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Date: Thu, 18 Sep 2014 17:19:55 +0400
From: Roman Rusakov <rusakovster@...il.com>
To: john-users@...ts.openwall.com
Subject: Re: nVidia Maxwell support (especially descrypt)?
Ideally, execution time must became 75% of old execution time.
Unfortunately, I have no Nvidia 750.
With AMD (GCN) cards I got good performance, when decreased number of VGPRs
to <128.
Code size for DES encrypt (raw DES, not password) was about 32K, but AFAIK
L1 instruction cache in AMD GCN cards is 16K, so decreasing of VGPRs can
hide latencies.
2014-09-18 17:07 GMT+04:00 Sayantan Datta <std2048@...il.com>:
> On Thu, Sep 18, 2014 at 5:36 PM, Roman Rusakov <rusakovster@...il.com>
> wrote:
>
> > Good day.
> >
> > I started work to optimize bitslice DES sboxes for Nvidia Maxwell
> > instruction set (particularly for LOP3.LUT).
> > Looks like gate count can be decreased by 9 (from ~33 to 24).
> > For example, S4 (only 17 gates).
> > ===
> > #include <stdio.h>
> >
> > typedef unsigned long long vtype;
> >
> > vtype lut3(vtype x,vtype y,vtype z,unsigned char m)
> > {
> > int i;
> > vtype r=0;
> > for(i=0;i<sizeof(vtype)*8;i++)
> > r|=(vtype)((m>>( (((x>>i)&1)<<2) | (((y>>i)&1)<<1) | ((z>>i)&1) ))&1) <<
> i;
> > return r;
> > }
> >
> > void s4(vtype a1, vtype a2, vtype a3, vtype a4, vtype a5, vtype a6,
> > vtype * out1, vtype * out2, vtype * out3, vtype * out4)
> > {
> > vtype x55AAFF00=lut3(a1,a4,a5,0x36);
> > vtype x00F00F00=lut3(a3,a4,a5,0x24);
> > vtype x1926330C=lut3(a2,a3,x55AAFF00,0xA4);
> > vtype x4CA36B59=lut3(x00F00F00,a1,x1926330C,0xB6);
> >
> > vtype x00FF55AA=lut3(a1,a4,a5,0x6C);
> > vtype x3FCC6E9D=lut3(a2,a3,x00FF55AA,0x5E);
> > vtype x6A7935C8=lut3(a1,x00F00F00,x3FCC6E9D,0xD6);
> >
> > vtype x5D016B55=lut3(a1,x4CA36B59,x00FF55AA,0xD4);
> > vtype x07AE9F5A=lut3(a3,x55AAFF00,x5D016B55,0xD6);
> > vtype x61C8F93C=lut3(a1,a2,x07AE9F5A,0x96);
> >
> > vtype x3=lut3(a6,x4CA36B59,x61C8F93C,0xC9);
> > vtype x4=lut3(a6,x4CA36B59,x61C8F93C,0x93);
> > *out3^=x3;
> > *out4^=x4;
> >
> > vtype x26DA5E91=x4CA36B59^x6A7935C8;
> > vtype x37217F22=lut3(a2,a4,x26DA5E91,0x72);
> > vtype x56E9861E=x37217F22^x61C8F93C;
> >
> > vtype x1=lut3(a6,x56E9861E,x6A7935C8,0x5C);
> > vtype x2=lut3(a6,x56E9861E,x6A7935C8,0x35);
> > *out1^=x1;
> > *out2^=x2;
> > }
> >
> > void main()
> > {
> > vtype a1,a2,a3,a4,a5,a6,x1,x2,x3,x4;
> > a1=0x5555555555555555;
> > a2=0x3333333333333333;
> > a3=0x0F0F0F0F0F0F0F0F;
> > a4=0x00FF00FF00FF00FF;
> > a5=0x0000FFFF0000FFFF;
> > a6=0x00000000FFFFFFFF;
> > x1=x2=x3=x4=0;
> > s4(a1,a2,a3,a4,a5,a6,&x1,&x2,&x3,&x4);
> > printf("%016llX\n",x1);
> > printf("%016llX\n",x2);
> > printf("%016llX\n",x3);
> > printf("%016llX\n",x4);
> > }
> > ===
> >
>
> How much impact does it have on performance ? I guess it also reduces the
> number of instruction which could translate into better utilization of
> i-cache provided you do the same for all 8 sboxes.
>
> Regards,
> Sayantan
>
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