Path: utzoo!utgpu!news-server.csri.toronto.edu!mailrus!wuarchive!decwrl!adobe!hawley
From: hawley@adobe.COM (Steve Hawley)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Can THINK C support wider types than normal?
Message-ID: <6910@adobe.UUCP>
Date: 1 Oct 90 00:35:43 GMT
References: <9216@potomac.ads.com>
Reply-To: hawley@adobe.UUCP (Steve Hawley)
Organization: Adobe Systems Incorporated, Mountain View
Lines: 42

In article <9216@potomac.ads.com> jtn@potomac.ads.com (John T. Nelson) writes:
>
>I know that THINK C uses 16 bit wide fields to store its int's and 32
>for longs, I have a piece of software, however, that would REALLY like
>to see 32-bit wide int's and the other types that Sun computers
>support.
>
>If THINK C can't accomodate longer types with some magic macro or
>switch then it means I'll have to redefine a LOT of code.
> 
>Any ideas?

Think C probably uses 16 bit ints because of the following sentiment in
Kernighan & Ritchie:
int    an integer, typically the natural size of integers on the host machine.

The Mac (and Think C) started with a 68000 processor which can do 16 bit
arithmetic with single instructions for all the basic operators.  Since 32-bit
multiplies and divides require the use of library routines, this doesn't seem
like a natural data type to be used as a default.

Since then the Mac has grown up a bit, and certain machines (with 68020s or
68030's) can now do 32-bit arithmetic with a single instruction without the
performance hit you would get on a 68000 using library routines.  Think C
(to my knowledge) has no provision for generating code for 32-bit ints
without explicitly using the long data type.

Add the following code to each of your files:
#ifdef THINK_C /* I think this is correct - check the manual */
#define int long /* a typedef might work too */
#endif

-or-
revamp your entire code to abstract the int data type to something else,
so you never actually use int.

Steve Hawley
hawley@adobe.com
-- 
"I'm sick and tired of being told that ordinary decent people are fed up with
being sick and tired.  I know I'm certainly not, and I'm sick and tired of
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