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Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcs!mcewan
From: mcewan@uiucdcs.CS.UIUC.EDU
Newsgroups: net.micro
Subject: Re: weird C behavior
Message-ID: <10400217@uiucdcs>
Date: Sun, 30-Mar-86 15:49:00 EST
Article-I.D.: uiucdcs.10400217
Posted: Sun Mar 30 15:49:00 1986
Date-Received: Wed, 2-Apr-86 00:42:51 EST
References: <557@utastro.UUCP>
Lines: 42
Nf-ID: #R:utastro.UUCP:557:uiucdcs:10400217:000:1612
Nf-From: uiucdcs.CS.UIUC.EDU!mcewan    Mar 30 14:49:00 1986


>> >Here is a short C program which gives correct output according to K & R.
>> >[...]  Try it on *your* 16-bit computer.
>> The code contains the following [paraphrased]:
>> 	printf("%d\n", 36864);
>> On a 16 bit machine, this should read
>> 	printf("%ld\n", 36864);
>> One alternative is to change Ed's original program to read
>> 	#define BIG ((int) 36864)
>
> Passed arguments should always be passed as an "int", I do believe.

Why? Are you saying that one should never have a function that accepts
long arguments (or short, char, float, pointer, etc., for that matter)?

> Changing the printf specification will  n e v e r  change what the
> C compiler does with the rest of the arguments!!

Never said it did. The constant "36864" is passed as a long no matter
what string is used in the "printf" - the only difference is that with
"%ld" printf correctly interprets and prints out the argument as a long.

>  Nather's original
> posting led me to believe he was using some kind of a 16/32 bit
> machine, with a C compiler that had not quite been consistent.  I.e.,
> on the comparison, all I could think was that a 16-bit int had sign-
> extended to compare with an IMPLICIT long constant (look at it: it's
> not an explicit long constant!).  This is inconsistent.

What is inconsistent about it? It is perfectly proper C.

>  However, an
> arg has to be explicitly declared; so the int default almost has to
> be honoured.

I'm afraid I don't understand what you mean.

			Scott McEwan
			{ihnp4,pur-ee}!uiucdcs!mcewan

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