Prefer even-odd D-register pairs.

We are sometimes allocatinog from the DPair register class which
contains odd-even pairs in addition to the Q registers.

Place the Q registers first in the DPair allocation order as they can be
copied with a single instruction. The odd-even pairs should only be
allocated as a last resort.

llvm-svn: 153699
GitOrigin-RevId: 2f2897372ac3b502f679bdc24c938d5bd936e109
1 file changed