[Scummvm-devel] Wii & Gamecube (resp. PowerPC) vs. unaligned memory access

[Max Horn]

Hi Andre, hi all

I was wondering why we set need_memalign=yes for the Wii and Gamecube ports in ScummVM's configure script.

So far, I thought that PowerPC and x86 are the two archs where unaligned memory access is handled in a relatively decent way -- of course still slower than aligned access, but otherwise fine (in particular, the CPU handles it natively, no OS fault handler or anything like that is involved). The bit on PowerPC I still know from past Mac development work; and various sources on the net seem to confirm it, e.g. <http://www.ibm.com/developerworks/library/pa-dalign/> or some Linux kernel developers <http://lwn.net/Articles/277201/>. Also, Hubert just confirmed that unaligned access seems to work fine on his PowerPC AmigaOS machine

Is the PowerPC processor used in Gamecube and Wii different / crippled in this regard?


Cheers,
Max