CCS/TMS320F28335: The CCS 7.0 Compiler is slower than the CCS 5.0 compiler, why?

Hainan Wang

Part Number: TMS320F28335

Tool/software: Code Composer Studio

Hi, there

I am previously working with CCS 5.0, and I recently upgraded to CCS7.0, here's the problem I see:

One of my project, which is a big one, runs faster with the output file compiled by old CCS 5.0 compiler. Here's is my guess:

In that project, I used a lot structures , for example

Controller[n].error.overpower = 1

For this instruction, If the n is a variable, the CPU need to calculate the address of the variable real time, this kind of slow it a lot down. So, previously in CCS5.0, what I do is use constant instead of variables:

Controller[0].error.overpower = 1

This seems to greatly increased the speed. The compiler seems to pre-calculate the address in the compile stage. The down side of this is more coding effort and code size, which I can take.

However, with the new CCS7.0 compiler, this seems not working, it always calculate the address real time, no matter it is constant or not.

Could you tell me what I need to do to make the compiler calculate the address of a variable at the compiling stage, not the real time.

Or, what I can do to reduce the address calculation at real time?

Thanks

Eric

over 7 years ago

0 Ki over 7 years ago

TI__Guru**** 463941 points

Hello Eric,

Note that while each CCS version comes with a particular version of the compiler, it is not tied to it. Meaning you can use multiple versions of the compiler with a CCS version. So when you discuss compiler versions, you need to provide the actual compiler version number, not the CCS version.

See: http://processors.wiki.ti.com/index.php/Compiler_Version_Numbers_and_What_They_Mean

Also given the fact discussed above, the next thing to try is to use the same compiler version you used with CCSv5.0 with CCSv7.0. If the issue cannot be reproduced when using the older compiler version in CCSv7.0, then we can conclude that the root cause is with the actual compiler and not CCS itself. If the issue can be reproduced, then it could be a project migration issue or something related.

How to use an older version of the compiler with a CCS version? see: http://processors.wiki.ti.com/index.php/Compiler_Installation_and_Selection

Please let us know what you find.

Thanks

0 Hainan Wang over 7 years ago in reply to Ki

Intellectual 450 points

I did not see the older version of compiler in my CCS7.0. Is that an option when you install the CCS7.0, do I need to re-install it?

Thanks

Eric

0 Ki over 7 years ago in reply to Hainan Wang

TI__Guru**** 463941 points

Hi Eric,
Did you see the article I posted in my prior link?
processors.wiki.ti.com/.../Compiler_Installation_and_Selection

If you have v5 also installed on the same machine, use the steps in the link above to point v7 to the compiler from v5. If you don't have v5 installed on the same machine, you can download a standalone version (link to the download in the url above) or use the technique listed in the link below:
processors.wiki.ti.com/.../Updating_CCSv6

Thanks
ki

0 Hainan Wang over 7 years ago in reply to Ki

Intellectual 450 points

I tried to reinstall the CCSV7, I didn't see anywhere can let me select to install the old version compiler. Could you advice?
Thanks, Eric

0 Ki over 7 years ago in reply to Hainan Wang

TI__Guru**** 463941 points

Please see this video:
www.youtube.com/watch

Thanks
ki

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CCS/TMS320F28335: The CCS 7.0 Compiler is slower than the CCS 5.0 compiler, why?