I am currently porting my 32-bit C++ DSP audio processing project on Analog Devices Sharc DSP processor to 64-bit processing on Raspberry A53 AArch64, my target platform is Raspberry Pi, 3B+ maybe 4. In order to implement IIR filtering I want to use arm_biquad_cascade_df2T_f64() together with a supplementary init function that implements the state array needed to process data in a block-based manner. it seems to work with 64-bit. But I have doubts if they are suitable and optimized for AArch64 as generally CMSIS is labeled 32-bit and there is a folloiwng statement in the documentation:
"For Neon version, this array is bigger. If numstages = 4x + y, then the array has size: 32*x + 5*y and it must be initialized using the function arm_biquad_cascade_df2T_compute_coefs_f32 which is taking the standard array coefficient as parameters."
So there is a 32-bit function and no trace of 64-bit for Neon.
My application is quite performance critical so I would like to learn if CMSIS functions will work and are optimized for AArch64 ?
Pawel