newlib-cygwin/winsup/mingw/mingwex/complex/csqrtf.c

50 lines
841 B
C
Executable File

#include <math.h>
#include <complex.h>
float complex csqrtf (float complex Z)
{
float complex Res;
float r;
float x = __real__ Z;
float y = __imag__ Z;
if (y == 0.0f)
{
if (x < 0.0f)
{
__real__ Res = 0.0f;
__imag__ Res = sqrtf (-x);
}
else
{
__real__ Res = sqrtf (x);
__imag__ Res = 0.0f;
}
}
else if (x == 0.0f)
{
r = sqrtf(0.5f * fabsf (y));
__real__ Res = r;
__imag__ Res = y > 0 ? r : -r;
}
else
{
float t = sqrtf (2 * (_hypot (__real__ Z, __imag__ Z) + fabsf (x)));
float u = t / 2.0f;
if ( x > 0.0f)
{
__real__ Res = u;
__imag__ Res = y / t;
}
else
{
__real__ Res = fabsf (y / t);
__imag__ Res = y < 0 ? -u : u;
}
}
return Res;
}