Date: Wed, 21 Mar 2012 13:08:56 +0400 From: Solar Designer <solar@...nwall.com> To: john-dev@...ts.openwall.com Subject: Re: SSSE3 PSHUFB (was: AMD Bulldozer and XOP) On Wed, Mar 21, 2012 at 09:49:36AM +0200, Milen Rangelov wrote: > Yes, it was the SSSE3 PSHUFB instruction. I am not that well acquainted > with the JtR code, That's the point - it is an opportunity for you to get more acquainted with the JtR code. > so that I guess it would be better if someone that knows > what he's doing applies such a change. Long term, it may be better if you get involved with JtR development. ;-) > The overall idea is very simple - since SHA1 expects input in w...w > to be in big-endian byte order (and the final result needs to be converted > to little-endian), we have two options - either do it before we load input > into xmm registers (slow), or use some bitwise magic with SSE2. What I used > before was some bit twiddling hack using several bitwise operations. I > realized that this can be performed using just one PSHUFB instruction, like > that: > > > __m128i swapmask = _mm_set_epi32(0x00010203, 0x04050607, 0x08090a0b, > 0x0c0d0e0f ); Yes, that's how I understood you. Thanks, Alexander
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