Re: [RFC] cleanup patches for strings

From: cutaway
Date: Tue Jun 21 2005 - 07:25:17 EST


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@xxxxxxxxxxxxx>
To: <cutaway@xxxxxxxxxxxxx>; "Jesper Juhl" <juhl-lkml@xxxxxx>;
"linux-kernel" <linux-kernel@xxxxxxxxxxxxxxx>
>
> 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
>

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