From mboxrd@z Thu Jan  1 00:00:00 1970
From: Mateusz Marzantowicz <mateuszm@server.pl>
Subject: Re: GCC Optimization?
Date: Tue, 23 Nov 2004 17:43:26 +0100
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> Second question:
> What does mov $0x0,%eax? Why dont they use xor %eax and what is it good for?
> 

It's because GCC was designed for more processors than only x86 based 
and in some cases it won't work. With optimization enabled you will find 
there xorl %eax, %eax instead of mov $0x0,%ea

Regards