math/s_csinh_template.c

   1 /* Complex sine hyperbole function for float types.
   2    Copyright (C) 1997-2023 Free Software Foundation, Inc.
   3    This file is part of the GNU C Library.
   4
   5    The GNU C Library is free software; you can redistribute it and/or
   6    modify it under the terms of the GNU Lesser General Public
   7    License as published by the Free Software Foundation; either
   8    version 2.1 of the License, or (at your option) any later version.
   9
  10    The GNU C Library is distributed in the hope that it will be useful,
  11    but WITHOUT ANY WARRANTY; without even the implied warranty of
  12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13    Lesser General Public License for more details.
  14
  15    You should have received a copy of the GNU Lesser General Public
  16    License along with the GNU C Library; if not, see
  17    <https://www.gnu.org/licenses/>.  */
  18
  19 #include <complex.h>
  20 #include <fenv.h>
  21 #include <math.h>
  22 #include <math_private.h>
  23 #include <math-underflow.h>
  24 #include <float.h>
  25
  26 CFLOAT
  27 M_DECL_FUNC (__csinh) (CFLOAT x)
  28 {
  29   CFLOAT retval;
  30   int negate = signbit (__real__ x);
  31   int rcls = fpclassify (__real__ x);
  32   int icls = fpclassify (__imag__ x);
  33
  34   __real__ x = M_FABS (__real__ x);
  35
  36   if (__glibc_likely (rcls >= FP_ZERO))
  37     {
  38       /* Real part is finite.  */
  39       if (__glibc_likely (icls >= FP_ZERO))
  40         {
  41           /* Imaginary part is finite.  */
  42           const int t = (int) ((M_MAX_EXP - 1) * M_MLIT (M_LN2));
  43           FLOAT sinix, cosix;
  44
  45           if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))
  46             {
  47               M_SINCOS (__imag__ x, &sinix, &cosix);
  48             }
  49           else
  50             {
  51               sinix = __imag__ x;
  52               cosix = 1;
  53             }
  54
  55           if (negate)
  56             cosix = -cosix;
  57
  58           if (M_FABS (__real__ x) > t)
  59             {
  60               FLOAT exp_t = M_EXP (t);
  61               FLOAT rx = M_FABS (__real__ x);
  62               if (signbit (__real__ x))
  63                 cosix = -cosix;
  64               rx -= t;
  65               sinix *= exp_t / 2;
  66               cosix *= exp_t / 2;
  67               if (rx > t)
  68                 {
  69                   rx -= t;
  70                   sinix *= exp_t;
  71                   cosix *= exp_t;
  72                 }
  73               if (rx > t)
  74                 {
  75                   /* Overflow (original real part of x > 3t).  */
  76                   __real__ retval = M_MAX * cosix;
  77                   __imag__ retval = M_MAX * sinix;
  78                 }
  79               else
  80                 {
  81                   FLOAT exp_val = M_EXP (rx);
  82                   __real__ retval = exp_val * cosix;
  83                   __imag__ retval = exp_val * sinix;
  84                 }
  85             }
  86           else
  87             {
  88               __real__ retval = M_SINH (__real__ x) * cosix;
  89               __imag__ retval = M_COSH (__real__ x) * sinix;
  90             }
  91
  92           math_check_force_underflow_complex (retval);
  93         }
  94       else
  95         {
  96           if (rcls == FP_ZERO)
  97             {
  98               /* Real part is 0.0.  */
  99               __real__ retval = M_COPYSIGN (0, negate ? -1 : 1);
 100               __imag__ retval = __imag__ x - __imag__ x;
 101             }
 102           else
 103             {
 104               __real__ retval = M_NAN;
 105               __imag__ retval = M_NAN;
 106
 107               feraiseexcept (FE_INVALID);
 108             }
 109         }
 110     }
 111   else if (rcls == FP_INFINITE)
 112     {
 113       /* Real part is infinite.  */
 114       if (__glibc_likely (icls > FP_ZERO))
 115         {
 116           /* Imaginary part is finite.  */
 117           FLOAT sinix, cosix;
 118
 119           if (__glibc_likely (M_FABS (__imag__ x) > M_MIN))
 120             {
 121               M_SINCOS (__imag__ x, &sinix, &cosix);
 122             }
 123           else
 124             {
 125               sinix = __imag__ x;
 126               cosix = 1;
 127             }
 128
 129           __real__ retval = M_COPYSIGN (M_HUGE_VAL, cosix);
 130           __imag__ retval = M_COPYSIGN (M_HUGE_VAL, sinix);
 131
 132           if (negate)
 133             __real__ retval = -__real__ retval;
 134         }
 135       else if (icls == FP_ZERO)
 136         {
 137           /* Imaginary part is 0.0.  */
 138           __real__ retval = negate ? -M_HUGE_VAL : M_HUGE_VAL;
 139           __imag__ retval = __imag__ x;
 140         }
 141       else
 142         {
 143           __real__ retval = M_HUGE_VAL;
 144           __imag__ retval = __imag__ x - __imag__ x;
 145         }
 146     }
 147   else
 148     {
 149       __real__ retval = M_NAN;
 150       __imag__ retval = __imag__ x == 0 ? __imag__ x : M_NAN;
 151     }
 152
 153   return retval;
 154 }
 155
 156 declare_mgen_alias (__csinh, csinh)