[monocasa]

r3k didn't really need atomics. It wasn't SMP, and being a braindead simple 5-stage RISC, a syscall to atomic primitives was in the neighborhood of as cheap as atomic instructions are today. Cheaper if you were already in a KSEG.

And load delays are annoying when writing asm manually, but not for the C compiler.

And yeah, addu was in MIPS-I.