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From: mwm@eris.berkeley.edu (Mike Meyer)
Newsgroups: net.lang.c
Subject: Re: Significant deficiency in C
Message-ID: <1372@jade.BERKELEY.EDU>
Date: Thu, 2-Oct-86 07:54:08 EDT
Article-I.D.: jade.1372
Posted: Thu Oct  2 07:54:08 1986
Date-Received: Sat, 4-Oct-86 11:00:06 EDT
References: <4200@brl-smoke.ARPA> <6129@alice.uUCp>
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Reply-To: mwm@eris.UUCP (Mike Meyer)
Organization: Missionaria Phonibalonica
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In article <6129@alice.uUCp> ark@alice.UucP (Andrew Koenig) writes:
>One would think that for many char operations it is possible for
>the compiler to figure out that doing it in 8 bits and expanding to
>16 at the end only if necessary will give the same result as expanding
>to 16 bits immediately.
>
>Can you give us some examples of code that you think would be
>impossible to get right without changing the rules?

Yes. How about (from a bug report on Lattice C in net.micro.amiga):

	char	x = 0XFF, y = 2, z ;

	z = (x + y) / 2 ;

If you do this in character arithmetic, you get 0 (1/2). If you do it
as something longer, you get 128.

Of course, whether or not is is "right" is open to question.

	<mike