# For reference! This code delivers ~80% of rc4-amd64.pl
# performance on the same Opteron machine.
# (**) This number requires compressed key schedule set up by
-# private_RC4_set_key [see commentary below for further details].
+# RC4_set_key [see commentary below for further details].
#
# <appro@fy.chalmers.se>
+# May 2011
+#
+# Optimize for Core2 and Westmere [and incidentally Opteron]. Current
+# performance in cycles per processed byte (less is better) and
+# improvement relative to previous version of this module is:
+#
+# Pentium 10.2 # original numbers
+# Pentium III 7.8(*)
+# Intel P4 7.5
+#
+# Opteron 6.1/+20% # new MMX numbers
+# Core2 5.3/+67%(**)
+# Westmere 5.1/+94%(**)
+# Sandy Bridge 5.0/+8%
+# Atom 12.6/+6%
+#
+# (*) PIII can actually deliver 6.6 cycles per byte with MMX code,
+# but this specific code performs poorly on Core2. And vice
+# versa, below MMX/SSE code delivering 5.8/7.1 on Core2 performs
+# poorly on PIII, at 8.0/14.5:-( As PIII is not a "hot" CPU
+# [anymore], I chose to discard PIII-specific code path and opt
+# for original IALU-only code, which is why MMX/SSE code path
+# is guarded by SSE2 bit (see below), not MMX/SSE.
+# (**) Performance vs. block size on Core2 and Westmere had a maximum
+# at ... 64 bytes block size. And it was quite a maximum, 40-60%
+# in comparison to largest 8KB block size. Above improvement
+# coefficients are for the largest block size.
+
$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
push(@INC,"${dir}","${dir}../../perlasm");
require "x86asm.pl";
&$func ($out,&DWP(0,$dat,$ty,4));
}
+if ($alt=0) {
+ # >20% faster on Atom and Sandy Bridge[!], 8% faster on Opteron,
+ # but ~40% slower on Core2 and Westmere... Attempt to add movz
+ # brings down Opteron by 25%, Atom and Sandy Bridge by 15%, yet
+ # on Core2 with movz it's almost 20% slower than below alternative
+ # code... Yes, it's a total mess...
+ my @XX=($xx,$out);
+ $RC4_loop_mmx = sub { # SSE actually...
+ my $i=shift;
+ my $j=$i<=0?0:$i>>1;
+ my $mm=$i<=0?"mm0":"mm".($i&1);
+
+ &add (&LB($yy),&LB($tx));
+ &lea (@XX[1],&DWP(1,@XX[0]));
+ &pxor ("mm2","mm0") if ($i==0);
+ &psllq ("mm1",8) if ($i==0);
+ &and (@XX[1],0xff);
+ &pxor ("mm0","mm0") if ($i<=0);
+ &mov ($ty,&DWP(0,$dat,$yy,4));
+ &mov (&DWP(0,$dat,$yy,4),$tx);
+ &pxor ("mm1","mm2") if ($i==0);
+ &mov (&DWP(0,$dat,$XX[0],4),$ty);
+ &add (&LB($ty),&LB($tx));
+ &movd (@XX[0],"mm7") if ($i==0);
+ &mov ($tx,&DWP(0,$dat,@XX[1],4));
+ &pxor ("mm1","mm1") if ($i==1);
+ &movq ("mm2",&QWP(0,$inp)) if ($i==1);
+ &movq (&QWP(-8,(@XX[0],$inp)),"mm1") if ($i==0);
+ &pinsrw ($mm,&DWP(0,$dat,$ty,4),$j);
+
+ push (@XX,shift(@XX)) if ($i>=0);
+ }
+} else {
+ # Using pinsrw here improves performane on Intel CPUs by 2-3%, but
+ # brings down AMD by 7%...
+ $RC4_loop_mmx = sub {
+ my $i=shift;
+
+ &add (&LB($yy),&LB($tx));
+ &psllq ("mm1",8*(($i-1)&7)) if (abs($i)!=1);
+ &mov ($ty,&DWP(0,$dat,$yy,4));
+ &mov (&DWP(0,$dat,$yy,4),$tx);
+ &mov (&DWP(0,$dat,$xx,4),$ty);
+ &inc ($xx);
+ &add ($ty,$tx);
+ &movz ($xx,&LB($xx)); # (*)
+ &movz ($ty,&LB($ty)); # (*)
+ &pxor ("mm2",$i==1?"mm0":"mm1") if ($i>=0);
+ &movq ("mm0",&QWP(0,$inp)) if ($i<=0);
+ &movq (&QWP(-8,($out,$inp)),"mm2") if ($i==0);
+ &mov ($tx,&DWP(0,$dat,$xx,4));
+ &movd ($i>0?"mm1":"mm2",&DWP(0,$dat,$ty,4));
+
+ # (*) This is the key to Core2 and Westmere performance.
+ # Whithout movz out-of-order execution logic confuses
+ # itself and fails to reorder loads and stores. Problem
+ # appears to be fixed in Sandy Bridge...
+ }
+}
+
+&external_label("OPENSSL_ia32cap_P");
+
# void RC4(RC4_KEY *key,size_t len,const unsigned char *inp,unsigned char *out);
&function_begin("RC4");
&mov ($dat,&wparam(0)); # load key schedule pointer
&and ($ty,-4); # how many 4-byte chunks?
&jz (&label("loop1"));
+ &test ($ty,-8);
+ &mov (&wparam(3),$out); # $out as accumulator in these loops
+ &jz (&label("go4loop4"));
+
+ &picmeup($out,"OPENSSL_ia32cap_P");
+ &bt (&DWP(0,$out),26); # check SSE2 bit [could have been MMX]
+ &jnc (&label("go4loop4"));
+
+ &mov ($out,&wparam(3)) if (!$alt);
+ &movd ("mm7",&wparam(3)) if ($alt);
+ &and ($ty,-8);
+ &lea ($ty,&DWP(-8,$inp,$ty));
+ &mov (&DWP(-4,$dat),$ty); # save input+(len/8)*8-8
+
+ &$RC4_loop_mmx(-1);
+ &jmp(&label("loop_mmx_enter"));
+
+ &set_label("loop_mmx",16);
+ &$RC4_loop_mmx(0);
+ &set_label("loop_mmx_enter");
+ for ($i=1;$i<8;$i++) { &$RC4_loop_mmx($i); }
+ &mov ($ty,$yy);
+ &xor ($yy,$yy); # this is second key to Core2
+ &mov (&LB($yy),&LB($ty)); # and Westmere performance...
+ &cmp ($inp,&DWP(-4,$dat));
+ &lea ($inp,&DWP(8,$inp));
+ &jb (&label("loop_mmx"));
+
+ if ($alt) {
+ &movd ($out,"mm7");
+ &pxor ("mm2","mm0");
+ &psllq ("mm1",8);
+ &pxor ("mm1","mm2");
+ &movq (&QWP(-8,$out,$inp),"mm1");
+ } else {
+ &psllq ("mm1",56);
+ &pxor ("mm2","mm1");
+ &movq (&QWP(-8,$out,$inp),"mm2");
+ }
+ &emms ();
+
+ &cmp ($inp,&wparam(1)); # compare to input+len
+ &je (&label("done"));
+ &jmp (&label("loop1"));
+
+&set_label("go4loop4",16);
&lea ($ty,&DWP(-4,$inp,$ty));
&mov (&wparam(2),$ty); # save input+(len/4)*4-4
- &mov (&wparam(3),$out); # $out as accumulator in this loop
- &set_label("loop4",16);
+ &set_label("loop4");
for ($i=0;$i<4;$i++) { RC4_loop($i); }
&ror ($out,8);
&xor ($out,&DWP(0,$inp));
&set_label("done");
&dec (&LB($xx));
- &mov (&BP(-4,$dat),&LB($yy)); # save key->y
+ &mov (&DWP(-4,$dat),$yy); # save key->y
&mov (&BP(-8,$dat),&LB($xx)); # save key->x
&set_label("abort");
&function_end("RC4");
$ido="ecx";
$idx="edx";
-&external_label("OPENSSL_ia32cap_P");
-
-# void private_RC4_set_key(RC4_KEY *key,int len,const unsigned char *data);
-&function_begin("private_RC4_set_key");
+# void RC4_set_key(RC4_KEY *key,int len,const unsigned char *data);
+&function_begin("RC4_set_key");
&mov ($out,&wparam(0)); # load key
&mov ($idi,&wparam(1)); # load len
&mov ($inp,&wparam(2)); # load data
&xor ("eax","eax");
&mov (&DWP(-8,$out),"eax"); # key->x=0;
&mov (&DWP(-4,$out),"eax"); # key->y=0;
-&function_end("private_RC4_set_key");
+&function_end("RC4_set_key");
# const char *RC4_options(void);
&function_begin_B("RC4_options");
&blindpop("eax");
&lea ("eax",&DWP(&label("opts")."-".&label("pic_point"),"eax"));
&picmeup("edx","OPENSSL_ia32cap_P");
- &bt (&DWP(0,"edx"),20);
- &jnc (&label("skip"));
- &add ("eax",12);
- &set_label("skip");
+ &mov ("edx",&DWP(0,"edx"));
+ &bt ("edx",20);
+ &jc (&label("1xchar"));
+ &bt ("edx",26);
+ &jnc (&label("ret"));
+ &add ("eax",25);
+ &ret ();
+&set_label("1xchar");
+ &add ("eax",12);
+&set_label("ret");
&ret ();
&set_label("opts",64);
&asciz ("rc4(4x,int)");
&asciz ("rc4(1x,char)");
+&asciz ("rc4(8x,mmx)");
&asciz ("RC4 for x86, CRYPTOGAMS by <appro\@openssl.org>");
&align (64);
&function_end_B("RC4_options");
projects / openssl.git / blobdiff