efficient implementation of sqrt on C64x+

Jogging Song

Hi,all
In the vision library, a function is available for Bhattacharya Distance calculation.
According to the definition of Bhattacharya Distance, square root need to be computed.
I was wondering whether such complex functions implementations from C runtime library are efficient
enough. Do engineers have to find other ways to optimize them?

Best Regards
Jogging

over 15 years ago

0 Bernie Thompson TI over 15 years ago

TI__Mastermind 41665 points

I suspect just the standard C runtime (RTS) is being used, I don't recall coming across an optimized sqrt() function for C64x+. There is a fast RTS library for C64x here however it does not seem to cover any changes to the sqrt() function.

0 Gagan Maur over 15 years ago

TI__Expert 8150 points

Jogging. It is not optimal to use floating point representation directly on fixed point devices. Also, runtime support ibrary implementation for say floating point sqrt will not be the most optimal. I don't believe that is what is being used in VLIB. Are you interested in getting an optimal sqrt implementation on C6x? Did you consider IQMath http://focus.ti.com/docs/toolsw/folders/print/sprc542.html?

Regards,
Gagan

0 Senthil Kumar Yogamani over 15 years ago in reply to Gagan Maur

TI__Intellectual 1450 points

Jogging,

The implementation is based on an efficient fixed point square root algorithm.

Regards

Senthil

0 Jogging Song over 15 years ago in reply to Senthil Kumar Yogamani

Intellectual 685 points

Thanks, all
I take a look at the IQMath library. It contains optimized
mathematical functions.

Senthil, do you use the fixed point square root from IQ math library?
If no, why?

Best regards
Jogging

0 Senthil Kumar Yogamani over 15 years ago in reply to Jogging Song

TI__Intellectual 1450 points

Jogging,

I did not implement it.

May be the developer reused IQ math library implementation. I am not aware of it.

Regards
Senthil

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efficient implementation of sqrt on C64x+