glibc/sysdeps/ieee754/ldbl-96/s_frexpl.c
Joseph Myers 88283451b2 Fix frexp (NaN) (bug 20250).
Various implementations of frexp functions return sNaN for sNaN
input.  This patch fixes them to add such arguments to themselves so
that qNaN is returned.

Tested for x86_64, x86, mips64 and powerpc.

	[BZ #20250]
	* sysdeps/i386/fpu/s_frexpl.S (__frexpl): Add non-finite input to
	itself.
	* sysdeps/ieee754/dbl-64/s_frexp.c (__frexp): Add non-finite or
	zero input to itself.
	* sysdeps/ieee754/dbl-64/wordsize-64/s_frexp.c (__frexp):
	Likewise.
	* sysdeps/ieee754/flt-32/s_frexpf.c (__frexpf): Likewise.
	* sysdeps/ieee754/ldbl-128/s_frexpl.c (__frexpl): Likewise.
	* sysdeps/ieee754/ldbl-128ibm/s_frexpl.c (__frexpl): Likewise.
	* sysdeps/ieee754/ldbl-96/s_frexpl.c (__frexpl): Likewise.
	* math/libm-test.inc (frexp_test_data): Add sNaN tests.
2016-06-13 17:27:19 +00:00

62 lines
1.5 KiB
C

/* s_frexpl.c -- long double version of s_frexp.c.
* Conversion to long double by Ulrich Drepper,
* Cygnus Support, 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.
* ====================================================
*/
#if defined(LIBM_SCCS) && !defined(lint)
static char rcsid[] = "$NetBSD: $";
#endif
/*
* for non-zero x
* x = frexpl(arg,&exp);
* return a long double fp quantity x such that 0.5 <= |x| <1.0
* and the corresponding binary exponent "exp". That is
* arg = x*2^exp.
* If arg is inf, 0.0, or NaN, then frexpl(arg,&exp) returns arg
* with *exp=0.
*/
#include <float.h>
#include <math.h>
#include <math_private.h>
static const long double
#if LDBL_MANT_DIG == 64
two65 = 3.68934881474191032320e+19L; /* 0x4040, 0x80000000, 0x00000000 */
#else
# error "Cannot handle this MANT_DIG"
#endif
long double __frexpl(long double x, int *eptr)
{
u_int32_t se, hx, ix, lx;
GET_LDOUBLE_WORDS(se,hx,lx,x);
ix = 0x7fff&se;
*eptr = 0;
if(ix==0x7fff||((ix|hx|lx)==0)) return x + x; /* 0,inf,nan */
if (ix==0x0000) { /* subnormal */
x *= two65;
GET_LDOUBLE_EXP(se,x);
ix = se&0x7fff;
*eptr = -65;
}
*eptr += ix-16382;
se = (se & 0x8000) | 0x3ffe;
SET_LDOUBLE_EXP(x,se);
return x;
}
weak_alias (__frexpl, frexpl)