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Final touches to rc4/asm/rc4-596.pl, +52% better performance on AMD core.

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This commit is contained in:
Andy Polyakov 2004-11-29 21:12:58 +00:00
parent 5022e4ecdf
commit 7a3240e319
1 changed files with 32 additions and 16 deletions
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48
crypto/rc4/asm/rc4-586.pl
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@ -1,6 +1,25 @@
#!/usr/local/bin/perl
# define for pentium pro friendly version
# At some point it became apparent that the original SSLeay RC4
# assembler implementation performs suboptimal on latest IA-32
# microarchitectures. After re-tuning performance has changed as
# following:
#
# Pentium +0%
# Pentium III +17%
# AMD +52%(*)
# P4 +180%(**)
#
# (*) This number is actually a trade-off:-) It's possible to
# achieve +72%, but at the cost of -48% off PIII performance.
# In other words code performing further 13% faster on AMD
# would perform almost 2 times slower on Intel PIII...
# For reference! This code delivers ~80% of rc4-amd64.pl
# performance on same Opteron machine.
# (**) This number requires compressed key schedule set up by
# RC4_set_key, see commentary section in rc4_skey.c for
# further details.
# <appro@fy.chalmers.se>
push(@INC,"perlasm","../../perlasm");
require "x86asm.pl";
@ -46,20 +65,16 @@ sub RC4_loop
# Moved out
# &mov( $tx, &DWP(0,$d,$x,4)) if $p < 0;
&add( $y, $tx);
&and( $y, 0xff);
&inc( $x); # NEXT ROUND
&add( &LB($y), &LB($tx));
&inc( &LB($x)); # NEXT ROUND
&mov( $ty, &DWP(0,$d,$y,4));
# XXX
&mov( &DWP(-4,$d,$x,4),$ty); # AGI
&add( $ty, $tx);
&and( $x, 0xff); # NEXT ROUND
&and( $ty, 0xff);
&mov( &DWP(0,$d,$y,4),$tx);
&nop();
&mov( $ty, &DWP(0,$d,$ty,4));
&mov( $tx, &DWP(0,$d,$x,4)) if $p < 1; # NEXT ROUND
# XXX
&and( $ty, 0xff);
&mov( $tx, &DWP(0,$d,$x,4)) if $p < 1; # NEXT ROUND
&mov( $ty, &DWP(0,$d,$ty,4));
if (!$char)
{
@ -99,19 +114,20 @@ sub RC4
&push("ebp");
&push("ebx");
&push("esi");
&push("edi");
&xor( $x, $x); # avoid partial register stalls
&push("edi");
&xor( $y, $y); # avoid partial register stalls
&mov( $d, &wparam(0)); # key
&mov( $in, &wparam(2));
&mov( $x, &DWP(0,$d,"",1));
&mov( $y, &DWP(4,$d,"",1));
&movb( &LB($x), &BP(0,$d,"",1));
&movb( &LB($y), &BP(4,$d,"",1));
&mov( $out, &wparam(3));
&inc( $x);
&inc( &LB($x));
&stack_push(3); # 3 temp variables
&add( $d, 8);
&and( $x, 0xff);
# detect compressed schedule, see commentary section in rc4_skey.c...
&cmp(&DWP(256,$d),-1);
@ -200,7 +216,7 @@ sub RC4
&set_label("finished");
&dec( $x);
&stack_pop(3);
&mov( &DWP(-4,$d,"",0),$y);
&movb( &BP(-4,$d,"",0),&LB($y));
&movb( &BP(-8,$d,"",0),&LB($x));
&function_end($name);