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Date: Mon, 9 Mar 2015 14:24:49 +0530
From: Sayantan Datta <std2048@...il.com>
To: john-dev <john-dev@...ts.openwall.com>
Subject: Re: 256/128 bit integer arithmatic

On Mon, Mar 9, 2015 at 1:07 AM, magnum <john.magnum@...hmail.com> wrote:

> They are emulated though, probably similar to using hi/lo 64-bit structs.


I have my own emulation based on 64bit uint in HI, LO configuration for
performing modulo operations specific to my requirements and it's much
faster than native 128bit modulo operations.  I tried to do the three 64bit
modulo operations required for emulating 128bit modulo using avx intrinsics
but it turns out there are no integer division built_ins in gcc, let alone
modulo operations. No wonder modulo operations are slow!!

Regards,
Sayantan

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