> This patch does not change rs6000/s390 since I don't have machines to
> test them, but I suppose the default behavior is the same since they
> enable flag_unroll_loops at O2.

There are Power (rs6000) systems in the Compile Farm.

Trial Linux on Z (s390x) VMs are available through the Linux Community
Cloud.
https://linuxone.cloud.marist.edu/#/register?flag=VM

Thanks, David