18:23:56dougk_trying to look at the PPC64 requirements, just discovered the most insanely horrible restriction: Load/Store of 8-byte values don't accept an immediate displacement that is other than a multiple of 4. Basically kills subtracting lowtag "for free".
18:25:25stassatssurely, there are different load/stores?
18:31:57dougk_it's always going to cost us an instruction to load index to register. load/store of size 1,2,4 byte allow any displacement. 8 byte explicitly robs the low 2 bits of your displacement, and moreover, assumes they're 0.
18:32:45stassatsi guess my idea of reusing the same codebase for ppc64 doesn't hold water