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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 <math.h>
#include <math_private.h>
static const double huge = 1.0e300;
double
__ceil(double x)
{
int64_t i0,i;
int32_t j0;
EXTRACT_WORDS64(i0,x);
j0 = ((i0>>52)&0x7ff)-0x3ff;
if(j0<=51) {
if(j0<0) { /* raise inexact if x != 0 */
math_force_eval(huge+x);/* return 0*sign(x) if |x|<1 */
if(i0<0) {i0=INT64_C(0x8000000000000000);}
else if(i0!=0) { i0=INT64_C(0x3ff0000000000000);}
} else {
i = INT64_C(0x000fffffffffffff)>>j0;
if((i0&i)==0) return x; /* x is integral */
math_force_eval(huge+x); /* raise inexact flag */
if(i0>0) i0 += UINT64_C(0x0010000000000000)>>j0;
i0 &= (~i);
}
} else {
if(j0==0x400) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
INSERT_WORDS64(x,i0);
return x;
}
#ifndef __ceil
weak_alias (__ceil, ceil)
# ifdef NO_LONG_DOUBLE
strong_alias (__ceil, __ceill)
weak_alias (__ceil, ceill)
# endif
#endif
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