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Mail Archives: djgpp/1998/08/25/00:50:00

From: GAMMELJL AT SLU DOT EDU
Date: Mon, 24 Aug 1998 23:47:27 -0500 (CDT)
Subject: assembly language
To: djgpp AT delorie DOT com
Message-id: <01J1008M3AKY94I14V@SLU.EDU>
Organization: SAINT LOUIS UNIVERSITY St. Louis, MO
MIME-version: 1.0

     I have an example of two .s files generated by the gxx compiler 
which differ only in that one has
               xorl %edx,%edx
where the other has
               movl $0x0,%edx
When one goes ahead and compiles these two .s files with
               gxx filename.s
both produce executables (a.exe) which, however, produce different
results.  The results in the movl case are correct, whereas the results
in the xorl case are incorrect.
     I have used the DOS file compare utility (fc) to check that the
differences in the two .s files are what I say they are.  
     The example is too long to transmit via e-mail, but I will be
glad to land-mail the source code on a floppy should that become
necessary.  Perhaps I am wrong in thinking that the xorl above and
the movl above should produce the same results.

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