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From: <cutaway@bellsouth.net>
To: "Denis Vlasenko" <vda@ilport.com.ua>,
	"Jesper Juhl" <juhl-lkml@dif.dk>,
	"linux-kernel" <linux-kernel@vger.kernel.org>
Cc: "Andrew Morton" <akpm@osdl.org>,
	"Jeff Garzik" <jgarzik@pobox.com>,
	"Domen Puncer" <domen@coderock.org>
Subject: Re: [RFC] cleanup patches for strings
Date: Tue, 21 Jun 2005 09:08:34 -0400	[thread overview]
Message-ID: <004c01c57662$5eacc260$2800000a@pc365dualp2> (raw)
In-Reply-To: <200506211402.48554.vda@ilport.com.ua>

Memory is memory.  Pushed from the stack or as a 4 byte immediate value you
still have to get those 4 bytes somewhere  although with the pointer you DO
actually stand a chance GCC might enregister the pointer variable.

Sure you don't think instruction bytes fetching is free ;->

BTW, I don't give a shit about the size advantage.  Put the 3 byte EBP ref
and the 5 byte push imm32 in a loop and measure them - I know what the
answer will be.


----- Original Message ----- 
From: "Denis Vlasenko" <vda@ilport.com.ua>
To: <cutaway@bellsouth.net>; "Jesper Juhl" <juhl-lkml@dif.dk>;
"linux-kernel" <linux-kernel@vger.kernel.org>
>
> But that 3 byte push is fetching data from stack, while 5 byte const push
> does not. I ike smaller code, but not _this_ much.
>
> Also this smallish size advantage may be i386-specific only.
> --
> vda
>


  reply	other threads:[~2005-06-21 12:18 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2005-06-20 22:46 Jesper Juhl
2005-06-21  6:58 ` cutaway
2005-06-21 11:02   ` Denis Vlasenko
2005-06-21 13:08     ` cutaway [this message]
2005-06-21 13:06       ` Denis Vlasenko
2005-06-21 14:38         ` cutaway
2005-06-21 13:52           ` Denis Vlasenko
2005-06-21 13:20       ` Denis Vlasenko
2005-06-21  8:59 ` Alexey Dobriyan
2005-06-21  9:31   ` Jörn Engel
2005-06-21 20:47     ` Jesper Juhl
2005-06-21  9:04 ` Andrey Panin
2005-06-21 10:59 ` Denis Vlasenko
2005-06-21 21:24   ` Jean Delvare
2005-06-21 22:33     ` cutaway
2005-06-21 21:49       ` Jean Delvare
2005-06-21 23:11         ` cutaway
2005-06-22  0:16           ` Brian Gerst
2005-06-21 21:12 ` Horst von Brand

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