[Bug rtl-optimization/87902] [9 Regression] Shrink-wrapping multiple conditions

[segher at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87902

--- Comment #2 from Segher Boessenkool <segher at gcc dot gnu.org> ---
So why does it use r12 there if it could use r2?  That's an RA problem.
This is related to PR87708, in a way.

prepare_shrinkwrap needs a good overhaul.  Moving all copies down also
*degrades* code quality, more often if you don't restrict it to the
first BB.