gcc/libquadmath/math/nearbyintq.c
Tobias Burnus 737df6e617 complex.c (csqrtq): NaN and INF fixes.
2012-10-31  Tobias Burnus  <burnus@net-b.de>
            Joseph Myers <joseph@codesourcery.com>
            David S. Miller <davem@davemloft.net>
            Ulrich Drepper <drepper@redhat.com>
            Marek Polacek <polacek@redhat.com>:
            Petr Baudis <pasky@suse.cz>

        * math/complex.c (csqrtq): NaN and INF fixes.
        * math/sqrtq.c (sqrt): NaN, INF and < 0 fixes.
        * math/expm1q.c (expm1q): Changes from GLIBC. Use expq for
        large parameters. Fix errno for boundary conditions.
        * math/finiteq.c (finiteq): Add comment.
        * math/fmaq.c (fmaq): Changes from GLIBC. Fix missing underflows
        and bad results for some subnormal results. Fix sign of inexact
        zero return. Fix sign of exact zero return.
        Ensure additions are not scheduled after fetestexcept.
        * math/jnq.c (jnq): Changes from GLIBC. Set up errno properly
        for ynq. Fix jnq precision.
        * math/nearbyintq.c (nearbyintq): Changes from GLIBC. Do not
        manipulate bits before adding and subtracting TWO112[sx].
        * math/rintq.c (rintq): Ditto.
        * math/scalbnq.c (scalbnq): Changes from GLIBC. Fix integer
        overflow.


Co-Authored-By: David S. Miller <davem@davemloft.net>
Co-Authored-By: Joseph Myers <joseph@codesourcery.com>
Co-Authored-By: Ulrich Drepper <drepper@redhat.com>

From-SVN: r193037
2012-10-31 16:46:59 +01:00

80 lines
1.8 KiB
C

/* 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 i1;
__float128 w,t;
GET_FLT128_WORDS64(i0,i1,x);
sx = (((uint64_t)i0)>>63);
j0 = ((i0>>48)&0x7fff)-0x3fff;
if(j0<112) {
if(j0<0) {
#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 {
if(j0==0x4000) return x+x; /* inf or NaN */
else return x; /* x is integral */
}
#ifdef USE_FENV_H
feholdexcept (&env);
#endif
w = TWO112[sx]+x;
t = w-TWO112[sx];
#ifdef USE_FENV_H
fesetenv (&env);
#endif
return t;
}