TMS320F28069: TMS320F28069PNT Automatic Shift Operation Use for Multiplication and Division for Performance?

Jim Warren

Part Number: TMS320F28069

Can you tell me if the TMS320F28069PNT Microcontroller (or the Control Law Accelerator) has any built in optimization for multiplication and division operations that automatically use shift operations "under the hood" to increase performance?

-Jim

over 8 years ago

0 Vishal_Coelho over 8 years ago

TI__Mastermind 20850 points

For integer divide, multiply by 2 i do believe the optimizer will use arithmetic shifts on both the c28x and the CLA. Both cores have the assembly instructions to do them.

0 Jim Warren over 8 years ago in reply to Vishal_Coelho

Prodigy 250 points

Thank You Vishal.

So this happens automatically without any special setup or configuration?

-Jim

0 Vishal_Coelho over 8 years ago in reply to Jim Warren

TI__Mastermind 20850 points

I believe it happens when you set the optimization level to O2 in the project properties. I am going to push this over to the compiler forum so they can confirm

0 Jim Warren over 8 years ago in reply to Vishal_Coelho

Prodigy 250 points

Thank you Vishal. Let me know what they find...

Regards,

-Jim

0 George Mock over 8 years ago in reply to Jim Warren

TI__Guru**** 249900 points

Use the build flag --opt_level=[0-4] to enable optimization. Generally speaking, the higher the level used, the more optimization occurs.

As for a multiply or divide by a power of 2 ... Such expressions are changed to shifts. This occurs without regard to the --opt_level setting.

For more general information on this topic, please see the section titled What Kind of Optimization Is Being Performed in the C2000 compiler manual.

Thanks and regards,

-George

0 Jim Warren over 8 years ago in reply to George Mock

Prodigy 250 points

Thank you George. I was trying to decide if "manually optimizing" mathematical operations such as a division operation could be performed by just using the appropriate left shift operations in code, but it sounds like the compiler does this already?

-Jim

0 George Mock over 8 years ago in reply to Jim Warren

TI__Guru**** 249900 points

It is highly likely. To be sure, build with the option -s, then inspect the resulting compiler generated assembly. It is in a file with same name as the source file, but the extension changed to .asm.

Thanks and regards,

-George

0 Jim Warren over 8 years ago in reply to George Mock

Prodigy 250 points

Thank you George.

-Jim

Code Composer Studio™︎

Code Composer Studio forum

TMS320F28069: TMS320F28069PNT Automatic Shift Operation Use for Multiplication and Division for Performance?