cl@datlog.co.uk (Charles Lambert) (10/11/88)
Apropos the "NULL pointer" argument chip@ateng.ateng.com (Chip Salzenberg) writes: > After all, bitwise representation is not the only issue. Sometimes > pointers are _larger_ than ints! Worse than that: during a rather arcane discussion in comp.std.c I read that pointers to different objects may be different sizes. Forgetting the LONG/SHORT NEAR/FAR perversion of Intel memory models, does anyone know how widespread this kind of implementation is and what are the foremost systems involved? Charlie
henry@utzoo.uucp (Henry Spencer) (10/22/88)
In article <881@dlhpedg.co.uk> cl@datlog.co.uk (Charles Lambert) writes: >...pointers to different objects may be different sizes. Forgetting the >LONG/SHORT NEAR/FAR perversion of Intel memory models, does anyone know how >widespread this kind of implementation is and what are the foremost systems >involved? It happens on most machines whose memory is organized by words rather than bytes. The exceptions are machines which have "spare bits" in their normal pointer format. The Data General machines are this way, in particular. The Crays are also word-organized, but I think they have spare bits. There are undoubtedly other machines, mostly old ones, with word-based memory architectures. It's not enormously common, but it happens often enough to make it hard to ignore. -- The meek can have the Earth; | Henry Spencer at U of Toronto Zoology the rest of us have other plans.|uunet!attcan!utzoo!henry henry@zoo.toronto.edu