rginda%netscape.com 48d051ff56 reverting old volatile fix for 24892 and replacing with cls' union patch.
spider and xpshell now pass the related testcases.
author=cls, r=me


git-svn-id: svn://10.0.0.236/trunk@78760 18797224-902f-48f8-a5cc-f745e15eee43
2000-09-11 20:56:33 +00:00

127 lines
3.5 KiB
C

/* -*- Mode: C; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*-
*
* The contents of this file are subject to the Netscape Public
* License Version 1.1 (the "License"); you may not use this file
* except in compliance with the License. You may obtain a copy of
* the License at http://www.mozilla.org/NPL/
*
* Software distributed under the License is distributed on an "AS
* IS" basis, WITHOUT WARRANTY OF ANY KIND, either express oqr
* implied. See the License for the specific language governing
* rights and limitations under the License.
*
* The Original Code is Mozilla Communicator client code, released
* March 31, 1998.
*
* The Initial Developer of the Original Code is Sun Microsystems,
* Inc. Portions created by Netscape are
* Copyright (C) 1998 Netscape Communications Corporation. All
* Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the
* terms of the GNU Public License (the "GPL"), in which case the
* provisions of the GPL are applicable instead of those above.
* If you wish to allow use of your version of this file only
* under the terms of the GPL and not to allow others to use your
* version of this file under the NPL, indicate your decision by
* deleting the provisions above and replace them with the notice
* and other provisions required by the GPL. If you do not delete
* the provisions above, a recipient may use your version of this
* file under either the NPL or the GPL.
*/
/* @(#)s_rint.c 1.3 95/01/18 */
/*
* ====================================================
* 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.
* ====================================================
*/
/*
* rint(x)
* Return x rounded to integral value according to the prevailing
* rounding mode.
* Method:
* Using floating addition.
* Exception:
* Inexact flag raised if x not equal to rint(x).
*/
#include "fdlibm.h"
#ifdef __STDC__
static const double
#else
static double
#endif
TWO52[2]={
4.50359962737049600000e+15, /* 0x43300000, 0x00000000 */
-4.50359962737049600000e+15, /* 0xC3300000, 0x00000000 */
};
#ifdef __STDC__
double fd_rint(double x)
#else
double fd_rint(x)
double x;
#endif
{
int i0,j0,sx;
unsigned i,i1;
double w,t;
fd_twoints u;
u.d = x;
i0 = __HI(u);
sx = (i0>>31)&1;
i1 = __LO(u);
j0 = ((i0>>20)&0x7ff)-0x3ff;
if(j0<20) {
if(j0<0) {
if(((i0&0x7fffffff)|i1)==0) return x;
i1 |= (i0&0x0fffff);
i0 &= 0xfffe0000;
i0 |= ((i1|-(int)i1)>>12)&0x80000;
u.d = x;
__HI(u)=i0;
x = u.d;
w = TWO52[sx]+x;
t = w-TWO52[sx];
u.d = t;
i0 = __HI(u);
__HI(u) = (i0&0x7fffffff)|(sx<<31);
t = u.d;
return t;
} else {
i = (0x000fffff)>>j0;
if(((i0&i)|i1)==0) return x; /* x is integral */
i>>=1;
if(((i0&i)|i1)!=0) {
if(j0==19) i1 = 0x40000000; else
i0 = (i0&(~i))|((0x20000)>>j0);
}
}
} else if (j0>51) {
if(j0==0x400) return x+x; /* inf or NaN */
else return x; /* x is integral */
} else {
i = ((unsigned)(0xffffffff))>>(j0-20);
if((i1&i)==0) return x; /* x is integral */
i>>=1;
if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-20));
}
u.d = x;
__HI(u) = i0;
__LO(u) = i1;
x = u.d;
w = TWO52[sx]+x;
return w-TWO52[sx];
}