mirror of
git://sourceware.org/git/glibc.git
synced 2024-12-03 04:01:43 +08:00
85 lines
2.0 KiB
C
85 lines
2.0 KiB
C
/* s_ceill.c -- long double version of s_ceil.c.
|
|
* Conversion to IEEE quad long double by Jakub Jelinek, jj@ultra.linux.cz.
|
|
*/
|
|
|
|
/*
|
|
* ====================================================
|
|
* 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: $";
|
|
#endif
|
|
|
|
/*
|
|
* ceill(x)
|
|
* Return x rounded toward -inf to integral value
|
|
* Method:
|
|
* Bit twiddling.
|
|
* Exception:
|
|
* Inexact flag raised if x not equal to ceil(x).
|
|
*/
|
|
|
|
#include "math.h"
|
|
#include "math_private.h"
|
|
|
|
#ifdef __STDC__
|
|
static const long double huge = 1.0e4930;
|
|
#else
|
|
static long double huge = 1.0e4930;
|
|
#endif
|
|
|
|
#ifdef __STDC__
|
|
long double __ceill(long double x)
|
|
#else
|
|
long double __ceill(x)
|
|
long double x;
|
|
#endif
|
|
{
|
|
int64_t i0,i1,j0;
|
|
u_int64_t i,j;
|
|
GET_LDOUBLE_WORDS64(i0,i1,x);
|
|
j0 = ((i0>>48)&0x7fff)-0x3fff;
|
|
if(j0<48) {
|
|
if(j0<0) { /* raise inexact if x != 0 */
|
|
if(huge+x>0.0) {/* return 0*sign(x) if |x|<1 */
|
|
if(i0<0) {i0=0x8000000000000000ULL;i1=0;}
|
|
else if((i0|i1)!=0) { i0=0x3fff000000000000ULL;i1=0;}
|
|
}
|
|
} else {
|
|
i = (0x7fffffffffffffffULL)>>j0;
|
|
if(((i0&i)|i1)==0) return x; /* x is integral */
|
|
if(huge+x>0.0) { /* raise inexact flag */
|
|
if(i0>0) i0 += (0x0001000000000000LL)>>j0;
|
|
i0 &= (~i); i1=0;
|
|
}
|
|
}
|
|
} else if (j0>111) {
|
|
if(j0==0x4000) return x+x; /* inf or NaN */
|
|
else return x; /* x is integral */
|
|
} else {
|
|
i = -1ULL>>(j0-48);
|
|
if((i1&i)==0) return x; /* x is integral */
|
|
if(huge+x>0.0) { /* raise inexact flag */
|
|
if(i0>0) {
|
|
if(j0==48) i0+=1;
|
|
else {
|
|
j = i1+(1LL<<(112-j0));
|
|
if(j<i1) i0 +=1 ; /* got a carry */
|
|
i1=j;
|
|
}
|
|
}
|
|
i1 &= (~i);
|
|
}
|
|
}
|
|
SET_LDOUBLE_WORDS64(x,i0,i1);
|
|
return x;
|
|
}
|
|
weak_alias (__ceill, ceill)
|