https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70873
Bernd Schmidt <bernds at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|NEW |UNCONFIRMED
Ever confirmed|1 |0
--- Comment #6 from Bernd Schmidt <bernds at gcc dot gnu.org> ---
So the problem seems to be peep2 runs before regrename. If you always want to
generate two instructions there, then yes, a splitter would probably be better.
Actually just changing define_peephole2 to define_split seems to do the trick,
can you try whether that fixes the performance regression (I don't have a
Haswell machine)?
