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Diffstat (limited to 'sysdeps/generic/s_cprojl.c')
| -rw-r--r-- | sysdeps/generic/s_cprojl.c | 48 |
1 files changed, 48 insertions, 0 deletions
diff --git a/sysdeps/generic/s_cprojl.c b/sysdeps/generic/s_cprojl.c new file mode 100644 index 0000000000..c70cdc47db --- /dev/null +++ b/sysdeps/generic/s_cprojl.c @@ -0,0 +1,48 @@ +/* Compute projection of complex long double value to Riemann sphere. + Copyright (C) 1997, 1999 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Lesser General Public + License as published by the Free Software Foundation; either + version 2.1 of the License, or (at your option) any later version. + + The GNU C Library 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 + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public + License along with the GNU C Library; if not, write to the Free + Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA + 02111-1307 USA. */ + +#include <complex.h> +#include <math.h> + + +__complex__ long double +__cprojl (__complex__ long double x) +{ + __complex__ long double res; + + if (isnan (__real__ x) && isnan (__imag__ x)) + return x; + else if (!isfinite (__real__ x) || !isfinite (__imag__ x)) + { + __real__ res = INFINITY; + __imag__ res = __copysignl (0.0, __imag__ x); + } + else + { + long double den = (__real__ x * __real__ x + __imag__ x * __imag__ x + + 1.0); + + __real__ res = (2.0 * __real__ x) / den; + __imag__ res = (2.0 * __imag__ x) / den; + } + + return res; +} +weak_alias (__cprojl, cprojl) |