__kernel_cospi
c = -__kernel_cospi(1 - ax);
c = ix == 0 ? 1 : __kernel_cospi(ax);
c = -__kernel_cospi(1 - ax);
return (__kernel_cospi(ax));
s = __kernel_cospi(0.5 - ax);
s = __kernel_cospi(ax - 0.5);
s = __kernel_cospi(0.5 - ax);
s = __kernel_cospi(ax - 0.5);