#!/usr/bin/env perl

# ====================================================================
# 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/.
# ====================================================================

# SHA256 block procedure for ARMv4. May 2007.

# Performance is ~2x better than gcc 3.4 generated code and in "abso-
# lute" terms is ~2250 cycles per 64-byte block or ~35 cycles per
# byte [on single-issue Xscale PXA250 core].

# July 2010.
#
# Rescheduling for dual-issue pipeline resulted in 22% improvement on
# Cortex A8 core and ~20 cycles per processed byte.

# February 2011.
#
# Profiler-assisted and platform-specific optimization resulted in 16%
# improvement on Cortex A8 core and ~15.4 cycles per processed byte.

# September 2013.
#
# Add NEON implementation. On Cortex A8 it was measured to process one
# byte in 12.5 cycles or 23% faster than integer-only code. Snapdragon
# S4 does it in 12.5 cycles too, but it's 50% faster than integer-only
# code (meaning that latter performs sub-optimally, nothing was done
# about it).

# May 2014.
#
# Add ARMv8 code path performing at 2.0 cpb on Apple A7.

while (($output=shift) && ($output!~/^\w[\w\-]*\.\w+$/)) {}
open STDOUT,">$output";

$ctx="r0";	$t0="r0";
$inp="r1";	$t4="r1";
$len="r2";	$t1="r2";
$T1="r3";	$t3="r3";
$A="r4";
$B="r5";
$C="r6";
$D="r7";
$E="r8";
$F="r9";
$G="r10";
$H="r11";
@V=($A,$B,$C,$D,$E,$F,$G,$H);
$t2="r12";
$Ktbl="r14";

@Sigma0=( 2,13,22);
@Sigma1=( 6,11,25);
@sigma0=( 7,18, 3);
@sigma1=(17,19,10);

sub BODY_00_15 {
my ($i,$a,$b,$c,$d,$e,$f,$g,$h) = @_;

$code.=<<___ if ($i<16);
#if __ARM_ARCH__>=7
	@ ldr	$t1,[$inp],#4			@ $i
# if $i==15
	str	$inp,[sp,#17*4]			@ make room for $t4
# endif
	eor	$t0,$e,$e,ror#`$Sigma1[1]-$Sigma1[0]`
	add	$a,$a,$t2			@ h+=Maj(a,b,c) from the past
	eor	$t0,$t0,$e,ror#`$Sigma1[2]-$Sigma1[0]`	@ Sigma1(e)
	rev	$t1,$t1
#else
	@ ldrb	$t1,[$inp,#3]			@ $i
	add	$a,$a,$t2			@ h+=Maj(a,b,c) from the past
	ldrb	$t2,[$inp,#2]
	ldrb	$t0,[$inp,#1]
	orr	$t1,$t1,$t2,lsl#8
	ldrb	$t2,[$inp],#4
	orr	$t1,$t1,$t0,lsl#16
# if $i==15
	str	$inp,[sp,#17*4]			@ make room for $t4
# endif
	eor	$t0,$e,$e,ror#`$Sigma1[1]-$Sigma1[0]`
	orr	$t1,$t1,$t2,lsl#24
	eor	$t0,$t0,$e,ror#`$Sigma1[2]-$Sigma1[0]`	@ Sigma1(e)
#endif
___
$code.=<<___;
	ldr	$t2,[$Ktbl],#4			@ *K256++
	add	$h,$h,$t1			@ h+=X[i]
	str	$t1,[sp,#`$i%16`*4]
	eor	$t1,$f,$g
	add	$h,$h,$t0,ror#$Sigma1[0]	@ h+=Sigma1(e)
	and	$t1,$t1,$e
	add	$h,$h,$t2			@ h+=K256[i]
	eor	$t1,$t1,$g			@ Ch(e,f,g)
	eor	$t0,$a,$a,ror#`$Sigma0[1]-$Sigma0[0]`
	add	$h,$h,$t1			@ h+=Ch(e,f,g)
#if $i==31
	and	$t2,$t2,#0xff
	cmp	$t2,#0xf2			@ done?
#endif
#if $i<15
# if __ARM_ARCH__>=7
	ldr	$t1,[$inp],#4			@ prefetch
# else
	ldrb	$t1,[$inp,#3]
# endif
	eor	$t2,$a,$b			@ a^b, b^c in next round
#else
	ldr	$t1,[sp,#`($i+2)%16`*4]		@ from future BODY_16_xx
	eor	$t2,$a,$b			@ a^b, b^c in next round
	ldr	$t4,[sp,#`($i+15)%16`*4]	@ from future BODY_16_xx
#endif
	eor	$t0,$t0,$a,ror#`$Sigma0[2]-$Sigma0[0]`	@ Sigma0(a)
	and	$t3,$t3,$t2			@ (b^c)&=(a^b)
	add	$d,$d,$h			@ d+=h
	eor	$t3,$t3,$b			@ Maj(a,b,c)
	add	$h,$h,$t0,ror#$Sigma0[0]	@ h+=Sigma0(a)
	@ add	$h,$h,$t3			@ h+=Maj(a,b,c)
___
	($t2,$t3)=($t3,$t2);
}

sub BODY_16_XX {
my ($i,$a,$b,$c,$d,$e,$f,$g,$h) = @_;

$code.=<<___;
	@ ldr	$t1,[sp,#`($i+1)%16`*4]		@ $i
	@ ldr	$t4,[sp,#`($i+14)%16`*4]
	mov	$t0,$t1,ror#$sigma0[0]
	add	$a,$a,$t2			@ h+=Maj(a,b,c) from the past
	mov	$t2,$t4,ror#$sigma1[0]
	eor	$t0,$t0,$t1,ror#$sigma0[1]
	eor	$t2,$t2,$t4,ror#$sigma1[1]
	eor	$t0,$t0,$t1,lsr#$sigma0[2]	@ sigma0(X[i+1])
	ldr	$t1,[sp,#`($i+0)%16`*4]
	eor	$t2,$t2,$t4,lsr#$sigma1[2]	@ sigma1(X[i+14])
	ldr	$t4,[sp,#`($i+9)%16`*4]

	add	$t2,$t2,$t0
	eor	$t0,$e,$e,ror#`$Sigma1[1]-$Sigma1[0]`	@ from BODY_00_15
	add	$t1,$t1,$t2
	eor	$t0,$t0,$e,ror#`$Sigma1[2]-$Sigma1[0]`	@ Sigma1(e)
	add	$t1,$t1,$t4			@ X[i]
___
	&BODY_00_15(@_);
}

$code=<<___;
#include "arm_arch.h"

.text
.code	32

.type	K256,%object
.align	5
K256:
.word	0x428a2f98,0x71374491,0xb5c0fbcf,0xe9b5dba5
.word	0x3956c25b,0x59f111f1,0x923f82a4,0xab1c5ed5
.word	0xd807aa98,0x12835b01,0x243185be,0x550c7dc3
.word	0x72be5d74,0x80deb1fe,0x9bdc06a7,0xc19bf174
.word	0xe49b69c1,0xefbe4786,0x0fc19dc6,0x240ca1cc
.word	0x2de92c6f,0x4a7484aa,0x5cb0a9dc,0x76f988da
.word	0x983e5152,0xa831c66d,0xb00327c8,0xbf597fc7
.word	0xc6e00bf3,0xd5a79147,0x06ca6351,0x14292967
.word	0x27b70a85,0x2e1b2138,0x4d2c6dfc,0x53380d13
.word	0x650a7354,0x766a0abb,0x81c2c92e,0x92722c85
.word	0xa2bfe8a1,0xa81a664b,0xc24b8b70,0xc76c51a3
.word	0xd192e819,0xd6990624,0xf40e3585,0x106aa070
.word	0x19a4c116,0x1e376c08,0x2748774c,0x34b0bcb5
.word	0x391c0cb3,0x4ed8aa4a,0x5b9cca4f,0x682e6ff3
.word	0x748f82ee,0x78a5636f,0x84c87814,0x8cc70208
.word	0x90befffa,0xa4506ceb,0xbef9a3f7,0xc67178f2
.size	K256,.-K256
.word	0				@ terminator
.LOPENSSL_armcap:
.word	OPENSSL_armcap_P-sha256_block_data_order
.align	5

.global	sha256_block_data_order
.type	sha256_block_data_order,%function
sha256_block_data_order:
	sub	r3,pc,#8		@ sha256_block_data_order
	add	$len,$inp,$len,lsl#6	@ len to point at the end of inp
#if __ARM_ARCH__>=7
	ldr	r12,.LOPENSSL_armcap
	ldr	r12,[r3,r12]		@ OPENSSL_armcap_P
	tst	r12,#ARMV8_SHA256
	bne	.LARMv8
	tst	r12,#ARMV7_NEON
	bne	.LNEON
#endif
	stmdb	sp!,{$ctx,$inp,$len,r4-r11,lr}
	ldmia	$ctx,{$A,$B,$C,$D,$E,$F,$G,$H}
	sub	$Ktbl,r3,#256+32	@ K256
	sub	sp,sp,#16*4		@ alloca(X[16])
.Loop:
# if __ARM_ARCH__>=7
	ldr	$t1,[$inp],#4
# else
	ldrb	$t1,[$inp,#3]
# endif
	eor	$t3,$B,$C		@ magic
	eor	$t2,$t2,$t2
___
for($i=0;$i<16;$i++)	{ &BODY_00_15($i,@V); unshift(@V,pop(@V)); }
$code.=".Lrounds_16_xx:\n";
for (;$i<32;$i++)	{ &BODY_16_XX($i,@V); unshift(@V,pop(@V)); }
$code.=<<___;
	ldreq	$t3,[sp,#16*4]		@ pull ctx
	bne	.Lrounds_16_xx

	add	$A,$A,$t2		@ h+=Maj(a,b,c) from the past
	ldr	$t0,[$t3,#0]
	ldr	$t1,[$t3,#4]
	ldr	$t2,[$t3,#8]
	add	$A,$A,$t0
	ldr	$t0,[$t3,#12]
	add	$B,$B,$t1
	ldr	$t1,[$t3,#16]
	add	$C,$C,$t2
	ldr	$t2,[$t3,#20]
	add	$D,$D,$t0
	ldr	$t0,[$t3,#24]
	add	$E,$E,$t1
	ldr	$t1,[$t3,#28]
	add	$F,$F,$t2
	ldr	$inp,[sp,#17*4]		@ pull inp
	ldr	$t2,[sp,#18*4]		@ pull inp+len
	add	$G,$G,$t0
	add	$H,$H,$t1
	stmia	$t3,{$A,$B,$C,$D,$E,$F,$G,$H}
	cmp	$inp,$t2
	sub	$Ktbl,$Ktbl,#256	@ rewind Ktbl
	bne	.Loop

	add	sp,sp,#`16+3`*4	@ destroy frame
#if __ARM_ARCH__>=5
	ldmia	sp!,{r4-r11,pc}
#else
	ldmia	sp!,{r4-r11,lr}
	tst	lr,#1
	moveq	pc,lr			@ be binary compatible with V4, yet
	bx	lr			@ interoperable with Thumb ISA:-)
#endif
.size	sha256_block_data_order,.-sha256_block_data_order
___
######################################################################
# NEON stuff
#
{{{
my @X=map("q$_",(0..3));
my ($T0,$T1,$T2,$T3,$T4,$T5)=("q8","q9","q10","q11","d24","d25");
my $Xfer=$t4;
my $j=0;

sub Dlo()   { shift=~m|q([1]?[0-9])|?"d".($1*2):"";     }
sub Dhi()   { shift=~m|q([1]?[0-9])|?"d".($1*2+1):"";   }

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";
}

sub Xupdate()
{ use integer;
  my $body = shift;
  my @insns = (&$body,&$body,&$body,&$body);
  my ($a,$b,$c,$d,$e,$f,$g,$h);

	&vext_8		($T0,@X[0],@X[1],4);	# X[1..4]
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vext_8		($T1,@X[2],@X[3],4);	# X[9..12]
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vshr_u32	($T2,$T0,$sigma0[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vadd_i32	(@X[0],@X[0],$T1);	# X[0..3] += X[9..12]
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vshr_u32	($T1,$T0,$sigma0[2]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vsli_32	($T2,$T0,32-$sigma0[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vshr_u32	($T3,$T0,$sigma0[1]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&veor		($T1,$T1,$T2);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vsli_32	($T3,$T0,32-$sigma0[1]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vshr_u32	($T4,&Dhi(@X[3]),$sigma1[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&veor		($T1,$T1,$T3);		# sigma0(X[1..4])
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vsli_32	($T4,&Dhi(@X[3]),32-$sigma1[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vshr_u32	($T5,&Dhi(@X[3]),$sigma1[2]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vadd_i32	(@X[0],@X[0],$T1);	# X[0..3] += sigma0(X[1..4])
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &veor		($T5,$T5,$T4);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vshr_u32	($T4,&Dhi(@X[3]),$sigma1[1]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vsli_32	($T4,&Dhi(@X[3]),32-$sigma1[1]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &veor		($T5,$T5,$T4);		# sigma1(X[14..15])
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vadd_i32	(&Dlo(@X[0]),&Dlo(@X[0]),$T5);# X[0..1] += sigma1(X[14..15])
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vshr_u32	($T4,&Dlo(@X[0]),$sigma1[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vsli_32	($T4,&Dlo(@X[0]),32-$sigma1[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vshr_u32	($T5,&Dlo(@X[0]),$sigma1[2]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &veor		($T5,$T5,$T4);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vshr_u32	($T4,&Dlo(@X[0]),$sigma1[1]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vld1_32	("{$T0}","[$Ktbl,:128]!");
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &vsli_32	($T4,&Dlo(@X[0]),32-$sigma1[1]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	  &veor		($T5,$T5,$T4);		# sigma1(X[16..17])
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vadd_i32	(&Dhi(@X[0]),&Dhi(@X[0]),$T5);# X[2..3] += sigma1(X[16..17])
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vadd_i32	($T0,$T0,@X[0]);
	 while($#insns>=2) { eval(shift(@insns)); }
	&vst1_32	("{$T0}","[$Xfer,:128]!");
	 eval(shift(@insns));
	 eval(shift(@insns));

	push(@X,shift(@X));		# "rotate" X[]
}

sub Xpreload()
{ use integer;
  my $body = shift;
  my @insns = (&$body,&$body,&$body,&$body);
  my ($a,$b,$c,$d,$e,$f,$g,$h);

	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vld1_32	("{$T0}","[$Ktbl,:128]!");
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vrev32_8	(@X[0],@X[0]);
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	 eval(shift(@insns));
	&vadd_i32	($T0,$T0,@X[0]);
	 foreach (@insns) { eval; }	# remaining instructions
	&vst1_32	("{$T0}","[$Xfer,:128]!");

	push(@X,shift(@X));		# "rotate" X[]
}

sub body_00_15 () {
	(
	'($a,$b,$c,$d,$e,$f,$g,$h)=@V;'.
	'&add	($h,$h,$t1)',			# h+=X[i]+K[i]
	'&eor	($t1,$f,$g)',
	'&eor	($t0,$e,$e,"ror#".($Sigma1[1]-$Sigma1[0]))',
	'&add	($a,$a,$t2)',			# h+=Maj(a,b,c) from the past
	'&and	($t1,$t1,$e)',
	'&eor	($t2,$t0,$e,"ror#".($Sigma1[2]-$Sigma1[0]))',	# Sigma1(e)
	'&eor	($t0,$a,$a,"ror#".($Sigma0[1]-$Sigma0[0]))',
	'&eor	($t1,$t1,$g)',			# Ch(e,f,g)
	'&add	($h,$h,$t2,"ror#$Sigma1[0]")',	# h+=Sigma1(e)
	'&eor	($t2,$a,$b)',			# a^b, b^c in next round
	'&eor	($t0,$t0,$a,"ror#".($Sigma0[2]-$Sigma0[0]))',	# Sigma0(a)
	'&add	($h,$h,$t1)',			# h+=Ch(e,f,g)
	'&ldr	($t1,sprintf "[sp,#%d]",4*(($j+1)&15))	if (($j&15)!=15);'.
	'&ldr	($t1,"[$Ktbl]")				if ($j==15);'.
	'&ldr	($t1,"[sp,#64]")			if ($j==31)',
	'&and	($t3,$t3,$t2)',			# (b^c)&=(a^b)
	'&add	($d,$d,$h)',			# d+=h
	'&add	($h,$h,$t0,"ror#$Sigma0[0]");'.	# h+=Sigma0(a)
	'&eor	($t3,$t3,$b)',			# Maj(a,b,c)
	'$j++;	unshift(@V,pop(@V)); ($t2,$t3)=($t3,$t2);'
	)
}

$code.=<<___;
#if __ARM_ARCH__>=7
.fpu	neon

.type	sha256_block_data_order_neon,%function
.align	4
sha256_block_data_order_neon:
.LNEON:
	stmdb	sp!,{r4-r12,lr}

	mov	$t2,sp
	sub	sp,sp,#16*4+16		@ alloca
	sub	$Ktbl,r3,#256+32	@ K256
	bic	sp,sp,#15		@ align for 128-bit stores

	vld1.8		{@X[0]},[$inp]!
	vld1.8		{@X[1]},[$inp]!
	vld1.8		{@X[2]},[$inp]!
	vld1.8		{@X[3]},[$inp]!
	vld1.32		{$T0},[$Ktbl,:128]!
	vld1.32		{$T1},[$Ktbl,:128]!
	vld1.32		{$T2},[$Ktbl,:128]!
	vld1.32		{$T3},[$Ktbl,:128]!
	vrev32.8	@X[0],@X[0]		@ yes, even on
	str		$ctx,[sp,#64]
	vrev32.8	@X[1],@X[1]		@ big-endian
	str		$inp,[sp,#68]
	mov		$Xfer,sp
	vrev32.8	@X[2],@X[2]
	str		$len,[sp,#72]
	vrev32.8	@X[3],@X[3]
	str		$t2,[sp,#76]		@ save original sp
	vadd.i32	$T0,$T0,@X[0]
	vadd.i32	$T1,$T1,@X[1]
	vst1.32		{$T0},[$Xfer,:128]!
	vadd.i32	$T2,$T2,@X[2]
	vst1.32		{$T1},[$Xfer,:128]!
	vadd.i32	$T3,$T3,@X[3]
	vst1.32		{$T2},[$Xfer,:128]!
	vst1.32		{$T3},[$Xfer,:128]!

	ldmia		$ctx,{$A-$H}
	sub		$Xfer,$Xfer,#64
	ldr		$t1,[sp,#0]
	eor		$t2,$t2,$t2
	eor		$t3,$B,$C
	b		.L_00_48

.align	4
.L_00_48:
___
	&Xupdate(\&body_00_15);
	&Xupdate(\&body_00_15);
	&Xupdate(\&body_00_15);
	&Xupdate(\&body_00_15);
$code.=<<___;
	teq	$t1,#0				@ check for K256 terminator
	ldr	$t1,[sp,#0]
	sub	$Xfer,$Xfer,#64
	bne	.L_00_48

	ldr		$inp,[sp,#68]
	ldr		$t0,[sp,#72]
	sub		$Ktbl,$Ktbl,#256	@ rewind $Ktbl
	teq		$inp,$t0
	subeq		$inp,$inp,#64		@ avoid SEGV
	vld1.8		{@X[0]},[$inp]!		@ load next input block
	vld1.8		{@X[1]},[$inp]!
	vld1.8		{@X[2]},[$inp]!
	vld1.8		{@X[3]},[$inp]!
	strne		$inp,[sp,#68]
	mov		$Xfer,sp
___
	&Xpreload(\&body_00_15);
	&Xpreload(\&body_00_15);
	&Xpreload(\&body_00_15);
	&Xpreload(\&body_00_15);
$code.=<<___;
	ldr	$t0,[$t1,#0]
	add	$A,$A,$t2			@ h+=Maj(a,b,c) from the past
	ldr	$t2,[$t1,#4]
	ldr	$t3,[$t1,#8]
	ldr	$t4,[$t1,#12]
	add	$A,$A,$t0			@ accumulate
	ldr	$t0,[$t1,#16]
	add	$B,$B,$t2
	ldr	$t2,[$t1,#20]
	add	$C,$C,$t3
	ldr	$t3,[$t1,#24]
	add	$D,$D,$t4
	ldr	$t4,[$t1,#28]
	add	$E,$E,$t0
	str	$A,[$t1],#4
	add	$F,$F,$t2
	str	$B,[$t1],#4
	add	$G,$G,$t3
	str	$C,[$t1],#4
	add	$H,$H,$t4
	str	$D,[$t1],#4
	stmia	$t1,{$E-$H}

	movne	$Xfer,sp
	ldrne	$t1,[sp,#0]
	eorne	$t2,$t2,$t2
	ldreq	sp,[sp,#76]			@ restore original sp
	eorne	$t3,$B,$C
	bne	.L_00_48

	ldmia	sp!,{r4-r12,pc}
.size	sha256_block_data_order_neon,.-sha256_block_data_order_neon
#endif
___
}}}
######################################################################
# ARMv8 stuff
#
{{{
my ($ABCD,$EFGH,$abcd)=map("q$_",(0..2));
my @MSG=map("q$_",(8..11));
my ($W0,$W1,$ABCD_SAVE,$EFGH_SAVE)=map("q$_",(12..15));
my $Ktbl="r3";

$code.=<<___;
#if __ARM_ARCH__>=7
.type	sha256_block_data_order_armv8,%function
.align	5
sha256_block_data_order_armv8:
.LARMv8:
	vld1.32	{$ABCD,$EFGH},[$ctx]
	sub	$Ktbl,r3,#sha256_block_data_order-K256

.Loop_v8:
	vld1.8		{@MSG[0]-@MSG[1]},[$inp]!
	vld1.8		{@MSG[2]-@MSG[3]},[$inp]!
	vld1.32		{$W0},[$Ktbl]!
	vrev32.8	@MSG[0],@MSG[0]
	vrev32.8	@MSG[1],@MSG[1]
	vrev32.8	@MSG[2],@MSG[2]
	vrev32.8	@MSG[3],@MSG[3]
	vmov		$ABCD_SAVE,$ABCD	@ offload
	vmov		$EFGH_SAVE,$EFGH
	teq		$inp,$len
___
for($i=0;$i<12;$i++) {
$code.=<<___;
	vld1.32		{$W1},[$Ktbl]!
	vadd.i32	$W0,$W0,@MSG[0]
	sha256su0	@MSG[0],@MSG[1]
	vmov		$abcd,$ABCD
	sha256h		$ABCD,$EFGH,$W0
	sha256h2	$EFGH,$abcd,$W0
	sha256su1	@MSG[0],@MSG[2],@MSG[3]
___
	($W0,$W1)=($W1,$W0);	push(@MSG,shift(@MSG));
}
$code.=<<___;
	vld1.32		{$W1},[$Ktbl]!
	vadd.i32	$W0,$W0,@MSG[0]
	vmov		$abcd,$ABCD
	sha256h		$ABCD,$EFGH,$W0
	sha256h2	$EFGH,$abcd,$W0

	vld1.32		{$W0},[$Ktbl]!
	vadd.i32	$W1,$W1,@MSG[1]
	vmov		$abcd,$ABCD
	sha256h		$ABCD,$EFGH,$W1
	sha256h2	$EFGH,$abcd,$W1

	vld1.32		{$W1},[$Ktbl]
	vadd.i32	$W0,$W0,@MSG[2]
	sub		$Ktbl,$Ktbl,#256-16	@ rewind
	vmov		$abcd,$ABCD
	sha256h		$ABCD,$EFGH,$W0
	sha256h2	$EFGH,$abcd,$W0

	vadd.i32	$W1,$W1,@MSG[3]
	vmov		$abcd,$ABCD
	sha256h		$ABCD,$EFGH,$W1
	sha256h2	$EFGH,$abcd,$W1

	vadd.i32	$ABCD,$ABCD,$ABCD_SAVE
	vadd.i32	$EFGH,$EFGH,$EFGH_SAVE
	bne		.Loop_v8

	vst1.32		{$ABCD,$EFGH},[$ctx]

	ret		@ bx lr
.size	sha256_block_data_order_armv8,.-sha256_block_data_order_armv8
#endif
___
}}}
$code.=<<___;
.asciz  "SHA256 block transform for ARMv4/NEON/ARMv8, CRYPTOGAMS by <appro\@openssl.org>"
.align	2
.comm   OPENSSL_armcap_P,4,4
___

{   my  %opcode = (
	"sha256h"	=> 0xf3000c40,	"sha256h2"	=> 0xf3100c40,
	"sha256su0"	=> 0xf3ba03c0,	"sha256su1"	=> 0xf3200c40	);

    sub unsha256 {
	my ($mnemonic,$arg)=@_;

	if ($arg =~ m/q([0-9]+)(?:,\s*q([0-9]+))?,\s*q([0-9]+)/o) {
	    my $word = $opcode{$mnemonic}|(($1&7)<<13)|(($1&8)<<19)
					 |(($2&7)<<17)|(($2&8)<<4)
					 |(($3&7)<<1) |(($3&8)<<2);
	    # since ARMv7 instructions are always encoded little-endian.
	    # correct solution is to use .inst directive, but older
	    # assemblers don't implement it:-(
	    sprintf ".byte\t0x%02x,0x%02x,0x%02x,0x%02x\t@ %s %s",
			$word&0xff,($word>>8)&0xff,
			($word>>16)&0xff,($word>>24)&0xff,
			$mnemonic,$arg;
	}
    }
}

foreach (split($/,$code)) {

	s/\`([^\`]*)\`/eval $1/geo;

	s/\b(sha256\w+)\s+(q.*)/unsha256($1,$2)/geo;

	s/\bret\b/bx	lr/go		or
	s/\bbx\s+lr\b/.word\t0xe12fff1e/go;	# make it possible to compile with -march=armv4

	print $_,"\n";
}

close STDOUT; # enforce flush