glibc/math/s_csin_template.c

163 lines
3.7 KiB
C

/* Complex sine function for float types.
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 <math-underflow.h>
#include <float.h>
CFLOAT
M_DECL_FUNC (__csin) (CFLOAT x)
{
CFLOAT retval;
int negate = signbit (__real__ x);
int rcls = fpclassify (__real__ x);
int icls = fpclassify (__imag__ x);
__real__ x = M_FABS (__real__ x);
if (__glibc_likely (icls >= FP_ZERO))
{
/* Imaginary part is finite. */
if (__glibc_likely (rcls >= FP_ZERO))
{
/* Real part is finite. */
const int t = (int) ((M_MAX_EXP - 1) * M_MLIT (M_LN2));
FLOAT sinix, cosix;
if (__glibc_likely (__real__ x > M_MIN))
{
M_SINCOS (__real__ x, &sinix, &cosix);
}
else
{
sinix = __real__ x;
cosix = 1;
}
if (negate)
sinix = -sinix;
if (M_FABS (__imag__ x) > t)
{
FLOAT exp_t = M_EXP (t);
FLOAT ix = M_FABS (__imag__ x);
if (signbit (__imag__ x))
cosix = -cosix;
ix -= t;
sinix *= exp_t / 2;
cosix *= exp_t / 2;
if (ix > t)
{
ix -= t;
sinix *= exp_t;
cosix *= exp_t;
}
if (ix > t)
{
/* Overflow (original imaginary part of x > 3t). */
__real__ retval = M_MAX * sinix;
__imag__ retval = M_MAX * cosix;
}
else
{
FLOAT exp_val = M_EXP (ix);
__real__ retval = exp_val * sinix;
__imag__ retval = exp_val * cosix;
}
}
else
{
__real__ retval = M_COSH (__imag__ x) * sinix;
__imag__ retval = M_SINH (__imag__ x) * cosix;
}
math_check_force_underflow_complex (retval);
}
else
{
if (icls == FP_ZERO)
{
/* Imaginary part is 0.0. */
__real__ retval = __real__ x - __real__ x;
__imag__ retval = __imag__ x;
}
else
{
__real__ retval = M_NAN;
__imag__ retval = M_NAN;
feraiseexcept (FE_INVALID);
}
}
}
else if (icls == FP_INFINITE)
{
/* Imaginary part is infinite. */
if (rcls == FP_ZERO)
{
/* Real part is 0.0. */
__real__ retval = M_COPYSIGN (0, negate ? -1 : 1);
__imag__ retval = __imag__ x;
}
else if (rcls > FP_ZERO)
{
/* Real part is finite. */
FLOAT sinix, cosix;
if (__glibc_likely (__real__ x > M_MIN))
{
M_SINCOS (__real__ x, &sinix, &cosix);
}
else
{
sinix = __real__ x;
cosix = 1;
}
__real__ retval = M_COPYSIGN (M_HUGE_VAL, sinix);
__imag__ retval = M_COPYSIGN (M_HUGE_VAL, cosix);
if (negate)
__real__ retval = -__real__ retval;
if (signbit (__imag__ x))
__imag__ retval = -__imag__ retval;
}
else
{
__real__ retval = __real__ x - __real__ x;
__imag__ retval = M_HUGE_VAL;
}
}
else
{
if (rcls == FP_ZERO)
__real__ retval = M_COPYSIGN (0, negate ? -1 : 1);
else
__real__ retval = M_NAN;
__imag__ retval = M_NAN;
}
return retval;
}
declare_mgen_alias (__csin, csin)