[Hardware] The market of ASICs (One GigaKey / Second?) [Repost]

[Martin Klingensmith]

John,
I didn't use your code generator. It was all manual labor unfortunately.
--
Martin K

John L. Bass wrote:
> As you might note from Martin's post, this easily generates verilog with minor changes.
>
> Have fun!
> John
>
>
> 	Date: Sun, 8 Aug 2004 21:58:10 -0600
> 	From: jbass at dmsd.com
> 	To: hardware at lists.distributed.net
> 	Subject: Re: [Hardware] The market of ASICs (One GigaKey / Second?)
>
> 	Elektron <elektron_rc5 at yahoo.ca> writes:
> 	> Imagine loops are unrolled, since the % is incredibly wasteful. The 
> 	> B=L[0] line may be able to have a hard-coded value of A in some systems 
> 	> for a marginal speed increase (not PPC though). We don't decrypt. We 
> 	> encrypt the plaintext to check that it matches the ciphertext (most 
> 	> cores do this, and either way it's just as fast, except as mentioned, 
> 	> the last round is faster).
>
> 	That's pretty much what I did several years back, while trying to construct
> 	an FPGA based RC5 engine. The starting point was a C based code generator
> 	to build C and VHDL RC5 engines.
>
> 	I still having found the VHDL RC5 tools, but this is a prototype of the
> 	C code RC5 core generator. It still isn't perfect, but gives the C compiler
> 	lots of locality hints to pull all the terms into registers and discard
> 	the writes which can be a bottleneck on small write-thru based caches.
> 	Later gcc versions nearly get it perfect with -O3
>
> 	John
>
> 	/*
> 	 * Construct unrolled RC5 key check core
> 	 * John L. Bass, Copyright 2001
> 	 */
> 	main( )
> 	{
> 		const unsigned int P = 0xB7E15163;
> 		const unsigned int Q = 0x9E3779B9;
> 		
> 		unsigned int S[26];
> 		unsigned int e, i, s, l;
>
> 		/* round 0 */
> 		S[0]= P;
> 		for (s=1;s<26;s++)
> 			S[s]= S[s-1] + Q;
> 		l=0;
> 		printf("\t\tL%d = key0 = count;\n",l);
> 		printf("\t\tL%d = key1 = count>>32;\n",l+1);
>
> 		printf("\t\tS%d = ROTL3(0x%08x]);\n",
> 			s,S[s-26]);
> 		printf("\t\tL0 = ROTL(L0 + S%d, S%d);\n",
> 			s,s);
> 		s++;
>
> 		/* rounds 0,1 */
> 		for (;s<(2*26);s++,l^=1)
> 		{
> 			printf("\t\tS%d = ROTL3(0x%08x + S%d + %s);\n",
> 				s,S[s-26],s-1,l?"L1":"L0");
> 			printf("\t\t%s = ROTL(%s + S%d + %s, S%d + %s);\n",
> 				l?"L0":"L1",l?"L0":"L1",s,l?"L1":"L0",s,l?"L1":"L0");
> 		}
>
> 		/* rounds 2,3 */
> 		for (;s<(4*26);s++,l^=1)
> 		{
> 			printf("\t\tS%d = ROTL3(S%d + S%d + %s);\n",
> 				s,s-26,s-1,l?"L1":"L0");
> 			if(s != 103)
> 			printf("\t\t%s = ROTL(%s + S%d + %s, S%d + %s);\n",
> 				l?"L0":"L1",l?"L0":"L1",s,l?"L1":"L0",s,l?"L1":"L0");
> 			if(s == 78)
> 			    printf("\t\tE0 = plain0 + S%d;\n",s);
> 			if(s == 79)
> 			    printf("\t\tE1 = plain1 + S%d;\n",s);
> 			if(s > 79)
> 			printf("\t\tE%d = ROTL(E0 ^ E1, E%d) + S%d;\n",
> 				(s)%2,(s+1)%2,s);
> 		}
> 	}
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