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Diffstat (limited to 'math/s_cexp.c')
| -rw-r--r-- | math/s_cexp.c | 127 |
1 files changed, 127 insertions, 0 deletions
diff --git a/math/s_cexp.c b/math/s_cexp.c new file mode 100644 index 0000000000..5a299b7687 --- /dev/null +++ b/math/s_cexp.c @@ -0,0 +1,127 @@ +/* Return value of complex exponential function for double complex 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 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 <fenv.h> +#include <math.h> + +#include "math_private.h" + + +__complex__ double +__cexp (__complex__ double x) +{ + __complex__ double retval; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (rcls >= FP_ZERO) + { + /* Real part is finite. */ + if (icls >= FP_ZERO) + { + /* Imaginary part is finite. */ + double exp_val = __ieee754_exp (__real__ x); + double sinix, cosix; + + __sincos (__imag__ x, &sinix, &cosix); + + if (isfinite (exp_val)) + { + __real__ retval = exp_val * cosix; + __imag__ retval = exp_val * sinix; + } + else + { + __real__ retval = __copysign (exp_val, cosix); + __imag__ retval = __copysign (exp_val, sinix); + } + } + else + { + /* If the imaginary part is +-inf or NaN and the real part + is not +-inf the result is NaN + iNaN. */ + __real__ retval = __nan (""); + __imag__ retval = __nan (""); + +#ifdef FE_INVALID + feraiseexcept (FE_INVALID); +#endif + } + } + else if (rcls == FP_INFINITE) + { + /* Real part is infinite. */ + if (icls >= FP_ZERO) + { + /* Imaginary part is finite. */ + double value = signbit (__real__ x) ? 0.0 : HUGE_VAL; + + if (icls == FP_ZERO) + { + /* Imaginary part is 0.0. */ + __real__ retval = value; + __imag__ retval = __imag__ x; + } + else + { + double sinix, cosix; + + __sincos (__imag__ x, &sinix, &cosix); + + __real__ retval = __copysign (value, cosix); + __imag__ retval = __copysign (value, sinix); + } + } + else if (signbit (__real__ x) == 0) + { + __real__ retval = HUGE_VAL; + __imag__ retval = __nan (""); + +#ifdef FE_INVALID + if (icls == FP_INFINITE) + feraiseexcept (FE_INVALID); +#endif + } + else + { + __real__ retval = 0.0; + __imag__ retval = __copysign (0.0, __imag__ x); + } + } + else + { + /* If the real part is NaN the result is NaN + iNaN. */ + __real__ retval = __nan (""); + __imag__ retval = __nan (""); + +#ifdef FE_INVALID + if (rcls != FP_NAN || icls != FP_NAN) + feraiseexcept (FE_INVALID); +#endif + } + + return retval; +} +weak_alias (__cexp, cexp) +#ifdef NO_LONG_DOUBLE +strong_alias (__cexp, __cexpl) +weak_alias (__cexp, cexpl) +#endif |