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Cc: dave.taht@bufferbloat.net, nanditad@google.com, netdev@vger.kernel.org,
	codel@lists.bufferbloat.net, ycheng@google.com,
	shemminger@vyatta.com, mattmathis@google.com
Subject: Re: [Codel] [PATCH net-next] codel: use Newton method instead of
 sqrt() and divides
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From: Eric Dumazet <eric.dumazet@gmail.com>
Date: Sat, 12 May 2012 22:40:56 +0200

> 24 bit of precision for the reciprocal value is more than enough (Van
> suggested 16 bits in fact), so we have actually room for 7 bits if
> needed.

Using a u16 would also work for me.

> By the way, gcc on x86 generates nice "and 0xfffffffe,%eax" instruction
> for (vars->rec_inv_sqrt << 1).

Yeah but what do stores of ->rec_inv_sqrt look like?