I haven't seen any problems with a kernel compiled from 8-July sources even with weeks of compiling, and a netbsd-7 kernel and userland compiled from this morning at least boots and has been compiling for a few hours without problems.Do you explicitly specify HAVE_GCC=48 somewhere, or you just tried it with the default gcc 4.5.3? If you are using the default gcc 4.5.3, your first post means that kernels compiled by gcc 4.5.3 with -O2 didn't work but works with -O2 -fno-reorder-blocks?
Yes. It didn't work before you committed the optimization change, and then did work after you committed.
I'm compiling everything now with HAVE_GCC=48 and will report back when I test it.
Thanks, John