For some reason VS_32 ends up factoring into the pressure heuristics
even though we should never see a virtual register with this class.
When SGPRs are reserved for register spilling, this for some reason
triggers reg-crit scheduling.
Setting isAllocatable = 0 may help with this since that seems to remove
it from the default implementation's generated table.
llvm-svn: 252321
These were all using the default 32-bit VALU write class,
but the i64/f64 compares are half rate.
I'm not sure this is really correct, because they are still using
the write to VALU write class, even though they really write
to the SALU.
llvm-svn: 248582
Matt Arsenault