#! /usr/bin/env perl

# Copyright 2011-2020 The OpenSSL Project Authors. All Rights Reserved.

#

# Licensed under the OpenSSL license (the "License").  You may not use

# this file except in compliance with the License.  You can obtain a copy

# in the file LICENSE in the source distribution or at

# https://www.openssl.org/source/license.html

#

# ====================================================================

# 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/.

# ====================================================================

#

# May 2011

#

# The module implements bn_GF2m_mul_2x2 polynomial multiplication used

# in bn_gf2m.c. It's kind of low-hanging mechanical port from C for

# the time being... gcc 4.3 appeared to generate poor code, therefore

# the effort. And indeed, the module delivers 55%-90%(*) improvement

# on heaviest ECDSA verify and ECDH benchmarks for 163- and 571-bit

# key lengths on z990, 30%-55%(*) - on z10, and 70%-110%(*) - on z196.

# This is for 64-bit build. In 32-bit "highgprs" case improvement is

# even higher, for example on z990 it was measured 80%-150%. ECDSA

# sign is modest 9%-12% faster. Keep in mind that these coefficients

# are not ones for bn_GF2m_mul_2x2 itself, as not all CPU time is

# burnt in it...

#

# (*)	gcc 4.1 was observed to deliver better results than gcc 4.3,

#	so that improvement coefficients can vary from one specific

#	setup to another.

$flavour = shift;

if ($flavour =~ /3[12]/) {

        $SIZE_T=4;

        $g="";

} else {

        $SIZE_T=8;

        $g="g";

}

while (($output=shift) && ($output!~/\w[\w\-]*\.\w+$/)) {}

open STDOUT,">$output";

$stdframe=16*$SIZE_T+4*8;

$rp="%r2";

$a1="%r3";

$a0="%r4";

$b1="%r5";

$b0="%r6";

$ra="%r14";

$sp="%r15";

@T=("%r0","%r1");

@i=("%r12","%r13");

($a1,$a2,$a4,$a8,$a12,$a48)=map("%r$_",(6..11));

($lo,$hi,$b)=map("%r$_",(3..5)); $a=$lo; $mask=$a8;

$code.=<<___;

.text

.type	_mul_1x1,\@function

.align	16

_mul_1x1:

	lgr	$a1,$a

	sllg	$a2,$a,1

	sllg	$a4,$a,2

	sllg	$a8,$a,3

	srag	$lo,$a1,63			# broadcast 63rd bit

	nihh	$a1,0x1fff

	srag	@i[0],$a2,63			# broadcast 62nd bit

	nihh	$a2,0x3fff

	srag	@i[1],$a4,63			# broadcast 61st bit

	nihh	$a4,0x7fff

	ngr	$lo,$b

	ngr	@i[0],$b

	ngr	@i[1],$b

	lghi	@T[0],0

	lgr	$a12,$a1

	stg	@T[0],`$stdframe+0*8`($sp)	# tab[0]=0

	xgr	$a12,$a2

	stg	$a1,`$stdframe+1*8`($sp)	# tab[1]=a1

	 lgr	$a48,$a4

	stg	$a2,`$stdframe+2*8`($sp)	# tab[2]=a2

	 xgr	$a48,$a8

	stg	$a12,`$stdframe+3*8`($sp)	# tab[3]=a1^a2

	 xgr	$a1,$a4

	stg	$a4,`$stdframe+4*8`($sp)	# tab[4]=a4

	xgr	$a2,$a4

	stg	$a1,`$stdframe+5*8`($sp)	# tab[5]=a1^a4

	xgr	$a12,$a4

	stg	$a2,`$stdframe+6*8`($sp)	# tab[6]=a2^a4

	 xgr	$a1,$a48

	stg	$a12,`$stdframe+7*8`($sp)	# tab[7]=a1^a2^a4

	 xgr	$a2,$a48

	stg	$a8,`$stdframe+8*8`($sp)	# tab[8]=a8

	xgr	$a12,$a48

	stg	$a1,`$stdframe+9*8`($sp)	# tab[9]=a1^a8

	 xgr	$a1,$a4

	stg	$a2,`$stdframe+10*8`($sp)	# tab[10]=a2^a8

	 xgr	$a2,$a4

	stg	$a12,`$stdframe+11*8`($sp)	# tab[11]=a1^a2^a8

	xgr	$a12,$a4

	stg	$a48,`$stdframe+12*8`($sp)	# tab[12]=a4^a8

	 srlg	$hi,$lo,1

	stg	$a1,`$stdframe+13*8`($sp)	# tab[13]=a1^a4^a8

	 sllg	$lo,$lo,63

	stg	$a2,`$stdframe+14*8`($sp)	# tab[14]=a2^a4^a8

	 srlg	@T[0],@i[0],2

	stg	$a12,`$stdframe+15*8`($sp)	# tab[15]=a1^a2^a4^a8

	lghi	$mask,`0xf<<3`

	sllg	$a1,@i[0],62

	 sllg	@i[0],$b,3

	srlg	@T[1],@i[1],3

	 ngr	@i[0],$mask

	sllg	$a2,@i[1],61

	 srlg	@i[1],$b,4-3

	xgr	$hi,@T[0]

	 ngr	@i[1],$mask

	xgr	$lo,$a1

	xgr	$hi,@T[1]

	xgr	$lo,$a2

	xg	$lo,$stdframe(@i[0],$sp)

	srlg	@i[0],$b,8-3

	ngr	@i[0],$mask

___

for($n=1;$n<14;$n++) {

$code.=<<___;

	lg	@T[1],$stdframe(@i[1],$sp)

	srlg	@i[1],$b,`($n+2)*4`-3

	sllg	@T[0],@T[1],`$n*4`

	ngr	@i[1],$mask

	srlg	@T[1],@T[1],`64-$n*4`

	xgr	$lo,@T[0]

	xgr	$hi,@T[1]

___

	push(@i,shift(@i)); push(@T,shift(@T));

}

$code.=<<___;

	lg	@T[1],$stdframe(@i[1],$sp)

	sllg	@T[0],@T[1],`$n*4`

	srlg	@T[1],@T[1],`64-$n*4`

	xgr	$lo,@T[0]

	xgr	$hi,@T[1]

	lg	@T[0],$stdframe(@i[0],$sp)

	sllg	@T[1],@T[0],`($n+1)*4`

	srlg	@T[0],@T[0],`64-($n+1)*4`

	xgr	$lo,@T[1]

	xgr	$hi,@T[0]

	br	$ra

.size	_mul_1x1,.-_mul_1x1

.globl	bn_GF2m_mul_2x2

.type	bn_GF2m_mul_2x2,\@function

.align	16

bn_GF2m_mul_2x2:

	stm${g}	%r3,%r15,3*$SIZE_T($sp)

	lghi	%r1,-$stdframe-128

	la	%r0,0($sp)

	la	$sp,0(%r1,$sp)			# alloca

	st${g}	%r0,0($sp)			# back chain

___

if ($SIZE_T==8) {

my @r=map("%r$_",(6..9));

$code.=<<___;

	bras	$ra,_mul_1x1			# a1·b1

	stmg	$lo,$hi,16($rp)

	lg	$a,`$stdframe+128+4*$SIZE_T`($sp)

	lg	$b,`$stdframe+128+6*$SIZE_T`($sp)

	bras	$ra,_mul_1x1			# a0·b0

	stmg	$lo,$hi,0($rp)

	lg	$a,`$stdframe+128+3*$SIZE_T`($sp)

	lg	$b,`$stdframe+128+5*$SIZE_T`($sp)

	xg	$a,`$stdframe+128+4*$SIZE_T`($sp)

	xg	$b,`$stdframe+128+6*$SIZE_T`($sp)

	bras	$ra,_mul_1x1			# (a0+a1)·(b0+b1)

	lmg	@r[0],@r[3],0($rp)

	xgr	$lo,$hi

	xgr	$hi,@r[1]

	xgr	$lo,@r[0]

	xgr	$hi,@r[2]

	xgr	$lo,@r[3]

	xgr	$hi,@r[3]

	xgr	$lo,$hi

	stg	$hi,16($rp)

	stg	$lo,8($rp)

___

} else {

$code.=<<___;

	sllg	%r3,%r3,32

	sllg	%r5,%r5,32

	or	%r3,%r4

	or	%r5,%r6

	bras	$ra,_mul_1x1

	rllg	$lo,$lo,32

	rllg	$hi,$hi,32

	stmg	$lo,$hi,0($rp)

___

}

$code.=<<___;

	lm${g}	%r6,%r15,`$stdframe+128+6*$SIZE_T`($sp)

	br	$ra

.size	bn_GF2m_mul_2x2,.-bn_GF2m_mul_2x2

.string	"GF(2^m) Multiplication for s390x, CRYPTOGAMS by <appro\@openssl.org>"

___

$code =~ s/\`([^\`]*)\`/eval($1)/gem;

print $code;

close STDOUT or die "error closing STDOUT: $!";