ghash-x86[_64].pl: ~15% improvement on Atom Silvermont
[openssl.git] / crypto / modes / asm / ghash-x86.pl
index 1b9adfbc72e040fbabbce60badf9bf12f0bce69b..23a5527b30af3b5df82de4d64d0899d6359d14c0 100644 (file)
 # 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
 # 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 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,
@@ -40,8 +42,8 @@
 #
 # 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
 #
 # 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}","${dir}../../perlasm");
 require "x86asm.pl";
@@ -331,7 +343,7 @@ if (!$x86only) {{{
 
 &static_label("rem_4bit");
 
-if (0) {{      # "May" MMX version is kept for reference...
+if (!$sse2) {{ # pure-MMX "May" version...
 
 $S=12;         # shift factor for rem_4bit
 
@@ -635,7 +647,7 @@ sub mmx_loop() {
     { my @lo  = ("mm0","mm1","mm2");
       my @hi  = ("mm3","mm4","mm5");
       my @tmp = ("mm6","mm7");
-      my $off1=0,$off2=0,$i;
+      my ($off1,$off2,$i) = (0,0,);
 
       &add     ($Htbl,128);                    # optimize for size
       &lea     ("edi",&DWP(16+128,"esp"));
@@ -822,17 +834,18 @@ $len="ebx";
 &static_label("bswap");
 
 sub clmul64x64_T2 {    # minimal "register" pressure
-my ($Xhi,$Xi,$Hkey)=@_;
+my ($Xhi,$Xi,$Hkey,$HK)=@_;
 
        &movdqa         ($Xhi,$Xi);             #
        &pshufd         ($T1,$Xi,0b01001110);
-       &pshufd         ($T2,$Hkey,0b01001110);
+       &pshufd         ($T2,$Hkey,0b01001110)  if (!defined($HK));
        &pxor           ($T1,$Xi);              #
-       &pxor           ($T2,$Hkey);
+       &pxor           ($T2,$Hkey)             if (!defined($HK));
+                       $HK=$T2                 if (!defined($HK));
 
        &pclmulqdq      ($Xi,$Hkey,0x00);       #######
        &pclmulqdq      ($Xhi,$Hkey,0x11);      #######
-       &pclmulqdq      ($T1,$T2,0x00);         #######
+       &pclmulqdq      ($T1,$HK,0x00);         #######
        &xorps          ($T1,$Xi);              #
        &xorps          ($T1,$Xhi);             #
 
@@ -879,31 +892,32 @@ if (1) {          # Algorithm 9 with <<1 twist.
                        # below. Algorithm 9 was therefore chosen for
                        # further optimization...
 
-sub reduction_alg9 {   # 17/13 times faster than Intel version
+sub reduction_alg9 {   # 17/11 times faster than Intel version
 my ($Xhi,$Xi) = @_;
 
        # 1st phase
-       &movdqa         ($T1,$Xi)               #
+       &movdqa         ($T2,$Xi);              #
+       &movdqa         ($T1,$Xi);
+       &psllq          ($Xi,5);
+       &pxor           ($T1,$Xi);              #
        &psllq          ($Xi,1);
        &pxor           ($Xi,$T1);              #
-       &psllq          ($Xi,5);                #
-       &pxor           ($Xi,$T1);              #
        &psllq          ($Xi,57);               #
-       &movdqa         ($T2,$Xi);              #
+       &movdqa         ($T1,$Xi);              #
        &pslldq         ($Xi,8);
-       &psrldq         ($T2,8);                #
-       &pxor           ($Xi,$T1);
-       &pxor           ($Xhi,$T2);             #
+       &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,$T2);              #
-       &pxor           ($T2,$Xhi);
-       &psrlq          ($Xi,1);                #
-       &pxor           ($Xi,$T2);              #
+       &pxor           ($Xi,$Xhi)              #
 }
 
 &function_begin_B("gcm_init_clmul");
@@ -937,8 +951,14 @@ my ($Xhi,$Xi) = @_;
        &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");
@@ -956,8 +976,9 @@ my ($Xhi,$Xi) = @_;
        &movdqa         ($T3,&QWP(0,$const));
        &movups         ($Hkey,&QWP(0,$Htbl));
        &pshufb         ($Xi,$T3);
+       &movups         ($T2,&QWP(32,$Htbl));
 
-       &clmul64x64_T2  ($Xhi,$Xi,$Hkey);
+       &clmul64x64_T2  ($Xhi,$Xi,$Hkey,$T2);
        &reduction_alg9 ($Xhi,$Xi);
 
        &pshufb         ($Xi,$T3);
@@ -994,79 +1015,109 @@ my ($Xhi,$Xi) = @_;
        &movdqu         ($Xn,&QWP(16,$inp));    # Ii+1
        &pshufb         ($T1,$T3);
        &pshufb         ($Xn,$T3);
+       &movdqu         ($T3,&QWP(32,$Htbl));
        &pxor           ($Xi,$T1);              # Ii+Xi
 
-       &clmul64x64_T2  ($Xhn,$Xn,$Hkey);       # H*Ii+1
+       &pshufd         ($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            ();
 
-       &lea            ($inp,&DWP(32,$inp));   # i+=2
        &sub            ($len,0x20);
        &jbe            (&label("even_tail"));
+       &jmp            (&label("mod_loop"));
 
-&set_label("mod_loop");
-       &clmul64x64_T2  ($Xhi,$Xi,$Hkey);       # H^2*(Ii+Xi)
-       &movdqu         ($T1,&QWP(0,$inp));     # Ii
-       &movups         ($Hkey,&QWP(0,$Htbl));  # load H
+&set_label("mod_loop",32);
+       &pshufd         ($T2,$Xi,0b01001110);   # H^2*(Ii+Xi)
+       &movdqa         ($Xhi,$Xi);
+       &pxor           ($T2,$Xi);              #
+       &nop            ();
 
-       &pxor           ($Xi,$Xn);              # (H*Ii+1) + H^2*(Ii+Xi)
-       &pxor           ($Xhi,$Xhn);
+       &pclmulqdq      ($Xi,$Hkey,0x00);       #######
+       &pclmulqdq      ($Xhi,$Hkey,0x11);      #######
+       &pclmulqdq      ($T2,$T3,0x10);         #######
+       &movups         ($Hkey,&QWP(0,$Htbl));  # load H
 
-       &movdqu         ($Xn,&QWP(16,$inp));    # Ii+1
-       &pshufb         ($T1,$T3);
-       &pshufb         ($Xn,$T3);
+       &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);             #
 
-       &movdqa         ($T3,$Xn);              #&clmul64x64_TX ($Xhn,$Xn,$Hkey); H*Ii+1
-       &movdqa         ($Xhn,$Xn);
-        &pxor          ($Xhi,$T1);             # "Ii+Xi", consume early
+        &pshufb        ($Xhn,$T3);
+       &pxor           ($T2,$T1);              #
 
-         &movdqa       ($T1,$Xi)               #&reduction_alg9($Xhi,$Xi); 1st phase
+       &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,$T1);              #
-         &psllq        ($Xi,5);                #
-         &pxor         ($Xi,$T1);              #
        &pclmulqdq      ($Xn,$Hkey,0x00);       #######
+       &movups         ($T3,&QWP(32,$Htbl));
          &psllq        ($Xi,57);               #
-         &movdqa       ($T2,$Xi);              #
+         &movdqa       ($T1,$Xi);              #
          &pslldq       ($Xi,8);
-         &psrldq       ($T2,8);                #       
-         &pxor         ($Xi,$T1);
-       &pshufd         ($T1,$T3,0b01001110);
+         &psrldq       ($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,$T2);             #
-       &pxor           ($T1,$T3);
-       &pshufd         ($T3,$Hkey,0b01001110);
-       &pxor           ($T3,$Hkey);            #
-
        &pclmulqdq      ($Xhn,$Hkey,0x11);      #######
-         &movdqa       ($T2,$Xi);              # 2nd phase
+       &movups         ($Hkey,&QWP(16,$Htbl)); # load H^2
+         &pxor         ($T2,$Xi);
          &psrlq        ($Xi,5);
          &pxor         ($Xi,$T2);              #
          &psrlq        ($Xi,1);                #
-         &pxor         ($Xi,$T2);              #
-         &pxor         ($T2,$Xhi);
-         &psrlq        ($Xi,1);                #
-         &pxor         ($Xi,$T2);              #
-
+         &pxor         ($Xi,$Xhi)              #
        &pclmulqdq      ($T1,$T3,0x00);         #######
-       &movups         ($Hkey,&QWP(16,$Htbl)); # load H^2
-       &xorps          ($T1,$Xn);              #
-       &xorps          ($T1,$Xhn);             #
-
-       &movdqa         ($T3,$T1);              #
-       &psrldq         ($T1,8);
-       &pslldq         ($T3,8);                #
-       &pxor           ($Xhn,$T1);
-       &pxor           ($Xn,$T3);              #
-       &movdqa         ($T3,&QWP(0,$const));
 
        &lea            ($inp,&DWP(32,$inp));
        &sub            ($len,0x20);
        &ja             (&label("mod_loop"));
 
 &set_label("even_tail");
-       &clmul64x64_T2  ($Xhi,$Xi,$Hkey);       # H^2*(Ii+Xi)
+       &pshufd         ($T2,$Xi,0b01001110);   # H^2*(Ii+Xi)
+       &movdqa         ($Xhi,$Xi);
+       &pxor           ($T2,$Xi);              #
 
-       &pxor           ($Xi,$Xn);              # (H*Ii+1) + H^2*(Ii+Xi)
-       &pxor           ($Xhi,$Xhn);
+       &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);
 
@@ -1273,13 +1324,6 @@ my ($Xhi,$Xi)=@_;
 &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<<$S);
 &set_label("rem_8bit",64);
        &data_short(0x0000,0x01C2,0x0384,0x0246,0x0708,0x06CA,0x048C,0x054E);
        &data_short(0x0E10,0x0FD2,0x0D94,0x0C56,0x0918,0x08DA,0x0A9C,0x0B5E);
@@ -1313,6 +1357,13 @@ my ($Xhi,$Xi)=@_;
        &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>");