1 /* Return arc sine of complex double value. 2 Copyright (C) 1997 Free Software Foundation, Inc. 3 This file is part of the GNU C Library. 4 Contributed by Ulrich Drepper <drepper@cygnus.com>, 1997. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library; if not, write to the Free 18 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 19 02111-1307 USA. */ 20 21 #include <complex.h> 22 #include <math.h> 23 24 25 __complex__ double 26 __casin (__complex__ double x) 27 { 28 __complex__ double res; 29 30 if (isnan (__real__ x) || isnan (__imag__ x)) 31 { 32 if (__real__ x == 0.0) 33 { 34 res = x; 35 } 36 else if (__isinf (__real__ x) || __isinf (__imag__ x)) 37 { 38 __real__ res = __nan (""); 39 __imag__ res = __copysign (HUGE_VAL, __imag__ x); 40 } 41 else 42 { 43 __real__ res = __nan (""); 44 __imag__ res = __nan (""); 45 } 46 } 47 else 48 { 49 __complex__ double y; 50 51 __real__ y = -__imag__ x; 52 __imag__ y = __real__ x; 53 54 y = __casinh (y); 55 56 __real__ res = __imag__ y; 57 __imag__ res = -__real__ y; 58 } 59 60 return res; 61 } 62 weak_alias (__casin, casin) 63 #ifdef NO_LONG_DOUBLE 64 strong_alias (__casin, __casinl) 65 weak_alias (__casin, casinl) 66 #endif 67