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From: Herbert Rosmanith <herp@wildsau.idv-edu.uni-linz.ac.at>
Message-Id: <200108311437.f7VEbUF24800@wildsau.idv-edu.uni-linz.ac.at>
Subject: Re: [IDEA+RFC] Possible solution for min()/max() war
In-Reply-To: <200108311428.f7VEStH24660@wildsau.idv-edu.uni-linz.ac.at> from Herbert Rosmanith at "Aug 31, 1 04:28:55 pm"
To: herp@wildsau (none Herbert Rosmanith)
Date: Fri, 31 Aug 2001 16:37:29 +0200 (MET DST)
Cc: ptb@it.uc3m.es, zippel@linux-m68k.org, patl@cag.lcs.mit.edu,
        linux-kernel@vger.kernel.org
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> which compiles to:
> 
>   :      movw $65535,-2(%ebp)
>   :      movb $-2,-3(%ebp)
>   :      xorl %eax,%eax
>   :      movw -2(%ebp),%ax
>   :      movsbl -3(%ebp),%edx
>   :      cmpl %edx,%eax
>   :      jle .L3
> 
> you see this? short and char get expanded to 32bit int (I have a x86),
> and a signed comparison can be done without danger. "jle" jumps if
> SF != OF, which accounts to "op1 < op2" in a signed compare. the
> "unsigned short" quantum gets expanded to an "unsigned int", which
                                               ^^^^^^^^^^^^^^

yikes, this should really read "signed int".