Re: Optimization around mul and restoring r1
Oleksandr Redchuk <[email protected]>
| Newsgroups | gmane.comp.hardware.avr.gcc |
|---|---|
| Message-ID | <CALyibe9w3CCKDNcTyFjioa7fzGVUuv9vyAWkBjNDr0kbPVt3bg@mail.gmail.com> |
2013/10/2 Georg-Johann Lay <[email protected]> > David Brown schrieb: > >> In general, it would be a good thing to delay the zeroing of r1, and it >> is worth searching the issue database for previous issues and filing a >> new "missed optimisation" issue if it is not there already: >> > > IMHO everyone working on the avr back-end is aware of this problem. > May be, reassigning __zero_reg__ to R2 and using R1:R0 as __temp_reg_hi__:__temp_reg__ will be better but I can't estimate both complexity of changes and code size/perfomance gain effect. -- wbr, ReAl _______________________________________________ AVR-GCC-list mailing list [email protected] https://lists.nongnu.org/mailman/listinfo/avr-gcc-list