0-20);`
63			`if((i1&i)==0) return x; /* x is integral */`
64			`if(huge+x>0.0) { /* raise inexact flag */`
65			`if(i0>0) {`
66			`if(j0==20) i0+=1;`
67			`else {`
68			`j = i1 + (1<<(52-j0));`
69			`if(j<i1) i0+=1; /* got a carry */`
70			`i1 = j;`
71			`}`
72			`}`
73			`i1 &= (~i);`
74			`}`
75			`}`
76			`INSERT_WORDS(x,i0,i1);`
77			`return x;`
78			`}`
79
80			`#endif /* _DOUBLE_IS_32BITS */`

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[/] [or1k/] [trunk/] [newlib/] [newlib/] [libm/] [math/] [s_ceil.c] - Blame information for rev 1774