Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!rutgers!ll-xn!husc6!hao!scdpyr!cruff
From: cruff@scdpyr.UUCP (Craig Ruff)
Newsgroups: comp.lang.c
Subject: Re: C machine
Message-ID: <253@scdpyr.UUCP>
Date: 30 Dec 87 15:12:03 GMT
References: <7535@alice.UUCP> <8226@steinmetz.steinmetz.UUCP> <461@auvax.UUCP> <163@bhjat.UUCP> <9961@mimsy.UUCP> <1987Dec28.163403.24137@sq.uucp>
Reply-To: cruff@scdpyr.UUCP (Craig Ruff)
Organization: Natl Ctr Atmospheric Research, Boulder, CO
Lines: 32

In article <1987Dec28.163403.24137@sq.uucp> msb@sq.UUCP (Mark Brader) writes:
>
>On the topic of of short/int/long, Chris Torek (chris@mimsy.UUCP) writes:
>> Nope.  The dpANS says only that short >= 16 bits, int >= 16 bits, and
>> long >= 32 bits.
>
>This is misleading in the context; the dpANS *also* says that short <= int
>and int <= long.  So the method adopted by a 64-bit machine in the past,
>where long = 32 bits "because that's what everybody assumes", and
>int = 64 bits "because that's the natural size", would be non-conforming.

Here is the scoop on some Cray machines.  All numbers are in bits, in the
format precision(memory), where memory = amount of memory to store item.

		Cray-1, Cray X-MP	Cray-2
		-----------------	------------
	char	8(8)			8(8)
	int	64(64)			32(64)
	short	24(64)			32(64)
	long	64(64)			64(64)
	float	64(64)			64(64)
	double	64(64)			64(64)
	char *	64(64)			64(64)
	other *	24(64)			24(64)

Note that these are the not-all-pointers-are-alike machines, and pointers
cannot always be converted to ints and back again.  Character pointers are
stored as a 24 bit word address and a 3 bit offset (in the most significant
bits).
-- 
Craig Ruff      NCAR                         INTERNET: cruff@scdpyr.UCAR.EDU
(303) 497-1211  P.O. Box 3000                   CSNET: cruff@ncar.CSNET
		Boulder, CO  80307               UUCP: cruff@scdpyr.UUCP