| #! /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 <appro@openssl.org> 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. |
| |
| # This file was patched in BoringSSL to remove the variable-time 4-bit |
| # implementation. |
| |
| $0 =~ m/(.*[\/\\])[^\/\\]+$/; $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) { $sse2=1 if (/-DOPENSSL_IA32_SSE2/); } |
| |
| if (!$x86only) {{{ |
| 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 |
| }} # $sse2 |
| }}} # !$x86only |
| |
| &asciz("GHASH for x86, CRYPTOGAMS by <appro\@openssl.org>"); |
| &asm_finish(); |
| |
| close STDOUT or die "error closing 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... |
