From 08825b907d933e80bba6077a545831978fa950f4 Mon Sep 17 00:00:00 2001
From: "Jason A. Donenfeld" <Jason@zx2c4.com>
Date: Thu, 8 Nov 2018 17:08:22 +0100
Subject: chacha20,poly1305: switch to perlasm originals on mips and arm

We also separate out Eric Biggers' Cortex A7 implementation into its own
file.
---
 src/crypto/zinc/chacha20/chacha20-arm.pl | 1227 ++++++++++++++++++++++++++++++
 1 file changed, 1227 insertions(+)
 create mode 100644 src/crypto/zinc/chacha20/chacha20-arm.pl

(limited to 'src/crypto/zinc/chacha20/chacha20-arm.pl')

diff --git a/src/crypto/zinc/chacha20/chacha20-arm.pl b/src/crypto/zinc/chacha20/chacha20-arm.pl
new file mode 100644
index 0000000..3621957
--- /dev/null
+++ b/src/crypto/zinc/chacha20/chacha20-arm.pl
@@ -0,0 +1,1227 @@
+#!/usr/bin/env perl
+# SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
+#
+# This code is taken from the OpenSSL project but the author, Andy Polyakov,
+# has relicensed it under the licenses specified in the SPDX header above.
+# The original headers, including the original license headers, are
+# included below for completeness.
+#
+# ====================================================================
+# Written by Andy Polyakov <appro@openssl.org> for the OpenSSL
+# project. The module is, however, dual licensed under OpenSSL and
+# CRYPTOGAMS licenses depending on where you obtain it. For further
+# details see http://www.openssl.org/~appro/cryptogams/.
+# ====================================================================
+#
+# December 2014
+#
+# ChaCha20 for ARMv4.
+#
+# September 2018
+#
+# Improve scalar performance per Eric Biggers' suggestion to eliminate
+# separate rotates. This requires b[0..3] and d[0..3] to be maintained
+# pre-rotated, hence odd twists prior inner loop and when accumulating
+# key material. Since amount of instructions is reduced as result, even
+# NEON performance is improved somewhat, most notably by ~9% on low-end
+# Cortex-A5/A7. Full unroll was shown to provide even better scalar
+# performance on Cortex-A5/A7, naturally at the cost of manyfold size
+# increase. We let it be. Oversized code works in benchmarks, but is not
+# necessarily optimal in real life, when it's likely to be out-of-cache
+# upon entry and evict significant part of cache upon completion.
+#
+# Performance in cycles per byte out of large buffer.
+#
+#			IALU/gcc-4.4    1xNEON      3xNEON+1xIALU
+#
+# Cortex-A5		14.2(*)/+160%   21.8        12.9(**)
+# Cortex-A8		10.2(*)/+190%   13.9        6.10
+# Cortex-A9		10.8(*)/+150%   14.3        6.50
+# Cortex-A15		11.0/+40%       16.0        4.90
+# Snapdragon S4		13.9(***)/+90%  13.6        4.90
+#
+# (*)	most "favourable" result for aligned data on little-endian
+#	processor, result for misaligned data is 10-15% lower;
+# (**)	pure 4xNEON [with "vertical" layout] was shown to provide ~8%
+#	better performance on Cortex-A5/A7, but not on others;
+# (***)	it's 17% slower than original, trade-off is considered
+#	acceptable, because of improvement on others, specifically
+#	+36% on Cortex-A5/A7 and +20% on Cortex-A9;
+
+$flavour = shift;
+if ($flavour=~/\w[\w\-]*\.\w+$/) { $output=$flavour; undef $flavour; }
+else { while (($output=shift) && ($output!~/\w[\w\-]*\.\w+$/)) {} }
+
+if ($flavour && $flavour ne "void") {
+    $0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
+    ( $xlate="${dir}arm-xlate.pl" and -f $xlate ) or
+    ( $xlate="${dir}../../perlasm/arm-xlate.pl" and -f $xlate) or
+    die "can't locate arm-xlate.pl";
+
+    open STDOUT,"| \"$^X\" $xlate $flavour $output";
+} else {
+    open STDOUT,">$output";
+}
+
+sub AUTOLOAD()		# thunk [simplified] x86-style perlasm
+{ my $opcode = $AUTOLOAD; $opcode =~ s/.*:://; $opcode =~ s/_/\./;
+  my $arg = pop;
+    $arg = "#$arg" if ($arg*1 eq $arg);
+    $code .= "\t$opcode\t".join(',',@_,$arg)."\n";
+}
+
+my @x=map("r$_",(0..7,"x","x","x","x",12,"x",14,"x"));
+my @t=map("r$_",(8..11));
+
+sub ROUND {
+my ($a0,$b0,$c0,$d0)=@_;
+my ($a1,$b1,$c1,$d1)=map(($_&~3)+(($_+1)&3),($a0,$b0,$c0,$d0));
+my ($a2,$b2,$c2,$d2)=map(($_&~3)+(($_+1)&3),($a1,$b1,$c1,$d1));
+my ($a3,$b3,$c3,$d3)=map(($_&~3)+(($_+1)&3),($a2,$b2,$c2,$d2));
+my $odd = $d0&1;
+my ($xc,$xc_) = (@t[0..1]);
+my ($xd,$xd_) = $odd ? (@t[2],@x[$d1]) : (@x[$d0],@t[2]);
+my @ret;
+
+	# Consider order in which variables are addressed by their
+	# index:
+	#
+	#       a   b   c   d
+	#
+	#       0   4   8  12 < even round
+	#       1   5   9  13
+	#       2   6  10  14
+	#       3   7  11  15
+	#       0   5  10  15 < odd round
+	#       1   6  11  12
+	#       2   7   8  13
+	#       3   4   9  14
+	#
+	# 'a', 'b' are permanently allocated in registers, @x[0..7],
+	# while 'c's and pair of 'd's are maintained in memory. If
+	# you observe 'c' column, you'll notice that pair of 'c's is
+	# invariant between rounds. This means that we have to reload
+	# them once per round, in the middle. This is why you'll see
+	# bunch of 'c' stores and loads in the middle, but none in
+	# the beginning or end. If you observe 'd' column, you'll
+	# notice that 15 and 13 are reused in next pair of rounds.
+	# This is why these two are chosen for offloading to memory,
+	# to make loads count more.
+							push @ret,(
+	"&add	(@x[$a0],@x[$a0],@x[$b0],'ror#13')",
+	 "&add	(@x[$a1],@x[$a1],@x[$b1],'ror#13')",
+	"&eor	($xd,@x[$a0],$xd,'ror#24')",
+	 "&eor	($xd_,@x[$a1],$xd_,'ror#24')",
+
+	"&add	($xc,$xc,$xd,'ror#16')",
+	 "&add	($xc_,$xc_,$xd_,'ror#16')",
+	"&eor	(@x[$b0],$xc, @x[$b0],'ror#13')",
+	 "&eor	(@x[$b1],$xc_,@x[$b1],'ror#13')",
+
+	"&add	(@x[$a0],@x[$a0],@x[$b0],'ror#20')",
+	 "&add	(@x[$a1],@x[$a1],@x[$b1],'ror#20')",
+	"&eor	($xd,@x[$a0],$xd,'ror#16')",
+	 "&eor	($xd_,@x[$a1],$xd_,'ror#16')"		);
+							push @ret,(
+	"&str	($xd,'[sp,#4*(16+$d0)]')"		) if ($odd);
+							push @ret,(
+	"&add	($xc,$xc,$xd,'ror#24')"			);
+							push @ret,(
+	"&ldr	($xd,'[sp,#4*(16+$d2)]')"		) if ($odd);
+							push @ret,(
+	 "&str	($xd_,'[sp,#4*(16+$d1)]')"		) if (!$odd);
+							push @ret,(
+	 "&add	($xc_,$xc_,$xd_,'ror#24')"		);
+							push @ret,(
+	 "&ldr	($xd_,'[sp,#4*(16+$d3)]')"		) if (!$odd);
+							push @ret,(
+	"&str	($xc,'[sp,#4*(16+$c0)]')",
+	"&eor	(@x[$b0],@x[$b0],$xc,'ror#12')",
+	 "&str	($xc_,'[sp,#4*(16+$c1)]')",
+	 "&eor	(@x[$b1],@x[$b1],$xc_,'ror#12')"	);
+
+	$xd=@x[$d2]					if (!$odd);
+	$xd_=@x[$d3]					if ($odd);
+							push @ret,(
+	"&ldr	($xc,'[sp,#4*(16+$c2)]')",
+	"&add	(@x[$a2],@x[$a2],@x[$b2],'ror#13')",
+	 "&ldr	($xc_,'[sp,#4*(16+$c3)]')",
+	 "&add	(@x[$a3],@x[$a3],@x[$b3],'ror#13')",
+	"&eor	($xd,@x[$a2],$xd,'ror#24')",
+	 "&eor	($xd_,@x[$a3],$xd_,'ror#24')",
+
+	"&add	($xc,$xc,$xd,'ror#16')",
+	 "&add	($xc_,$xc_,$xd_,'ror#16')",
+	"&eor	(@x[$b2],$xc, @x[$b2],'ror#13')",
+	 "&eor	(@x[$b3],$xc_,@x[$b3],'ror#13')",
+
+	"&add	(@x[$a2],@x[$a2],@x[$b2],'ror#20')",
+	 "&add	(@x[$a3],@x[$a3],@x[$b3],'ror#20')",
+	"&eor	($xd,@x[$a2],$xd,'ror#16')",
+	 "&eor	($xd_,@x[$a3],$xd_,'ror#16')",
+
+	"&add	($xc,$xc,$xd,'ror#24')",
+	 "&add	($xc_,$xc_,$xd_,'ror#24')",
+	"&eor	(@x[$b2],@x[$b2],$xc,'ror#12')",
+	 "&eor	(@x[$b3],@x[$b3],$xc_,'ror#12')"	);
+
+	@ret;
+}
+
+$code.=<<___;
+#ifndef __KERNEL__
+# include "arm_arch.h"
+#else
+# define __ARM_ARCH__ __LINUX_ARM_ARCH__
+# define __ARM_MAX_ARCH__ __LINUX_ARM_ARCH__
+# define ChaCha20_ctr32 chacha20_arm_cryptogams
+# define ChaCha20_neon  chacha20_neon
+#endif
+
+.text
+#if defined(__thumb2__) || defined(__clang__)
+.syntax	unified
+# define ldrhsb	ldrbhs
+#endif
+#if defined(__thumb2__)
+.thumb
+#else
+.code	32
+#endif
+
+.align	5
+.Lsigma:
+.long	0x61707865,0x3320646e,0x79622d32,0x6b206574	@ endian-neutral
+.Lone:
+.long	1,0,0,0
+.Lrot8:
+.long	0x02010003,0x06050407
+#if __ARM_MAX_ARCH__>=7 && !defined(__KERNEL__)
+.LOPENSSL_armcap:
+.word   OPENSSL_armcap_P-.LChaCha20_ctr32
+#else
+.word	-1
+#endif
+
+.globl	ChaCha20_ctr32
+.type	ChaCha20_ctr32,%function
+.align	5
+ChaCha20_ctr32:
+.LChaCha20_ctr32:
+	ldr	r12,[sp,#0]		@ pull pointer to counter and nonce
+	stmdb	sp!,{r0-r2,r4-r11,lr}
+#if __ARM_ARCH__<7 && !defined(__thumb2__)
+	sub	r14,pc,#16		@ ChaCha20_ctr32
+#else
+	adr	r14,.LChaCha20_ctr32
+#endif
+	cmp	r2,#0			@ len==0?
+#ifdef	__thumb2__
+	itt	eq
+#endif
+	addeq	sp,sp,#4*3
+	beq	.Lno_data
+#if __ARM_MAX_ARCH__>=7 && !defined(__KERNEL__)
+	cmp	r2,#192			@ test len
+	bls	.Lshort
+	ldr	r4,[r14,#-24]
+	ldr	r4,[r14,r4]
+# ifdef	__APPLE__
+	ldr	r4,[r4]
+# endif
+	tst	r4,#ARMV7_NEON
+	bne	.LChaCha20_neon
+.Lshort:
+#endif
+	ldmia	r12,{r4-r7}		@ load counter and nonce
+	sub	sp,sp,#4*(16)		@ off-load area
+	sub	r14,r14,#64		@ .Lsigma
+	stmdb	sp!,{r4-r7}		@ copy counter and nonce
+	ldmia	r3,{r4-r11}		@ load key
+	ldmia	r14,{r0-r3}		@ load sigma
+	stmdb	sp!,{r4-r11}		@ copy key
+	stmdb	sp!,{r0-r3}		@ copy sigma
+	str	r10,[sp,#4*(16+10)]	@ off-load "@x[10]"
+	str	r11,[sp,#4*(16+11)]	@ off-load "@x[11]"
+	b	.Loop_outer_enter
+
+.align	4
+.Loop_outer:
+	ldmia	sp,{r0-r9}		@ load key material
+	str	@t[3],[sp,#4*(32+2)]	@ save len
+	str	r12,  [sp,#4*(32+1)]	@ save inp
+	str	r14,  [sp,#4*(32+0)]	@ save out
+.Loop_outer_enter:
+	ldr	@t[3], [sp,#4*(15)]
+	 mov	@x[4],@x[4],ror#19	@ twist b[0..3]
+	ldr	@x[12],[sp,#4*(12)]	@ modulo-scheduled load
+	 mov	@x[5],@x[5],ror#19
+	ldr	@t[2], [sp,#4*(13)]
+	 mov	@x[6],@x[6],ror#19
+	ldr	@x[14],[sp,#4*(14)]
+	 mov	@x[7],@x[7],ror#19
+	mov	@t[3],@t[3],ror#8	@ twist d[0..3]
+	mov	@x[12],@x[12],ror#8
+	mov	@t[2],@t[2],ror#8
+	mov	@x[14],@x[14],ror#8
+	str	@t[3], [sp,#4*(16+15)]
+	mov	@t[3],#10
+	b	.Loop
+
+.align	4
+.Loop:
+	subs	@t[3],@t[3],#1
+___
+	foreach (&ROUND(0, 4, 8,12)) { eval; }
+	foreach (&ROUND(0, 5,10,15)) { eval; }
+$code.=<<___;
+	bne	.Loop
+
+	ldr	@t[3],[sp,#4*(32+2)]	@ load len
+
+	str	@t[0], [sp,#4*(16+8)]	@ modulo-scheduled store
+	str	@t[1], [sp,#4*(16+9)]
+	str	@x[12],[sp,#4*(16+12)]
+	str	@t[2], [sp,#4*(16+13)]
+	str	@x[14],[sp,#4*(16+14)]
+
+	@ at this point we have first half of 512-bit result in
+	@ @x[0-7] and second half at sp+4*(16+8)
+
+	cmp	@t[3],#64		@ done yet?
+#ifdef	__thumb2__
+	itete	lo
+#endif
+	addlo	r12,sp,#4*(0)		@ shortcut or ...
+	ldrhs	r12,[sp,#4*(32+1)]	@ ... load inp
+	addlo	r14,sp,#4*(0)		@ shortcut or ...
+	ldrhs	r14,[sp,#4*(32+0)]	@ ... load out
+
+	ldr	@t[0],[sp,#4*(0)]	@ load key material
+	ldr	@t[1],[sp,#4*(1)]
+
+#if __ARM_ARCH__>=6 || !defined(__ARMEB__)
+# if __ARM_ARCH__<7
+	orr	@t[2],r12,r14
+	tst	@t[2],#3		@ are input and output aligned?
+	ldr	@t[2],[sp,#4*(2)]
+	bne	.Lunaligned
+	cmp	@t[3],#64		@ restore flags
+# else
+	ldr	@t[2],[sp,#4*(2)]
+# endif
+	ldr	@t[3],[sp,#4*(3)]
+
+	add	@x[0],@x[0],@t[0]	@ accumulate key material
+	add	@x[1],@x[1],@t[1]
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[0],[r12],#16		@ load input
+	ldrhs	@t[1],[r12,#-12]
+
+	add	@x[2],@x[2],@t[2]
+	add	@x[3],@x[3],@t[3]
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[2],[r12,#-8]
+	ldrhs	@t[3],[r12,#-4]
+# if __ARM_ARCH__>=6 && defined(__ARMEB__)
+	rev	@x[0],@x[0]
+	rev	@x[1],@x[1]
+	rev	@x[2],@x[2]
+	rev	@x[3],@x[3]
+# endif
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[0],@x[0],@t[0]	@ xor with input
+	eorhs	@x[1],@x[1],@t[1]
+	 add	@t[0],sp,#4*(4)
+	str	@x[0],[r14],#16		@ store output
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[2],@x[2],@t[2]
+	eorhs	@x[3],@x[3],@t[3]
+	 ldmia	@t[0],{@t[0]-@t[3]}	@ load key material
+	str	@x[1],[r14,#-12]
+	str	@x[2],[r14,#-8]
+	str	@x[3],[r14,#-4]
+
+	add	@x[4],@t[0],@x[4],ror#13 @ accumulate key material
+	add	@x[5],@t[1],@x[5],ror#13
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[0],[r12],#16		@ load input
+	ldrhs	@t[1],[r12,#-12]
+	add	@x[6],@t[2],@x[6],ror#13
+	add	@x[7],@t[3],@x[7],ror#13
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[2],[r12,#-8]
+	ldrhs	@t[3],[r12,#-4]
+# if __ARM_ARCH__>=6 && defined(__ARMEB__)
+	rev	@x[4],@x[4]
+	rev	@x[5],@x[5]
+	rev	@x[6],@x[6]
+	rev	@x[7],@x[7]
+# endif
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[4],@x[4],@t[0]
+	eorhs	@x[5],@x[5],@t[1]
+	 add	@t[0],sp,#4*(8)
+	str	@x[4],[r14],#16		@ store output
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[6],@x[6],@t[2]
+	eorhs	@x[7],@x[7],@t[3]
+	str	@x[5],[r14,#-12]
+	 ldmia	@t[0],{@t[0]-@t[3]}	@ load key material
+	str	@x[6],[r14,#-8]
+	 add	@x[0],sp,#4*(16+8)
+	str	@x[7],[r14,#-4]
+
+	ldmia	@x[0],{@x[0]-@x[7]}	@ load second half
+
+	add	@x[0],@x[0],@t[0]	@ accumulate key material
+	add	@x[1],@x[1],@t[1]
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[0],[r12],#16		@ load input
+	ldrhs	@t[1],[r12,#-12]
+# ifdef	__thumb2__
+	itt	hi
+# endif
+	 strhi	@t[2],[sp,#4*(16+10)]	@ copy "@x[10]" while at it
+	 strhi	@t[3],[sp,#4*(16+11)]	@ copy "@x[11]" while at it
+	add	@x[2],@x[2],@t[2]
+	add	@x[3],@x[3],@t[3]
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[2],[r12,#-8]
+	ldrhs	@t[3],[r12,#-4]
+# if __ARM_ARCH__>=6 && defined(__ARMEB__)
+	rev	@x[0],@x[0]
+	rev	@x[1],@x[1]
+	rev	@x[2],@x[2]
+	rev	@x[3],@x[3]
+# endif
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[0],@x[0],@t[0]
+	eorhs	@x[1],@x[1],@t[1]
+	 add	@t[0],sp,#4*(12)
+	str	@x[0],[r14],#16		@ store output
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[2],@x[2],@t[2]
+	eorhs	@x[3],@x[3],@t[3]
+	str	@x[1],[r14,#-12]
+	 ldmia	@t[0],{@t[0]-@t[3]}	@ load key material
+	str	@x[2],[r14,#-8]
+	str	@x[3],[r14,#-4]
+
+	add	@x[4],@t[0],@x[4],ror#24 @ accumulate key material
+	add	@x[5],@t[1],@x[5],ror#24
+# ifdef	__thumb2__
+	itt	hi
+# endif
+	 addhi	@t[0],@t[0],#1		@ next counter value
+	 strhi	@t[0],[sp,#4*(12)]	@ save next counter value
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[0],[r12],#16		@ load input
+	ldrhs	@t[1],[r12,#-12]
+	add	@x[6],@t[2],@x[6],ror#24
+	add	@x[7],@t[3],@x[7],ror#24
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhs	@t[2],[r12,#-8]
+	ldrhs	@t[3],[r12,#-4]
+# if __ARM_ARCH__>=6 && defined(__ARMEB__)
+	rev	@x[4],@x[4]
+	rev	@x[5],@x[5]
+	rev	@x[6],@x[6]
+	rev	@x[7],@x[7]
+# endif
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[4],@x[4],@t[0]
+	eorhs	@x[5],@x[5],@t[1]
+# ifdef	__thumb2__
+	 it	ne
+# endif
+	 ldrne	@t[0],[sp,#4*(32+2)]	@ re-load len
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	eorhs	@x[6],@x[6],@t[2]
+	eorhs	@x[7],@x[7],@t[3]
+	str	@x[4],[r14],#16		@ store output
+	str	@x[5],[r14,#-12]
+# ifdef	__thumb2__
+	it	hs
+# endif
+	 subhs	@t[3],@t[0],#64		@ len-=64
+	str	@x[6],[r14,#-8]
+	str	@x[7],[r14,#-4]
+	bhi	.Loop_outer
+
+	beq	.Ldone
+# if __ARM_ARCH__<7
+	b	.Ltail
+
+.align	4
+.Lunaligned:				@ unaligned endian-neutral path
+	cmp	@t[3],#64		@ restore flags
+# endif
+#endif
+#if __ARM_ARCH__<7
+	ldr	@t[3],[sp,#4*(3)]
+___
+for ($i=0;$i<16;$i+=4) {
+my $j=$i&0x7;
+my $twist="";
+if ($i==4)     { $twist = ",ror#13"; }
+elsif ($i==12) { $twist = ",ror#24"; }
+
+$code.=<<___	if ($i==4);
+	add	@x[0],sp,#4*(16+8)
+___
+$code.=<<___	if ($i==8);
+	ldmia	@x[0],{@x[0]-@x[7]}		@ load second half
+# ifdef	__thumb2__
+	itt	hi
+# endif
+	strhi	@t[2],[sp,#4*(16+10)]		@ copy "@x[10]"
+	strhi	@t[3],[sp,#4*(16+11)]		@ copy "@x[11]"
+___
+$code.=<<___;
+	add	@x[$j+0],@t[0],@x[$j+0]$twist	@ accumulate key material
+___
+$code.=<<___	if ($i==12);
+# ifdef	__thumb2__
+	itt	hi
+# endif
+	addhi	@t[0],@t[0],#1			@ next counter value
+	strhi	@t[0],[sp,#4*(12)]		@ save next counter value
+___
+$code.=<<___;
+	add	@x[$j+1],@t[1],@x[$j+1]$twist
+	add	@x[$j+2],@t[2],@x[$j+2]$twist
+# ifdef	__thumb2__
+	itete	lo
+# endif
+	eorlo	@t[0],@t[0],@t[0]		@ zero or ...
+	ldrhsb	@t[0],[r12],#16			@ ... load input
+	eorlo	@t[1],@t[1],@t[1]
+	ldrhsb	@t[1],[r12,#-12]
+
+	add	@x[$j+3],@t[3],@x[$j+3]$twist
+# ifdef	__thumb2__
+	itete	lo
+# endif
+	eorlo	@t[2],@t[2],@t[2]
+	ldrhsb	@t[2],[r12,#-8]
+	eorlo	@t[3],@t[3],@t[3]
+	ldrhsb	@t[3],[r12,#-4]
+
+	eor	@x[$j+0],@t[0],@x[$j+0]		@ xor with input (or zero)
+	eor	@x[$j+1],@t[1],@x[$j+1]
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhsb	@t[0],[r12,#-15]		@ load more input
+	ldrhsb	@t[1],[r12,#-11]
+	eor	@x[$j+2],@t[2],@x[$j+2]
+	 strb	@x[$j+0],[r14],#16		@ store output
+	eor	@x[$j+3],@t[3],@x[$j+3]
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhsb	@t[2],[r12,#-7]
+	ldrhsb	@t[3],[r12,#-3]
+	 strb	@x[$j+1],[r14,#-12]
+	eor	@x[$j+0],@t[0],@x[$j+0],lsr#8
+	 strb	@x[$j+2],[r14,#-8]
+	eor	@x[$j+1],@t[1],@x[$j+1],lsr#8
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhsb	@t[0],[r12,#-14]		@ load more input
+	ldrhsb	@t[1],[r12,#-10]
+	 strb	@x[$j+3],[r14,#-4]
+	eor	@x[$j+2],@t[2],@x[$j+2],lsr#8
+	 strb	@x[$j+0],[r14,#-15]
+	eor	@x[$j+3],@t[3],@x[$j+3],lsr#8
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhsb	@t[2],[r12,#-6]
+	ldrhsb	@t[3],[r12,#-2]
+	 strb	@x[$j+1],[r14,#-11]
+	eor	@x[$j+0],@t[0],@x[$j+0],lsr#8
+	 strb	@x[$j+2],[r14,#-7]
+	eor	@x[$j+1],@t[1],@x[$j+1],lsr#8
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhsb	@t[0],[r12,#-13]		@ load more input
+	ldrhsb	@t[1],[r12,#-9]
+	 strb	@x[$j+3],[r14,#-3]
+	eor	@x[$j+2],@t[2],@x[$j+2],lsr#8
+	 strb	@x[$j+0],[r14,#-14]
+	eor	@x[$j+3],@t[3],@x[$j+3],lsr#8
+# ifdef	__thumb2__
+	itt	hs
+# endif
+	ldrhsb	@t[2],[r12,#-5]
+	ldrhsb	@t[3],[r12,#-1]
+	 strb	@x[$j+1],[r14,#-10]
+	 strb	@x[$j+2],[r14,#-6]
+	eor	@x[$j+0],@t[0],@x[$j+0],lsr#8
+	 strb	@x[$j+3],[r14,#-2]
+	eor	@x[$j+1],@t[1],@x[$j+1],lsr#8
+	 strb	@x[$j+0],[r14,#-13]
+	eor	@x[$j+2],@t[2],@x[$j+2],lsr#8
+	 strb	@x[$j+1],[r14,#-9]
+	eor	@x[$j+3],@t[3],@x[$j+3],lsr#8
+	 strb	@x[$j+2],[r14,#-5]
+	 strb	@x[$j+3],[r14,#-1]
+___
+$code.=<<___	if ($i<12);
+	add	@t[0],sp,#4*(4+$i)
+	ldmia	@t[0],{@t[0]-@t[3]}		@ load key material
+___
+}
+$code.=<<___;
+# ifdef	__thumb2__
+	it	ne
+# endif
+	ldrne	@t[0],[sp,#4*(32+2)]		@ re-load len
+# ifdef	__thumb2__
+	it	hs
+# endif
+	subhs	@t[3],@t[0],#64			@ len-=64
+	bhi	.Loop_outer
+
+	beq	.Ldone
+#endif
+
+.Ltail:
+	ldr	r12,[sp,#4*(32+1)]	@ load inp
+	add	@t[1],sp,#4*(0)
+	ldr	r14,[sp,#4*(32+0)]	@ load out
+
+.Loop_tail:
+	ldrb	@t[2],[@t[1]],#1	@ read buffer on stack
+	ldrb	@t[3],[r12],#1		@ read input
+	subs	@t[0],@t[0],#1
+	eor	@t[3],@t[3],@t[2]
+	strb	@t[3],[r14],#1		@ store output
+	bne	.Loop_tail
+
+.Ldone:
+	add	sp,sp,#4*(32+3)
+.Lno_data:
+#if __ARM_ARCH__>=5
+	ldmia	sp!,{r4-r11,pc}
+#else
+	ldmia	sp!,{r4-r12,lr}
+	tst	lr,#1
+	moveq	pc,lr			@ be binary compatible with V4, yet
+	.long	0xe12fff1e		@ interoperable with Thumb ISA:-)
+#endif
+.size	ChaCha20_ctr32,.-ChaCha20_ctr32
+___
+
+{{{
+my ($a0,$b0,$c0,$d0,$a1,$b1,$c1,$d1,$a2,$b2,$c2,$d2,$t0,$t1,$t2,$t3) =
+    map("q$_",(0..15));
+
+# This can replace vshr-by-24+vsli-by-8. It gives ~3% improvement on
+# Cortex-A5/A7, but hurts Cortex-A9 by 5% and Snapdragon S4 by 14%!
+sub vperm()
+{ my ($dst,$src,$tbl) = @_;
+    $code .= "	vtbl.8	$dst#lo,{$src#lo},$tbl#lo\n";
+    $code .= "	vtbl.8	$dst#hi,{$src#hi},$tbl#lo\n";
+}
+
+sub NEONROUND {
+my $odd = pop;
+my ($a,$b,$c,$d,$t)=@_;
+
+	(
+	"&vadd_i32	($a,$a,$b)",
+	"&veor		($d,$d,$a)",
+	"&vrev32_16	($d,$d)",	# vrot ($d,16)
+
+	"&vadd_i32	($c,$c,$d)",
+	"&veor		($t,$b,$c)",
+	"&vshr_u32	($b,$t,20)",
+	"&vsli_32	($b,$t,12)",
+
+	"&vadd_i32	($a,$a,$b)",
+	"&veor		($t,$d,$a)",
+	"&vshr_u32	($d,$t,24)",
+	"&vsli_32	($d,$t,8)",
+	#"&vperm	($d,$t,$t3)",
+
+	"&vadd_i32	($c,$c,$d)",
+	"&veor		($t,$b,$c)",
+	"&vshr_u32	($b,$t,25)",
+	"&vsli_32	($b,$t,7)",
+
+	"&vext_8	($c,$c,$c,8)",
+	"&vext_8	($b,$b,$b,$odd?12:4)",
+	"&vext_8	($d,$d,$d,$odd?4:12)"
+	);
+}
+
+$code.=<<___;
+#if __ARM_MAX_ARCH__>=7
+.arch	armv7-a
+.fpu	neon
+
+# ifdef __KERNEL__
+.globl	ChaCha20_neon
+@ For optimal performance it's appropriate for caller to enforce
+@ minimum input length, 193 bytes is suggested.
+# endif
+.type	ChaCha20_neon,%function
+.align	5
+ChaCha20_neon:
+	ldr		r12,[sp,#0]		@ pull pointer to counter and nonce
+	stmdb		sp!,{r0-r2,r4-r11,lr}
+.LChaCha20_neon:
+	adr		r14,.Lsigma
+	vstmdb		sp!,{d8-d15}		@ ABI spec says so
+	stmdb		sp!,{r0-r3}
+
+	vld1.32		{$b0-$c0},[r3]		@ load key
+	ldmia		r3,{r4-r11}		@ load key
+
+	sub		sp,sp,#4*(16+16)
+	vld1.32		{$d0},[r12]		@ load counter and nonce
+	add		r12,sp,#4*8
+	ldmia		r14,{r0-r3}		@ load sigma
+	vld1.32		{$a0},[r14]!		@ load sigma
+	vld1.32		{$t0},[r14]!		@ one
+	@ vld1.32	{$t3#lo},[r14]		@ rot8
+	vst1.32		{$c0-$d0},[r12]		@ copy 1/2key|counter|nonce
+	vst1.32		{$a0-$b0},[sp]		@ copy sigma|1/2key
+
+	str		r10,[sp,#4*(16+10)]	@ off-load "@x[10]"
+	str		r11,[sp,#4*(16+11)]	@ off-load "@x[11]"
+	vshl.i32	$t1#lo,$t0#lo,#1	@ two
+	vstr		$t0#lo,[sp,#4*(16+0)]
+	vshl.i32	$t2#lo,$t0#lo,#2	@ four
+	vstr		$t1#lo,[sp,#4*(16+2)]
+	vmov		$a1,$a0
+	vstr		$t2#lo,[sp,#4*(16+4)]
+	vmov		$a2,$a0
+	@ vstr		$t3#lo,[sp,#4*(16+6)]
+	vmov		$b1,$b0
+	vmov		$b2,$b0
+	b		.Loop_neon_enter
+
+.align	4
+.Loop_neon_outer:
+	ldmia		sp,{r0-r9}		@ load key material
+	cmp		@t[3],#64*2		@ if len<=64*2
+	bls		.Lbreak_neon		@ switch to integer-only
+	@ vldr		$t3#lo,[sp,#4*(16+6)]	@ rot8
+	vmov		$a1,$a0
+	str		@t[3],[sp,#4*(32+2)]	@ save len
+	vmov		$a2,$a0
+	str		r12,  [sp,#4*(32+1)]	@ save inp
+	vmov		$b1,$b0
+	str		r14,  [sp,#4*(32+0)]	@ save out
+	vmov		$b2,$b0
+.Loop_neon_enter:
+	ldr		@t[3], [sp,#4*(15)]
+	 mov		@x[4],@x[4],ror#19	@ twist b[0..3]
+	vadd.i32	$d1,$d0,$t0		@ counter+1
+	ldr		@x[12],[sp,#4*(12)]	@ modulo-scheduled load
+	 mov		@x[5],@x[5],ror#19
+	vmov		$c1,$c0
+	ldr		@t[2], [sp,#4*(13)]
+	 mov		@x[6],@x[6],ror#19
+	vmov		$c2,$c0
+	ldr		@x[14],[sp,#4*(14)]
+	 mov		@x[7],@x[7],ror#19
+	vadd.i32	$d2,$d1,$t0		@ counter+2
+	add		@x[12],@x[12],#3	@ counter+3
+	mov		@t[3],@t[3],ror#8	@ twist d[0..3]
+	mov		@x[12],@x[12],ror#8
+	mov		@t[2],@t[2],ror#8
+	mov		@x[14],@x[14],ror#8
+	str		@t[3], [sp,#4*(16+15)]
+	mov		@t[3],#10
+	b		.Loop_neon
+
+.align	4
+.Loop_neon:
+	subs		@t[3],@t[3],#1
+___
+	my @thread0=&NEONROUND($a0,$b0,$c0,$d0,$t0,0);
+	my @thread1=&NEONROUND($a1,$b1,$c1,$d1,$t1,0);
+	my @thread2=&NEONROUND($a2,$b2,$c2,$d2,$t2,0);
+	my @thread3=&ROUND(0,4,8,12);
+
+	foreach (@thread0) {
+		eval;			eval(shift(@thread3));
+		eval(shift(@thread1));	eval(shift(@thread3));
+		eval(shift(@thread2));	eval(shift(@thread3));
+	}
+
+	@thread0=&NEONROUND($a0,$b0,$c0,$d0,$t0,1);
+	@thread1=&NEONROUND($a1,$b1,$c1,$d1,$t1,1);
+	@thread2=&NEONROUND($a2,$b2,$c2,$d2,$t2,1);
+	@thread3=&ROUND(0,5,10,15);
+
+	foreach (@thread0) {
+		eval;			eval(shift(@thread3));
+		eval(shift(@thread1));	eval(shift(@thread3));
+		eval(shift(@thread2));	eval(shift(@thread3));
+	}
+$code.=<<___;
+	bne		.Loop_neon
+
+	add		@t[3],sp,#32
+	vld1.32		{$t0-$t1},[sp]		@ load key material
+	vld1.32		{$t2-$t3},[@t[3]]
+
+	ldr		@t[3],[sp,#4*(32+2)]	@ load len
+
+	str		@t[0], [sp,#4*(16+8)]	@ modulo-scheduled store
+	str		@t[1], [sp,#4*(16+9)]
+	str		@x[12],[sp,#4*(16+12)]
+	str		@t[2], [sp,#4*(16+13)]
+	str		@x[14],[sp,#4*(16+14)]
+
+	@ at this point we have first half of 512-bit result in
+	@ @x[0-7] and second half at sp+4*(16+8)
+
+	ldr		r12,[sp,#4*(32+1)]	@ load inp
+	ldr		r14,[sp,#4*(32+0)]	@ load out
+
+	vadd.i32	$a0,$a0,$t0		@ accumulate key material
+	vadd.i32	$a1,$a1,$t0
+	vadd.i32	$a2,$a2,$t0
+	vldr		$t0#lo,[sp,#4*(16+0)]	@ one
+
+	vadd.i32	$b0,$b0,$t1
+	vadd.i32	$b1,$b1,$t1
+	vadd.i32	$b2,$b2,$t1
+	vldr		$t1#lo,[sp,#4*(16+2)]	@ two
+
+	vadd.i32	$c0,$c0,$t2
+	vadd.i32	$c1,$c1,$t2
+	vadd.i32	$c2,$c2,$t2
+	vadd.i32	$d1#lo,$d1#lo,$t0#lo	@ counter+1
+	vadd.i32	$d2#lo,$d2#lo,$t1#lo	@ counter+2
+
+	vadd.i32	$d0,$d0,$t3
+	vadd.i32	$d1,$d1,$t3
+	vadd.i32	$d2,$d2,$t3
+
+	cmp		@t[3],#64*4
+	blo		.Ltail_neon
+
+	vld1.8		{$t0-$t1},[r12]!	@ load input
+	 mov		@t[3],sp
+	vld1.8		{$t2-$t3},[r12]!
+	veor		$a0,$a0,$t0		@ xor with input
+	veor		$b0,$b0,$t1
+	vld1.8		{$t0-$t1},[r12]!
+	veor		$c0,$c0,$t2
+	veor		$d0,$d0,$t3
+	vld1.8		{$t2-$t3},[r12]!
+
+	veor		$a1,$a1,$t0
+	 vst1.8		{$a0-$b0},[r14]!	@ store output
+	veor		$b1,$b1,$t1
+	vld1.8		{$t0-$t1},[r12]!
+	veor		$c1,$c1,$t2
+	 vst1.8		{$c0-$d0},[r14]!
+	veor		$d1,$d1,$t3
+	vld1.8		{$t2-$t3},[r12]!
+
+	veor		$a2,$a2,$t0
+	 vld1.32	{$a0-$b0},[@t[3]]!	@ load for next iteration
+	 veor		$t0#hi,$t0#hi,$t0#hi
+	 vldr		$t0#lo,[sp,#4*(16+4)]	@ four
+	veor		$b2,$b2,$t1
+	 vld1.32	{$c0-$d0},[@t[3]]
+	veor		$c2,$c2,$t2
+	 vst1.8		{$a1-$b1},[r14]!
+	veor		$d2,$d2,$t3
+	 vst1.8		{$c1-$d1},[r14]!
+
+	vadd.i32	$d0#lo,$d0#lo,$t0#lo	@ next counter value
+	vldr		$t0#lo,[sp,#4*(16+0)]	@ one
+
+	ldmia		sp,{@t[0]-@t[3]}	@ load key material
+	add		@x[0],@x[0],@t[0]	@ accumulate key material
+	ldr		@t[0],[r12],#16		@ load input
+	 vst1.8		{$a2-$b2},[r14]!
+	add		@x[1],@x[1],@t[1]
+	ldr		@t[1],[r12,#-12]
+	 vst1.8		{$c2-$d2},[r14]!
+	add		@x[2],@x[2],@t[2]
+	ldr		@t[2],[r12,#-8]
+	add		@x[3],@x[3],@t[3]
+	ldr		@t[3],[r12,#-4]
+# ifdef	__ARMEB__
+	rev		@x[0],@x[0]
+	rev		@x[1],@x[1]
+	rev		@x[2],@x[2]
+	rev		@x[3],@x[3]
+# endif
+	eor		@x[0],@x[0],@t[0]	@ xor with input
+	 add		@t[0],sp,#4*(4)
+	eor		@x[1],@x[1],@t[1]
+	str		@x[0],[r14],#16		@ store output
+	eor		@x[2],@x[2],@t[2]
+	str		@x[1],[r14,#-12]
+	eor		@x[3],@x[3],@t[3]
+	 ldmia		@t[0],{@t[0]-@t[3]}	@ load key material
+	str		@x[2],[r14,#-8]
+	str		@x[3],[r14,#-4]
+
+	add		@x[4],@t[0],@x[4],ror#13 @ accumulate key material
+	ldr		@t[0],[r12],#16		@ load input
+	add		@x[5],@t[1],@x[5],ror#13
+	ldr		@t[1],[r12,#-12]
+	add		@x[6],@t[2],@x[6],ror#13
+	ldr		@t[2],[r12,#-8]
+	add		@x[7],@t[3],@x[7],ror#13
+	ldr		@t[3],[r12,#-4]
+# ifdef	__ARMEB__
+	rev		@x[4],@x[4]
+	rev		@x[5],@x[5]
+	rev		@x[6],@x[6]
+	rev		@x[7],@x[7]
+# endif
+	eor		@x[4],@x[4],@t[0]
+	 add		@t[0],sp,#4*(8)
+	eor		@x[5],@x[5],@t[1]
+	str		@x[4],[r14],#16		@ store output
+	eor		@x[6],@x[6],@t[2]
+	str		@x[5],[r14,#-12]
+	eor		@x[7],@x[7],@t[3]
+	 ldmia		@t[0],{@t[0]-@t[3]}	@ load key material
+	str		@x[6],[r14,#-8]
+	 add		@x[0],sp,#4*(16+8)
+	str		@x[7],[r14,#-4]
+
+	ldmia		@x[0],{@x[0]-@x[7]}	@ load second half
+
+	add		@x[0],@x[0],@t[0]	@ accumulate key material
+	ldr		@t[0],[r12],#16		@ load input
+	add		@x[1],@x[1],@t[1]
+	ldr		@t[1],[r12,#-12]
+# ifdef	__thumb2__
+	it	hi
+# endif
+	 strhi		@t[2],[sp,#4*(16+10)]	@ copy "@x[10]" while at it
+	add		@x[2],@x[2],@t[2]
+	ldr		@t[2],[r12,#-8]
+# ifdef	__thumb2__
+	it	hi
+# endif
+	 strhi		@t[3],[sp,#4*(16+11)]	@ copy "@x[11]" while at it
+	add		@x[3],@x[3],@t[3]
+	ldr		@t[3],[r12,#-4]
+# ifdef	__ARMEB__
+	rev		@x[0],@x[0]
+	rev		@x[1],@x[1]
+	rev		@x[2],@x[2]
+	rev		@x[3],@x[3]
+# endif
+	eor		@x[0],@x[0],@t[0]
+	 add		@t[0],sp,#4*(12)
+	eor		@x[1],@x[1],@t[1]
+	str		@x[0],[r14],#16		@ store output
+	eor		@x[2],@x[2],@t[2]
+	str		@x[1],[r14,#-12]
+	eor		@x[3],@x[3],@t[3]
+	 ldmia		@t[0],{@t[0]-@t[3]}	@ load key material
+	str		@x[2],[r14,#-8]
+	str		@x[3],[r14,#-4]
+
+	add		@x[4],@t[0],@x[4],ror#24 @ accumulate key material
+	 add		@t[0],@t[0],#4		@ next counter value
+	add		@x[5],@t[1],@x[5],ror#24
+	 str		@t[0],[sp,#4*(12)]	@ save next counter value
+	ldr		@t[0],[r12],#16		@ load input
+	add		@x[6],@t[2],@x[6],ror#24
+	 add		@x[4],@x[4],#3		@ counter+3
+	ldr		@t[1],[r12,#-12]
+	add		@x[7],@t[3],@x[7],ror#24
+	ldr		@t[2],[r12,#-8]
+	ldr		@t[3],[r12,#-4]
+# ifdef	__ARMEB__
+	rev		@x[4],@x[4]
+	rev		@x[5],@x[5]
+	rev		@x[6],@x[6]
+	rev		@x[7],@x[7]
+# endif
+	eor		@x[4],@x[4],@t[0]
+# ifdef	__thumb2__
+	it	hi
+# endif
+	 ldrhi		@t[0],[sp,#4*(32+2)]	@ re-load len
+	eor		@x[5],@x[5],@t[1]
+	eor		@x[6],@x[6],@t[2]
+	str		@x[4],[r14],#16		@ store output
+	eor		@x[7],@x[7],@t[3]
+	str		@x[5],[r14,#-12]
+	 sub		@t[3],@t[0],#64*4	@ len-=64*4
+	str		@x[6],[r14,#-8]
+	str		@x[7],[r14,#-4]
+	bhi		.Loop_neon_outer
+
+	b		.Ldone_neon
+
+.align	4
+.Lbreak_neon:
+	@ harmonize NEON and integer-only stack frames: load data
+	@ from NEON frame, but save to integer-only one; distance
+	@ between the two is 4*(32+4+16-32)=4*(20).
+
+	str		@t[3], [sp,#4*(20+32+2)]	@ save len
+	 add		@t[3],sp,#4*(32+4)
+	str		r12,   [sp,#4*(20+32+1)]	@ save inp
+	str		r14,   [sp,#4*(20+32+0)]	@ save out
+
+	ldr		@x[12],[sp,#4*(16+10)]
+	ldr		@x[14],[sp,#4*(16+11)]
+	 vldmia		@t[3],{d8-d15}			@ fulfill ABI requirement
+	str		@x[12],[sp,#4*(20+16+10)]	@ copy "@x[10]"
+	str		@x[14],[sp,#4*(20+16+11)]	@ copy "@x[11]"
+
+	ldr		@t[3], [sp,#4*(15)]
+	 mov		@x[4],@x[4],ror#19		@ twist b[0..3]
+	ldr		@x[12],[sp,#4*(12)]		@ modulo-scheduled load
+	 mov		@x[5],@x[5],ror#19
+	ldr		@t[2], [sp,#4*(13)]
+	 mov		@x[6],@x[6],ror#19
+	ldr		@x[14],[sp,#4*(14)]
+	 mov		@x[7],@x[7],ror#19
+	mov		@t[3],@t[3],ror#8		@ twist d[0..3]
+	mov		@x[12],@x[12],ror#8
+	mov		@t[2],@t[2],ror#8
+	mov		@x[14],@x[14],ror#8
+	str		@t[3], [sp,#4*(20+16+15)]
+	add		@t[3],sp,#4*(20)
+	vst1.32		{$a0-$b0},[@t[3]]!		@ copy key
+	add		sp,sp,#4*(20)			@ switch frame
+	vst1.32		{$c0-$d0},[@t[3]]
+	mov		@t[3],#10
+	b		.Loop				@ go integer-only
+
+.align	4
+.Ltail_neon:
+	cmp		@t[3],#64*3
+	bhs		.L192_or_more_neon
+	cmp		@t[3],#64*2
+	bhs		.L128_or_more_neon
+	cmp		@t[3],#64*1
+	bhs		.L64_or_more_neon
+
+	add		@t[0],sp,#4*(8)
+	vst1.8		{$a0-$b0},[sp]
+	add		@t[2],sp,#4*(0)
+	vst1.8		{$c0-$d0},[@t[0]]
+	b		.Loop_tail_neon
+
+.align	4
+.L64_or_more_neon:
+	vld1.8		{$t0-$t1},[r12]!
+	vld1.8		{$t2-$t3},[r12]!
+	veor		$a0,$a0,$t0
+	veor		$b0,$b0,$t1
+	veor		$c0,$c0,$t2
+	veor		$d0,$d0,$t3
+	vst1.8		{$a0-$b0},[r14]!
+	vst1.8		{$c0-$d0},[r14]!
+
+	beq		.Ldone_neon
+
+	add		@t[0],sp,#4*(8)
+	vst1.8		{$a1-$b1},[sp]
+	add		@t[2],sp,#4*(0)
+	vst1.8		{$c1-$d1},[@t[0]]
+	sub		@t[3],@t[3],#64*1	@ len-=64*1
+	b		.Loop_tail_neon
+
+.align	4
+.L128_or_more_neon:
+	vld1.8		{$t0-$t1},[r12]!
+	vld1.8		{$t2-$t3},[r12]!
+	veor		$a0,$a0,$t0
+	veor		$b0,$b0,$t1
+	vld1.8		{$t0-$t1},[r12]!
+	veor		$c0,$c0,$t2
+	veor		$d0,$d0,$t3
+	vld1.8		{$t2-$t3},[r12]!
+
+	veor		$a1,$a1,$t0
+	veor		$b1,$b1,$t1
+	 vst1.8		{$a0-$b0},[r14]!
+	veor		$c1,$c1,$t2
+	 vst1.8		{$c0-$d0},[r14]!
+	veor		$d1,$d1,$t3
+	vst1.8		{$a1-$b1},[r14]!
+	vst1.8		{$c1-$d1},[r14]!
+
+	beq		.Ldone_neon
+
+	add		@t[0],sp,#4*(8)
+	vst1.8		{$a2-$b2},[sp]
+	add		@t[2],sp,#4*(0)
+	vst1.8		{$c2-$d2},[@t[0]]
+	sub		@t[3],@t[3],#64*2	@ len-=64*2
+	b		.Loop_tail_neon
+
+.align	4
+.L192_or_more_neon:
+	vld1.8		{$t0-$t1},[r12]!
+	vld1.8		{$t2-$t3},[r12]!
+	veor		$a0,$a0,$t0
+	veor		$b0,$b0,$t1
+	vld1.8		{$t0-$t1},[r12]!
+	veor		$c0,$c0,$t2
+	veor		$d0,$d0,$t3
+	vld1.8		{$t2-$t3},[r12]!
+
+	veor		$a1,$a1,$t0
+	veor		$b1,$b1,$t1
+	vld1.8		{$t0-$t1},[r12]!
+	veor		$c1,$c1,$t2
+	 vst1.8		{$a0-$b0},[r14]!
+	veor		$d1,$d1,$t3
+	vld1.8		{$t2-$t3},[r12]!
+
+	veor		$a2,$a2,$t0
+	 vst1.8		{$c0-$d0},[r14]!
+	veor		$b2,$b2,$t1
+	 vst1.8		{$a1-$b1},[r14]!
+	veor		$c2,$c2,$t2
+	 vst1.8		{$c1-$d1},[r14]!
+	veor		$d2,$d2,$t3
+	vst1.8		{$a2-$b2},[r14]!
+	vst1.8		{$c2-$d2},[r14]!
+
+	beq		.Ldone_neon
+
+	ldmia		sp,{@t[0]-@t[3]}	@ load key material
+	add		@x[0],@x[0],@t[0]	@ accumulate key material
+	 add		@t[0],sp,#4*(4)
+	add		@x[1],@x[1],@t[1]
+	add		@x[2],@x[2],@t[2]
+	add		@x[3],@x[3],@t[3]
+	 ldmia		@t[0],{@t[0]-@t[3]}	@ load key material
+
+	add		@x[4],@t[0],@x[4],ror#13 @ accumulate key material
+	 add		@t[0],sp,#4*(8)
+	add		@x[5],@t[1],@x[5],ror#13
+	add		@x[6],@t[2],@x[6],ror#13
+	add		@x[7],@t[3],@x[7],ror#13
+	 ldmia		@t[0],{@t[0]-@t[3]}	@ load key material
+# ifdef	__ARMEB__
+	rev		@x[0],@x[0]
+	rev		@x[1],@x[1]
+	rev		@x[2],@x[2]
+	rev		@x[3],@x[3]
+	rev		@x[4],@x[4]
+	rev		@x[5],@x[5]
+	rev		@x[6],@x[6]
+	rev		@x[7],@x[7]
+# endif
+	stmia		sp,{@x[0]-@x[7]}
+	 add		@x[0],sp,#4*(16+8)
+
+	ldmia		@x[0],{@x[0]-@x[7]}	@ load second half
+
+	add		@x[0],@x[0],@t[0]	@ accumulate key material
+	 add		@t[0],sp,#4*(12)
+	add		@x[1],@x[1],@t[1]
+	add		@x[2],@x[2],@t[2]
+	add		@x[3],@x[3],@t[3]
+	 ldmia		@t[0],{@t[0]-@t[3]}	@ load key material
+
+	add		@x[4],@t[0],@x[4],ror#24 @ accumulate key material
+	 add		@t[0],sp,#4*(8)
+	add		@x[5],@t[1],@x[5],ror#24
+	 add		@x[4],@x[4],#3		@ counter+3
+	add		@x[6],@t[2],@x[6],ror#24
+	add		@x[7],@t[3],@x[7],ror#24
+	 ldr		@t[3],[sp,#4*(32+2)]	@ re-load len
+# ifdef	__ARMEB__
+	rev		@x[0],@x[0]
+	rev		@x[1],@x[1]
+	rev		@x[2],@x[2]
+	rev		@x[3],@x[3]
+	rev		@x[4],@x[4]
+	rev		@x[5],@x[5]
+	rev		@x[6],@x[6]
+	rev		@x[7],@x[7]
+# endif
+	stmia		@t[0],{@x[0]-@x[7]}
+	 add		@t[2],sp,#4*(0)
+	 sub		@t[3],@t[3],#64*3	@ len-=64*3
+
+.Loop_tail_neon:
+	ldrb		@t[0],[@t[2]],#1	@ read buffer on stack
+	ldrb		@t[1],[r12],#1		@ read input
+	subs		@t[3],@t[3],#1
+	eor		@t[0],@t[0],@t[1]
+	strb		@t[0],[r14],#1		@ store output
+	bne		.Loop_tail_neon
+
+.Ldone_neon:
+	add		sp,sp,#4*(32+4)
+	vldmia		sp,{d8-d15}
+	add		sp,sp,#4*(16+3)
+	ldmia		sp!,{r4-r11,pc}
+.size	ChaCha20_neon,.-ChaCha20_neon
+# ifndef __KERNEL__
+.comm	OPENSSL_armcap_P,4,4
+# endif
+#endif
+___
+}}}
+
+open SELF,$0;
+while(<SELF>) {
+	next if (/^#!/);
+	last if (!s/^#/@/ and !/^$/);
+	print;
+}
+close SELF;
+
+foreach (split("\n",$code)) {
+	s/\`([^\`]*)\`/eval $1/geo;
+
+	s/\bq([0-9]+)#(lo|hi)/sprintf "d%d",2*$1+($2 eq "hi")/geo;
+
+	print $_,"\n";
+}
+close STDOUT;
-- 
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