--- /dev/null
+#!/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/.
+# ====================================================================
+#
+# ECP_NISTZ256 module for ARMv8.
+#
+# February 2015.
+#
+# Original ECP_NISTZ256 submission targeting x86_64 is detailed in
+# http://eprint.iacr.org/2013/816.
+#
+# with/without -DECP_NISTZ256_ASM(*)
+# Apple A7 +140-590%
+# Cortex-A53 +135-720%
+# Cortex-A57 +145-570%
+# X-Gene +120-700%
+# Denver +150-740%
+#
+# (*) comparison is not really "fair", because it's compared to C
+# implementation, unlike other similar cases that is;
+#
+# Ranges denote minimum and maximum improvement coefficients depending
+# on benchmark. Lower coefficients are for ECDSA sign, server-side
+# operation. Keep in mind that +500% means 6x improvement.
+
+$flavour = shift;
+while (($output=shift) && ($output!~/^\w[\w\-]*\.\w+$/)) {}
+
+$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
+( $xlate="${dir}arm-xlate.pl" and -f $xlate ) or
+( $xlate="${dir}../../perlasm/arm-xlate.pl" and -f $xlate) or
+die "can't locate arm-xlate.pl";
+
+open OUT,"| \"$^X\" $xlate $flavour $output";
+*STDOUT=*OUT;
+
+{
+my ($rp,$ap,$bp,$bi,$a0,$a1,$a2,$a3,$t0,$t1,$t2,$t3,$poly1,$poly3,
+ $acc0,$acc1,$acc2,$acc3,$acc4,$acc5) =
+ map("x$_",(0..17,19,20));
+
+my ($acc6,$acc7)=($ap,$bp); # used in __ecp_nistz256_sqr_mont
+
+$code.=<<___;
+#include "arm_arch.h"
+
+.text
+___
+########################################################################
+# Convert ecp_nistz256_table.c to layout expected by ecp_nistz_gather_w7
+#
+$0 =~ m/(.*[\/\\])[^\/\\]+$/; $dir=$1;
+open TABLE,"<ecp_nistz256_table.c" or
+open TABLE,"<${dir}../ecp_nistz256_table.c" or
+die "failed to open ecp_nistz256_table.c:",$!;
+
+use integer;
+
+foreach(<TABLE>) {
+ s/TOBN\(\s*(0x[0-9a-f]+),\s*(0x[0-9a-f]+)\s*\)/push @arr,hex($2),hex($1)/geo;
+}
+close TABLE;
+
+# See ecp_nistz256_table.c for explanation for why it's 64*16*37.
+# 64*16*37-1 is because $#arr returns last valid index or @arr, not
+# amount of elements.
+die "insane number of elements" if ($#arr != 64*16*37-1);
+
+$code.=<<___;
+.globl ecp_nistz256_precomputed
+.type ecp_nistz256_precomputed,%object
+.align 12
+ecp_nistz256_precomputed:
+___
+########################################################################
+# this conversion smashes P256_POINT_AFFINE by individual bytes with
+# 64 byte interval, similar to
+# 1111222233334444
+# 1234123412341234
+for(1..37) {
+ @tbl = splice(@arr,0,64*16);
+ for($i=0;$i<64;$i++) {
+ undef @line;
+ for($j=0;$j<64;$j++) {
+ push @line,(@tbl[$j*16+$i/4]>>(($i%4)*8))&0xff;
+ }
+ $code.=".byte\t";
+ $code.=join(',',map { sprintf "0x%02x",$_} @line);
+ $code.="\n";
+ }
+}
+$code.=<<___;
+.size ecp_nistz256_precomputed,.-ecp_nistz256_precomputed
+.align 5
+.Lpoly:
+.quad 0xffffffffffffffff,0x00000000ffffffff,0x0000000000000000,0xffffffff00000001
+.LRR: // 2^512 mod P precomputed for NIST P256 polynomial
+.quad 0x0000000000000003,0xfffffffbffffffff,0xfffffffffffffffe,0x00000004fffffffd
+.Lone_mont:
+.quad 0x0000000000000001,0xffffffff00000000,0xffffffffffffffff,0x00000000fffffffe
+.Lone:
+.quad 1,0,0,0
+.asciz "ECP_NISTZ256 for ARMv8, CRYPTOGAMS by <appro\@openssl.org>"
+
+// void ecp_nistz256_to_mont(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_to_mont
+.type ecp_nistz256_to_mont,%function
+.align 6
+ecp_nistz256_to_mont:
+ stp x29,x30,[sp,#-32]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+
+ ldr $bi,.LRR // bp[0]
+ ldp $a0,$a1,[$ap]
+ ldp $a2,$a3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+ adr $bp,.LRR // &bp[0]
+
+ bl __ecp_nistz256_mul_mont
+
+ ldp x19,x20,[sp,#16]
+ ldp x29,x30,[sp],#32
+ ret
+.size ecp_nistz256_to_mont,.-ecp_nistz256_to_mont
+
+// void ecp_nistz256_from_mont(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_from_mont
+.type ecp_nistz256_from_mont,%function
+.align 4
+ecp_nistz256_from_mont:
+ stp x29,x30,[sp,#-32]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+
+ mov $bi,#1 // bp[0]
+ ldp $a0,$a1,[$ap]
+ ldp $a2,$a3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+ adr $bp,.Lone // &bp[0]
+
+ bl __ecp_nistz256_mul_mont
+
+ ldp x19,x20,[sp,#16]
+ ldp x29,x30,[sp],#32
+ ret
+.size ecp_nistz256_from_mont,.-ecp_nistz256_from_mont
+
+// void ecp_nistz256_mul_mont(BN_ULONG x0[4],const BN_ULONG x1[4],
+// const BN_ULONG x2[4]);
+.globl ecp_nistz256_mul_mont
+.type ecp_nistz256_mul_mont,%function
+.align 4
+ecp_nistz256_mul_mont:
+ stp x29,x30,[sp,#-32]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+
+ ldr $bi,[$bp] // bp[0]
+ ldp $a0,$a1,[$ap]
+ ldp $a2,$a3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ bl __ecp_nistz256_mul_mont
+
+ ldp x19,x20,[sp,#16]
+ ldp x29,x30,[sp],#32
+ ret
+.size ecp_nistz256_mul_mont,.-ecp_nistz256_mul_mont
+
+// void ecp_nistz256_sqr_mont(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_sqr_mont
+.type ecp_nistz256_sqr_mont,%function
+.align 4
+ecp_nistz256_sqr_mont:
+ stp x29,x30,[sp,#-32]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+
+ ldp $a0,$a1,[$ap]
+ ldp $a2,$a3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ bl __ecp_nistz256_sqr_mont
+
+ ldp x19,x20,[sp,#16]
+ ldp x29,x30,[sp],#32
+ ret
+.size ecp_nistz256_sqr_mont,.-ecp_nistz256_sqr_mont
+
+// void ecp_nistz256_add(BN_ULONG x0[4],const BN_ULONG x1[4],
+// const BN_ULONG x2[4]);
+.globl ecp_nistz256_add
+.type ecp_nistz256_add,%function
+.align 4
+ecp_nistz256_add:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ ldp $acc0,$acc1,[$ap]
+ ldp $t0,$t1,[$bp]
+ ldp $acc2,$acc3,[$ap,#16]
+ ldp $t2,$t3,[$bp,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ bl __ecp_nistz256_add
+
+ ldp x29,x30,[sp],#16
+ ret
+.size ecp_nistz256_add,.-ecp_nistz256_add
+
+// void ecp_nistz256_div_by_2(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_div_by_2
+.type ecp_nistz256_div_by_2,%function
+.align 4
+ecp_nistz256_div_by_2:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ ldp $acc0,$acc1,[$ap]
+ ldp $acc2,$acc3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ bl __ecp_nistz256_div_by_2
+
+ ldp x29,x30,[sp],#16
+ ret
+.size ecp_nistz256_div_by_2,.-ecp_nistz256_div_by_2
+
+// void ecp_nistz256_mul_by_2(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_mul_by_2
+.type ecp_nistz256_mul_by_2,%function
+.align 4
+ecp_nistz256_mul_by_2:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ ldp $acc0,$acc1,[$ap]
+ ldp $acc2,$acc3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+ mov $t0,$acc0
+ mov $t1,$acc1
+ mov $t2,$acc2
+ mov $t3,$acc3
+
+ bl __ecp_nistz256_add // ret = a+a // 2*a
+
+ ldp x29,x30,[sp],#16
+ ret
+.size ecp_nistz256_mul_by_2,.-ecp_nistz256_mul_by_2
+
+// void ecp_nistz256_mul_by_3(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_mul_by_3
+.type ecp_nistz256_mul_by_3,%function
+.align 4
+ecp_nistz256_mul_by_3:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ ldp $acc0,$acc1,[$ap]
+ ldp $acc2,$acc3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+ mov $t0,$acc0
+ mov $t1,$acc1
+ mov $t2,$acc2
+ mov $t3,$acc3
+ mov $a0,$acc0
+ mov $a1,$acc1
+ mov $a2,$acc2
+ mov $a3,$acc3
+
+ bl __ecp_nistz256_add // ret = a+a // 2*a
+
+ mov $t0,$a0
+ mov $t1,$a1
+ mov $t2,$a2
+ mov $t3,$a3
+
+ bl __ecp_nistz256_add // ret += a // 2*a+a=3*a
+
+ ldp x29,x30,[sp],#16
+ ret
+.size ecp_nistz256_mul_by_3,.-ecp_nistz256_mul_by_3
+
+// void ecp_nistz256_sub(BN_ULONG x0[4],const BN_ULONG x1[4],
+// const BN_ULONG x2[4]);
+.globl ecp_nistz256_sub
+.type ecp_nistz256_sub,%function
+.align 4
+ecp_nistz256_sub:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ ldp $acc0,$acc1,[$ap]
+ ldp $acc2,$acc3,[$ap,#16]
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ bl __ecp_nistz256_sub_from
+
+ ldp x29,x30,[sp],#16
+ ret
+.size ecp_nistz256_sub,.-ecp_nistz256_sub
+
+// void ecp_nistz256_neg(BN_ULONG x0[4],const BN_ULONG x1[4]);
+.globl ecp_nistz256_neg
+.type ecp_nistz256_neg,%function
+.align 4
+ecp_nistz256_neg:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ mov $bp,$ap
+ mov $acc0,xzr // a = 0
+ mov $acc1,xzr
+ mov $acc2,xzr
+ mov $acc3,xzr
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ bl __ecp_nistz256_sub_from
+
+ ldp x29,x30,[sp],#16
+ ret
+.size ecp_nistz256_neg,.-ecp_nistz256_neg
+
+// note that __ecp_nistz256_mul_mont expects a[0-3] input pre-loaded
+// to $a0-$a3 and b[0] - to $bi
+.type __ecp_nistz256_mul_mont,%function
+.align 4
+__ecp_nistz256_mul_mont:
+ mul $acc0,$a0,$bi // a[0]*b[0]
+ umulh $t0,$a0,$bi
+
+ mul $acc1,$a1,$bi // a[1]*b[0]
+ umulh $t1,$a1,$bi
+
+ mul $acc2,$a2,$bi // a[2]*b[0]
+ umulh $t2,$a2,$bi
+
+ mul $acc3,$a3,$bi // a[3]*b[0]
+ umulh $t3,$a3,$bi
+ ldr $bi,[$bp,#8] // b[1]
+
+ adds $acc1,$acc1,$t0 // accumulate high parts of multiplication
+ lsl $t0,$acc0,#32
+ adcs $acc2,$acc2,$t1
+ lsr $t1,$acc0,#32
+ adcs $acc3,$acc3,$t2
+ adc $acc4,xzr,$t3
+ mov $acc5,xzr
+___
+for($i=1;$i<4;$i++) {
+ # Reduction iteration is normally performed by accumulating
+ # result of multiplication of modulus by "magic" digit [and
+ # omitting least significant word, which is guaranteed to
+ # be 0], but thanks to special form of modulus and "magic"
+ # digit being equal to least significant word, it can be
+ # performed with additions and subtractions alone. Indeed:
+ #
+ # ffff0001.00000000.0000ffff.ffffffff
+ # * abcdefgh
+ # + xxxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx.abcdefgh
+ #
+ # Now observing that ff..ff*x = (2^n-1)*x = 2^n*x-x, we
+ # rewrite above as:
+ #
+ # xxxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx.abcdefgh
+ # + abcdefgh.abcdefgh.0000abcd.efgh0000.00000000
+ # - 0000abcd.efgh0000.00000000.00000000.abcdefgh
+ #
+ # or marking redundant operations:
+ #
+ # xxxxxxxx.xxxxxxxx.xxxxxxxx.xxxxxxxx.--------
+ # + abcdefgh.abcdefgh.0000abcd.efgh0000.--------
+ # - 0000abcd.efgh0000.--------.--------.--------
+
+$code.=<<___;
+ subs $t2,$acc0,$t0 // "*0xffff0001"
+ sbc $t3,$acc0,$t1
+ adds $acc0,$acc1,$t0 // +=acc[0]<<96 and omit acc[0]
+ mul $t0,$a0,$bi // lo(a[0]*b[i])
+ adcs $acc1,$acc2,$t1
+ mul $t1,$a1,$bi // lo(a[1]*b[i])
+ adcs $acc2,$acc3,$t2 // +=acc[0]*0xffff0001
+ mul $t2,$a2,$bi // lo(a[2]*b[i])
+ adcs $acc3,$acc4,$t3
+ mul $t3,$a3,$bi // lo(a[3]*b[i])
+ adc $acc4,$acc5,xzr
+
+ adds $acc0,$acc0,$t0 // accumulate low parts of multiplication
+ umulh $t0,$a0,$bi // hi(a[0]*b[i])
+ adcs $acc1,$acc1,$t1
+ umulh $t1,$a1,$bi // hi(a[1]*b[i])
+ adcs $acc2,$acc2,$t2
+ umulh $t2,$a2,$bi // hi(a[2]*b[i])
+ adcs $acc3,$acc3,$t3
+ umulh $t3,$a3,$bi // hi(a[3]*b[i])
+ adc $acc4,$acc4,xzr
+___
+$code.=<<___ if ($i<3);
+ ldr $bi,[$bp,#8*($i+1)] // b[$i+1]
+___
+$code.=<<___;
+ adds $acc1,$acc1,$t0 // accumulate high parts of multiplication
+ lsl $t0,$acc0,#32
+ adcs $acc2,$acc2,$t1
+ lsr $t1,$acc0,#32
+ adcs $acc3,$acc3,$t2
+ adcs $acc4,$acc4,$t3
+ adc $acc5,xzr,xzr
+___
+}
+$code.=<<___;
+ // last reduction
+ subs $t2,$acc0,$t0 // "*0xffff0001"
+ sbc $t3,$acc0,$t1
+ adds $acc0,$acc1,$t0 // +=acc[0]<<96 and omit acc[0]
+ adcs $acc1,$acc2,$t1
+ adcs $acc2,$acc3,$t2 // +=acc[0]*0xffff0001
+ adcs $acc3,$acc4,$t3
+ adc $acc4,$acc5,xzr
+
+ adds $t0,$acc0,#1 // subs $t0,$acc0,#-1 // tmp = ret-modulus
+ sbcs $t1,$acc1,$poly1
+ sbcs $t2,$acc2,xzr
+ sbcs $t3,$acc3,$poly3
+ sbcs xzr,$acc4,xzr // did it borrow?
+
+ csel $acc0,$acc0,$t0,lo // ret = borrow ? ret : ret-modulus
+ csel $acc1,$acc1,$t1,lo
+ csel $acc2,$acc2,$t2,lo
+ stp $acc0,$acc1,[$rp]
+ csel $acc3,$acc3,$t3,lo
+ stp $acc2,$acc3,[$rp,#16]
+
+ ret
+.size __ecp_nistz256_mul_mont,.-__ecp_nistz256_mul_mont
+
+// note that __ecp_nistz256_sqr_mont expects a[0-3] input pre-loaded
+// to $a0-$a3
+.type __ecp_nistz256_sqr_mont,%function
+.align 4
+__ecp_nistz256_sqr_mont:
+ // | | | | | |a1*a0| |
+ // | | | | |a2*a0| | |
+ // | |a3*a2|a3*a0| | | |
+ // | | | |a2*a1| | | |
+ // | | |a3*a1| | | | |
+ // *| | | | | | | | 2|
+ // +|a3*a3|a2*a2|a1*a1|a0*a0|
+ // |--+--+--+--+--+--+--+--|
+ // |A7|A6|A5|A4|A3|A2|A1|A0|, where Ax is $accx, i.e. follow $accx
+ //
+ // "can't overflow" below mark carrying into high part of
+ // multiplication result, which can't overflow, because it
+ // can never be all ones.
+
+ mul $acc1,$a1,$a0 // a[1]*a[0]
+ umulh $t1,$a1,$a0
+ mul $acc2,$a2,$a0 // a[2]*a[0]
+ umulh $t2,$a2,$a0
+ mul $acc3,$a3,$a0 // a[3]*a[0]
+ umulh $acc4,$a3,$a0
+
+ adds $acc2,$acc2,$t1 // accumulate high parts of multiplication
+ mul $t0,$a2,$a1 // a[2]*a[1]
+ umulh $t1,$a2,$a1
+ adcs $acc3,$acc3,$t2
+ mul $t2,$a3,$a1 // a[3]*a[1]
+ umulh $t3,$a3,$a1
+ adc $acc4,$acc4,xzr // can't overflow
+
+ mul $acc5,$a3,$a2 // a[3]*a[2]
+ umulh $acc6,$a3,$a2
+
+ adds $t1,$t1,$t2 // accumulate high parts of multiplication
+ mul $acc0,$a0,$a0 // a[0]*a[0]
+ adc $t2,$t3,xzr // can't overflow
+
+ adds $acc3,$acc3,$t0 // accumulate low parts of multiplication
+ umulh $a0,$a0,$a0
+ adcs $acc4,$acc4,$t1
+ mul $t1,$a1,$a1 // a[1]*a[1]
+ adcs $acc5,$acc5,$t2
+ umulh $a1,$a1,$a1
+ adc $acc6,$acc6,xzr // can't overflow
+
+ adds $acc1,$acc1,$acc1 // acc[1-6]*=2
+ mul $t2,$a2,$a2 // a[2]*a[2]
+ adcs $acc2,$acc2,$acc2
+ umulh $a2,$a2,$a2
+ adcs $acc3,$acc3,$acc3
+ mul $t3,$a3,$a3 // a[3]*a[3]
+ adcs $acc4,$acc4,$acc4
+ umulh $a3,$a3,$a3
+ adcs $acc5,$acc5,$acc5
+ adcs $acc6,$acc6,$acc6
+ adc $acc7,xzr,xzr
+
+ adds $acc1,$acc1,$a0 // +a[i]*a[i]
+ adcs $acc2,$acc2,$t1
+ adcs $acc3,$acc3,$a1
+ adcs $acc4,$acc4,$t2
+ adcs $acc5,$acc5,$a2
+ lsl $t0,$acc0,#32
+ adcs $acc6,$acc6,$t3
+ lsr $t1,$acc0,#32
+ adc $acc7,$acc7,$a3
+___
+for($i=0;$i<3;$i++) { # reductions, see commentary in
+ # multiplication for details
+$code.=<<___;
+ subs $t2,$acc0,$t0 // "*0xffff0001"
+ sbc $t3,$acc0,$t1
+ adds $acc0,$acc1,$t0 // +=acc[0]<<96 and omit acc[0]
+ adcs $acc1,$acc2,$t1
+ lsl $t0,$acc0,#32
+ adcs $acc2,$acc3,$t2 // +=acc[0]*0xffff0001
+ lsr $t1,$acc0,#32
+ adc $acc3,$t3,xzr // can't overflow
+___
+}
+$code.=<<___;
+ subs $t2,$acc0,$t0 // "*0xffff0001"
+ sbc $t3,$acc0,$t1
+ adds $acc0,$acc1,$t0 // +=acc[0]<<96 and omit acc[0]
+ adcs $acc1,$acc2,$t1
+ adcs $acc2,$acc3,$t2 // +=acc[0]*0xffff0001
+ adc $acc3,$t3,xzr // can't overflow
+
+ adds $acc0,$acc0,$acc4 // accumulate upper half
+ adcs $acc1,$acc1,$acc5
+ adcs $acc2,$acc2,$acc6
+ adcs $acc3,$acc3,$acc7
+ adc $acc4,xzr,xzr
+
+ adds $t0,$acc0,#1 // subs $t0,$acc0,#-1 // tmp = ret-modulus
+ sbcs $t1,$acc1,$poly1
+ sbcs $t2,$acc2,xzr
+ sbcs $t3,$acc3,$poly3
+ sbcs xzr,$acc4,xzr // did it borrow?
+
+ csel $acc0,$acc0,$t0,lo // ret = borrow ? ret : ret-modulus
+ csel $acc1,$acc1,$t1,lo
+ csel $acc2,$acc2,$t2,lo
+ stp $acc0,$acc1,[$rp]
+ csel $acc3,$acc3,$t3,lo
+ stp $acc2,$acc3,[$rp,#16]
+
+ ret
+.size __ecp_nistz256_sqr_mont,.-__ecp_nistz256_sqr_mont
+
+// Note that __ecp_nistz256_add expects both input vectors pre-loaded to
+// $a0-$a3 and $t0-$t3. This is done because it's used in multiple
+// contexts, e.g. in multiplication by 2 and 3...
+.type __ecp_nistz256_add,%function
+.align 4
+__ecp_nistz256_add:
+ adds $acc0,$acc0,$t0 // ret = a+b
+ adcs $acc1,$acc1,$t1
+ adcs $acc2,$acc2,$t2
+ adcs $acc3,$acc3,$t3
+ adc $ap,xzr,xzr // zap $ap
+
+ adds $t0,$acc0,#1 // subs $t0,$a0,#-1 // tmp = ret-modulus
+ sbcs $t1,$acc1,$poly1
+ sbcs $t2,$acc2,xzr
+ sbc $t3,$acc3,$poly3
+ cmp $ap,xzr // did addition carry?
+
+ csel $acc0,$acc0,$t0,eq // ret = carry ? ret-modulus : ret
+ csel $acc1,$acc1,$t1,eq
+ csel $acc2,$acc2,$t2,eq
+ stp $acc0,$acc1,[$rp]
+ csel $acc3,$acc3,$t3,eq
+ stp $acc2,$acc3,[$rp,#16]
+
+ ret
+.size __ecp_nistz256_add,.-__ecp_nistz256_add
+
+.type __ecp_nistz256_sub_from,%function
+.align 4
+__ecp_nistz256_sub_from:
+ ldp $t0,$t1,[$bp]
+ ldp $t2,$t3,[$bp,#16]
+ subs $acc0,$acc0,$t0 // ret = a-b
+ sbcs $acc1,$acc1,$t1
+ sbcs $acc2,$acc2,$t2
+ sbcs $acc3,$acc3,$t3
+ sbc $ap,xzr,xzr // zap $ap
+
+ subs $t0,$acc0,#1 // adds $t0,$a0,#-1 // tmp = ret+modulus
+ adcs $t1,$acc1,$poly1
+ adcs $t2,$acc2,xzr
+ adc $t3,$acc3,$poly3
+ cmp $ap,xzr // did subtraction borrow?
+
+ csel $acc0,$acc0,$t0,eq // ret = borrow ? ret+modulus : ret
+ csel $acc1,$acc1,$t1,eq
+ csel $acc2,$acc2,$t2,eq
+ stp $acc0,$acc1,[$rp]
+ csel $acc3,$acc3,$t3,eq
+ stp $acc2,$acc3,[$rp,#16]
+
+ ret
+.size __ecp_nistz256_sub_from,.-__ecp_nistz256_sub_from
+
+.type __ecp_nistz256_sub_morf,%function
+.align 4
+__ecp_nistz256_sub_morf:
+ ldp $t0,$t1,[$bp]
+ ldp $t2,$t3,[$bp,#16]
+ subs $acc0,$t0,$acc0 // ret = b-a
+ sbcs $acc1,$t1,$acc1
+ sbcs $acc2,$t2,$acc2
+ sbcs $acc3,$t3,$acc3
+ sbc $ap,xzr,xzr // zap $ap
+
+ subs $t0,$acc0,#1 // adds $t0,$a0,#-1 // tmp = ret+modulus
+ adcs $t1,$acc1,$poly1
+ adcs $t2,$acc2,xzr
+ adc $t3,$acc3,$poly3
+ cmp $ap,xzr // did subtraction borrow?
+
+ csel $acc0,$acc0,$t0,eq // ret = borrow ? ret+modulus : ret
+ csel $acc1,$acc1,$t1,eq
+ csel $acc2,$acc2,$t2,eq
+ stp $acc0,$acc1,[$rp]
+ csel $acc3,$acc3,$t3,eq
+ stp $acc2,$acc3,[$rp,#16]
+
+ ret
+.size __ecp_nistz256_sub_morf,.-__ecp_nistz256_sub_morf
+
+.type __ecp_nistz256_div_by_2,%function
+.align 4
+__ecp_nistz256_div_by_2:
+ subs $t0,$acc0,#1 // adds $t0,$a0,#-1 // tmp = a+modulus
+ adcs $t1,$acc1,$poly1
+ adcs $t2,$acc2,xzr
+ adcs $t3,$acc3,$poly3
+ adc $ap,xzr,xzr // zap $ap
+ tst $acc0,#1 // is a even?
+
+ csel $acc0,$acc0,$t0,eq // ret = even ? a : a+modulus
+ csel $acc1,$acc1,$t1,eq
+ csel $acc2,$acc2,$t2,eq
+ csel $acc3,$acc3,$t3,eq
+ csel $ap,xzr,$ap,eq
+
+ lsr $acc0,$acc0,#1 // ret >>= 1
+ orr $acc0,$acc0,$acc1,lsl#63
+ lsr $acc1,$acc1,#1
+ orr $acc1,$acc1,$acc2,lsl#63
+ lsr $acc2,$acc2,#1
+ orr $acc2,$acc2,$acc3,lsl#63
+ lsr $acc3,$acc3,#1
+ stp $acc0,$acc1,[$rp]
+ orr $acc3,$acc3,$ap,lsl#63
+ stp $acc2,$acc3,[$rp,#16]
+
+ ret
+.size __ecp_nistz256_div_by_2,.-__ecp_nistz256_div_by_2
+___
+########################################################################
+# following subroutines are "literal" implemetation of those found in
+# ecp_nistz256.c
+#
+########################################################################
+# void ecp_nistz256_point_double(P256_POINT *out,const P256_POINT *inp);
+#
+{
+my ($S,$M,$Zsqr,$tmp0)=map(32*$_,(0..3));
+# above map() describes stack layout with 4 temporary
+# 256-bit vectors on top.
+my ($rp_real,$ap_real) = map("x$_",(21,22));
+
+$code.=<<___;
+.globl ecp_nistz256_point_double
+.type ecp_nistz256_point_double,%function
+.align 5
+ecp_nistz256_point_double:
+ stp x29,x30,[sp,#-48]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+ stp x21,x22,[sp,#32]
+ sub sp,sp,#32*4
+
+ ldp $acc0,$acc1,[$ap,#32]
+ mov $rp_real,$rp
+ ldp $acc2,$acc3,[$ap,#48]
+ mov $ap_real,$ap
+ ldr $poly1,.Lpoly+8
+ mov $t0,$acc0
+ ldr $poly3,.Lpoly+24
+ mov $t1,$acc1
+ ldp $a0,$a1,[$ap_real,#64] // forward load for p256_sqr_mont
+ mov $t2,$acc2
+ mov $t3,$acc3
+ ldp $a2,$a3,[$ap_real,#64+16]
+ add $rp,sp,#$S
+ bl __ecp_nistz256_add // p256_mul_by_2(S, in_y);
+
+ add $rp,sp,#$Zsqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Zsqr, in_z);
+
+ ldp $t0,$t1,[$ap_real]
+ ldp $t2,$t3,[$ap_real,#16]
+ mov $a0,$acc0 // put Zsqr aside for p256_sub
+ mov $a1,$acc1
+ mov $a2,$acc2
+ mov $a3,$acc3
+ add $rp,sp,#$M
+ bl __ecp_nistz256_add // p256_add(M, Zsqr, in_x);
+
+ add $bp,$ap_real,#0
+ mov $acc0,$a0 // restore Zsqr
+ mov $acc1,$a1
+ ldp $a0,$a1,[sp,#$S] // forward load for p256_sqr_mont
+ mov $acc2,$a2
+ mov $acc3,$a3
+ ldp $a2,$a3,[sp,#$S+16]
+ add $rp,sp,#$Zsqr
+ bl __ecp_nistz256_sub_morf // p256_sub(Zsqr, in_x, Zsqr);
+
+ add $rp,sp,#$S
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(S, S);
+
+ ldr $bi,[$ap_real,#32]
+ ldp $a0,$a1,[$ap_real,#64]
+ ldp $a2,$a3,[$ap_real,#64+16]
+ add $bp,$ap_real,#32
+ add $rp,sp,#$tmp0
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(tmp0, in_z, in_y);
+
+ mov $t0,$acc0
+ mov $t1,$acc1
+ ldp $a0,$a1,[sp,#$S] // forward load for p256_sqr_mont
+ mov $t2,$acc2
+ mov $t3,$acc3
+ ldp $a2,$a3,[sp,#$S+16]
+ add $rp,$rp_real,#64
+ bl __ecp_nistz256_add // p256_mul_by_2(res_z, tmp0);
+
+ add $rp,sp,#$tmp0
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(tmp0, S);
+
+ ldr $bi,[sp,#$Zsqr] // forward load for p256_mul_mont
+ ldp $a0,$a1,[sp,#$M]
+ ldp $a2,$a3,[sp,#$M+16]
+ add $rp,$rp_real,#32
+ bl __ecp_nistz256_div_by_2 // p256_div_by_2(res_y, tmp0);
+
+ add $bp,sp,#$Zsqr
+ add $rp,sp,#$M
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(M, M, Zsqr);
+
+ mov $t0,$acc0 // duplicate M
+ mov $t1,$acc1
+ mov $t2,$acc2
+ mov $t3,$acc3
+ mov $a0,$acc0 // put M aside
+ mov $a1,$acc1
+ mov $a2,$acc2
+ mov $a3,$acc3
+ add $rp,sp,#$M
+ bl __ecp_nistz256_add
+ mov $t0,$a0 // restore M
+ mov $t1,$a1
+ ldr $bi,[$ap_real] // forward load for p256_mul_mont
+ mov $t2,$a2
+ ldp $a0,$a1,[sp,#$S]
+ mov $t3,$a3
+ ldp $a2,$a3,[sp,#$S+16]
+ bl __ecp_nistz256_add // p256_mul_by_3(M, M);
+
+ add $bp,$ap_real,#0
+ add $rp,sp,#$S
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S, S, in_x);
+
+ mov $t0,$acc0
+ mov $t1,$acc1
+ ldp $a0,$a1,[sp,#$M] // forward load for p256_sqr_mont
+ mov $t2,$acc2
+ mov $t3,$acc3
+ ldp $a2,$a3,[sp,#$M+16]
+ add $rp,sp,#$tmp0
+ bl __ecp_nistz256_add // p256_mul_by_2(tmp0, S);
+
+ add $rp,$rp_real,#0
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(res_x, M);
+
+ add $bp,sp,#$tmp0
+ bl __ecp_nistz256_sub_from // p256_sub(res_x, res_x, tmp0);
+
+ add $bp,sp,#$S
+ add $rp,sp,#$S
+ bl __ecp_nistz256_sub_morf // p256_sub(S, S, res_x);
+
+ ldr $bi,[sp,#$M]
+ mov $a0,$acc0 // copy S
+ mov $a1,$acc1
+ mov $a2,$acc2
+ mov $a3,$acc3
+ add $bp,sp,#$M
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S, S, M);
+
+ add $bp,$rp_real,#32
+ add $rp,$rp_real,#32
+ bl __ecp_nistz256_sub_from // p256_sub(res_y, S, res_y);
+
+ add sp,x29,#0 // destroy frame
+ ldp x19,x20,[x29,#16]
+ ldp x21,x22,[x29,#32]
+ ldp x29,x30,[sp],#48
+ ret
+.size ecp_nistz256_point_double,.-ecp_nistz256_point_double
+___
+}
+
+########################################################################
+# void ecp_nistz256_point_add(P256_POINT *out,const P256_POINT *in1,
+# const P256_POINT *in2);
+{
+my ($res_x,$res_y,$res_z,
+ $H,$Hsqr,$R,$Rsqr,$Hcub,
+ $U1,$U2,$S1,$S2)=map(32*$_,(0..11));
+my ($Z1sqr, $Z2sqr) = ($Hsqr, $Rsqr);
+# above map() describes stack layout with 12 temporary
+# 256-bit vectors on top.
+my ($rp_real,$ap_real,$bp_real,$in1infty,$in2infty,$temp)=map("x$_",(21..26));
+
+$code.=<<___;
+.globl ecp_nistz256_point_add
+.type ecp_nistz256_point_add,%function
+.align 5
+ecp_nistz256_point_add:
+ stp x29,x30,[sp,#-80]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+ stp x21,x22,[sp,#32]
+ stp x23,x24,[sp,#48]
+ stp x25,x26,[sp,#64]
+ sub sp,sp,#32*12
+
+ ldp $a0,$a1,[$bp]
+ ldp $a2,$a3,[$bp,#16]
+ ldp $t0,$t1,[$bp,#32]
+ ldp $t2,$t3,[$bp,#48]
+ mov $rp_real,$rp
+ mov $ap_real,$ap
+ mov $bp_real,$bp
+ orr $a0,$a0,$a1
+ orr $a2,$a2,$a3
+ ldp $acc0,$acc1,[$ap]
+ orr $t0,$t0,$t1
+ orr $t2,$t2,$t3
+ ldp $acc2,$acc3,[$ap,#16]
+ orr $a0,$a0,$a2
+ orr $t2,$t0,$t2
+ ldp $t0,$t1,[$ap,#32]
+ orr $in2infty,$a0,$t2
+ cmp $in2infty,#0
+ ldp $t2,$t3,[$ap,#48]
+ csetm $in2infty,ne // !in2infty
+
+ ldp $a0,$a1,[$bp_real,#64] // forward load for p256_sqr_mont
+ orr $acc0,$acc0,$acc1
+ orr $acc2,$acc2,$acc3
+ ldp $a2,$a3,[$bp_real,#64+16]
+ orr $t0,$t0,$t1
+ orr $t2,$t2,$t3
+ orr $acc0,$acc0,$acc2
+ orr $t0,$t0,$t2
+ orr $in1infty,$acc0,$t0
+ cmp $in1infty,#0
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+ csetm $in1infty,ne // !in1infty
+
+ add $rp,sp,#$Z2sqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Z2sqr, in2_z);
+
+ ldp $a0,$a1,[$ap_real,#64]
+ ldp $a2,$a3,[$ap_real,#64+16]
+ add $rp,sp,#$Z1sqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Z1sqr, in1_z);
+
+ ldr $bi,[$bp_real,#64]
+ ldp $a0,$a1,[sp,#$Z2sqr]
+ ldp $a2,$a3,[sp,#$Z2sqr+16]
+ add $bp,$bp_real,#64
+ add $rp,sp,#$S1
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S1, Z2sqr, in2_z);
+
+ ldr $bi,[$ap_real,#64]
+ ldp $a0,$a1,[sp,#$Z1sqr]
+ ldp $a2,$a3,[sp,#$Z1sqr+16]
+ add $bp,$ap_real,#64
+ add $rp,sp,#$S2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S2, Z1sqr, in1_z);
+
+ ldr $bi,[$ap_real,#32]
+ ldp $a0,$a1,[sp,#$S1]
+ ldp $a2,$a3,[sp,#$S1+16]
+ add $bp,$ap_real,#32
+ add $rp,sp,#$S1
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S1, S1, in1_y);
+
+ ldr $bi,[$bp_real,#32]
+ ldp $a0,$a1,[sp,#$S2]
+ ldp $a2,$a3,[sp,#$S2+16]
+ add $bp,$bp_real,#32
+ add $rp,sp,#$S2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S2, S2, in2_y);
+
+ add $bp,sp,#$S1
+ ldr $bi,[sp,#$Z2sqr] // forward load for p256_mul_mont
+ ldp $a0,$a1,[$ap_real]
+ ldp $a2,$a3,[$ap_real,#16]
+ add $rp,sp,#$R
+ bl __ecp_nistz256_sub_from // p256_sub(R, S2, S1);
+
+ orr $acc0,$acc0,$acc1 // see if result is zero
+ orr $acc2,$acc2,$acc3
+ orr $temp,$acc0,$acc2
+
+ add $bp,sp,#$Z2sqr
+ add $rp,sp,#$U1
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(U1, in1_x, Z2sqr);
+
+ ldr $bi,[sp,#$Z1sqr]
+ ldp $a0,$a1,[$bp_real]
+ ldp $a2,$a3,[$bp_real,#16]
+ add $bp,sp,#$Z1sqr
+ add $rp,sp,#$U2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(U2, in2_x, Z1sqr);
+
+ add $bp,sp,#$U1
+ ldp $a0,$a1,[sp,#$R] // forward load for p256_sqr_mont
+ ldp $a2,$a3,[sp,#$R+16]
+ add $rp,sp,#$H
+ bl __ecp_nistz256_sub_from // p256_sub(H, U2, U1);
+
+ orr $acc0,$acc0,$acc1 // see if result is zero
+ orr $acc2,$acc2,$acc3
+ orr $acc0,$acc0,$acc2
+ tst $acc0,$acc0
+ b.ne .Ladd_proceed // is_equal(U1,U2)?
+
+ tst $in1infty,$in2infty
+ b.eq .Ladd_proceed // (in1infty || in2infty)?
+
+ tst $temp,$temp
+ b.eq .Ladd_proceed // is_equal(S1,S2)?
+
+ eor $a0,$a0,$a0
+ eor $a1,$a1,$a1
+ stp $a0,$a1,[$rp_real]
+ stp $a0,$a1,[$rp_real,#16]
+ stp $a0,$a1,[$rp_real,#32]
+ stp $a0,$a1,[$rp_real,#48]
+ stp $a0,$a1,[$rp_real,#64]
+ stp $a0,$a1,[$rp_real,#80]
+ b .Ladd_done
+
+.align 4
+.Ladd_proceed:
+ add $rp,sp,#$Rsqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Rsqr, R);
+
+ ldr $bi,[$ap_real,#64]
+ ldp $a0,$a1,[sp,#$H]
+ ldp $a2,$a3,[sp,#$H+16]
+ add $bp,$ap_real,#64
+ add $rp,sp,#$res_z
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(res_z, H, in1_z);
+
+ ldp $a0,$a1,[sp,#$H]
+ ldp $a2,$a3,[sp,#$H+16]
+ add $rp,sp,#$Hsqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Hsqr, H);
+
+ ldr $bi,[$bp_real,#64]
+ ldp $a0,$a1,[sp,#$res_z]
+ ldp $a2,$a3,[sp,#$res_z+16]
+ add $bp,$bp_real,#64
+ add $rp,sp,#$res_z
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(res_z, res_z, in2_z);
+
+ ldr $bi,[sp,#$H]
+ ldp $a0,$a1,[sp,#$Hsqr]
+ ldp $a2,$a3,[sp,#$Hsqr+16]
+ add $bp,sp,#$H
+ add $rp,sp,#$Hcub
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(Hcub, Hsqr, H);
+
+ ldr $bi,[sp,#$Hsqr]
+ ldp $a0,$a1,[sp,#$U1]
+ ldp $a2,$a3,[sp,#$U1+16]
+ add $bp,sp,#$Hsqr
+ add $rp,sp,#$U2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(U2, U1, Hsqr);
+
+ mov $t0,$acc0
+ mov $t1,$acc1
+ mov $t2,$acc2
+ mov $t3,$acc3
+ add $rp,sp,#$Hsqr
+ bl __ecp_nistz256_add // p256_mul_by_2(Hsqr, U2);
+
+ add $bp,sp,#$Rsqr
+ add $rp,sp,#$res_x
+ bl __ecp_nistz256_sub_morf // p256_sub(res_x, Rsqr, Hsqr);
+
+ add $bp,sp,#$Hcub
+ bl __ecp_nistz256_sub_from // p256_sub(res_x, res_x, Hcub);
+
+ add $bp,sp,#$U2
+ ldr $bi,[sp,#$Hcub] // forward load for p256_mul_mont
+ ldp $a0,$a1,[sp,#$S1]
+ ldp $a2,$a3,[sp,#$S1+16]
+ add $rp,sp,#$res_y
+ bl __ecp_nistz256_sub_morf // p256_sub(res_y, U2, res_x);
+
+ add $bp,sp,#$Hcub
+ add $rp,sp,#$S2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S2, S1, Hcub);
+
+ ldr $bi,[sp,#$R]
+ ldp $a0,$a1,[sp,#$res_y]
+ ldp $a2,$a3,[sp,#$res_y+16]
+ add $bp,sp,#$R
+ add $rp,sp,#$res_y
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(res_y, res_y, R);
+
+ add $bp,sp,#$S2
+ bl __ecp_nistz256_sub_from // p256_sub(res_y, res_y, S2);
+
+ ldp $a0,$a1,[sp,#$res_x] // res
+ ldp $a2,$a3,[sp,#$res_x+16]
+ ldp $t0,$t1,[$bp_real] // in2
+ ldp $t2,$t3,[$bp_real,#16]
+___
+for($i=0;$i<64;$i+=32) { # conditional moves
+$code.=<<___;
+ ldp $acc0,$acc1,[$ap_real,#$i] // in1
+ cmp $in1infty,#0 // !$in1intfy, remember?
+ ldp $acc2,$acc3,[$ap_real,#$i+16]
+ csel $t0,$a0,$t0,ne
+ csel $t1,$a1,$t1,ne
+ ldp $a0,$a1,[sp,#$res_x+$i+32] // res
+ csel $t2,$a2,$t2,ne
+ csel $t3,$a3,$t3,ne
+ cmp $in2infty,#0 // !$in2intfy, remember?
+ ldp $a2,$a3,[sp,#$res_x+$i+48]
+ csel $acc0,$t0,$acc0,ne
+ csel $acc1,$t1,$acc1,ne
+ ldp $t0,$t1,[$bp_real,#$i+32] // in2
+ csel $acc2,$t2,$acc2,ne
+ csel $acc3,$t3,$acc3,ne
+ ldp $t2,$t3,[$bp_real,#$i+48]
+ stp $acc0,$acc1,[$rp_real,#$i]
+ stp $acc2,$acc3,[$rp_real,#$i+16]
+___
+}
+$code.=<<___;
+ ldp $acc0,$acc1,[$ap_real,#$i] // in1
+ cmp $in1infty,#0 // !$in1intfy, remember?
+ ldp $acc2,$acc3,[$ap_real,#$i+16]
+ csel $t0,$a0,$t0,ne
+ csel $t1,$a1,$t1,ne
+ csel $t2,$a2,$t2,ne
+ csel $t3,$a3,$t3,ne
+ cmp $in2infty,#0 // !$in2intfy, remember?
+ csel $acc0,$t0,$acc0,ne
+ csel $acc1,$t1,$acc1,ne
+ csel $acc2,$t2,$acc2,ne
+ csel $acc3,$t3,$acc3,ne
+ stp $acc0,$acc1,[$rp_real,#$i]
+ stp $acc2,$acc3,[$rp_real,#$i+16]
+
+.Ladd_done:
+ add sp,x29,#0 // destroy frame
+ ldp x19,x20,[x29,#16]
+ ldp x21,x22,[x29,#32]
+ ldp x23,x24,[x29,#48]
+ ldp x25,x26,[x29,#64]
+ ldp x29,x30,[sp],#80
+ ret
+.size ecp_nistz256_point_add,.-ecp_nistz256_point_add
+___
+}
+
+########################################################################
+# void ecp_nistz256_point_add_affine(P256_POINT *out,const P256_POINT *in1,
+# const P256_POINT_AFFINE *in2);
+{
+my ($res_x,$res_y,$res_z,
+ $U2,$S2,$H,$R,$Hsqr,$Hcub,$Rsqr)=map(32*$_,(0..9));
+my $Z1sqr = $S2;
+# above map() describes stack layout with 10 temporary
+# 256-bit vectors on top.
+my ($rp_real,$ap_real,$bp_real,$in1infty,$in2infty,$temp)=map("x$_",(21..26));
+
+$code.=<<___;
+.globl ecp_nistz256_point_add_affine
+.type ecp_nistz256_point_add_affine,%function
+.align 5
+ecp_nistz256_point_add_affine:
+ stp x29,x30,[sp,#-80]!
+ add x29,sp,#0
+ stp x19,x20,[sp,#16]
+ stp x21,x22,[sp,#32]
+ stp x23,x24,[sp,#48]
+ stp x25,x26,[sp,#64]
+ sub sp,sp,#32*10
+
+ mov $rp_real,$rp
+ mov $ap_real,$ap
+ mov $bp_real,$bp
+ ldr $poly1,.Lpoly+8
+ ldr $poly3,.Lpoly+24
+
+ ldp $a0,$a1,[$ap]
+ ldp $a2,$a3,[$ap,#16]
+ ldp $t0,$t1,[$ap,#32]
+ ldp $t2,$t3,[$ap,#48]
+ orr $a0,$a0,$a1
+ orr $a2,$a2,$a3
+ orr $t0,$t0,$t1
+ orr $t2,$t2,$t3
+ orr $a0,$a0,$a2
+ orr $t0,$t0,$t2
+ orr $in1infty,$a0,$t0
+ cmp $in1infty,#0
+ csetm $in1infty,ne // !in1infty
+
+ ldp $a0,$a1,[$bp]
+ ldp $a2,$a3,[$bp,#16]
+ ldp $t0,$t1,[$bp,#32]
+ ldp $t2,$t3,[$bp,#48]
+ orr $a0,$a0,$a1
+ orr $a2,$a2,$a3
+ orr $t0,$t0,$t1
+ orr $t2,$t2,$t3
+ orr $a0,$a0,$a2
+ orr $t0,$t0,$t2
+ orr $in2infty,$a0,$t0
+ cmp $in2infty,#0
+ csetm $in2infty,ne // !in2infty
+
+ ldp $a0,$a1,[$ap_real,#64]
+ ldp $a2,$a3,[$ap_real,#64+16]
+ add $rp,sp,#$Z1sqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Z1sqr, in1_z);
+
+ mov $a0,$acc0
+ mov $a1,$acc1
+ mov $a2,$acc2
+ mov $a3,$acc3
+ ldr $bi,[$bp_real]
+ add $bp,$bp_real,#0
+ add $rp,sp,#$U2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(U2, Z1sqr, in2_x);
+
+ add $bp,$ap_real,#0
+ ldr $bi,[$ap_real,#64] // forward load for p256_mul_mont
+ ldp $a0,$a1,[sp,#$Z1sqr]
+ ldp $a2,$a3,[sp,#$Z1sqr+16]
+ add $rp,sp,#$H
+ bl __ecp_nistz256_sub_from // p256_sub(H, U2, in1_x);
+
+ add $bp,$ap_real,#64
+ add $rp,sp,#$S2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S2, Z1sqr, in1_z);
+
+ ldr $bi,[$ap_real,#64]
+ ldp $a0,$a1,[sp,#$H]
+ ldp $a2,$a3,[sp,#$H+16]
+ add $bp,$ap_real,#64
+ add $rp,sp,#$res_z
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(res_z, H, in1_z);
+
+ ldr $bi,[$bp_real,#32]
+ ldp $a0,$a1,[sp,#$S2]
+ ldp $a2,$a3,[sp,#$S2+16]
+ add $bp,$bp_real,#32
+ add $rp,sp,#$S2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S2, S2, in2_y);
+
+ add $bp,$ap_real,#32
+ ldp $a0,$a1,[sp,#$H] // forward load for p256_sqr_mont
+ ldp $a2,$a3,[sp,#$H+16]
+ add $rp,sp,#$R
+ bl __ecp_nistz256_sub_from // p256_sub(R, S2, in1_y);
+
+ add $rp,sp,#$Hsqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Hsqr, H);
+
+ ldp $a0,$a1,[sp,#$R]
+ ldp $a2,$a3,[sp,#$R+16]
+ add $rp,sp,#$Rsqr
+ bl __ecp_nistz256_sqr_mont // p256_sqr_mont(Rsqr, R);
+
+ ldr $bi,[sp,#$H]
+ ldp $a0,$a1,[sp,#$Hsqr]
+ ldp $a2,$a3,[sp,#$Hsqr+16]
+ add $bp,sp,#$H
+ add $rp,sp,#$Hcub
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(Hcub, Hsqr, H);
+
+ ldr $bi,[$ap_real]
+ ldp $a0,$a1,[sp,#$Hsqr]
+ ldp $a2,$a3,[sp,#$Hsqr+16]
+ add $bp,$ap_real,#0
+ add $rp,sp,#$U2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(U2, in1_x, Hsqr);
+
+ mov $t0,$acc0
+ mov $t1,$acc1
+ mov $t2,$acc2
+ mov $t3,$acc3
+ add $rp,sp,#$Hsqr
+ bl __ecp_nistz256_add // p256_mul_by_2(Hsqr, U2);
+
+ add $bp,sp,#$Rsqr
+ add $rp,sp,#$res_x
+ bl __ecp_nistz256_sub_morf // p256_sub(res_x, Rsqr, Hsqr);
+
+ add $bp,sp,#$Hcub
+ bl __ecp_nistz256_sub_from // p256_sub(res_x, res_x, Hcub);
+
+ add $bp,sp,#$U2
+ ldr $bi,[$ap_real,#32] // forward load for p256_mul_mont
+ ldp $a0,$a1,[sp,#$Hcub]
+ ldp $a2,$a3,[sp,#$Hcub+16]
+ add $rp,sp,#$res_y
+ bl __ecp_nistz256_sub_morf // p256_sub(res_y, U2, res_x);
+
+ add $bp,$ap_real,#32
+ add $rp,sp,#$S2
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(S2, in1_y, Hcub);
+
+ ldr $bi,[sp,#$R]
+ ldp $a0,$a1,[sp,#$res_y]
+ ldp $a2,$a3,[sp,#$res_y+16]
+ add $bp,sp,#$R
+ add $rp,sp,#$res_y
+ bl __ecp_nistz256_mul_mont // p256_mul_mont(res_y, res_y, R);
+
+ add $bp,sp,#$S2
+ bl __ecp_nistz256_sub_from // p256_sub(res_y, res_y, S2);
+
+ ldp $a0,$a1,[sp,#$res_x] // res
+ ldp $a2,$a3,[sp,#$res_x+16]
+ ldp $t0,$t1,[$bp_real] // in2
+ ldp $t2,$t3,[$bp_real,#16]
+___
+for($i=0;$i<64;$i+=32) { # conditional moves
+$code.=<<___;
+ ldp $acc0,$acc1,[$ap_real,#$i] // in1
+ cmp $in1infty,#0 // !$in1intfy, remember?
+ ldp $acc2,$acc3,[$ap_real,#$i+16]
+ csel $t0,$a0,$t0,ne
+ csel $t1,$a1,$t1,ne
+ ldp $a0,$a1,[sp,#$res_x+$i+32] // res
+ csel $t2,$a2,$t2,ne
+ csel $t3,$a3,$t3,ne
+ cmp $in2infty,#0 // !$in2intfy, remember?
+ ldp $a2,$a3,[sp,#$res_x+$i+48]
+ csel $acc0,$t0,$acc0,ne
+ csel $acc1,$t1,$acc1,ne
+ ldp $t0,$t1,[$bp_real,#$i+32] // in2
+ csel $acc2,$t2,$acc2,ne
+ csel $acc3,$t3,$acc3,ne
+ ldp $t2,$t3,[$bp_real,#$i+48]
+ stp $acc0,$acc1,[$rp_real,#$i]
+ stp $acc2,$acc3,[$rp_real,#$i+16]
+___
+}
+$code.=<<___;
+ ldp $acc0,$acc1,[$ap_real,#$i] // in1
+ cmp $in1infty,#0 // !$in1intfy, remember?
+ ldp $acc2,$acc3,[$ap_real,#$i+16]
+ csel $t0,$a0,$t0,ne
+ csel $t1,$a1,$t1,ne
+ csel $t2,$a2,$t2,ne
+ csel $t3,$a3,$t3,ne
+ cmp $in2infty,#0 // !$in2intfy, remember?
+ csel $acc0,$t0,$acc0,ne
+ csel $acc1,$t1,$acc1,ne
+ csel $acc2,$t2,$acc2,ne
+ csel $acc3,$t3,$acc3,ne
+ stp $acc0,$acc1,[$rp_real,#$i]
+ stp $acc2,$acc3,[$rp_real,#$i+16]
+
+ add sp,x29,#0 // destroy frame
+ ldp x19,x20,[x29,#16]
+ ldp x21,x22,[x29,#32]
+ ldp x23,x24,[x29,#48]
+ ldp x25,x26,[x29,#64]
+ ldp x29,x30,[sp],#80
+ ret
+.size ecp_nistz256_point_add_affine,.-ecp_nistz256_point_add_affine
+___
+} }
+
+########################################################################
+# scatter-gather subroutines
+{
+my ($out,$inp,$index,$mask)=map("x$_",(0..3));
+$code.=<<___;
+// void ecp_nistz256_scatter_w5(void *x0,const P256_POINT *x1,
+// int x2);
+.globl ecp_nistz256_scatter_w5
+.type ecp_nistz256_scatter_w5,%function
+.align 4
+ecp_nistz256_scatter_w5:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ add $out,$out,$index,lsl#2
+
+ ldp x4,x5,[$inp] // X
+ ldp x6,x7,[$inp,#16]
+ str w4,[$out,#64*0-4]
+ lsr x4,x4,#32
+ str w5,[$out,#64*1-4]
+ lsr x5,x5,#32
+ str w6,[$out,#64*2-4]
+ lsr x6,x6,#32
+ str w7,[$out,#64*3-4]
+ lsr x7,x7,#32
+ str w4,[$out,#64*4-4]
+ str w5,[$out,#64*5-4]
+ str w6,[$out,#64*6-4]
+ str w7,[$out,#64*7-4]
+ add $out,$out,#64*8
+
+ ldp x4,x5,[$inp,#32] // Y
+ ldp x6,x7,[$inp,#48]
+ str w4,[$out,#64*0-4]
+ lsr x4,x4,#32
+ str w5,[$out,#64*1-4]
+ lsr x5,x5,#32
+ str w6,[$out,#64*2-4]
+ lsr x6,x6,#32
+ str w7,[$out,#64*3-4]
+ lsr x7,x7,#32
+ str w4,[$out,#64*4-4]
+ str w5,[$out,#64*5-4]
+ str w6,[$out,#64*6-4]
+ str w7,[$out,#64*7-4]
+ add $out,$out,#64*8
+
+ ldp x4,x5,[$inp,#64] // Z
+ ldp x6,x7,[$inp,#80]
+ str w4,[$out,#64*0-4]
+ lsr x4,x4,#32
+ str w5,[$out,#64*1-4]
+ lsr x5,x5,#32
+ str w6,[$out,#64*2-4]
+ lsr x6,x6,#32
+ str w7,[$out,#64*3-4]
+ lsr x7,x7,#32
+ str w4,[$out,#64*4-4]
+ str w5,[$out,#64*5-4]
+ str w6,[$out,#64*6-4]
+ str w7,[$out,#64*7-4]
+
+ ldr x29,[sp],#16
+ ret
+.size ecp_nistz256_scatter_w5,.-ecp_nistz256_scatter_w5
+
+// void ecp_nistz256_gather_w5(P256_POINT *x0,const void *x1,
+// int x2);
+.globl ecp_nistz256_gather_w5
+.type ecp_nistz256_gather_w5,%function
+.align 4
+ecp_nistz256_gather_w5:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ cmp $index,xzr
+ csetm x3,ne
+ add $index,$index,x3
+ add $inp,$inp,$index,lsl#2
+
+ ldr w4,[$inp,#64*0]
+ ldr w5,[$inp,#64*1]
+ ldr w6,[$inp,#64*2]
+ ldr w7,[$inp,#64*3]
+ ldr w8,[$inp,#64*4]
+ ldr w9,[$inp,#64*5]
+ ldr w10,[$inp,#64*6]
+ ldr w11,[$inp,#64*7]
+ add $inp,$inp,#64*8
+ orr x4,x4,x8,lsl#32
+ orr x5,x5,x9,lsl#32
+ orr x6,x6,x10,lsl#32
+ orr x7,x7,x11,lsl#32
+ csel x4,x4,xzr,ne
+ csel x5,x5,xzr,ne
+ csel x6,x6,xzr,ne
+ csel x7,x7,xzr,ne
+ stp x4,x5,[$out] // X
+ stp x6,x7,[$out,#16]
+
+ ldr w4,[$inp,#64*0]
+ ldr w5,[$inp,#64*1]
+ ldr w6,[$inp,#64*2]
+ ldr w7,[$inp,#64*3]
+ ldr w8,[$inp,#64*4]
+ ldr w9,[$inp,#64*5]
+ ldr w10,[$inp,#64*6]
+ ldr w11,[$inp,#64*7]
+ add $inp,$inp,#64*8
+ orr x4,x4,x8,lsl#32
+ orr x5,x5,x9,lsl#32
+ orr x6,x6,x10,lsl#32
+ orr x7,x7,x11,lsl#32
+ csel x4,x4,xzr,ne
+ csel x5,x5,xzr,ne
+ csel x6,x6,xzr,ne
+ csel x7,x7,xzr,ne
+ stp x4,x5,[$out,#32] // Y
+ stp x6,x7,[$out,#48]
+
+ ldr w4,[$inp,#64*0]
+ ldr w5,[$inp,#64*1]
+ ldr w6,[$inp,#64*2]
+ ldr w7,[$inp,#64*3]
+ ldr w8,[$inp,#64*4]
+ ldr w9,[$inp,#64*5]
+ ldr w10,[$inp,#64*6]
+ ldr w11,[$inp,#64*7]
+ orr x4,x4,x8,lsl#32
+ orr x5,x5,x9,lsl#32
+ orr x6,x6,x10,lsl#32
+ orr x7,x7,x11,lsl#32
+ csel x4,x4,xzr,ne
+ csel x5,x5,xzr,ne
+ csel x6,x6,xzr,ne
+ csel x7,x7,xzr,ne
+ stp x4,x5,[$out,#64] // Z
+ stp x6,x7,[$out,#80]
+
+ ldr x29,[sp],#16
+ ret
+.size ecp_nistz256_gather_w5,.-ecp_nistz256_gather_w5
+
+// void ecp_nistz256_scatter_w7(void *x0,const P256_POINT_AFFINE *x1,
+// int x2);
+.globl ecp_nistz256_scatter_w7
+.type ecp_nistz256_scatter_w7,%function
+.align 4
+ecp_nistz256_scatter_w7:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ add $out,$out,$index
+ mov $index,#64/8
+.Loop_scatter_w7:
+ ldr x3,[$inp],#8
+ subs $index,$index,#1
+ prfm pstl1strm,[$out,#4096+64*0]
+ prfm pstl1strm,[$out,#4096+64*1]
+ prfm pstl1strm,[$out,#4096+64*2]
+ prfm pstl1strm,[$out,#4096+64*3]
+ prfm pstl1strm,[$out,#4096+64*4]
+ prfm pstl1strm,[$out,#4096+64*5]
+ prfm pstl1strm,[$out,#4096+64*6]
+ prfm pstl1strm,[$out,#4096+64*7]
+ strb w3,[$out,#64*0-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*1-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*2-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*3-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*4-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*5-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*6-1]
+ lsr x3,x3,#8
+ strb w3,[$out,#64*7-1]
+ add $out,$out,#64*8
+ b.ne .Loop_scatter_w7
+
+ ldr x29,[sp],#16
+ ret
+.size ecp_nistz256_scatter_w7,.-ecp_nistz256_scatter_w7
+
+// void ecp_nistz256_gather_w7(P256_POINT_AFFINE *x0,const void *x1,
+// int x2);
+.globl ecp_nistz256_gather_w7
+.type ecp_nistz256_gather_w7,%function
+.align 4
+ecp_nistz256_gather_w7:
+ stp x29,x30,[sp,#-16]!
+ add x29,sp,#0
+
+ cmp $index,xzr
+ csetm x3,ne
+ add $index,$index,x3
+ add $inp,$inp,$index
+ mov $index,#64/8
+ nop
+.Loop_gather_w7:
+ ldrb w4,[$inp,#64*0]
+ prfm pldl1strm,[$inp,#4096+64*0]
+ subs $index,$index,#1
+ ldrb w5,[$inp,#64*1]
+ prfm pldl1strm,[$inp,#4096+64*1]
+ ldrb w6,[$inp,#64*2]
+ prfm pldl1strm,[$inp,#4096+64*2]
+ ldrb w7,[$inp,#64*3]
+ prfm pldl1strm,[$inp,#4096+64*3]
+ ldrb w8,[$inp,#64*4]
+ prfm pldl1strm,[$inp,#4096+64*4]
+ ldrb w9,[$inp,#64*5]
+ prfm pldl1strm,[$inp,#4096+64*5]
+ ldrb w10,[$inp,#64*6]
+ prfm pldl1strm,[$inp,#4096+64*6]
+ ldrb w11,[$inp,#64*7]
+ prfm pldl1strm,[$inp,#4096+64*7]
+ add $inp,$inp,#64*8
+ orr x4,x4,x5,lsl#8
+ orr x6,x6,x7,lsl#8
+ orr x8,x8,x9,lsl#8
+ orr x4,x4,x6,lsl#16
+ orr x10,x10,x11,lsl#8
+ orr x4,x4,x8,lsl#32
+ orr x4,x4,x10,lsl#48
+ and x4,x4,x3
+ str x4,[$out],#8
+ b.ne .Loop_gather_w7
+
+ ldr x29,[sp],#16
+ ret
+.size ecp_nistz256_gather_w7,.-ecp_nistz256_gather_w7
+___
+}
+
+foreach (split("\n",$code)) {
+ s/\`([^\`]*)\`/eval $1/ge;
+
+ print $_,"\n";
+}
+close STDOUT; # enforce flush