M_PIl
? M_PIl - M_PI_4l : M_PI_4l)
__imag__ res = copysignl (signbit (__real__ x) ? M_PIl : 0.0,
__imag__ result = signbit (__real__ x) ? M_PIl : 0.0;
__imag__ result = signbit (__real__ x) ? M_PIl : 0.0;