Well, ~value isn't xor with an implicit variable in Blitz, it's explicitly bitwise complement (see the docs). And that doesn't reduce to XOr in x86 or PPC - they both have bitwise not ops. And an XOr with all bits reset is a nop, not a not!
Also, 'complement' is indeed the same as 'not' (but not any specific implementation of not, which may be bitwise or logical), and it isn't the same as 'two's complement'.
Also, 'complement' is indeed the same as 'not' (but not any specific implementation of not, which may be bitwise or logical), and it isn't the same as 'two's complement'.