FPU performances calculation - optimizing real time math

[Ron]

Hi

I am using nRF52832, S132 / SDK17, implementing an algorithm requiring some math,

for example I am doing a matrix multiplication with about 800 float multiplications, I understand that a multiplication taking 3 cycles from the ARM-M4, working with 32MHz; and optimizing for time, I am seeing it 2400 cycles to take more than 200us -Does that make sense?

is there some way (not algorithmically that is) to improve those performances? some other optimizing flag to be raised, FPU enableing? a way to allocate the memory to be more efficiently accessed? 

Is there some example/reference you can refer me to?

Thanks!

[Simonr]

Hi

Okay, that seems fine. If you've also added FLOAT_ABI_HARD to your preprocessor definitions, FPU should be enabled. In that case I'm not aware of any further ways to speed up calculations on an nRF52832. Is it necessary for your application to do these calculations faster?

Best regards,

Simon

[Ron]

Dear Simon

I would like to do it faster, but I am also generally surprised for it to take so long,

Can you give me some rough estimations about computation time with nRF52 with FPU, I think float multiplication should take 3 cycles, with 64MHz, according to my calculation 1000 multiplication should take about 15us. 

Thanks!