[PATCH] D49994: Allow constraining virtual register's class within reason

[Eli Friedman via Phabricator via llvm-commits]

efriedma added a comment.

I'd like an explanation for why the generated code is changing for AArch64... generating extra copies clearly seems like a downside.  And there isn't any obvious reason for this change to impact register allocation: on AArch64, all i32 register classes contain exactly the same set of allocatable registers.


https://reviews.llvm.org/D49994