Commit 68d9e764 authored by Andy Polyakov's avatar Andy Polyakov
Browse files

As was shown by Marc Bevand reordering of couple of load operations 

results in even higher performance gain of 3.3x:-) At least on
Opteron...
parent 8de69cf2

crypto/rc4/asm/rc4-amd64.pl

+23 −19
Original line number Diff line number Diff line
@@ -13,11 +13,18 @@ 
# Presumably it has everything to do with AMD cache architecture and

# RAW or whatever penalties. Once again! The module *requires* config

# line *without* RC4_CHAR! As for coding "secret," I bet on partial

# register arithmetics. For example instead 'inc %r8; and $255,%r8'

# register arithmetics. For example instead of 'inc %r8; and $255,%r8'

# I simply 'inc %r8b'. Even though optimization manual discourages

# to operate on partial registers, it turned out to be the best bet.

# At least for AMD... How IA32E would perform remains to be seen...



# As was shown by Marc Bevand reordering of couple of load operations

# results in even higher performance gain of 3.3x:-) At least on

# Opteron... For reference, 1x in this case is RC4_CHAR C-code

# compiled with gcc 3.3.2, which performs at ~54MBps per 1GHz clock.

# Latter means that if you want to *estimate* what to expect from

# *your* CPU, then multiply 54 by 3.3 and clock frequency in GHz.



$output=shift;



$win64a=1 if ($output =~ /win64a.[s|asm]/);
@@ -65,10 +72,10 @@ RC4: or $len,$len 
.Lentry:

___

$code=<<___ if (defined($win64a));

TEXT	SEGMENT

_TEXT	SEGMENT

PUBLIC	RC4

ALIGN	16

RC4	PROC NEAR

RC4	PROC

	or	$len,$len

	jne	.Lentry

	repret
@@ -87,47 +94,44 @@ $code.=<<___; 
	jz	.Lloop1

.align	16

.Lloop8:

	movq	`&PTR("QWORD:[$inp]")`,%rax



	inc	$XX#b

	movl	`&PTR("DWORD:[$dat+$XX*4]")`,$TX#d

	add	$TX#b,$YY#b

	movl	`&PTR("DWORD:[$dat+$YY*4]")`,$TY#d

	movl	$TX#d,`&PTR("DWORD:[$dat+$YY*4]")`

	movl	$TY#d,`&PTR("DWORD:[$dat+$XX*4]")`

	add	$TY#b,$TX#b

	add	$TX#b,$TY#b

	inc	$XX#b

	movl	`&PTR("DWORD:[$dat+$TX*4]")`,$TY#d

	xor	$TY,%rax

	movl	`&PTR("DWORD:[$dat+$XX*4]")`,$TX#d

	movb	`&PTR("BYTE:[$dat+$TY*4]")`,%al

___

for ($i=1;$i<=6;$i++) {

$code.=<<___;

	movl	`&PTR("DWORD:[$dat+$XX*4]")`,$TX#d

	add	$TX#b,$YY#b

	ror	\$8,%rax

	movl	`&PTR("DWORD:[$dat+$YY*4]")`,$TY#d

	movl	$TX#d,`&PTR("DWORD:[$dat+$YY*4]")`

	movl	$TY#d,`&PTR("DWORD:[$dat+$XX*4]")`

	add	$TY#b,$TX#b

	movl	`&PTR("DWORD:[$dat+$TX*4]")`,$TY#d

	shl	\$`8*$i`,$TY

	add	$TX#b,$TY#b

	inc	$XX#b

	xor	$TY,%rax

	movl	`&PTR("DWORD:[$dat+$XX*4]")`,$TX#d

	movb	`&PTR("BYTE:[$dat+$TY*4]")`,%al

___

}

$code.=<<___;

	movl	`&PTR("DWORD:[$dat+$XX*4]")`,$TX#d

	add	$TX#b,$YY#b

	ror	\$8,%rax

	movl	`&PTR("DWORD:[$dat+$YY*4]")`,$TY#d

	movl	$TX#d,`&PTR("DWORD:[$dat+$YY*4]")`

	movl	$TY#d,`&PTR("DWORD:[$dat+$XX*4]")`

	sub	\$8,$len

	add	$TY#b,$TX#b

	add	\$8,$out

	movl	`&PTR("DWORD:[$dat+$TX*4]")`,$TY#d

	shl	\$56,$TY

	movb	`&PTR("BYTE:[$dat+$TX*4]")`,%al

	ror	\$8,%rax

	add	\$8,$inp

	xor	$TY,%rax

	add	\$8,$out



	xor	`&PTR("QWORD:-8[$inp]")`,%rax

	mov	%rax,`&PTR("QWORD:-8[$out]")`



	test	\$-8,$len
@@ -166,7 +170,7 @@ $code.=<<___; 
___

$code.=<<___ if (defined($win64a));

RC4	ENDP

TEXT	ENDS

_TEXT	ENDS

END

___

$code.=<<___ if (!defined($win64a));