> So, my first approach was trying to simplify that, because nonzero_bits
> on the subreg operand say that no bits outside of QImode may be non-zero,
> both the zero_extend and subreg can be dropped. That is the simplify-rtx.c
> change. Then I've figured out that combine.c doesn't actually attemp
Hi!
Kai has reported his type demotion patches lead to a regression, which can
be seen also without his patches by doing the type demotion by hand.
test1 is optimized using *jcc_bt_mask instruction (combiner detects
this), but test2 isn't. In that case combiner first merges the and with
shift int
