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From: hue@netcom.UUCP (Jonathan Hue)
Newsgroups: comp.unix.aix,gnu.emacs.bug
Subject: Re: GNU Emacs 18.55 and AIX PS/2 1.1
Message-ID: <2896@netcom.UUCP>
Date: 12 Oct 89 05:27:01 GMT
References: <347@synsys.UUCP> <34525@srcsip.UUCP>
Reply-To: hue@netcom.UUCP (Jonathan Hue )
Distribution: na
Organization: NetCom- The Bay Area's Public Access Unix System {408 997-9175 guest}
Lines: 16

In article <34525@srcsip.UUCP> carciofi@SRC.Honeywell.COM (Jim Carciofini) writes:
>#define HAVE_PTYS
>/* Hack to get around apparent bug in AIX C compiler? "regex.c" appears to
>   assume that C will extend the sign bit when a char is cast to an int.
>   AIX C V1.1 does not do this. This hack does not work when compiler 
>   optimizations are turned on. Is there a better way to do this? */
>#undef SIGN_EXTEND_CHAR
>#define SIGN_EXTEND_CHAR(x) ((signed char) x)

It's not a bug - chars are unsigned in the PS/2's compiler.  It shouldn't 
extend the sign when promoting to an int.  When I brought up 18.52 I used
something like the following:

#define SIGN_EXTEND_CHAR(x) ((x) & 0x80 ? ((x) - 255) : (x))

-Jonathan