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Optimization flag -finline-functions

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markorman

Posted: Jun 20, 2012 - 03:01 PM

Joined: Feb 17, 2008
Posts: 33

I have a problem with optimization in my project.
If i compile with -O2 everything works fine. But when i use -O3 some functions doen't work properly anymore. I found out that source of this problem is optimization flag -finline-functions. Also when using this flag code size increase from ~33K to ~56K bytes. But the program runs a lot faster (sreen refreshes lot faster). Problem is that when i use certain function, one another doesn't work anymore.

I this know "bug"? what causes this?

clawson

Posted: Jun 20, 2012 - 03:23 PM

Joined: Jul 18, 2005
Posts: 62341
Location: (using avr-gcc in) Finchingfield, Essex, England

It sounds like the program might inadvertently be dependent on the small delay introduced by CALL/RET function invocation.

BTW what version of avr-gcc are you talking about? Some builds (especially in some Linux repositories) are known to have problems.

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