2018-01-08 20:19 GMT+04:00 Georg-Johann Lay <a...@gjlay.de>: > This PR skips saving of any registers in main. > > Attribute OS_main can do this as well, however we can just drop > any saves / restores in all optimized compilation -- not even > the test suite needs these saves. > > The feature can still be switched off by new -mno-OS_main > > Ok for trunk?
I like it. Please commit. > > > gcc/ > Don't save registers in main(). > > PR target/83737 > * doc/invoke.texi (AVR Options) [-mOS_main]: Document it. > * config/avr/avr.opt (-mOS_main): New target option. > * config/avr/avr.c (avr_in_main_p): New static function. > (avr_regs_to_save) [avr_in_main_p]: Return 0. > (avr_prologue_setup_frame): Don't save any regs if avr_in_main_p. > (avr_expand_epilogue): Same. > * common/config/avr/avr-common.c (avr_option_optimization_table): > Switch on -mOS_main for optimizing compilations.
