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author | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
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committer | Ulrich Drepper <drepper@redhat.com> | 1999-07-14 00:54:57 +0000 |
commit | abfbdde177c3a7155070dda1b2cdc8292054cc26 (patch) | |
tree | e021306b596381fbf8311d2b7eb294e918ff17c8 /sysdeps/generic/s_catanf.c | |
parent | 86421aa57ecfd70963ae66848bd6a6dd3b8e0fe6 (diff) | |
download | glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.gz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.tar.xz glibc-abfbdde177c3a7155070dda1b2cdc8292054cc26.zip |
Update.
Diffstat (limited to 'sysdeps/generic/s_catanf.c')
-rw-r--r-- | sysdeps/generic/s_catanf.c | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/sysdeps/generic/s_catanf.c b/sysdeps/generic/s_catanf.c new file mode 100644 index 0000000000..18881cd6c9 --- /dev/null +++ b/sysdeps/generic/s_catanf.c @@ -0,0 +1,85 @@ +/* Return arc tangent of complex float value. + Copyright (C) 1997 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 Library General Public License as + published by the Free Software Foundation; either version 2 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. 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> + +#include "math_private.h" + + +__complex__ float +__catanf (__complex__ float x) +{ + __complex__ float res; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (rcls <= FP_INFINITE || icls <= FP_INFINITE) + { + if (rcls == FP_INFINITE) + { + __real__ res = __copysignf (M_PI_2, __real__ x); + __imag__ res = __copysignf (0.0, __imag__ x); + } + else if (icls == FP_INFINITE) + { + if (rcls >= FP_ZERO) + __real__ res = __copysignf (M_PI_2, __real__ x); + else + __real__ res = __nanf (""); + __imag__ res = __copysignf (0.0, __imag__ x); + } + else if (icls == FP_ZERO || icls == FP_INFINITE) + { + __real__ res = __nanf (""); + __imag__ res = __copysignf (0.0, __imag__ x); + } + else + { + __real__ res = __nanf (""); + __imag__ res = __nanf (""); + } + } + else if (rcls == FP_ZERO && icls == FP_ZERO) + { + res = x; + } + else + { + float r2, num, den; + + r2 = __real__ x * __real__ x; + + den = 1 - r2 - __imag__ x * __imag__ x; + + __real__ res = 0.5 * __ieee754_atan2f (2.0 * __real__ x, den); + + num = __imag__ x + 1.0; + num = r2 + num * num; + + den = __imag__ x - 1.0; + den = r2 + den * den; + + __imag__ res = 0.25 * __ieee754_logf (num / den); + } + + return res; +} +weak_alias (__catanf, catanf) |