#! /usr/bin/env perl # Copyright 2010-2016 The OpenSSL Project Authors. All Rights Reserved. # # Licensed under the OpenSSL license (the "License"). You may not use # this file except in compliance with the License. You can obtain a copy # in the file LICENSE in the source distribution or at # https://www.openssl.org/source/license.html # # ==================================================================== # Written by Andy Polyakov for the OpenSSL # project. The module is, however, dual licensed under OpenSSL and # CRYPTOGAMS licenses depending on where you obtain it. For further # details see http://www.openssl.org/~appro/cryptogams/. # ==================================================================== # # March, May, June 2010 # # 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 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(*) SSE assembler x86 assembler # # Pentium 105/111(**) - 50 # PIII 68 /75 12.2 24 # P4 125/125 17.8 84(***) # Opteron 66 /70 10.1 30 # Core2 54 /67 8.4 18 # Atom 105/105 16.8 53 # VIA Nano 69 /71 13.0 27 # # (*) 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 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, # which is actually more relevant, because assembler code is # position-independent; # (***) see comment in non-MMX routine for further details; # # To summarize, it's >2-5 times faster than gcc-generated code. To # anchor it to something else SHA1 assembler processes one byte in # ~7 cycles on contemporary x86 cores. As for choice of MMX/SSE # in particular, see comment at the end of the file... # May 2010 # # Add PCLMULQDQ version performing at 2.10 cycles per processed byte. # The question is how close is it to theoretical limit? The pclmulqdq # instruction latency appears to be 14 cycles and there can't be more # than 2 of them executing at any given time. This means that single # Karatsuba multiplication would take 28 cycles *plus* few cycles for # pre- and post-processing. Then multiplication has to be followed by # modulo-reduction. Given that aggregated reduction method [see # "Carry-less Multiplication and Its Usage for Computing the GCM Mode" # white paper by Intel] allows you to perform reduction only once in # a while we can assume that asymptotic performance can be estimated # as (28+Tmod/Naggr)/16, where Tmod is time to perform reduction # and Naggr is the aggregation factor. # # Before we proceed to this implementation let's have closer look at # the best-performing code suggested by Intel in their white paper. # By tracing inter-register dependencies Tmod is estimated as ~19 # cycles and Naggr chosen by Intel is 4, resulting in 2.05 cycles per # processed byte. As implied, this is quite optimistic estimate, # because it does not account for Karatsuba pre- and post-processing, # which for a single multiplication is ~5 cycles. Unfortunately Intel # does not provide performance data for GHASH alone. But benchmarking # AES_GCM_encrypt ripped out of Fig. 15 of the white paper with aadt # alone resulted in 2.46 cycles per byte of out 16KB buffer. Note that # the result accounts even for pre-computing of degrees of the hash # key H, but its portion is negligible at 16KB buffer size. # # Moving on to the implementation in question. Tmod is estimated as # ~13 cycles and Naggr is 2, giving asymptotic performance of ... # 2.16. How is it possible that measured performance is better than # optimistic theoretical estimate? There is one thing Intel failed # to recognize. By serializing GHASH with CTR in same subroutine # former's performance is really limited to above (Tmul + Tmod/Naggr) # equation. But if GHASH procedure is detached, the modulo-reduction # can be interleaved with Naggr-1 multiplications at instruction level # and under ideal conditions even disappear from the equation. So that # optimistic theoretical estimate for this implementation is ... # 28/16=1.75, and not 2.16. Well, it's probably way too optimistic, # at least for such small Naggr. I'd argue that (28+Tproc/Naggr), # where Tproc is time required for Karatsuba pre- and post-processing, # is more realistic estimate. In this case it gives ... 1.91 cycles. # Or in other words, depending on how well we can interleave reduction # and one of the two multiplications the performance should be between # 1.91 and 2.16. As already mentioned, this implementation processes # one byte out of 8KB buffer in 2.10 cycles, while x86_64 counterpart # - in 2.02. x86_64 performance is better, because larger register # bank allows to interleave reduction and multiplication better. # # Does it make sense to increase Naggr? To start with it's virtually # impossible in 32-bit mode, because of limited register bank # capacity. Otherwise improvement has to be weighed against slower # setup, as well as code size and complexity increase. As even # optimistic estimate doesn't promise 30% performance improvement, # there are currently no plans to increase Naggr. # # Special thanks to David Woodhouse for providing access to a # Westmere-based system on behalf of Intel Open Source Technology Centre. # January 2010 # # Tweaked to optimize transitions between integer and FP operations # on same XMM register, PCLMULQDQ subroutine was measured to process # one byte in 2.07 cycles on Sandy Bridge, and in 2.12 - on Westmere. # The minor regression on Westmere is outweighed by ~15% improvement # on Sandy Bridge. Strangely enough attempt to modify 64-bit code in # similar manner resulted in almost 20% degradation on Sandy Bridge, # where original 64-bit code processes one byte in 1.95 cycles. ##################################################################### # For reference, AMD Bulldozer processes one byte in 1.98 cycles in # 32-bit mode and 1.89 in 64-bit. # February 2013 # # Overhaul: aggregate Karatsuba post-processing, improve ILP in # reduction_alg9. Resulting performance is 1.96 cycles per byte on # Westmere, 1.95 - on Sandy/Ivy Bridge, 1.76 - on Bulldozer. $0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1; push(@INC,"${dir}","${dir}../../../perlasm"); require "x86asm.pl"; $output=pop; open STDOUT,">$output"; &asm_init($ARGV[0],$x86only = $ARGV[$#ARGV] eq "386"); $sse2=0; for (@ARGV) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); } ($Zhh,$Zhl,$Zlh,$Zll) = ("ebp","edx","ecx","ebx"); $inp = "edi"; $Htbl = "esi"; $unroll = 0; # Affects x86 loop. Folded loop performs ~7% worse # than unrolled, which has to be weighted against # 2.5x x86-specific code size reduction. sub x86_loop { my $off = shift; my $rem = "eax"; &mov ($Zhh,&DWP(4,$Htbl,$Zll)); &mov ($Zhl,&DWP(0,$Htbl,$Zll)); &mov ($Zlh,&DWP(12,$Htbl,$Zll)); &mov ($Zll,&DWP(8,$Htbl,$Zll)); &xor ($rem,$rem); # avoid partial register stalls on PIII # shrd practically kills P4, 2.5x deterioration, but P4 has # MMX code-path to execute. shrd runs tad faster [than twice # the shifts, move's and or's] on pre-MMX Pentium (as well as # PIII and Core2), *but* minimizes code size, spares register # and thus allows to fold the loop... if (!$unroll) { my $cnt = $inp; &mov ($cnt,15); &jmp (&label("x86_loop")); &set_label("x86_loop",16); for($i=1;$i<=2;$i++) { &mov (&LB($rem),&LB($Zll)); &shrd ($Zll,$Zlh,4); &and (&LB($rem),0xf); &shrd ($Zlh,$Zhl,4); &shrd ($Zhl,$Zhh,4); &shr ($Zhh,4); &xor ($Zhh,&DWP($off+16,"esp",$rem,4)); &mov (&LB($rem),&BP($off,"esp",$cnt)); if ($i&1) { &and (&LB($rem),0xf0); } else { &shl (&LB($rem),4); } &xor ($Zll,&DWP(8,$Htbl,$rem)); &xor ($Zlh,&DWP(12,$Htbl,$rem)); &xor ($Zhl,&DWP(0,$Htbl,$rem)); &xor ($Zhh,&DWP(4,$Htbl,$rem)); if ($i&1) { &dec ($cnt); &js (&label("x86_break")); } else { &jmp (&label("x86_loop")); } } &set_label("x86_break",16); } else { for($i=1;$i<32;$i++) { &comment($i); &mov (&LB($rem),&LB($Zll)); &shrd ($Zll,$Zlh,4); &and (&LB($rem),0xf); &shrd ($Zlh,$Zhl,4); &shrd ($Zhl,$Zhh,4); &shr ($Zhh,4); &xor ($Zhh,&DWP($off+16,"esp",$rem,4)); if ($i&1) { &mov (&LB($rem),&BP($off+15-($i>>1),"esp")); &and (&LB($rem),0xf0); } else { &mov (&LB($rem),&BP($off+15-($i>>1),"esp")); &shl (&LB($rem),4); } &xor ($Zll,&DWP(8,$Htbl,$rem)); &xor ($Zlh,&DWP(12,$Htbl,$rem)); &xor ($Zhl,&DWP(0,$Htbl,$rem)); &xor ($Zhh,&DWP(4,$Htbl,$rem)); } } &bswap ($Zll); &bswap ($Zlh); &bswap ($Zhl); if (!$x86only) { &bswap ($Zhh); } else { &mov ("eax",$Zhh); &bswap ("eax"); &mov ($Zhh,"eax"); } } if ($unroll) { &function_begin_B("_x86_gmult_4bit_inner"); &x86_loop(4); &ret (); &function_end_B("_x86_gmult_4bit_inner"); } sub deposit_rem_4bit { my $bias = shift; &mov (&DWP($bias+0, "esp"),0x0000<<16); &mov (&DWP($bias+4, "esp"),0x1C20<<16); &mov (&DWP($bias+8, "esp"),0x3840<<16); &mov (&DWP($bias+12,"esp"),0x2460<<16); &mov (&DWP($bias+16,"esp"),0x7080<<16); &mov (&DWP($bias+20,"esp"),0x6CA0<<16); &mov (&DWP($bias+24,"esp"),0x48C0<<16); &mov (&DWP($bias+28,"esp"),0x54E0<<16); &mov (&DWP($bias+32,"esp"),0xE100<<16); &mov (&DWP($bias+36,"esp"),0xFD20<<16); &mov (&DWP($bias+40,"esp"),0xD940<<16); &mov (&DWP($bias+44,"esp"),0xC560<<16); &mov (&DWP($bias+48,"esp"),0x9180<<16); &mov (&DWP($bias+52,"esp"),0x8DA0<<16); &mov (&DWP($bias+56,"esp"),0xA9C0<<16); &mov (&DWP($bias+60,"esp"),0xB5E0<<16); } if (!$x86only) {{{ &static_label("rem_4bit"); if (!$sse2) {{ # pure-MMX "May" version... # This code was removed since SSE2 is required for BoringSSL. The # outer structure of the code was retained to minimize future merge # conflicts. }} else {{ # "June" MMX version... # ... has slower "April" gcm_gmult_4bit_mmx with folded # loop. This is done to conserve code size... $S=16; # shift factor for rem_4bit sub mmx_loop() { # MMX version performs 2.8 times better on P4 (see comment in non-MMX # routine for further details), 40% better on Opteron and Core2, 50% # better on PIII... In other words effort is considered to be well # spent... my $inp = shift; my $rem_4bit = shift; my $cnt = $Zhh; my $nhi = $Zhl; my $nlo = $Zlh; my $rem = $Zll; my ($Zlo,$Zhi) = ("mm0","mm1"); my $tmp = "mm2"; &xor ($nlo,$nlo); # avoid partial register stalls on PIII &mov ($nhi,$Zll); &mov (&LB($nlo),&LB($nhi)); &mov ($cnt,14); &shl (&LB($nlo),4); &and ($nhi,0xf0); &movq ($Zlo,&QWP(8,$Htbl,$nlo)); &movq ($Zhi,&QWP(0,$Htbl,$nlo)); &movd ($rem,$Zlo); &jmp (&label("mmx_loop")); &set_label("mmx_loop",16); &psrlq ($Zlo,4); &and ($rem,0xf); &movq ($tmp,$Zhi); &psrlq ($Zhi,4); &pxor ($Zlo,&QWP(8,$Htbl,$nhi)); &mov (&LB($nlo),&BP(0,$inp,$cnt)); &psllq ($tmp,60); &pxor ($Zhi,&QWP(0,$rem_4bit,$rem,8)); &dec ($cnt); &movd ($rem,$Zlo); &pxor ($Zhi,&QWP(0,$Htbl,$nhi)); &mov ($nhi,$nlo); &pxor ($Zlo,$tmp); &js (&label("mmx_break")); &shl (&LB($nlo),4); &and ($rem,0xf); &psrlq ($Zlo,4); &and ($nhi,0xf0); &movq ($tmp,$Zhi); &psrlq ($Zhi,4); &pxor ($Zlo,&QWP(8,$Htbl,$nlo)); &psllq ($tmp,60); &pxor ($Zhi,&QWP(0,$rem_4bit,$rem,8)); &movd ($rem,$Zlo); &pxor ($Zhi,&QWP(0,$Htbl,$nlo)); &pxor ($Zlo,$tmp); &jmp (&label("mmx_loop")); &set_label("mmx_break",16); &shl (&LB($nlo),4); &and ($rem,0xf); &psrlq ($Zlo,4); &and ($nhi,0xf0); &movq ($tmp,$Zhi); &psrlq ($Zhi,4); &pxor ($Zlo,&QWP(8,$Htbl,$nlo)); &psllq ($tmp,60); &pxor ($Zhi,&QWP(0,$rem_4bit,$rem,8)); &movd ($rem,$Zlo); &pxor ($Zhi,&QWP(0,$Htbl,$nlo)); &pxor ($Zlo,$tmp); &psrlq ($Zlo,4); &and ($rem,0xf); &movq ($tmp,$Zhi); &psrlq ($Zhi,4); &pxor ($Zlo,&QWP(8,$Htbl,$nhi)); &psllq ($tmp,60); &pxor ($Zhi,&QWP(0,$rem_4bit,$rem,8)); &movd ($rem,$Zlo); &pxor ($Zhi,&QWP(0,$Htbl,$nhi)); &pxor ($Zlo,$tmp); &psrlq ($Zlo,32); # lower part of Zlo is already there &movd ($Zhl,$Zhi); &psrlq ($Zhi,32); &movd ($Zlh,$Zlo); &movd ($Zhh,$Zhi); &bswap ($Zll); &bswap ($Zhl); &bswap ($Zlh); &bswap ($Zhh); } &function_begin("gcm_gmult_4bit_mmx"); &mov ($inp,&wparam(0)); # load Xi &mov ($Htbl,&wparam(1)); # load Htable &call (&label("pic_point")); &set_label("pic_point"); &blindpop("eax"); &lea ("eax",&DWP(&label("rem_4bit")."-".&label("pic_point"),"eax")); &movz ($Zll,&BP(15,$inp)); &mmx_loop($inp,"eax"); &emms (); &mov (&DWP(12,$inp),$Zll); &mov (&DWP(4,$inp),$Zhl); &mov (&DWP(8,$inp),$Zlh); &mov (&DWP(0,$inp),$Zhh); &function_end("gcm_gmult_4bit_mmx"); ###################################################################### # Below subroutine is "528B" variant of "4-bit" GCM GHASH function # (see gcm128.c for details). It provides further 20-40% performance # improvement over above mentioned "May" version. &static_label("rem_8bit"); &function_begin("gcm_ghash_4bit_mmx"); { my ($Zlo,$Zhi) = ("mm7","mm6"); my $rem_8bit = "esi"; my $Htbl = "ebx"; # parameter block &mov ("eax",&wparam(0)); # Xi &mov ("ebx",&wparam(1)); # Htable &mov ("ecx",&wparam(2)); # inp &mov ("edx",&wparam(3)); # len &mov ("ebp","esp"); # original %esp &call (&label("pic_point")); &set_label ("pic_point"); &blindpop ($rem_8bit); &lea ($rem_8bit,&DWP(&label("rem_8bit")."-".&label("pic_point"),$rem_8bit)); &sub ("esp",512+16+16); # allocate stack frame... &and ("esp",-64); # ...and align it &sub ("esp",16); # place for (u8)(H[]<<4) &add ("edx","ecx"); # pointer to the end of input &mov (&DWP(528+16+0,"esp"),"eax"); # save Xi &mov (&DWP(528+16+8,"esp"),"edx"); # save inp+len &mov (&DWP(528+16+12,"esp"),"ebp"); # save original %esp { my @lo = ("mm0","mm1","mm2"); my @hi = ("mm3","mm4","mm5"); my @tmp = ("mm6","mm7"); my ($off1,$off2,$i) = (0,0,); &add ($Htbl,128); # optimize for size &lea ("edi",&DWP(16+128,"esp")); &lea ("ebp",&DWP(16+256+128,"esp")); # decompose Htable (low and high parts are kept separately), # generate Htable[]>>4, (u8)(Htable[]<<4), save to stack... for ($i=0;$i<18;$i++) { &mov ("edx",&DWP(16*$i+8-128,$Htbl)) if ($i<16); &movq ($lo[0],&QWP(16*$i+8-128,$Htbl)) if ($i<16); &psllq ($tmp[1],60) if ($i>1); &movq ($hi[0],&QWP(16*$i+0-128,$Htbl)) if ($i<16); &por ($lo[2],$tmp[1]) if ($i>1); &movq (&QWP($off1-128,"edi"),$lo[1]) if ($i>0 && $i<17); &psrlq ($lo[1],4) if ($i>0 && $i<17); &movq (&QWP($off1,"edi"),$hi[1]) if ($i>0 && $i<17); &movq ($tmp[0],$hi[1]) if ($i>0 && $i<17); &movq (&QWP($off2-128,"ebp"),$lo[2]) if ($i>1); &psrlq ($hi[1],4) if ($i>0 && $i<17); &movq (&QWP($off2,"ebp"),$hi[2]) if ($i>1); &shl ("edx",4) if ($i<16); &mov (&BP($i,"esp"),&LB("edx")) if ($i<16); unshift (@lo,pop(@lo)); # "rotate" registers unshift (@hi,pop(@hi)); unshift (@tmp,pop(@tmp)); $off1 += 8 if ($i>0); $off2 += 8 if ($i>1); } } &movq ($Zhi,&QWP(0,"eax")); &mov ("ebx",&DWP(8,"eax")); &mov ("edx",&DWP(12,"eax")); # load Xi &set_label("outer",16); { my $nlo = "eax"; my $dat = "edx"; my @nhi = ("edi","ebp"); my @rem = ("ebx","ecx"); my @red = ("mm0","mm1","mm2"); my $tmp = "mm3"; &xor ($dat,&DWP(12,"ecx")); # merge input data &xor ("ebx",&DWP(8,"ecx")); &pxor ($Zhi,&QWP(0,"ecx")); &lea ("ecx",&DWP(16,"ecx")); # inp+=16 #&mov (&DWP(528+12,"esp"),$dat); # save inp^Xi &mov (&DWP(528+8,"esp"),"ebx"); &movq (&QWP(528+0,"esp"),$Zhi); &mov (&DWP(528+16+4,"esp"),"ecx"); # save inp &xor ($nlo,$nlo); &rol ($dat,8); &mov (&LB($nlo),&LB($dat)); &mov ($nhi[1],$nlo); &and (&LB($nlo),0x0f); &shr ($nhi[1],4); &pxor ($red[0],$red[0]); &rol ($dat,8); # next byte &pxor ($red[1],$red[1]); &pxor ($red[2],$red[2]); # Just like in "May" version modulo-schedule for critical path in # 'Z.hi ^= rem_8bit[Z.lo&0xff^((u8)H[nhi]<<4)]<<48'. Final 'pxor' # is scheduled so late that rem_8bit[] has to be shifted *right* # by 16, which is why last argument to pinsrw is 2, which # corresponds to <<32=<<48>>16... for ($j=11,$i=0;$i<15;$i++) { if ($i>0) { &pxor ($Zlo,&QWP(16,"esp",$nlo,8)); # Z^=H[nlo] &rol ($dat,8); # next byte &pxor ($Zhi,&QWP(16+128,"esp",$nlo,8)); &pxor ($Zlo,$tmp); &pxor ($Zhi,&QWP(16+256+128,"esp",$nhi[0],8)); &xor (&LB($rem[1]),&BP(0,"esp",$nhi[0])); # rem^(H[nhi]<<4) } else { &movq ($Zlo,&QWP(16,"esp",$nlo,8)); &movq ($Zhi,&QWP(16+128,"esp",$nlo,8)); } &mov (&LB($nlo),&LB($dat)); &mov ($dat,&DWP(528+$j,"esp")) if (--$j%4==0); &movd ($rem[0],$Zlo); &movz ($rem[1],&LB($rem[1])) if ($i>0); &psrlq ($Zlo,8); # Z>>=8 &movq ($tmp,$Zhi); &mov ($nhi[0],$nlo); &psrlq ($Zhi,8); &pxor ($Zlo,&QWP(16+256+0,"esp",$nhi[1],8)); # Z^=H[nhi]>>4 &and (&LB($nlo),0x0f); &psllq ($tmp,56); &pxor ($Zhi,$red[1]) if ($i>1); &shr ($nhi[0],4); &pinsrw ($red[0],&WP(0,$rem_8bit,$rem[1],2),2) if ($i>0); unshift (@red,pop(@red)); # "rotate" registers unshift (@rem,pop(@rem)); unshift (@nhi,pop(@nhi)); } &pxor ($Zlo,&QWP(16,"esp",$nlo,8)); # Z^=H[nlo] &pxor ($Zhi,&QWP(16+128,"esp",$nlo,8)); &xor (&LB($rem[1]),&BP(0,"esp",$nhi[0])); # rem^(H[nhi]<<4) &pxor ($Zlo,$tmp); &pxor ($Zhi,&QWP(16+256+128,"esp",$nhi[0],8)); &movz ($rem[1],&LB($rem[1])); &pxor ($red[2],$red[2]); # clear 2nd word &psllq ($red[1],4); &movd ($rem[0],$Zlo); &psrlq ($Zlo,4); # Z>>=4 &movq ($tmp,$Zhi); &psrlq ($Zhi,4); &shl ($rem[0],4); # rem<<4 &pxor ($Zlo,&QWP(16,"esp",$nhi[1],8)); # Z^=H[nhi] &psllq ($tmp,60); &movz ($rem[0],&LB($rem[0])); &pxor ($Zlo,$tmp); &pxor ($Zhi,&QWP(16+128,"esp",$nhi[1],8)); &pinsrw ($red[0],&WP(0,$rem_8bit,$rem[1],2),2); &pxor ($Zhi,$red[1]); &movd ($dat,$Zlo); &pinsrw ($red[2],&WP(0,$rem_8bit,$rem[0],2),3); # last is <<48 &psllq ($red[0],12); # correct by <<16>>4 &pxor ($Zhi,$red[0]); &psrlq ($Zlo,32); &pxor ($Zhi,$red[2]); &mov ("ecx",&DWP(528+16+4,"esp")); # restore inp &movd ("ebx",$Zlo); &movq ($tmp,$Zhi); # 01234567 &psllw ($Zhi,8); # 1.3.5.7. &psrlw ($tmp,8); # .0.2.4.6 &por ($Zhi,$tmp); # 10325476 &bswap ($dat); &pshufw ($Zhi,$Zhi,0b00011011); # 76543210 &bswap ("ebx"); &cmp ("ecx",&DWP(528+16+8,"esp")); # are we done? &jne (&label("outer")); } &mov ("eax",&DWP(528+16+0,"esp")); # restore Xi &mov (&DWP(12,"eax"),"edx"); &mov (&DWP(8,"eax"),"ebx"); &movq (&QWP(0,"eax"),$Zhi); &mov ("esp",&DWP(528+16+12,"esp")); # restore original %esp &emms (); } &function_end("gcm_ghash_4bit_mmx"); }} if ($sse2) {{ ###################################################################### # PCLMULQDQ version. $Xip="eax"; $Htbl="edx"; $const="ecx"; $inp="esi"; $len="ebx"; ($Xi,$Xhi)=("xmm0","xmm1"); $Hkey="xmm2"; ($T1,$T2,$T3)=("xmm3","xmm4","xmm5"); ($Xn,$Xhn)=("xmm6","xmm7"); &static_label("bswap"); sub clmul64x64_T2 { # minimal "register" pressure my ($Xhi,$Xi,$Hkey,$HK)=@_; &movdqa ($Xhi,$Xi); # &pshufd ($T1,$Xi,0b01001110); &pshufd ($T2,$Hkey,0b01001110) if (!defined($HK)); &pxor ($T1,$Xi); # &pxor ($T2,$Hkey) if (!defined($HK)); $HK=$T2 if (!defined($HK)); &pclmulqdq ($Xi,$Hkey,0x00); ####### &pclmulqdq ($Xhi,$Hkey,0x11); ####### &pclmulqdq ($T1,$HK,0x00); ####### &xorps ($T1,$Xi); # &xorps ($T1,$Xhi); # &movdqa ($T2,$T1); # &psrldq ($T1,8); &pslldq ($T2,8); # &pxor ($Xhi,$T1); &pxor ($Xi,$T2); # } sub clmul64x64_T3 { # Even though this subroutine offers visually better ILP, it # was empirically found to be a tad slower than above version. # At least in gcm_ghash_clmul context. But it's just as well, # because loop modulo-scheduling is possible only thanks to # minimized "register" pressure... my ($Xhi,$Xi,$Hkey)=@_; &movdqa ($T1,$Xi); # &movdqa ($Xhi,$Xi); &pclmulqdq ($Xi,$Hkey,0x00); ####### &pclmulqdq ($Xhi,$Hkey,0x11); ####### &pshufd ($T2,$T1,0b01001110); # &pshufd ($T3,$Hkey,0b01001110); &pxor ($T2,$T1); # &pxor ($T3,$Hkey); &pclmulqdq ($T2,$T3,0x00); ####### &pxor ($T2,$Xi); # &pxor ($T2,$Xhi); # &movdqa ($T3,$T2); # &psrldq ($T2,8); &pslldq ($T3,8); # &pxor ($Xhi,$T2); &pxor ($Xi,$T3); # } if (1) { # Algorithm 9 with <<1 twist. # Reduction is shorter and uses only two # temporary registers, which makes it better # candidate for interleaving with 64x64 # multiplication. Pre-modulo-scheduled loop # was found to be ~20% faster than Algorithm 5 # below. Algorithm 9 was therefore chosen for # further optimization... sub reduction_alg9 { # 17/11 times faster than Intel version my ($Xhi,$Xi) = @_; # 1st phase &movdqa ($T2,$Xi); # &movdqa ($T1,$Xi); &psllq ($Xi,5); &pxor ($T1,$Xi); # &psllq ($Xi,1); &pxor ($Xi,$T1); # &psllq ($Xi,57); # &movdqa ($T1,$Xi); # &pslldq ($Xi,8); &psrldq ($T1,8); # &pxor ($Xi,$T2); &pxor ($Xhi,$T1); # # 2nd phase &movdqa ($T2,$Xi); &psrlq ($Xi,1); &pxor ($Xhi,$T2); # &pxor ($T2,$Xi); &psrlq ($Xi,5); &pxor ($Xi,$T2); # &psrlq ($Xi,1); # &pxor ($Xi,$Xhi) # } &function_begin_B("gcm_init_clmul"); &mov ($Htbl,&wparam(0)); &mov ($Xip,&wparam(1)); &call (&label("pic")); &set_label("pic"); &blindpop ($const); &lea ($const,&DWP(&label("bswap")."-".&label("pic"),$const)); &movdqu ($Hkey,&QWP(0,$Xip)); &pshufd ($Hkey,$Hkey,0b01001110);# dword swap # <<1 twist &pshufd ($T2,$Hkey,0b11111111); # broadcast uppermost dword &movdqa ($T1,$Hkey); &psllq ($Hkey,1); &pxor ($T3,$T3); # &psrlq ($T1,63); &pcmpgtd ($T3,$T2); # broadcast carry bit &pslldq ($T1,8); &por ($Hkey,$T1); # H<<=1 # magic reduction &pand ($T3,&QWP(16,$const)); # 0x1c2_polynomial &pxor ($Hkey,$T3); # if(carry) H^=0x1c2_polynomial # calculate H^2 &movdqa ($Xi,$Hkey); &clmul64x64_T2 ($Xhi,$Xi,$Hkey); &reduction_alg9 ($Xhi,$Xi); &pshufd ($T1,$Hkey,0b01001110); &pshufd ($T2,$Xi,0b01001110); &pxor ($T1,$Hkey); # Karatsuba pre-processing &movdqu (&QWP(0,$Htbl),$Hkey); # save H &pxor ($T2,$Xi); # Karatsuba pre-processing &movdqu (&QWP(16,$Htbl),$Xi); # save H^2 &palignr ($T2,$T1,8); # low part is H.lo^H.hi &movdqu (&QWP(32,$Htbl),$T2); # save Karatsuba "salt" &ret (); &function_end_B("gcm_init_clmul"); &function_begin_B("gcm_gmult_clmul"); &mov ($Xip,&wparam(0)); &mov ($Htbl,&wparam(1)); &call (&label("pic")); &set_label("pic"); &blindpop ($const); &lea ($const,&DWP(&label("bswap")."-".&label("pic"),$const)); &movdqu ($Xi,&QWP(0,$Xip)); &movdqa ($T3,&QWP(0,$const)); &movups ($Hkey,&QWP(0,$Htbl)); &pshufb ($Xi,$T3); &movups ($T2,&QWP(32,$Htbl)); &clmul64x64_T2 ($Xhi,$Xi,$Hkey,$T2); &reduction_alg9 ($Xhi,$Xi); &pshufb ($Xi,$T3); &movdqu (&QWP(0,$Xip),$Xi); &ret (); &function_end_B("gcm_gmult_clmul"); &function_begin("gcm_ghash_clmul"); &mov ($Xip,&wparam(0)); &mov ($Htbl,&wparam(1)); &mov ($inp,&wparam(2)); &mov ($len,&wparam(3)); &call (&label("pic")); &set_label("pic"); &blindpop ($const); &lea ($const,&DWP(&label("bswap")."-".&label("pic"),$const)); &movdqu ($Xi,&QWP(0,$Xip)); &movdqa ($T3,&QWP(0,$const)); &movdqu ($Hkey,&QWP(0,$Htbl)); &pshufb ($Xi,$T3); &sub ($len,0x10); &jz (&label("odd_tail")); ####### # Xi+2 =[H*(Ii+1 + Xi+1)] mod P = # [(H*Ii+1) + (H*Xi+1)] mod P = # [(H*Ii+1) + H^2*(Ii+Xi)] mod P # &movdqu ($T1,&QWP(0,$inp)); # Ii &movdqu ($Xn,&QWP(16,$inp)); # Ii+1 &pshufb ($T1,$T3); &pshufb ($Xn,$T3); &movdqu ($T3,&QWP(32,$Htbl)); &pxor ($Xi,$T1); # Ii+Xi &pshufd ($T1,$Xn,0b01001110); # H*Ii+1 &movdqa ($Xhn,$Xn); &pxor ($T1,$Xn); # &lea ($inp,&DWP(32,$inp)); # i+=2 &pclmulqdq ($Xn,$Hkey,0x00); ####### &pclmulqdq ($Xhn,$Hkey,0x11); ####### &pclmulqdq ($T1,$T3,0x00); ####### &movups ($Hkey,&QWP(16,$Htbl)); # load H^2 &nop (); &sub ($len,0x20); &jbe (&label("even_tail")); &jmp (&label("mod_loop")); &set_label("mod_loop",32); &pshufd ($T2,$Xi,0b01001110); # H^2*(Ii+Xi) &movdqa ($Xhi,$Xi); &pxor ($T2,$Xi); # &nop (); &pclmulqdq ($Xi,$Hkey,0x00); ####### &pclmulqdq ($Xhi,$Hkey,0x11); ####### &pclmulqdq ($T2,$T3,0x10); ####### &movups ($Hkey,&QWP(0,$Htbl)); # load H &xorps ($Xi,$Xn); # (H*Ii+1) + H^2*(Ii+Xi) &movdqa ($T3,&QWP(0,$const)); &xorps ($Xhi,$Xhn); &movdqu ($Xhn,&QWP(0,$inp)); # Ii &pxor ($T1,$Xi); # aggregated Karatsuba post-processing &movdqu ($Xn,&QWP(16,$inp)); # Ii+1 &pxor ($T1,$Xhi); # &pshufb ($Xhn,$T3); &pxor ($T2,$T1); # &movdqa ($T1,$T2); # &psrldq ($T2,8); &pslldq ($T1,8); # &pxor ($Xhi,$T2); &pxor ($Xi,$T1); # &pshufb ($Xn,$T3); &pxor ($Xhi,$Xhn); # "Ii+Xi", consume early &movdqa ($Xhn,$Xn); #&clmul64x64_TX ($Xhn,$Xn,$Hkey); H*Ii+1 &movdqa ($T2,$Xi); #&reduction_alg9($Xhi,$Xi); 1st phase &movdqa ($T1,$Xi); &psllq ($Xi,5); &pxor ($T1,$Xi); # &psllq ($Xi,1); &pxor ($Xi,$T1); # &pclmulqdq ($Xn,$Hkey,0x00); ####### &movups ($T3,&QWP(32,$Htbl)); &psllq ($Xi,57); # &movdqa ($T1,$Xi); # &pslldq ($Xi,8); &psrldq ($T1,8); # &pxor ($Xi,$T2); &pxor ($Xhi,$T1); # &pshufd ($T1,$Xhn,0b01001110); &movdqa ($T2,$Xi); # 2nd phase &psrlq ($Xi,1); &pxor ($T1,$Xhn); &pxor ($Xhi,$T2); # &pclmulqdq ($Xhn,$Hkey,0x11); ####### &movups ($Hkey,&QWP(16,$Htbl)); # load H^2 &pxor ($T2,$Xi); &psrlq ($Xi,5); &pxor ($Xi,$T2); # &psrlq ($Xi,1); # &pxor ($Xi,$Xhi) # &pclmulqdq ($T1,$T3,0x00); ####### &lea ($inp,&DWP(32,$inp)); &sub ($len,0x20); &ja (&label("mod_loop")); &set_label("even_tail"); &pshufd ($T2,$Xi,0b01001110); # H^2*(Ii+Xi) &movdqa ($Xhi,$Xi); &pxor ($T2,$Xi); # &pclmulqdq ($Xi,$Hkey,0x00); ####### &pclmulqdq ($Xhi,$Hkey,0x11); ####### &pclmulqdq ($T2,$T3,0x10); ####### &movdqa ($T3,&QWP(0,$const)); &xorps ($Xi,$Xn); # (H*Ii+1) + H^2*(Ii+Xi) &xorps ($Xhi,$Xhn); &pxor ($T1,$Xi); # aggregated Karatsuba post-processing &pxor ($T1,$Xhi); # &pxor ($T2,$T1); # &movdqa ($T1,$T2); # &psrldq ($T2,8); &pslldq ($T1,8); # &pxor ($Xhi,$T2); &pxor ($Xi,$T1); # &reduction_alg9 ($Xhi,$Xi); &test ($len,$len); &jnz (&label("done")); &movups ($Hkey,&QWP(0,$Htbl)); # load H &set_label("odd_tail"); &movdqu ($T1,&QWP(0,$inp)); # Ii &pshufb ($T1,$T3); &pxor ($Xi,$T1); # Ii+Xi &clmul64x64_T2 ($Xhi,$Xi,$Hkey); # H*(Ii+Xi) &reduction_alg9 ($Xhi,$Xi); &set_label("done"); &pshufb ($Xi,$T3); &movdqu (&QWP(0,$Xip),$Xi); &function_end("gcm_ghash_clmul"); } else { # Algorithm 5. Kept for reference purposes. sub reduction_alg5 { # 19/16 times faster than Intel version my ($Xhi,$Xi)=@_; # <<1 &movdqa ($T1,$Xi); # &movdqa ($T2,$Xhi); &pslld ($Xi,1); &pslld ($Xhi,1); # &psrld ($T1,31); &psrld ($T2,31); # &movdqa ($T3,$T1); &pslldq ($T1,4); &psrldq ($T3,12); # &pslldq ($T2,4); &por ($Xhi,$T3); # &por ($Xi,$T1); &por ($Xhi,$T2); # # 1st phase &movdqa ($T1,$Xi); &movdqa ($T2,$Xi); &movdqa ($T3,$Xi); # &pslld ($T1,31); &pslld ($T2,30); &pslld ($Xi,25); # &pxor ($T1,$T2); &pxor ($T1,$Xi); # &movdqa ($T2,$T1); # &pslldq ($T1,12); &psrldq ($T2,4); # &pxor ($T3,$T1); # 2nd phase &pxor ($Xhi,$T3); # &movdqa ($Xi,$T3); &movdqa ($T1,$T3); &psrld ($Xi,1); # &psrld ($T1,2); &psrld ($T3,7); # &pxor ($Xi,$T1); &pxor ($Xhi,$T2); &pxor ($Xi,$T3); # &pxor ($Xi,$Xhi); # } &function_begin_B("gcm_init_clmul"); &mov ($Htbl,&wparam(0)); &mov ($Xip,&wparam(1)); &call (&label("pic")); &set_label("pic"); &blindpop ($const); &lea ($const,&DWP(&label("bswap")."-".&label("pic"),$const)); &movdqu ($Hkey,&QWP(0,$Xip)); &pshufd ($Hkey,$Hkey,0b01001110);# dword swap # calculate H^2 &movdqa ($Xi,$Hkey); &clmul64x64_T3 ($Xhi,$Xi,$Hkey); &reduction_alg5 ($Xhi,$Xi); &movdqu (&QWP(0,$Htbl),$Hkey); # save H &movdqu (&QWP(16,$Htbl),$Xi); # save H^2 &ret (); &function_end_B("gcm_init_clmul"); &function_begin_B("gcm_gmult_clmul"); &mov ($Xip,&wparam(0)); &mov ($Htbl,&wparam(1)); &call (&label("pic")); &set_label("pic"); &blindpop ($const); &lea ($const,&DWP(&label("bswap")."-".&label("pic"),$const)); &movdqu ($Xi,&QWP(0,$Xip)); &movdqa ($Xn,&QWP(0,$const)); &movdqu ($Hkey,&QWP(0,$Htbl)); &pshufb ($Xi,$Xn); &clmul64x64_T3 ($Xhi,$Xi,$Hkey); &reduction_alg5 ($Xhi,$Xi); &pshufb ($Xi,$Xn); &movdqu (&QWP(0,$Xip),$Xi); &ret (); &function_end_B("gcm_gmult_clmul"); &function_begin("gcm_ghash_clmul"); &mov ($Xip,&wparam(0)); &mov ($Htbl,&wparam(1)); &mov ($inp,&wparam(2)); &mov ($len,&wparam(3)); &call (&label("pic")); &set_label("pic"); &blindpop ($const); &lea ($const,&DWP(&label("bswap")."-".&label("pic"),$const)); &movdqu ($Xi,&QWP(0,$Xip)); &movdqa ($T3,&QWP(0,$const)); &movdqu ($Hkey,&QWP(0,$Htbl)); &pshufb ($Xi,$T3); &sub ($len,0x10); &jz (&label("odd_tail")); ####### # Xi+2 =[H*(Ii+1 + Xi+1)] mod P = # [(H*Ii+1) + (H*Xi+1)] mod P = # [(H*Ii+1) + H^2*(Ii+Xi)] mod P # &movdqu ($T1,&QWP(0,$inp)); # Ii &movdqu ($Xn,&QWP(16,$inp)); # Ii+1 &pshufb ($T1,$T3); &pshufb ($Xn,$T3); &pxor ($Xi,$T1); # Ii+Xi &clmul64x64_T3 ($Xhn,$Xn,$Hkey); # H*Ii+1 &movdqu ($Hkey,&QWP(16,$Htbl)); # load H^2 &sub ($len,0x20); &lea ($inp,&DWP(32,$inp)); # i+=2 &jbe (&label("even_tail")); &set_label("mod_loop"); &clmul64x64_T3 ($Xhi,$Xi,$Hkey); # H^2*(Ii+Xi) &movdqu ($Hkey,&QWP(0,$Htbl)); # load H &pxor ($Xi,$Xn); # (H*Ii+1) + H^2*(Ii+Xi) &pxor ($Xhi,$Xhn); &reduction_alg5 ($Xhi,$Xi); ####### &movdqa ($T3,&QWP(0,$const)); &movdqu ($T1,&QWP(0,$inp)); # Ii &movdqu ($Xn,&QWP(16,$inp)); # Ii+1 &pshufb ($T1,$T3); &pshufb ($Xn,$T3); &pxor ($Xi,$T1); # Ii+Xi &clmul64x64_T3 ($Xhn,$Xn,$Hkey); # H*Ii+1 &movdqu ($Hkey,&QWP(16,$Htbl)); # load H^2 &sub ($len,0x20); &lea ($inp,&DWP(32,$inp)); &ja (&label("mod_loop")); &set_label("even_tail"); &clmul64x64_T3 ($Xhi,$Xi,$Hkey); # H^2*(Ii+Xi) &pxor ($Xi,$Xn); # (H*Ii+1) + H^2*(Ii+Xi) &pxor ($Xhi,$Xhn); &reduction_alg5 ($Xhi,$Xi); &movdqa ($T3,&QWP(0,$const)); &test ($len,$len); &jnz (&label("done")); &movdqu ($Hkey,&QWP(0,$Htbl)); # load H &set_label("odd_tail"); &movdqu ($T1,&QWP(0,$inp)); # Ii &pshufb ($T1,$T3); &pxor ($Xi,$T1); # Ii+Xi &clmul64x64_T3 ($Xhi,$Xi,$Hkey); # H*(Ii+Xi) &reduction_alg5 ($Xhi,$Xi); &movdqa ($T3,&QWP(0,$const)); &set_label("done"); &pshufb ($Xi,$T3); &movdqu (&QWP(0,$Xip),$Xi); &function_end("gcm_ghash_clmul"); } &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 &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(0x1C20,0x1DE2,0x1FA4,0x1E66,0x1B28,0x1AEA,0x18AC,0x196E); &data_short(0x1230,0x13F2,0x11B4,0x1076,0x1538,0x14FA,0x16BC,0x177E); &data_short(0x3840,0x3982,0x3BC4,0x3A06,0x3F48,0x3E8A,0x3CCC,0x3D0E); &data_short(0x3650,0x3792,0x35D4,0x3416,0x3158,0x309A,0x32DC,0x331E); &data_short(0x2460,0x25A2,0x27E4,0x2626,0x2368,0x22AA,0x20EC,0x212E); &data_short(0x2A70,0x2BB2,0x29F4,0x2836,0x2D78,0x2CBA,0x2EFC,0x2F3E); &data_short(0x7080,0x7142,0x7304,0x72C6,0x7788,0x764A,0x740C,0x75CE); &data_short(0x7E90,0x7F52,0x7D14,0x7CD6,0x7998,0x785A,0x7A1C,0x7BDE); &data_short(0x6CA0,0x6D62,0x6F24,0x6EE6,0x6BA8,0x6A6A,0x682C,0x69EE); &data_short(0x62B0,0x6372,0x6134,0x60F6,0x65B8,0x647A,0x663C,0x67FE); &data_short(0x48C0,0x4902,0x4B44,0x4A86,0x4FC8,0x4E0A,0x4C4C,0x4D8E); &data_short(0x46D0,0x4712,0x4554,0x4496,0x41D8,0x401A,0x425C,0x439E); &data_short(0x54E0,0x5522,0x5764,0x56A6,0x53E8,0x522A,0x506C,0x51AE); &data_short(0x5AF0,0x5B32,0x5974,0x58B6,0x5DF8,0x5C3A,0x5E7C,0x5FBE); &data_short(0xE100,0xE0C2,0xE284,0xE346,0xE608,0xE7CA,0xE58C,0xE44E); &data_short(0xEF10,0xEED2,0xEC94,0xED56,0xE818,0xE9DA,0xEB9C,0xEA5E); &data_short(0xFD20,0xFCE2,0xFEA4,0xFF66,0xFA28,0xFBEA,0xF9AC,0xF86E); &data_short(0xF330,0xF2F2,0xF0B4,0xF176,0xF438,0xF5FA,0xF7BC,0xF67E); &data_short(0xD940,0xD882,0xDAC4,0xDB06,0xDE48,0xDF8A,0xDDCC,0xDC0E); &data_short(0xD750,0xD692,0xD4D4,0xD516,0xD058,0xD19A,0xD3DC,0xD21E); &data_short(0xC560,0xC4A2,0xC6E4,0xC726,0xC268,0xC3AA,0xC1EC,0xC02E); &data_short(0xCB70,0xCAB2,0xC8F4,0xC936,0xCC78,0xCDBA,0xCFFC,0xCE3E); &data_short(0x9180,0x9042,0x9204,0x93C6,0x9688,0x974A,0x950C,0x94CE); &data_short(0x9F90,0x9E52,0x9C14,0x9DD6,0x9898,0x995A,0x9B1C,0x9ADE); &data_short(0x8DA0,0x8C62,0x8E24,0x8FE6,0x8AA8,0x8B6A,0x892C,0x88EE); &data_short(0x83B0,0x8272,0x8034,0x81F6,0x84B8,0x857A,0x873C,0x86FE); &data_short(0xA9C0,0xA802,0xAA44,0xAB86,0xAEC8,0xAF0A,0xAD4C,0xAC8E); &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 "); &asm_finish(); close STDOUT; # A question was risen about choice of vanilla MMX. Or rather why wasn't # SSE2 chosen instead? In addition to the fact that MMX runs on legacy # CPUs such as PIII, "4-bit" MMX version was observed to provide better # performance than *corresponding* SSE2 one even on contemporary CPUs. # SSE2 results were provided by Peter-Michael Hager. He maintains SSE2 # implementation featuring full range of lookup-table sizes, but with # per-invocation lookup table setup. Latter means that table size is # chosen depending on how much data is to be hashed in every given call, # more data - larger table. Best reported result for Core2 is ~4 cycles # per processed byte out of 64KB block. This number accounts even for # 64KB table setup overhead. As discussed in gcm128.c we choose to be # more conservative in respect to lookup table sizes, but how do the # results compare? Minimalistic "256B" MMX version delivers ~11 cycles # on same platform. As also discussed in gcm128.c, next in line "8-bit # Shoup's" or "4KB" method should deliver twice the performance of # "256B" one, in other words not worse than ~6 cycles per byte. It # should be also be noted that in SSE2 case improvement can be "super- # linear," i.e. more than twice, mostly because >>8 maps to single # instruction on SSE2 register. This is unlike "4-bit" case when >>4 # maps to same amount of instructions in both MMX and SSE2 cases. # Bottom line is that switch to SSE2 is considered to be justifiable # only in case we choose to implement "8-bit" method...