Message-ID: 3.0.6.32.20000428101918.026dc510@mailhost
To: tiff@olympiakos.com
Subject: VC++ Release build causes problems
From: John Aldridge <john.aldridge@informatix.co.uk>
Date: Fri, 28 Apr 2000 10:19:18 +0100
Sender: owner-tiff@olympiakos.com


>Me again.  I just loaded the strike image in The Gimp and saved it as an
>LZW compressed image and a non-compressed image.  The non-compressed
>image works PERFECTLY under both debug and release builds.  The LZW
>compressed image screws up royally under the release build but works
>fine in debug. 

There was a thread on something very like this a year or so ago.  The
conclusion then was that libtiff is assuming that

   int x = somthing; // assume 32 bit int
   y = x << 32;      // or any greater shift

would always yield zero.  However neither the C nor the C++ standard
guarantee this behaviour, and compilers are entitled not to implement it.
-- 
Cheers,
John

