newlib/winsup/mingw/mingwex/complex/cacosl.c

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/*
cacosl.c
Contributed by Danny Smith
2004-01-04
*/
#include <math.h>
#include <complex.h>
#if 0
/* cacos (Z) = -I * clog(Z + I * csqrt(1 - Z * Z)) */
long double complex cacosl (long double complex Z)
{
long double complex Res;
long double x, y;
x = __real__ Z;
y = __imag__ Z;
if (y == 0.0L)
{
__real__ Res = acosl (x);
__imag__ Res = 0.0L;
}
else
{
long double complex ZZ;
/* Z * Z = ((x - y) * (x + y)) + (2.0 * x * y) * I */
/* caculate 1 - Z * Z */
__real__ ZZ = 1.0L - (x - y) * (x + y);
__imag__ ZZ = -2.0L * x * y;
Res = csqrtl(ZZ);
/* calculate ZZ + I * sqrt (ZZ) */
__real__ ZZ = x - __imag__ Res;
__imag__ ZZ = y + __real__ Res;
ZZ = clogl(ZZ);
/* mult by -I */
__real__ Res = __imag__ ZZ;
__imag__ Res = - __real__ ZZ;
}
return Res;
}
#else
/* cacos ( Z ) = pi/2 - casin ( Z ) */
#ifndef _M_PI_2L
#define _M_PI_2L 1.5707963267948966192313L
#endif
long double complex cacosl (long double complex Z)
{
long double complex Res = casinl (Z);
__real__ Res = _M_PI_2L - __real__ Res;
__imag__ Res = - __imag__ Res;
return Res;
}
#endif