Path: utzoo!mnetor!uunet!seismo!sundc!pitstop!sun!amdcad!ames!rutgers!mtune!codas!killer!pollux!bobkat!m5
From: m5@bobkat.UUCP (Mike McNally )
Newsgroups: comp.lang.c
Subject: C compiler problems
Message-ID: <3372@bobkat.UUCP>
Date: 2 Feb 88 17:25:10 GMT
Reply-To: m5@bobkat.UUCP (Mike McNally (Man from Mars))
Distribution: na
Organization: Digital Lynx, Inc; Dallas, TX
Lines: 19
Summary: unsigned long constant folding is screwed up

Here's a good one I came across this morning.  Here's an expression:

    register unsigned long i;

    i = ((unsigned long) 0xffffffff / 10);

Guess what the variable ``i'' is set to?  Zero!  The compiler just
generates a CLRL instruction.  Obviously the constant folding code
does not include a special case for ``unsigned long''.

The bug is present in our in-house compiler, in GNU CC, and in the
Integrated Solutions 4.2 UNIX compiler.  Green Hills generates
correct code.

-- 
Mike McNally, mercifully employed at Digital Lynx ---
    Where Plano Road the Mighty Flood of Forest Lane doth meet,
    And Garland fair, whose perfumed air flows soft about my feet...
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