Re: 64-bit lossage

[Dave Love <d.love@dl.ac.uk>]

Ken Raeburn <raeburn@raeburn.org> writes:

> I don't think I've got access to an Irix64 system to test with;

For what it's worth, any remotely-recent system can run 64-bit (r4000
up, probably with Irix 5.2 up, but I can't remember for sure that for
back).

> Per-machine definitions of macros dependent on low-level details of
> the lisp implementation.  It's cleaner if the lisp implementation is
> based on information about the architecture, and not partially
> rewritten for some architectures.

The machine and system files are a horrible mess in general, and that
often leads to real problems.

> The macros as they stand in lisp.h do appear to be fairly clean for
> 64-bit support.  They assume that "long" will be 64 bits when pointers
> are, and that "_LP64" is defined in that case, but switching to "long
> long" if "long" isn't big enough should actually be quite easy.

Good but it wasn't trivial when we last tried.

> I think the make_gap_smaller code is new on the trunk since the
> current release branch was started; that's what caused mmap_realloc to
> be called to unmap some pages.  I want to look a bit more closely,
> though, and see if there are other cases that could cause similar
> problems on the release branch.

Good.  (I use the released version in anger on tru64 without
problems.)

> It wasn't trying to fix one problem.  The patches I had in progress
> made the problem disappear for me;

Not for me, for what it's worth.  Only disabling use of mmap did.