Assume I have the following:
Ipp64fVector my_all_real_vector Ipp64fcVector my_complex_vector
and I want to multiply them.
Is it faster to split complex and do 2 real multiplies and rebuild complex, or make real into complex and do complex multiplies??
ippsCplxToReal_64fc(my_complex_vector, my_real_parts, my_imag_parts); ippsMul_64f_I(my_all_real_vector, my_real_parts); ippsMul_64f_I(my_all_real_vector, my_imag_parts); ippsRealToCplx_64f(my_real_parts, my_imag_parts, my_complex_vector);
ippsRealToCplx_64f(my_all_real_vector, NULL, my_real_but_complex_vec); ippsMul_64fc_I(my_real_but_complex_vec, my_complex_vector);
I did a quick test to compare and they came out close. I expected the real multiplies to beat the complex, but maybe the overhead to repack is significant. What is the recommended best practice in this scenario? (my vector lengths ~1k to ~26k)