[comp.sys.hp] 835 word sizes and byte ordering.

beshers@cs.cs.columbia.edu (Clifford Beshers) (06/07/89)

Can someone send me a brief description of the differences
between the word sizes and byte ordering of the 835 versus the
350 (m68k)?  I may have to port CC and cfront 1.2 to the 835 on
short notice and it cares about such things.

--
-----------------------------------------------
Cliff Beshers
Columbia University Computer Science Department
beshers@cs.columbia.edu

cunniff@hpfcdc.HP.COM (Ross Cunniff) (06/09/89)

> Can someone send me a brief description of the differences
> between the word sizes and byte ordering of the 835 versus the
> 350 (m68k)?  I may have to port CC and cfront 1.2 to the 835 on
> short notice and it cares about such things.

There is no difference in word sizes and byte ordering between the S300
and the S800.  Alignment, however, is another story (at least as far as
the C compilers go):

		S300	S800
	char	  1	  1
	short	  2	  2
	long	  2	  4
	float	  2	  4
	double	  2	  8
	struct	  2	Max of individual struct elem alignments

Of course, if you don't care about using the standard libc routines,
you can ignore these alignments and use your own.

> Cliff Beshers
> Columbia University Computer Science Department
> beshers@cs.columbia.edu

				Ross Cunniff
				Hewlett-Packard Colorado Language Lab
				...{ucbvax,hplabs}!hpfcla!cunniff
				cunniff%hpfcrt@hplabs.HP.COM

mike@hpfcdc.HP.COM (Mike McNelly) (06/10/89)

Get a copy of the HP-UX Portability Guide for HP 9000 Series 300 and 800
Computers, part number 98794-90046, for an extensive discussion of
alignment and word sizes.  There are other gotchas discussed that you
might want to learn about if you use bit fields or non-portable
consructs.

The part number given above is for release 6.5 on Series 300 and 3.0 on
Series 800.  For the manual that reflects the release you have, talk to
your HP sales rep.  Alignment and word size have not changed in recent
memory but newer releases do have additional programming aids to help
portability which are discussed in the manual.

Mike McNelly
mike%hpfcla@hplabs.hp.com