https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109907
--- Comment #9 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
(In reply to Georg-Johann Lay from comment #6)
> Quite impressive improvement. Maybe the last step can be achieved with a
> combiner pattern that combines extzv with a bit flip.
>
> One problem is usually that there is no canonical form (sometimes
> zero_extract, sometimes shift+and, sometimes with subregs for extraction or
> paradoxical subregs for wider types, different behaviour for MSB, etc.).
Right, In this case combine tries:
(set (reg/i:QI 24 r24)
(zero_extract:QI (xor:QI (reg:QI 54)
(const_int 64 [0x40]))
(const_int 1 [0x1])
(const_int 6 [0x6])))
Which puts the xor inside the zero_extract even but I think you could handle
that once my patch set goes in.
