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

[Jonas Paulsson via Phabricator via llvm-commits]

jonpa added a comment.

F6798478: tc_2spill.ll <https://reviews.llvm.org/F6798478>

This is the test case we were working with. Compile with

llc -mcpu=z13 ./tc_2spill.ll

Looking at it now, it seems that with the patch there are fewer COPYs directly after instruction selection, but it seems that in the output there are the same number of register moves, with the less desired difference that with the patch one of them is no longer hoisted out of the loop. So in this case it seems that the net result is one less hoisted register move... :-/


Repository:
  rL LLVM

https://reviews.llvm.org/D49994