CCS/TMS320F28379D: remark #30012

Alexey Gribov

Part Number: TMS320F28379D
Other Parts Discussed in Thread: C2000WARE

Tool/software: Code Composer Studio

I use CLA to calculate a state vector of the asynchronous machine. All the variables are 32 integers so I can use fixed-point calculations.

I get the #30012 remark on this: Z = (Z/100000+(Z%100000)/50000);

I've pasted this line to imitate regular round function. The operation '/' gives a result that isn't satisfactory for my requirements. Can anyone explain what the remark means or offer an easier way to emulate rounding function?

over 6 years ago

0 George Mock over 6 years ago

TI__Guru**** 232750 points

I am unable to reproduce that remark. Since I had to guess at several details, that is not surprising. Please submit a test case as described in the article How to Submit a Compiler Test Case.

Thanks and regards,

-George

0 Archaeologist over 6 years ago

TI__Guru* 84225 points

If you can, please try to make the divisor a power of two (try 1048576) so that the compiler can optimize the division to a shift.

0 Alexey Gribov over 6 years ago in reply to George Mock

Prodigy 30 points

This is basically slightly changed example from C2000WARE_1_00_01_00. Compiler - TIv16.9.1.LTS.question.rar

0 Alexey Gribov over 6 years ago in reply to Archaeologist

Prodigy 30 points

Unfortunately I can't. This number represents the time step I use in the discrete integration. Such change will result in inadequate result.

0 George Mock over 6 years ago

TI__Guru**** 232750 points

Alexey Gribov said:
I get the #30012 remark on this: Z = (Z/100000+(Z%100000)/50000);

You get a performance remark diagnostic because you use the build option --advice:performance=all.

"file.cla", line 535: advice #30012: (Performance) Signed division operation
   was not eliminated during optimization. Using inefficient fallback; consider
   modifying code to not require this operation.

As you've stated, you have to divide by a number that is not a power of 2. No source changes can be made. You could consider removing --advice:performance=all.

Thanks and regards,

-George

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CCS/TMS320F28379D: remark #30012