The gcc 6809 compiler is (at the time of writing) called with the options:

Which in general means - use CLEAN good C, since everything, even the tiniest thing will be regarded as an error (-Wall / - Werror).

Two notable options:

Tells the compiler that "int" is 8 bit, which means more verbose, the compiler knows following data types:

int is 8 bit
char is 8 bit
long is 16 bit

but int != char type wise

Ensures that gcc does not generate an additional framepointer for each function. If an additional framepointer is generated, it makes the generated code quite "bloated" and not extremely performant.

The above mentioned flags can be configured in the "project" panel of the "C" project. You can do much mischieve in changing them - be carefull!

Switching the checkbox "PeerC" off and on - restores the default settings!

If you set the option to "-fomit-frame-pointer" Vide automatically generates upon compile time a "#define OMMIT_FRAMEPOINTER=1" - so that you can check that with your sources.