[PATCH] D10717: Enhance loop rotation with existence of profile data in MachineBlockPlacement pass.

[David Li via llvm-commits]

davidxl added a comment.

This version LGTM as it is not enabled by default yet. There are a couple of followups to do:

1. collect extensively performance data (including PMU perf data), and possibly tune the parameters (for selected targets)
2. turn it on by default when tuning is done

3. think about how to better handle loop rotation cost analysis with the right ordering --- current way (from inside out) is less than ideal, as the compiler has to guess how header/exit blocks are connected with blocks in the enclosing chain (it has not been laid out yet).


http://reviews.llvm.org/D10717