mirror of
https://gitlab.com/rnger/amath
synced 2025-12-08 14:58:29 +00:00
114 lines
3.8 KiB
C
114 lines
3.8 KiB
C
/* @(#)s_ceil.c 1.3 95/01/18 */
|
|
|
|
/*
|
|
* Copyright (c) 2015 Carsten Larsen
|
|
* All rights reserved.
|
|
*
|
|
* Redistribution and use in source and binary forms, with or without
|
|
* modification, are permitted provided that the following conditions
|
|
* are met:
|
|
* 1. Redistributions of source code must retain the above copyright
|
|
* notice, this list of conditions and the following disclaimer.
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
|
* notice, this list of conditions and the following disclaimer in the
|
|
* documentation and/or other materials provided with the distribution.
|
|
*
|
|
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
|
|
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
|
|
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
|
|
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
|
|
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
|
|
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
|
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
|
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
|
|
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
*
|
|
* The origin source code can be obtained from:
|
|
* http://www.netlib.org/fdlibm/s_ceil.c
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
*
|
|
* Developed at SunSoft, a Sun Microsystems, Inc. business.
|
|
* Permission to use, copy, modify, and distribute this
|
|
* software is freely granted, provided that this notice
|
|
* is preserved.
|
|
* ====================================================
|
|
*
|
|
*/
|
|
|
|
#include "prim.h"
|
|
|
|
static const double huge = 1.0e300;
|
|
|
|
/**
|
|
* @brief Mathematical ceiling function.
|
|
* @version 1.3
|
|
* @date 95/01/18
|
|
* @details
|
|
* <pre>
|
|
* Return x rounded toward -inf to integral value
|
|
* Method:
|
|
* Bit twiddling.
|
|
* Exception:
|
|
* Inexact flag raised if x not equal to ceil(x).
|
|
* </pre>
|
|
* @copyright Copyright (C) 1993 by Sun Microsystems, Inc. All rights reserved.
|
|
* @license Developed at SunSoft, a Sun Microsystems, Inc. business. Permission
|
|
* to use, copy, modify, and distribute this software is freely granted,
|
|
* provided that this notice is preserved.
|
|
*/
|
|
double ceil(double x)
|
|
{
|
|
sword i0,i1,j0;
|
|
uword 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 = ((uword)(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));
|
|
// NOTICE: Is this a correct cast?
|
|
if((sword)j<(sword)i1) i0+=1; /* got a carry */
|
|
i1 = j;
|
|
}
|
|
}
|
|
i1 &= (~i);
|
|
}
|
|
}
|
|
INSERT_WORDS(x,i0,i1);
|
|
return x;
|
|
}
|