lib/glibc
1
0
Fork 0
mirror of https://sourceware.org/git/glibc.git synced 2025-07-29 11:41:21 +03:00
Code Activity

Fix clog overflow/underflow (bug 13629).

Browse Source
This commit is contained in:
Joseph Myers
2012-03-19 20:13:10 +00:00
parent 7726d6a95d
commit 1897ad4432
10 changed files with 322 additions and 22 deletions
Download Patch File Download Diff File Expand all files Collapse all files

27
math/s_clogl.c
View File

@ -1,5 +1,5 @@
/* Compute complex natural logarithm.
Copyright (C) 1997, 1998, 2011 Free Software Foundation, Inc.
Copyright (C) 1997-2012 Free Software Foundation, Inc.
This file is part of the GNU C Library.
Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997.
@ -20,7 +20,7 @@
#include <complex.h>
#include <math.h>
#include <math_private.h>
#include <float.h>
__complex__ long double
__clogl (__complex__ long double x)
@ -40,8 +40,27 @@ __clogl (__complex__ long double x)
else if (__builtin_expect (rcls != FP_NAN && icls != FP_NAN, 1))
{
/* Neither real nor imaginary part is NaN. */
__real__ result = __ieee754_logl (__ieee754_hypotl (__real__ x,
__imag__ x));
long double d;
int scale = 0;
if (fabsl (__real__ x) > LDBL_MAX / 2.0L
|| fabsl (__imag__ x) > LDBL_MAX / 2.0L)
{
scale = -1;
__real__ x = __scalbnl (__real__ x, scale);
__imag__ x = __scalbnl (__imag__ x, scale);
}
else if (fabsl (__real__ x) < LDBL_MIN
&& fabsl (__imag__ x) < LDBL_MIN)
{
scale = LDBL_MANT_DIG;
__real__ x = __scalbnl (__real__ x, scale);
__imag__ x = __scalbnl (__imag__ x, scale);
}
d = __ieee754_hypotl (__real__ x, __imag__ x);
__real__ result = __ieee754_logl (d) - scale * M_LN2l;
__imag__ result = __ieee754_atan2l (__imag__ x, __real__ x);
}
else