https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82989
--- Comment #19 from Wilco <wilco at gcc dot gnu.org> --- (In reply to sudi from comment #17) > Since this looks like a pretty invasive problem, according to my discussions > with Wilco and Kyrill, I think I will try to propose a smaller, but > temporary fix using the ?s and special casing 32 for this PR (which could go > in sooner). I will also open a new PR to handle this at the expand phase and > clean up the code aimed at gcc 9. Looking the history it seems the bad ?'s have been there a long time, since at least 2010. Initially the patterns used "w, ?r", thus forcing use of Neon in most cases. This was quickly discovered to be a bad idea and changed into "w, ?r, ?w" with the first w only enabled for non-cortex-a8 cores. Later "onlya8" was renamed to "avoid_neon_for_64bits" which remains the default today (eventhough that name doesn't actually mean what it says...). The anddi3_insn/iordi3_insn/xordi3_inst patterns were fixed by 8ee7dc6fa1a663c9eea8043f84951c1e073468ff when they were merged back into arm.md, so those use "w, r, ?w".
