CCS/AWR1642: How do I remove unused function from map file?

Kensuke

Expert 1140 points

Part Number: AWR1642

Tool/software: Code Composer Studio

Hi,

I am using Linker option --unused_section_elimination=on, but unused functions remain on the map file.

How do I remove unused function from map file? Are there any options? Are there any ways?

Thanks,

over 7 years ago

0 George Mock over 7 years ago

TI__Guru**** 251490 points

You are probably not using the compiler option --gen_func_subsections. This option causes each function to be placed in a separate input section. In turn, this makes it possible for the linker to remove the section/function that is not used/called.

Thanks and regards,

-George

0 Kensuke over 7 years ago in reply to George Mock

Expert 1140 points

Hi George,

Thank you! I got expected result.

One additional confirmation, do I need to turn --unused_section_elimination and --gen_func_subsections on at the same time?

Thanks,

0 George Mock over 7 years ago in reply to Kensuke

TI__Guru**** 251490 points

KH@ said:
do I need to turn --unused_section_elimination and --gen_func_subsections on at the same time?

Yes. But since --unused_section_elimination is on by default, you don't need to explicitly specify it.

-George

0 Kensuke over 7 years ago in reply to George Mock

Expert 1140 points

Hi George

I could remove unused function form symbol list by --gen_func_subsections, but the symbols from library are still remained.
Is it possible to remove unused functions from the library?
If possible, what should I do?

Thanks,

0 George Mock over 7 years ago in reply to Kensuke

TI__Guru**** 251490 points

I suspect one or more files in the library are not built --gen_func_subsections, and look like this ...

int function_that_is_called(/* args here */)
{
   /* code here */
}

int function_never_called(/* args here */)
{
   /* code here */
}

This object file is brought from the library into the application because your application calls function_that_is_called. The .text section in that file defines both functions. The linker cannot split up one section from one file like this .text section. So, your application ends up with both functions. If you can, rebuild the library with --gen_func_subsections.

Thanks and regards,

-George

0 Kensuke over 7 years ago in reply to George Mock

Expert 1140 points

Hi George,

Thank you so much your support.
What is the Proc./Cons. to use --gen_func_subsections?
ROM size?

Thanks,

0 George Mock over 7 years ago in reply to Kensuke

TI__Guru**** 251490 points

The advantage is not losing memory space to functions that are never called. The disadvantage varies between processors. Which processor is being used? The ARM Cortex-R4F, or the DSP C674x?

Thanks and regards,

-George

0 Kensuke over 7 years ago in reply to George Mock

Expert 1140 points

I am using both of processors the ARM Cortex-R4F and the DSP C674x.
And also I am using TDA3, so the ARM Cortex-M4 and the DSP C66x.

Thanks,

0 George Mock over 7 years ago in reply to Kensuke

TI__Guru**** 251490 points

Using --gen_func_subsections can, in some cases, cause code size to increase. To understand why, please see Appendix A in the application note Advanced Linker Techniques for Convenient and Efficient Memory Usage. In that app note, the term TMS470R1x means ARM. That is the old TI designation for the ARM processor family.

Thanks and regards,

-George

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CCS/AWR1642: How do I remove unused function from map file?