| /* Return value of complex exponential function for a float type. |
| Copyright (C) 1997-2018 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> |
| |
| CFLOAT |
| M_DECL_FUNC (__cexp) (CFLOAT x) |
| { |
| CFLOAT 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) ((M_MAX_EXP - 1) * M_MLIT (M_LN2)); |
| FLOAT sinix, cosix; |
| |
| if (__glibc_likely (M_FABS (__imag__ x) > M_MIN)) |
| { |
| M_SINCOS (__imag__ x, &sinix, &cosix); |
| } |
| else |
| { |
| sinix = __imag__ x; |
| cosix = 1; |
| } |
| |
| if (__real__ x > t) |
| { |
| FLOAT exp_t = M_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 = M_MAX * cosix; |
| __imag__ retval = M_MAX * sinix; |
| } |
| else |
| { |
| FLOAT exp_val = M_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 = M_NAN; |
| __imag__ retval = M_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. */ |
| FLOAT value = signbit (__real__ x) ? 0 : M_HUGE_VAL; |
| |
| if (icls == FP_ZERO) |
| { |
| /* Imaginary part is 0.0. */ |
| __real__ retval = value; |
| __imag__ retval = __imag__ x; |
| } |
| else |
| { |
| FLOAT sinix, cosix; |
| |
| if (__glibc_likely (M_FABS (__imag__ x) > M_MIN)) |
| { |
| M_SINCOS (__imag__ x, &sinix, &cosix); |
| } |
| else |
| { |
| sinix = __imag__ x; |
| cosix = 1; |
| } |
| |
| __real__ retval = M_COPYSIGN (value, cosix); |
| __imag__ retval = M_COPYSIGN (value, sinix); |
| } |
| } |
| else if (signbit (__real__ x) == 0) |
| { |
| __real__ retval = M_HUGE_VAL; |
| __imag__ retval = __imag__ x - __imag__ x; |
| } |
| else |
| { |
| __real__ retval = 0; |
| __imag__ retval = M_COPYSIGN (0, __imag__ x); |
| } |
| } |
| else |
| { |
| /* If the real part is NaN the result is NaN + iNaN unless the |
| imaginary part is zero. */ |
| __real__ retval = M_NAN; |
| if (icls == FP_ZERO) |
| __imag__ retval = __imag__ x; |
| else |
| { |
| __imag__ retval = M_NAN; |
| |
| if (rcls != FP_NAN || icls != FP_NAN) |
| feraiseexcept (FE_INVALID); |
| } |
| } |
| |
| return retval; |
| } |
| declare_mgen_alias (__cexp, cexp) |