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/* nearbyintq.c -- __float128 version of s_nearbyint.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.
* ====================================================
*/
/*
* nearbyintq(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 rintq(x).
*/
#include "quadmath-imp.h"
#ifdef HAVE_FENV_H
# include <fenv.h>
# if defined HAVE_FEHOLDEXCEPT && defined HAVE_FESETENV
# define USE_FENV_H
# endif
#endif
static const __float128
TWO112[2]={
5.19229685853482762853049632922009600E+33Q, /* 0x406F000000000000, 0 */
-5.19229685853482762853049632922009600E+33Q /* 0xC06F000000000000, 0 */
};
__float128
nearbyintq(__float128 x)
{
#ifdef USE_FENV_H
fenv_t env;
#endif
int64_t i0,j0,sx;
uint64_t i,i1;
__float128 w,t;
GET_FLT128_WORDS64(i0,i1,x);
sx = (((uint64_t)i0)>>63);
j0 = ((i0>>48)&0x7fff)-0x3fff;
if(j0<48) {
if(j0<0) {
if(((i0&0x7fffffffffffffffLL)|i1)==0) return x;
i1 |= (i0&0x0000ffffffffffffLL);
i0 &= 0xffffe00000000000ULL;
i0 |= ((i1|-i1)>>16)&0x0000800000000000LL;
SET_FLT128_MSW64(x,i0);
#ifdef USE_FENV_H
feholdexcept (&env);
#endif
w = TWO112[sx]+x;
t = w-TWO112[sx];
#ifdef USE_FENV_H
fesetenv (&env);
#endif
GET_FLT128_MSW64(i0,t);
SET_FLT128_MSW64(t,(i0&0x7fffffffffffffffLL)|(sx<<63));
return t;
} else {
i = (0x0000ffffffffffffLL)>>j0;
if(((i0&i)|i1)==0) return x; /* x is integral */
i>>=1;
if(((i0&i)|i1)!=0) {
if(j0==47) i1 = 0x4000000000000000ULL; else
i0 = (i0&(~i))|((0x0000200000000000LL)>>j0);
}
}
} 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 */
i>>=1;
if((i1&i)!=0) i1 = (i1&(~i))|((0x4000000000000000LL)>>(j0-48));
}
SET_FLT128_WORDS64(x,i0,i1);
#ifdef USE_FENV_H
feholdexcept (&env);
#endif
w = TWO112[sx]+x;
t = w-TWO112[sx];
#ifdef USE_FENV_H
fesetenv (&env);
#endif
return t;
}
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