-fdata-sections can increase code size if you have lots of small global - the compiler doesn't know where they will be placed and has to generate pointer litera

-fdata-sections can increase code size if you have lots of small global - the compiler doesn't know where they will be placed and has to generate pointer literals for all of them, in every function that use them (due to function sections). Without data sections it can generate one literal and then use relative addressing. I've been hitting that in embedded code with tight size constraints.