ghash-x86.pl: omit unreferenced rem_8bit from no-sse2 build.

# The module implements "4-bit" GCM GHASH function and underlying

# single multiplication operation in GF(2^128). "4-bit" means that it

# uses 256 bytes per-key table [+64/128 bytes fixed table]. It has two

# code paths: vanilla x86 and vanilla MMX. Former will be executed on

# 486 and Pentium, latter on all others. MMX GHASH features so called

# code paths: vanilla x86 and vanilla SSE. Former will be executed on

# 486 and Pentium, latter on all others. SSE GHASH features so called

# "528B" variant of "4-bit" method utilizing additional 256+16 bytes

# of per-key storage [+512 bytes shared table]. Performance results

# are for streamed GHASH subroutine and are expressed in cycles per

# processed byte, less is better:

#

#		gcc 2.95.3(*)	MMX assembler	x86 assembler

#		gcc 2.95.3(*)	SSE assembler	x86 assembler

#

# Pentium	105/111(**)	-		50

# PIII		68 /75		12.2		24

# (*)	gcc 3.4.x was observed to generate few percent slower code,

#	which is one of reasons why 2.95.3 results were chosen,

#	another reason is lack of 3.4.x results for older CPUs;

#	comparison with MMX results is not completely fair, because C

#	comparison with SSE results is not completely fair, because C

#	results are for vanilla "256B" implementation, while

#	assembler results are for "528B";-)

# (**)	second number is result for code compiled with -fPIC flag,

#

# To summarize, it's >2-5 times faster than gcc-generated code. To

# anchor it to something else SHA1 assembler processes one byte in

# 11-13 cycles on contemporary x86 cores. As for choice of MMX in

# particular, see comment at the end of the file...

# ~7 cycles on contemporary x86 cores. As for choice of MMX/SSE

# in particular, see comment at the end of the file...

# May 2010

#

&set_label("bswap",64);

	&data_byte(15,14,13,12,11,10,9,8,7,6,5,4,3,2,1,0);

	&data_byte(1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0xc2);	# 0x1c2_polynomial

}}	# $sse2

&set_label("rem_4bit",64);

	&data_word(0,0x0000<<$S,0,0x1C20<<$S,0,0x3840<<$S,0,0x2460<<$S);

	&data_word(0,0x7080<<$S,0,0x6CA0<<$S,0,0x48C0<<$S,0,0x54E0<<$S);

	&data_word(0,0xE100<<$S,0,0xFD20<<$S,0,0xD940<<$S,0,0xC560<<$S);

	&data_word(0,0x9180<<$S,0,0x8DA0<<$S,0,0xA9C0<<$S,0,0xB5E0<<$S);

&set_label("rem_8bit",64);

	&data_short(0x0000,0x01C2,0x0384,0x0246,0x0708,0x06CA,0x048C,0x054E);

	&data_short(0x0E10,0x0FD2,0x0D94,0x0C56,0x0918,0x08DA,0x0A9C,0x0B5E);

	&data_short(0xA7D0,0xA612,0xA454,0xA596,0xA0D8,0xA11A,0xA35C,0xA29E);

	&data_short(0xB5E0,0xB422,0xB664,0xB7A6,0xB2E8,0xB32A,0xB16C,0xB0AE);

	&data_short(0xBBF0,0xBA32,0xB874,0xB9B6,0xBCF8,0xBD3A,0xBF7C,0xBEBE);

}}	# $sse2

&set_label("rem_4bit",64);

	&data_word(0,0x0000<<$S,0,0x1C20<<$S,0,0x3840<<$S,0,0x2460<<$S);

	&data_word(0,0x7080<<$S,0,0x6CA0<<$S,0,0x48C0<<$S,0,0x54E0<<$S);

	&data_word(0,0xE100<<$S,0,0xFD20<<$S,0,0xD940<<$S,0,0xC560<<$S);

	&data_word(0,0x9180<<$S,0,0x8DA0<<$S,0,0xA9C0<<$S,0,0xB5E0<<$S);

}}}	# !$x86only

&asciz("GHASH for x86, CRYPTOGAMS by <appro\@openssl.org>");