https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77308
--- Comment #36 from wilco at gcc dot gnu.org --- (In reply to Bernd Edlinger from comment #34) > (In reply to Richard Earnshaw from comment #33) > > (In reply to Wilco from comment #32) > > > (In reply to Bernd Edlinger from comment #31) > > > > Furthermore, if I want to do -Os the third condition is FALSE too. > > > > But one ldrd must be shorter than two ldr ? > > > > > > > > That seems wrong... > > > > > > Indeed, on a target that supports LDRD you want to use LDRD if legal. LDM > > > should only be tried on Thumb-1. Emitting LDRD from a peephole when the > > > offset is in range will never increase code size so should always be > > > enabled. > > > > The logic is certainly strange. Some cores run LDRD less quickly than they > > can do LDM, or even two independent loads. I suspect the logic is meant to > > be: use LDRD if available and not (optimizing for speed on a slow > > LDRD-device). > > Ok, so instead of removing this completely I should change it to: > TARGET_LDRD > && (current_tune->prefer_ldrd_strd > || optimize_function_for_size_p (cfun)) That's better but still won't emit LDRD as it seems most cores have prefer_ldrd_strd disabled... Given that we currently always emit LDRD/STRD for DI mode accesses, this should just check TARGET_LDRD.
