Mercurial > gnulib
view lib/cbrt.c @ 17363:5a51fb7777a9
sys_select, sys_time: port 2013-01-30 Solaris 2.6 fix to Cygwin
Problem reported by Marco Atzeri in
<http://lists.gnu.org/archive/html/bug-gnulib/2013-03/msg00000.html>.
* lib/sys_select.in.h [HAVE_SYS_SELECT_H && _CYGWIN_SYS_TIME_H]:
Simply delegate to the system <sys/select.h> in this case too.
Also, pay attention to _GL_SYS_SELECT_H_REDIRECT_FROM_SYS_TIME_H only
if OSF/1, since otherwise Cygwin breaks, and it doesn't seem to
be needed on Solaris either.
* lib/sys_time.in.h [_CYGWIN_SYS_TIME_H]:
Simply delgate to the system <sys/time.h> in this case.
author | Paul Eggert <eggert@cs.ucla.edu> |
---|---|
date | Tue, 19 Mar 2013 09:08:47 -0700 |
parents | e542fd46ad6f |
children | 344018b6e5d7 |
line wrap: on
line source
/* Compute cubic root of double value. Copyright (C) 1997, 2012-2013 Free Software Foundation, Inc. Contributed by Dirk Alboth <dirka@uni-paderborn.de> and Ulrich Drepper <drepper@cygnus.com>, 1997. This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ #include <config.h> /* Specification. */ #include <math.h> /* MSVC with option -fp:strict refuses to compile constant initializers that contain floating-point operations. Pacify this compiler. */ #ifdef _MSC_VER # pragma fenv_access (off) #endif /* Code based on glibc/sysdeps/ieee754/dbl-64/s_cbrt.c. */ #define CBRT2 1.2599210498948731648 /* 2^(1/3) */ #define SQR_CBRT2 1.5874010519681994748 /* 2^(2/3) */ static const double factor[5] = { 1.0 / SQR_CBRT2, 1.0 / CBRT2, 1.0, CBRT2, SQR_CBRT2 }; double cbrt (double x) { if (isfinite (x) && x != 0.0) { double xm, ym, u, t2; int xe; /* Reduce X. XM now is an range 1.0 to 0.5. */ xm = frexp (fabs (x), &xe); u = (0.354895765043919860 + ((1.50819193781584896 + ((-2.11499494167371287 + ((2.44693122563534430 + ((-1.83469277483613086 + (0.784932344976639262 - 0.145263899385486377 * xm) * xm) * xm)) * xm)) * xm)) * xm)); t2 = u * u * u; ym = u * (t2 + 2.0 * xm) / (2.0 * t2 + xm) * factor[2 + xe % 3]; return ldexp (x > 0.0 ? ym : -ym, xe / 3); } else return x + x; }