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Diffstat (limited to 'math/s_cexp_template.c')
| -rw-r--r-- | math/s_cexp_template.c | 157 |
1 files changed, 157 insertions, 0 deletions
diff --git a/math/s_cexp_template.c b/math/s_cexp_template.c new file mode 100644 index 0000000000..3a476bde3c --- /dev/null +++ b/math/s_cexp_template.c @@ -0,0 +1,157 @@ +/* Return value of complex exponential function for double complex value. + Copyright (C) 1997-2016 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, see + <http://www.gnu.org/licenses/>. */ + +#include <complex.h> +#include <fenv.h> +#include <math.h> +#include <math_private.h> +#include <float.h> + +__complex__ double +__cexp (__complex__ double x) +{ + __complex__ double retval; + int rcls = fpclassify (__real__ x); + int icls = fpclassify (__imag__ x); + + if (__glibc_likely (rcls >= FP_ZERO)) + { + /* Real part is finite. */ + if (__glibc_likely (icls >= FP_ZERO)) + { + /* Imaginary part is finite. */ + const int t = (int) ((DBL_MAX_EXP - 1) * M_LN2); + double sinix, cosix; + + if (__glibc_likely (fabs (__imag__ x) > DBL_MIN)) + { + __sincos (__imag__ x, &sinix, &cosix); + } + else + { + sinix = __imag__ x; + cosix = 1.0; + } + + if (__real__ x > t) + { + double exp_t = __ieee754_exp (t); + __real__ x -= t; + sinix *= exp_t; + cosix *= exp_t; + if (__real__ x > t) + { + __real__ x -= t; + sinix *= exp_t; + cosix *= exp_t; + } + } + if (__real__ x > t) + { + /* Overflow (original real part of x > 3t). */ + __real__ retval = DBL_MAX * cosix; + __imag__ retval = DBL_MAX * sinix; + } + else + { + double exp_val = __ieee754_exp (__real__ x); + __real__ retval = exp_val * cosix; + __imag__ retval = exp_val * sinix; + } + math_check_force_underflow_complex (retval); + } + 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 (""); + + feraiseexcept (FE_INVALID); + } + } + else if (__glibc_likely (rcls == FP_INFINITE)) + { + /* Real part is infinite. */ + if (__glibc_likely (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; + + if (__glibc_likely (fabs (__imag__ x) > DBL_MIN)) + { + __sincos (__imag__ x, &sinix, &cosix); + } + else + { + sinix = __imag__ x; + cosix = 1.0; + } + + __real__ retval = __copysign (value, cosix); + __imag__ retval = __copysign (value, sinix); + } + } + else if (signbit (__real__ x) == 0) + { + __real__ retval = HUGE_VAL; + __imag__ retval = __nan (""); + + if (icls == FP_INFINITE) + feraiseexcept (FE_INVALID); + } + else + { + __real__ retval = 0.0; + __imag__ retval = __copysign (0.0, __imag__ x); + } + } + else + { + /* If the real part is NaN the result is NaN + iNaN unless the + imaginary part is zero. */ + __real__ retval = __nan (""); + if (icls == FP_ZERO) + __imag__ retval = __imag__ x; + else + { + __imag__ retval = __nan (""); + + if (rcls != FP_NAN || icls != FP_NAN) + feraiseexcept (FE_INVALID); + } + } + + return retval; +} +weak_alias (__cexp, cexp) +#ifdef NO_LONG_DOUBLE +strong_alias (__cexp, __cexpl) +weak_alias (__cexp, cexpl) +#endif |