xref: /openbsd-src/lib/libcrypto/rc4/asm/rc4-x86_64.pl (revision a0d14d739afa2e3e2324debb5dbc6796689e80d6)
1#!/usr/bin/env perl
2#
3# ====================================================================
4# Written by Andy Polyakov <appro@fy.chalmers.se> for the OpenSSL
5# project. The module is, however, dual licensed under OpenSSL and
6# CRYPTOGAMS licenses depending on where you obtain it. For further
7# details see http://www.openssl.org/~appro/cryptogams/.
8# ====================================================================
9#
10# July 2004
11#
12# 2.22x RC4 tune-up:-) It should be noted though that my hand [as in
13# "hand-coded assembler"] doesn't stand for the whole improvement
14# coefficient. It turned out that eliminating RC4_CHAR from config
15# line results in ~40% improvement (yes, even for C implementation).
16# Presumably it has everything to do with AMD cache architecture and
17# RAW or whatever penalties. Once again! The module *requires* config
18# line *without* RC4_CHAR! As for coding "secret," I bet on partial
19# register arithmetics. For example instead of 'inc %r8; and $255,%r8'
20# I simply 'inc %r8b'. Even though optimization manual discourages
21# to operate on partial registers, it turned out to be the best bet.
22# At least for AMD... How IA32E would perform remains to be seen...
23
24# November 2004
25#
26# As was shown by Marc Bevand reordering of couple of load operations
27# results in even higher performance gain of 3.3x:-) At least on
28# Opteron... For reference, 1x in this case is RC4_CHAR C-code
29# compiled with gcc 3.3.2, which performs at ~54MBps per 1GHz clock.
30# Latter means that if you want to *estimate* what to expect from
31# *your* Opteron, then multiply 54 by 3.3 and clock frequency in GHz.
32
33# November 2004
34#
35# Intel P4 EM64T core was found to run the AMD64 code really slow...
36# The only way to achieve comparable performance on P4 was to keep
37# RC4_CHAR. Kind of ironic, huh? As it's apparently impossible to
38# compose blended code, which would perform even within 30% marginal
39# on either AMD and Intel platforms, I implement both cases. See
40# rc4_skey.c for further details...
41
42# April 2005
43#
44# P4 EM64T core appears to be "allergic" to 64-bit inc/dec. Replacing
45# those with add/sub results in 50% performance improvement of folded
46# loop...
47
48# May 2005
49#
50# As was shown by Zou Nanhai loop unrolling can improve Intel EM64T
51# performance by >30% [unlike P4 32-bit case that is]. But this is
52# provided that loads are reordered even more aggressively! Both code
53# paths, AMD64 and EM64T, reorder loads in essentially same manner
54# as my IA-64 implementation. On Opteron this resulted in modest 5%
55# improvement [I had to test it], while final Intel P4 performance
56# achieves respectful 432MBps on 2.8GHz processor now. For reference.
57# If executed on Xeon, current RC4_CHAR code-path is 2.7x faster than
58# RC4_INT code-path. While if executed on Opteron, it's only 25%
59# slower than the RC4_INT one [meaning that if CPU �-arch detection
60# is not implemented, then this final RC4_CHAR code-path should be
61# preferred, as it provides better *all-round* performance].
62
63# March 2007
64#
65# Intel Core2 was observed to perform poorly on both code paths:-( It
66# apparently suffers from some kind of partial register stall, which
67# occurs in 64-bit mode only [as virtually identical 32-bit loop was
68# observed to outperform 64-bit one by almost 50%]. Adding two movzb to
69# cloop1 boosts its performance by 80%! This loop appears to be optimal
70# fit for Core2 and therefore the code was modified to skip cloop8 on
71# this CPU.
72
73# May 2010
74#
75# Intel Westmere was observed to perform suboptimally. Adding yet
76# another movzb to cloop1 improved performance by almost 50%! Core2
77# performance is improved too, but nominally...
78
79# May 2011
80#
81# The only code path that was not modified is P4-specific one. Non-P4
82# Intel code path optimization is heavily based on submission by Maxim
83# Perminov, Maxim Locktyukhin and Jim Guilford of Intel. I've used
84# some of the ideas even in attempt to optimize the original RC4_INT
85# code path... Current performance in cycles per processed byte (less
86# is better) and improvement coefficients relative to previous
87# version of this module are:
88#
89# Opteron	5.3/+0%(*)
90# P4		6.5
91# Core2		6.2/+15%(**)
92# Westmere	4.2/+60%
93# Sandy Bridge	4.2/+120%
94# Atom		9.3/+80%
95#
96# (*)	But corresponding loop has less instructions, which should have
97#	positive effect on upcoming Bulldozer, which has one less ALU.
98#	For reference, Intel code runs at 6.8 cpb rate on Opteron.
99# (**)	Note that Core2 result is ~15% lower than corresponding result
100#	for 32-bit code, meaning that it's possible to improve it,
101#	but more than likely at the cost of the others (see rc4-586.pl
102#	to get the idea)...
103
104$flavour = shift;
105$output  = shift;
106if ($flavour =~ /\./) { $output = $flavour; undef $flavour; }
107
108$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
109( $xlate="${dir}x86_64-xlate.pl" and -f $xlate ) or
110( $xlate="${dir}../../perlasm/x86_64-xlate.pl" and -f $xlate) or
111die "can't locate x86_64-xlate.pl";
112
113open OUT,"| \"$^X\" $xlate $flavour $output";
114*STDOUT=*OUT;
115
116$dat="%rdi";	    # arg1
117$len="%rsi";	    # arg2
118$inp="%rdx";	    # arg3
119$out="%rcx";	    # arg4
120
121{
122$code=<<___;
123.text
124.extern	OPENSSL_ia32cap_P
125.hidden	OPENSSL_ia32cap_P
126
127.globl	rc4_internal
128.type	rc4_internal,\@function,4
129.align	16
130rc4_internal:
131	_CET_ENDBR
132	or	$len,$len
133	jne	.Lentry
134	ret
135.Lentry:
136	push	%rbx
137	push	%r12
138	push	%r13
139.Lprologue:
140	mov	$len,%r11
141	mov	$inp,%r12
142	mov	$out,%r13
143___
144my $len="%r11";		# reassign input arguments
145my $inp="%r12";
146my $out="%r13";
147
148my @XX=("%r10","%rsi");
149my @TX=("%rax","%rbx");
150my $YY="%rcx";
151my $TY="%rdx";
152
153$code.=<<___;
154	xor	$XX[0],$XX[0]
155	xor	$YY,$YY
156
157	lea	8($dat),$dat
158	mov	-8($dat),$XX[0]#b
159	mov	-4($dat),$YY#b
160	cmpl	\$-1,256($dat)
161	je	.LRC4_CHAR
162	mov	OPENSSL_ia32cap_P(%rip),%r8d
163	xor	$TX[1],$TX[1]
164	inc	$XX[0]#b
165	sub	$XX[0],$TX[1]
166	sub	$inp,$out
167	movl	($dat,$XX[0],4),$TX[0]#d
168	test	\$-16,$len
169	jz	.Lloop1
170	bt	\$IA32CAP_BIT0_INTEL,%r8d	# Intel CPU?
171	jc	.Lintel
172	and	\$7,$TX[1]
173	lea	1($XX[0]),$XX[1]
174	jz	.Loop8
175	sub	$TX[1],$len
176.Loop8_warmup:
177	add	$TX[0]#b,$YY#b
178	movl	($dat,$YY,4),$TY#d
179	movl	$TX[0]#d,($dat,$YY,4)
180	movl	$TY#d,($dat,$XX[0],4)
181	add	$TY#b,$TX[0]#b
182	inc	$XX[0]#b
183	movl	($dat,$TX[0],4),$TY#d
184	movl	($dat,$XX[0],4),$TX[0]#d
185	xorb	($inp),$TY#b
186	movb	$TY#b,($out,$inp)
187	lea	1($inp),$inp
188	dec	$TX[1]
189	jnz	.Loop8_warmup
190
191	lea	1($XX[0]),$XX[1]
192	jmp	.Loop8
193.align	16
194.Loop8:
195___
196for ($i=0;$i<8;$i++) {
197$code.=<<___ if ($i==7);
198	add	\$8,$XX[1]#b
199___
200$code.=<<___;
201	add	$TX[0]#b,$YY#b
202	movl	($dat,$YY,4),$TY#d
203	movl	$TX[0]#d,($dat,$YY,4)
204	movl	`4*($i==7?-1:$i)`($dat,$XX[1],4),$TX[1]#d
205	ror	\$8,%r8				# ror is redundant when $i=0
206	movl	$TY#d,4*$i($dat,$XX[0],4)
207	add	$TX[0]#b,$TY#b
208	movb	($dat,$TY,4),%r8b
209___
210push(@TX,shift(@TX)); #push(@XX,shift(@XX));	# "rotate" registers
211}
212$code.=<<___;
213	add	\$8,$XX[0]#b
214	ror	\$8,%r8
215	sub	\$8,$len
216
217	xor	($inp),%r8
218	mov	%r8,($out,$inp)
219	lea	8($inp),$inp
220
221	test	\$-8,$len
222	jnz	.Loop8
223	cmp	\$0,$len
224	jne	.Lloop1
225	jmp	.Lexit
226
227.align	16
228.Lintel:
229	test	\$-32,$len
230	jz	.Lloop1
231	and	\$15,$TX[1]
232	jz	.Loop16_is_hot
233	sub	$TX[1],$len
234.Loop16_warmup:
235	add	$TX[0]#b,$YY#b
236	movl	($dat,$YY,4),$TY#d
237	movl	$TX[0]#d,($dat,$YY,4)
238	movl	$TY#d,($dat,$XX[0],4)
239	add	$TY#b,$TX[0]#b
240	inc	$XX[0]#b
241	movl	($dat,$TX[0],4),$TY#d
242	movl	($dat,$XX[0],4),$TX[0]#d
243	xorb	($inp),$TY#b
244	movb	$TY#b,($out,$inp)
245	lea	1($inp),$inp
246	dec	$TX[1]
247	jnz	.Loop16_warmup
248
249	mov	$YY,$TX[1]
250	xor	$YY,$YY
251	mov	$TX[1]#b,$YY#b
252
253.Loop16_is_hot:
254	lea	($dat,$XX[0],4),$XX[1]
255___
256sub RC4_loop {
257  my $i=shift;
258  my $j=$i<0?0:$i;
259  my $xmm="%xmm".($j&1);
260
261    $code.="	add	\$16,$XX[0]#b\n"		if ($i==15);
262    $code.="	movdqu	($inp),%xmm2\n"			if ($i==15);
263    $code.="	add	$TX[0]#b,$YY#b\n"		if ($i<=0);
264    $code.="	movl	($dat,$YY,4),$TY#d\n";
265    $code.="	pxor	%xmm0,%xmm2\n"			if ($i==0);
266    $code.="	psllq	\$8,%xmm1\n"			if ($i==0);
267    $code.="	pxor	$xmm,$xmm\n"			if ($i<=1);
268    $code.="	movl	$TX[0]#d,($dat,$YY,4)\n";
269    $code.="	add	$TY#b,$TX[0]#b\n";
270    $code.="	movl	`4*($j+1)`($XX[1]),$TX[1]#d\n"	if ($i<15);
271    $code.="	movz	$TX[0]#b,$TX[0]#d\n";
272    $code.="	movl	$TY#d,4*$j($XX[1])\n";
273    $code.="	pxor	%xmm1,%xmm2\n"			if ($i==0);
274    $code.="	lea	($dat,$XX[0],4),$XX[1]\n"	if ($i==15);
275    $code.="	add	$TX[1]#b,$YY#b\n"		if ($i<15);
276    $code.="	pinsrw	\$`($j>>1)&7`,($dat,$TX[0],4),$xmm\n";
277    $code.="	movdqu	%xmm2,($out,$inp)\n"		if ($i==0);
278    $code.="	lea	16($inp),$inp\n"		if ($i==0);
279    $code.="	movl	($XX[1]),$TX[1]#d\n"		if ($i==15);
280}
281	RC4_loop(-1);
282$code.=<<___;
283	jmp	.Loop16_enter
284.align	16
285.Loop16:
286___
287
288for ($i=0;$i<16;$i++) {
289    $code.=".Loop16_enter:\n"		if ($i==1);
290	RC4_loop($i);
291	push(@TX,shift(@TX)); 		# "rotate" registers
292}
293$code.=<<___;
294	mov	$YY,$TX[1]
295	xor	$YY,$YY			# keyword to partial register
296	sub	\$16,$len
297	mov	$TX[1]#b,$YY#b
298	test	\$-16,$len
299	jnz	.Loop16
300
301	psllq	\$8,%xmm1
302	pxor	%xmm0,%xmm2
303	pxor	%xmm1,%xmm2
304	movdqu	%xmm2,($out,$inp)
305	lea	16($inp),$inp
306
307	cmp	\$0,$len
308	jne	.Lloop1
309	jmp	.Lexit
310
311.align	16
312.Lloop1:
313	add	$TX[0]#b,$YY#b
314	movl	($dat,$YY,4),$TY#d
315	movl	$TX[0]#d,($dat,$YY,4)
316	movl	$TY#d,($dat,$XX[0],4)
317	add	$TY#b,$TX[0]#b
318	inc	$XX[0]#b
319	movl	($dat,$TX[0],4),$TY#d
320	movl	($dat,$XX[0],4),$TX[0]#d
321	xorb	($inp),$TY#b
322	movb	$TY#b,($out,$inp)
323	lea	1($inp),$inp
324	dec	$len
325	jnz	.Lloop1
326	jmp	.Lexit
327
328.align	16
329.LRC4_CHAR:
330	add	\$1,$XX[0]#b
331	movzb	($dat,$XX[0]),$TX[0]#d
332	test	\$-8,$len
333	jz	.Lcloop1
334	jmp	.Lcloop8
335.align	16
336.Lcloop8:
337	mov	($inp),%r8d
338	mov	4($inp),%r9d
339___
340# unroll 2x4-wise, because 64-bit rotates kill Intel P4...
341for ($i=0;$i<4;$i++) {
342$code.=<<___;
343	add	$TX[0]#b,$YY#b
344	lea	1($XX[0]),$XX[1]
345	movzb	($dat,$YY),$TY#d
346	movzb	$XX[1]#b,$XX[1]#d
347	movzb	($dat,$XX[1]),$TX[1]#d
348	movb	$TX[0]#b,($dat,$YY)
349	cmp	$XX[1],$YY
350	movb	$TY#b,($dat,$XX[0])
351	jne	.Lcmov$i			# Intel cmov is sloooow...
352	mov	$TX[0],$TX[1]
353.Lcmov$i:
354	add	$TX[0]#b,$TY#b
355	xor	($dat,$TY),%r8b
356	ror	\$8,%r8d
357___
358push(@TX,shift(@TX)); push(@XX,shift(@XX));	# "rotate" registers
359}
360for ($i=4;$i<8;$i++) {
361$code.=<<___;
362	add	$TX[0]#b,$YY#b
363	lea	1($XX[0]),$XX[1]
364	movzb	($dat,$YY),$TY#d
365	movzb	$XX[1]#b,$XX[1]#d
366	movzb	($dat,$XX[1]),$TX[1]#d
367	movb	$TX[0]#b,($dat,$YY)
368	cmp	$XX[1],$YY
369	movb	$TY#b,($dat,$XX[0])
370	jne	.Lcmov$i			# Intel cmov is sloooow...
371	mov	$TX[0],$TX[1]
372.Lcmov$i:
373	add	$TX[0]#b,$TY#b
374	xor	($dat,$TY),%r9b
375	ror	\$8,%r9d
376___
377push(@TX,shift(@TX)); push(@XX,shift(@XX));	# "rotate" registers
378}
379$code.=<<___;
380	lea	-8($len),$len
381	mov	%r8d,($out)
382	lea	8($inp),$inp
383	mov	%r9d,4($out)
384	lea	8($out),$out
385
386	test	\$-8,$len
387	jnz	.Lcloop8
388	cmp	\$0,$len
389	jne	.Lcloop1
390	jmp	.Lexit
391___
392$code.=<<___;
393.align	16
394.Lcloop1:
395	add	$TX[0]#b,$YY#b
396	movzb	$YY#b,$YY#d
397	movzb	($dat,$YY),$TY#d
398	movb	$TX[0]#b,($dat,$YY)
399	movb	$TY#b,($dat,$XX[0])
400	add	$TX[0]#b,$TY#b
401	add	\$1,$XX[0]#b
402	movzb	$TY#b,$TY#d
403	movzb	$XX[0]#b,$XX[0]#d
404	movzb	($dat,$TY),$TY#d
405	movzb	($dat,$XX[0]),$TX[0]#d
406	xorb	($inp),$TY#b
407	lea	1($inp),$inp
408	movb	$TY#b,($out)
409	lea	1($out),$out
410	sub	\$1,$len
411	jnz	.Lcloop1
412	jmp	.Lexit
413
414.align	16
415.Lexit:
416	sub	\$1,$XX[0]#b
417	movl	$XX[0]#d,-8($dat)
418	movl	$YY#d,-4($dat)
419
420	mov	(%rsp),%r13
421	mov	8(%rsp),%r12
422	mov	16(%rsp),%rbx
423	add	\$24,%rsp
424.Lepilogue:
425	ret
426.size	rc4_internal,.-rc4_internal
427___
428}
429
430$idx="%r8";
431$ido="%r9";
432
433$code.=<<___;
434.globl	rc4_set_key_internal
435.type	rc4_set_key_internal,\@function,3
436.align	16
437rc4_set_key_internal:
438	_CET_ENDBR
439	lea	8($dat),$dat
440	lea	($inp,$len),$inp
441	neg	$len
442	mov	$len,%rcx
443	xor	%eax,%eax
444	xor	$ido,$ido
445	xor	%r10,%r10
446	xor	%r11,%r11
447
448	mov	OPENSSL_ia32cap_P(%rip),$idx#d
449	bt	\$IA32CAP_BIT0_INTELP4,$idx#d	# RC4_CHAR?
450	jc	.Lc1stloop
451	jmp	.Lw1stloop
452
453.align	16
454.Lw1stloop:
455	mov	%eax,($dat,%rax,4)
456	add	\$1,%al
457	jnc	.Lw1stloop
458
459	xor	$ido,$ido
460	xor	$idx,$idx
461.align	16
462.Lw2ndloop:
463	mov	($dat,$ido,4),%r10d
464	add	($inp,$len,1),$idx#b
465	add	%r10b,$idx#b
466	add	\$1,$len
467	mov	($dat,$idx,4),%r11d
468	cmovz	%rcx,$len
469	mov	%r10d,($dat,$idx,4)
470	mov	%r11d,($dat,$ido,4)
471	add	\$1,$ido#b
472	jnc	.Lw2ndloop
473	jmp	.Lexit_key
474
475.align	16
476.Lc1stloop:
477	mov	%al,($dat,%rax)
478	add	\$1,%al
479	jnc	.Lc1stloop
480
481	xor	$ido,$ido
482	xor	$idx,$idx
483.align	16
484.Lc2ndloop:
485	mov	($dat,$ido),%r10b
486	add	($inp,$len),$idx#b
487	add	%r10b,$idx#b
488	add	\$1,$len
489	mov	($dat,$idx),%r11b
490	jnz	.Lcnowrap
491	mov	%rcx,$len
492.Lcnowrap:
493	mov	%r10b,($dat,$idx)
494	mov	%r11b,($dat,$ido)
495	add	\$1,$ido#b
496	jnc	.Lc2ndloop
497	movl	\$-1,256($dat)
498
499.align	16
500.Lexit_key:
501	xor	%eax,%eax
502	mov	%eax,-8($dat)
503	mov	%eax,-4($dat)
504	ret
505.size	rc4_set_key_internal,.-rc4_set_key_internal
506___
507
508sub reg_part {
509my ($reg,$conv)=@_;
510    if ($reg =~ /%r[0-9]+/)	{ $reg .= $conv; }
511    elsif ($conv eq "b")	{ $reg =~ s/%[er]([^x]+)x?/%$1l/;	}
512    elsif ($conv eq "w")	{ $reg =~ s/%[er](.+)/%$1/;		}
513    elsif ($conv eq "d")	{ $reg =~ s/%[er](.+)/%e$1/;		}
514    return $reg;
515}
516
517$code =~ s/(%[a-z0-9]+)#([bwd])/reg_part($1,$2)/gem;
518$code =~ s/\`([^\`]*)\`/eval $1/gem;
519
520print $code;
521
522close STDOUT;
523