Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!cs.utexas.edu!natinst!bigtex!pmafire!dave
From: dave@pmafire.UUCP (Dave Remien)
Newsgroups: comp.unix.microport
Subject: Re: 386/3.0e bug in cc
Summary: Yup - It's a bug in pcc
Keywords: unsigned in constant expressions
Message-ID: <585@pmafire.UUCP>
Date: 3 Feb 89 18:37:43 GMT
References: <524@sdrc.UUCP>
Reply-To: dave@pmafire.UUCP (Dave Remien)
Followup-To: comp.unix.microport
Organization: WINCO, INEL, Idaho
Lines: 33

In article <524@sdrc.UUCP> scjones@sdrc.UUCP (Larry Jones) writes:
:>I just ran across a bug in the c compiler on 386/3.0e.  If you
:>compare an unsigned constant expression to a signed constant
:>expression, the result of the comparison is computed at compile
:>time using a SIGNED comparison rather than an UNSIGNED comparison.
:>
:>For example:
:>
:>	~(unsigned)0 < 1000
:>
:>is evaluated as 1 when it should clearly be 0.  If you stick in a
:>variable so that the compiler has to generate code, the code gets
:>the right answer.

It's there, all right, using the cc (AT&T portable C compiler also used in
Bell Tech's System V/386), but not in either the Greenhills nor GNU C
compilers. Seems like a good reason to go GNU, yes? Actually, the
Greenhills C is pretty good as well; I just don't really like reading
the advertising for every module that gets compiled.

:>
:>----
:>Larry Jones                         UUCP: uunet!sdrc!scjones
:>SDRC                                      scjones@sdrc.UU.NET
:>2000 Eastman Dr.                    BIX:  ltl
:>Milford, OH  45150                  AT&T: (513) 576-2070
:>"When all else fails, read the directions."


-- 
Dave Remien - WINCO Computer Engineering Group (only somewhat confused, now)
Work - 208-526-3523 Home - 208-524-1906 UUCP Path: ...!bigtex!pmafire!dave 
"How can you be in two places at once, when you're not anywhere at all..."