Cheers Karlos
Found VAsm here and downloaded it, need to start studying PPC opcodes now...
Most obvious differences from 68k assembly are:
1) It's a load/store architecture. None of the basic arithmetic/logic operations work on effective address operands like they can on 68K. One reason why you have so many registers
2) Not as many effective addressing modes (for load/store), but all the obvious ones are more or less covered (indirect, indirect with displacement, indirect with increment/decrement).
3) Triple operand instructions. Well, most of them are of the form A @ B -> C, where any of A, B and C can be the same register. Some instructions take even more operands.
4) Bit positions are enumerated the opposite way round for bitwise/bitfield type operations. Thus Bit 0 is the MSB, rather than the LSB.
5) There are useful bitwise operations (such as masked rotate and masked shift, fused floating point multiply-add) that exist as single instructions on ppc that are good for improving performance of certain algorithms.
6) Optional CC update. Basically, most logic/arithmetic instructions have a notation that allows you to decide whether or not you want the side effects of that instruction to be written to the condition codes. This is especially useful once you start to optimise your code by reordering instructions and you don't want to destroy condition codes that you need to test later.
