ZENITH@l66a.ladc.bull.COM (ZENITH) (07/18/89)
_not_ a multiple of eight? I'm entertaining the notion of porting Icon to run on the Bull (nee Honeywell) DPS-8 architecture, under the CP-6 operating system; the salient feature of this hardware is its nine-bit bytes (36-bit words). Am I likely to run into any major headaches as a result of this? - Andy -
kwalker@ARIZONA.EDU ("Kenneth Walker") (07/19/89)
Date: Mon, 17 Jul 89 11:33 PDT
From: ZENITH <uunet!l66a.ladc.bull.com!ZENITH>
Reply-To: Zenith/A_Birner <uunet!l66a.ladc.bull.com!Zenith/A_Birner>
Has anyone worked at porting Icon to a machine with a word size that is
_not_ a multiple of eight? I'm entertaining the notion of porting Icon
to run on the Bull (nee Honeywell) DPS-8 architecture, under the CP-6
operating system; the salient feature of this hardware is its nine-bit
bytes (36-bit words). Am I likely to run into any major headaches as a
result of this?
You will probably run into headaches. The implementation of Icon has
become a lot more portable in the last few releases so it is hard
to judge just how difficult it will be (some of it depends on how robust
your C compiler is, of course). There is actually a configuration parameter
for specifying the number of bits/byte. It seems to only be used in the linker.
I am not sure anyone has tried setting it to a number other than 8. At one
time there were problems with the random number generator, but I think
that has been fixed to work as long as you have at least 32 bit integers
(someone can correct me if I am wrong.)
Is the DPS-8 a byte addressable machine or do byte pointers have a special
form like they do in the Cray (so far no one has managed a port of Icon
to that machine)? Are pointers and ints (or longs) the same size?
We can try to give you some advice if you decide to attempt the port. You
can address questions to icon-project@arizona.edu or directly to me (though
I may pass them on if I can't answer them).
Ken Walker / Computer Science Dept / Univ of Arizona / Tucson, AZ 85721
+1 602 621 2858 kwalker@Arizona.EDU {uunet|allegra|noao}!arizona!kwalker