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/* s_rintl.c -- long double version of s_rint.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, drepper@cygnus.com.
*/
/* Adapted for use as nearbyint by Ulrich Drepper <drepper@cygnus.com>. */
/*
* ====================================================
* 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.
* ====================================================
*/
/*
* rintl(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 rintl(x).
*/
#include <fenv.h>
#include "math.h"
#include "math_private.h"
#ifdef __STDC__
static const long double
#else
static long double
#endif
TWO63[2]={
9.223372036854775808000000e+18, /* 0x403E, 0x00000000, 0x00000000 */
-9.223372036854775808000000e+18 /* 0xC03E, 0x00000000, 0x00000000 */
};
#ifdef __STDC__
long double __nearbyintl(long double x)
#else
long double __nearbyintl(x)
long double x;
#endif
{
fenv_t env;
int32_t se,j0,sx;
u_int32_t i,i0,i1;
long double w,t;
GET_LDOUBLE_WORDS(se,i0,i1,x);
sx = (se>>15)&1;
j0 = (se&0x7fff)-0x3fff;
if(j0<31) {
if(j0<0) {
if(((se&0x7fff)|i0|i1)==0) return x;
i1 |= i0;
i0 &= 0xe0000000;
i0 |= (i1|-i1)&0x80000000;
SET_LDOUBLE_MSW(x,i0);
feholdexcept (&env);
w = TWO63[sx]+x;
t = w-TWO63[sx];
fesetenv (&env);
GET_LDOUBLE_EXP(i0,t);
SET_LDOUBLE_EXP(t,(i0&0x7fff)|(sx<<15));
return t;
} else {
i = (0x7fffffff)>>j0;
if(((i0&i)|i1)==0) return x; /* x is integral */
i>>=1;
if(((i0&i)|i1)!=0) {
if(j0==31) i1 = 0x40000000; else
i0 = (i0&(~i))|((0x20000000)>>j0);
/* Shouldn't this be
if (j0 >= 30) i1 = 0x80000000 >> (j0 - 30);
i0 = (i0&(~i))|((0x20000000)>>j0);
If yes, this should be correct in s_rint and
s_rintf, too. -- drepper@cygnus.com */
}
}
} else if (j0>62) {
if(j0==0x4000) return x+x; /* inf or NaN */
else return x; /* x is integral */
} else {
i = ((u_int32_t)(0xffffffff))>>(j0-31);
if((i1&i)==0) return x; /* x is integral */
i>>=1;
if((i1&i)!=0) i1 = (i1&(~i))|((0x40000000)>>(j0-31));
}
SET_LDOUBLE_WORDS(x,se,i0,i1);
feholdexcept (&env);
w = TWO63[sx]+x;
t = w-TWO63[sx];
fesetenv (&env);
return t;
}
weak_alias (__nearbyintl, nearbyintl)
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