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From: henry@utzoo.UUCP (Henry Spencer)
Newsgroups: net.lang.c,net.micro.pc
Subject: Re: Signed char - What Foolishness Is This!
Message-ID: <7250@utzoo.UUCP>
Date: Mon, 20-Oct-86 15:06:19 EDT
Article-I.D.: utzoo.7250
Posted: Mon Oct 20 15:06:19 1986
Date-Received: Mon, 20-Oct-86 15:06:19 EDT
References: <8719@duke.duke.UUCP>
Organization: U of Toronto Zoology
Lines: 22

> 1)      Do other C compilers make 'char' a signed quantity by default?

Yes.  Almost any C compiler for machines like the PDP11, the VAX, the
8088, and so forth, will.

> 2)      What possible justification is there for this default?  Is not
> 'char' primarily a logical (as opposed to mathematical) quantity?  ...

The problem started with the PDP11, the first machine C was implemented
on.  A minor quirk of the 11 made it substantially more efficient to
manipulate characters as signed entities.  This hardware quirk has been
carried over, unfortunately, into a good many newer machines that have
imitated the 11 to some degree.  Compilers for these machines have a
choice of generating inefficient code or using signed characters.  Since
any decent C documentation warns you that the signedness or lack thereof
of characters is not portable, this is considered legitimate.

I believe Dennis is on record as mildly regretting the original decision
to go along with the hardware's prejudices, but it's a bit late now.
-- 
				Henry Spencer @ U of Toronto Zoology
				{allegra,ihnp4,decvax,pyramid}!utzoo!henry