In revision #8872, I have improved splitting of live-ranges. This yielded a nice improvement in generated code. However, for hc08 and s08 there is a regression test that no longer builds. Since all other ports seem to be fine with the changes in the splitting of live-ranges, I believe this is a bug in the hc08/s08 port, since it is a high-level optimization that works for the other ports.
To reproduce the issue, remove the !TARGET_HC08_LIKE in line 969 of SDCClrange.c.