--- /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 ARMv4.
+#
+# October 2014.
+#
+# Original ECP_NISTZ256 submission targeting x86_64 is detailed in
+# http://eprint.iacr.org/2013/816. In the process of adaptation
+# original .c module was made 32-bit savvy in order to make this
+# implementation possible.
+#
+# with/without -DECP_NISTZ256_ASM
+# Cortex-A8 +53-170%
+# Cortex-A9 +76-205%
+# Cortex-A15 +100-316%
+# Snapdragon S4 +66-187%
+#
+# Ranges denote minimum and maximum improvement coefficients depending
+# on benchmark. Lower coefficients are for ECDSA sign, server-side
+# operation. Keep in mind that +200% means 3x 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 $output";
+*STDOUT=*OUT;
+
+$code.=<<___;
+#include "arm_arch.h"
+
+.text
+.code 32
+___
+########################################################################
+# 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
+.LRR: @ 2^512 mod P precomputed for NIST P256 polynomial
+.long 0x00000003, 0x00000000, 0xffffffff, 0xfffffffb
+.long 0xfffffffe, 0xffffffff, 0xfffffffd, 0x00000004
+.Lone:
+.long 1,0,0,0,0,0,0,0
+.asciz "ECP_NISTZ256 for ARMv4, CRYPTOGAMS by <appro\@openssl.org>"
+.align 6
+___
+
+########################################################################
+# common register layout, note that $t2 is link register, so that if
+# internal subroutine uses $t2, then it has to offload lr...
+
+($r_ptr,$a_ptr,$b_ptr,$ff,$a0,$a1,$a2,$a3,$a4,$a5,$a6,$a7,$t1,$t2)=
+ map("r$_",(0..12,14));
+($t0,$t3)=($ff,$a_ptr);
+
+$code.=<<___;
+@ void ecp_nistz256_to_mont(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_to_mont
+.type ecp_nistz256_to_mont,%function
+ecp_nistz256_to_mont:
+ adr $b_ptr,.LRR
+ b .Lecp_nistz256_mul_mont
+.size ecp_nistz256_to_mont,.-ecp_nistz256_to_mont
+
+@ void ecp_nistz256_from_mont(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_from_mont
+.type ecp_nistz256_from_mont,%function
+ecp_nistz256_from_mont:
+ adr $b_ptr,.Lone
+ b .Lecp_nistz256_mul_mont
+.size ecp_nistz256_from_mont,.-ecp_nistz256_from_mont
+
+@ void ecp_nistz256_mul_by_2(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_mul_by_2
+.type ecp_nistz256_mul_by_2,%function
+.align 4
+ecp_nistz256_mul_by_2:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_mul_by_2
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_mul_by_2,.-ecp_nistz256_mul_by_2
+
+.type _ecp_nistz256_mul_by_2,%function
+.align 4
+_ecp_nistz256_mul_by_2:
+ ldr $a0,[$a_ptr,#0]
+ ldr $a1,[$a_ptr,#4]
+ ldr $a2,[$a_ptr,#8]
+ adds $a0,$a0,$a0 @ a[0:7]+=a[0:7], i.e. add with itself
+ ldr $a3,[$a_ptr,#12]
+ adcs $a1,$a1,$a1
+ ldr $a4,[$a_ptr,#16]
+ adcs $a2,$a2,$a2
+ ldr $a5,[$a_ptr,#20]
+ adcs $a3,$a3,$a3
+ ldr $a6,[$a_ptr,#24]
+ adcs $a4,$a4,$a4
+ ldr $a7,[$a_ptr,#28]
+ adcs $a5,$a5,$a5
+ adcs $a6,$a6,$a6
+ mov $ff,#0
+ adcs $a7,$a7,$a7
+ movcs $ff,#-1 @ $ff = carry ? -1 : 0
+
+ b .Lreduce_by_sub
+.size _ecp_nistz256_mul_by_2,.-_ecp_nistz256_mul_by_2
+
+@ void ecp_nistz256_add(BN_ULONG r0[8],const BN_ULONG r1[8],
+@ const BN_ULONG r2[8]);
+.globl ecp_nistz256_add
+.type ecp_nistz256_add,%function
+.align 4
+ecp_nistz256_add:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_add
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_add,.-ecp_nistz256_add
+
+.type _ecp_nistz256_add,%function
+.align 4
+_ecp_nistz256_add:
+ str lr,[sp,#-4]! @ push lr
+
+ ldr $a0,[$a_ptr,#0]
+ ldr $a1,[$a_ptr,#4]
+ ldr $a2,[$a_ptr,#8]
+ ldr $a3,[$a_ptr,#12]
+ ldr $a4,[$a_ptr,#16]
+ ldr $t0,[$b_ptr,#0]
+ ldr $a5,[$a_ptr,#20]
+ ldr $t1,[$b_ptr,#4]
+ ldr $a6,[$a_ptr,#24]
+ ldr $t2,[$b_ptr,#8]
+ ldr $a7,[$a_ptr,#28]
+ ldr $t3,[$b_ptr,#12]
+ adds $a0,$a0,$t0
+ ldr $t0,[$b_ptr,#16]
+ adcs $a1,$a1,$t1
+ ldr $t1,[$b_ptr,#20]
+ adcs $a2,$a2,$t2
+ ldr $t2,[$b_ptr,#24]
+ adcs $a3,$a3,$t3
+ ldr $t3,[$b_ptr,#28]
+ adcs $a4,$a4,$t0
+ adcs $a5,$a5,$t1
+ adcs $a6,$a6,$t2
+ mov $ff,#0
+ adcs $a7,$a7,$t3
+ movcs $ff,#-1 @ $ff = carry ? -1 : 0, "broadcast" carry
+ ldr lr,[sp],#4 @ pop lr
+
+.Lreduce_by_sub:
+
+ @ if a+b carries, subtract modulus.
+ @
+ @ Note that because mod has special form, i.e. consists of
+ @ 0xffffffff, 1 and 0s, we can conditionally synthesize it by
+ @ using value of broadcasted carry as a whole or extracting
+ @ single bit. Follow $ff register...
+
+ subs $a0,$a0,$ff @ subtract synthesized modulus
+ sbcs $a1,$a1,$ff
+ str $a0,[$r_ptr,#0]
+ sbcs $a2,$a2,$ff
+ str $a1,[$r_ptr,#4]
+ sbcs $a3,$a3,#0
+ str $a2,[$r_ptr,#8]
+ sbcs $a4,$a4,#0
+ str $a3,[$r_ptr,#12]
+ sbcs $a5,$a5,#0
+ str $a4,[$r_ptr,#16]
+ sbcs $a6,$a6,$ff,lsr#31
+ str $a5,[$r_ptr,#20]
+ sbcs $a7,$a7,$ff
+ str $a6,[$r_ptr,#24]
+ str $a7,[$r_ptr,#28]
+
+ mov pc,lr
+.size _ecp_nistz256_add,.-_ecp_nistz256_add
+
+@ void ecp_nistz256_mul_by_3(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_mul_by_3
+.type ecp_nistz256_mul_by_3,%function
+.align 4
+ecp_nistz256_mul_by_3:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_mul_by_3
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_mul_by_3,.-ecp_nistz256_mul_by_3
+
+.type _ecp_nistz256_mul_by_3,%function
+.align 4
+_ecp_nistz256_mul_by_3:
+ str lr,[sp,#-4]! @ push lr
+
+ @ As multiplication by 3 is performed as 2*n+n, below are inline
+ @ copies of _ecp_nistz256_mul_by_2 and _ecp_nistz256_add, see
+ @ corresponding subroutines for details.
+
+ ldr $a0,[$a_ptr,#0]
+ ldr $a1,[$a_ptr,#4]
+ ldr $a2,[$a_ptr,#8]
+ adds $a0,$a0,$a0 @ a[0:7]+=a[0:7]
+ ldr $a3,[$a_ptr,#12]
+ adcs $a1,$a1,$a1
+ ldr $a4,[$a_ptr,#16]
+ adcs $a2,$a2,$a2
+ ldr $a5,[$a_ptr,#20]
+ adcs $a3,$a3,$a3
+ ldr $a6,[$a_ptr,#24]
+ adcs $a4,$a4,$a4
+ ldr $a7,[$a_ptr,#28]
+ adcs $a5,$a5,$a5
+ adcs $a6,$a6,$a6
+ mov $ff,#0
+ adcs $a7,$a7,$a7
+ movcs $ff,#-1 @ $ff = carry ? -1 : 0, "broadcast" carry
+
+ subs $a0,$a0,$ff @ subtract synthesized modulus, see
+ @ .Lreduce_by_sub for details, except
+ @ that we don't write anything to
+ @ memory, but keep intermediate
+ @ results in registers...
+ sbcs $a1,$a1,$ff
+ sbcs $a2,$a2,$ff
+ sbcs $a3,$a3,#0
+ sbcs $a4,$a4,#0
+ ldr $b_ptr,[$a_ptr,#0]
+ sbcs $a5,$a5,#0
+ ldr $t1,[$a_ptr,#4]
+ sbcs $a6,$a6,$ff,lsr#31
+ ldr $t2,[$a_ptr,#8]
+ sbcs $a7,$a7,$ff
+
+ ldr $t0,[$a_ptr,#12]
+ adds $a0,$a0,$b_ptr @ 2*a[0:7]+=a[0:7]
+ ldr $b_ptr,[$a_ptr,#16]
+ adcs $a1,$a1,$t1
+ ldr $t1,[$a_ptr,#20]
+ adcs $a2,$a2,$t2
+ ldr $t2,[$a_ptr,#24]
+ adcs $a3,$a3,$t0
+ ldr $t3,[$a_ptr,#28]
+ adcs $a4,$a4,$b_ptr
+ adcs $a5,$a5,$t1
+ adcs $a6,$a6,$t2
+ mov $ff,#0
+ adcs $a7,$a7,$t3
+ movcs $ff,#-1 @ $ff = carry ? -1 : 0, "broadcast" carry
+ ldr lr,[sp],#4 @ pop lr
+
+ b .Lreduce_by_sub
+.size ecp_nistz256_mul_by_3,.-ecp_nistz256_mul_by_3
+
+@ void ecp_nistz256_div_by_2(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_div_by_2
+.type ecp_nistz256_div_by_2,%function
+.align 4
+ecp_nistz256_div_by_2:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_div_by_2
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_div_by_2,.-ecp_nistz256_div_by_2
+
+.type _ecp_nistz256_div_by_2,%function
+.align 4
+_ecp_nistz256_div_by_2:
+ @ ret = (a is odd ? a+mod : a) >> 1
+
+ ldr $a0,[$a_ptr,#0]
+ ldr $a1,[$a_ptr,#4]
+ ldr $a2,[$a_ptr,#8]
+ mov $ff,$a0,lsl#31 @ place least significant bit to most
+ @ significant position, now arithmetic
+ @ right shift by 31 will produce -1 or
+ @ 0, while logical rigth shift 1 or 0,
+ @ this is how modulus is conditionally
+ @ synthesized in this case...
+ ldr $a3,[$a_ptr,#12]
+ adds $a0,$a0,$ff,asr#31
+ ldr $a4,[$a_ptr,#16]
+ adcs $a1,$a1,$ff,asr#31
+ ldr $a5,[$a_ptr,#20]
+ adcs $a2,$a2,$ff,asr#31
+ ldr $a6,[$a_ptr,#24]
+ adcs $a3,$a3,#0
+ ldr $a7,[$a_ptr,#28]
+ adcs $a4,$a4,#0
+ mov $a0,$a0,lsr#1 @ a[0:7]>>=1, we can start early
+ @ because it doesn't affect flags
+ adcs $a5,$a5,#0
+ orr $a0,$a0,$a1,lsl#31
+ adcs $a6,$a6,$ff,lsr#31
+ mov $b_ptr,#0
+ adcs $a7,$a7,$ff,asr#31
+ mov $a1,$a1,lsr#1
+ adc $b_ptr,$b_ptr,#0 @ top-most carry bit from addition
+
+ orr $a1,$a1,$a2,lsl#31
+ mov $a2,$a2,lsr#1
+ str $a0,[$r_ptr,#0]
+ orr $a2,$a2,$a3,lsl#31
+ mov $a3,$a3,lsr#1
+ str $a1,[$r_ptr,#4]
+ orr $a3,$a3,$a4,lsl#31
+ mov $a4,$a4,lsr#1
+ str $a2,[$r_ptr,#8]
+ orr $a4,$a4,$a5,lsl#31
+ mov $a5,$a5,lsr#1
+ str $a3,[$r_ptr,#12]
+ orr $a5,$a5,$a6,lsl#31
+ mov $a6,$a6,lsr#1
+ str $a4,[$r_ptr,#16]
+ orr $a6,$a6,$a7,lsl#31
+ mov $a7,$a7,lsr#1
+ str $a5,[$r_ptr,#20]
+ orr $a7,$a7,$b_ptr,lsl#31 @ don't forget the top-most carry bit
+ str $a6,[$r_ptr,#24]
+ str $a7,[$r_ptr,#28]
+
+ mov pc,lr
+.size _ecp_nistz256_div_by_2,.-_ecp_nistz256_div_by_2
+
+@ void ecp_nistz256_sub(BN_ULONG r0[8],const BN_ULONG r1[8],
+@ const BN_ULONG r2[8]);
+.globl ecp_nistz256_sub
+.type ecp_nistz256_sub,%function
+.align 4
+ecp_nistz256_sub:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_sub
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_sub,.-ecp_nistz256_sub
+
+.type _ecp_nistz256_sub,%function
+.align 4
+_ecp_nistz256_sub:
+ str lr,[sp,#-4]! @ push lr
+
+ ldr $a0,[$a_ptr,#0]
+ ldr $a1,[$a_ptr,#4]
+ ldr $a2,[$a_ptr,#8]
+ ldr $a3,[$a_ptr,#12]
+ ldr $a4,[$a_ptr,#16]
+ ldr $t0,[$b_ptr,#0]
+ ldr $a5,[$a_ptr,#20]
+ ldr $t1,[$b_ptr,#4]
+ ldr $a6,[$a_ptr,#24]
+ ldr $t2,[$b_ptr,#8]
+ ldr $a7,[$a_ptr,#28]
+ ldr $t3,[$b_ptr,#12]
+ subs $a0,$a0,$t0
+ ldr $t0,[$b_ptr,#16]
+ sbcs $a1,$a1,$t1
+ ldr $t1,[$b_ptr,#20]
+ sbcs $a2,$a2,$t2
+ ldr $t2,[$b_ptr,#24]
+ sbcs $a3,$a3,$t3
+ ldr $t3,[$b_ptr,#28]
+ sbcs $a4,$a4,$t0
+ sbcs $a5,$a5,$t1
+ sbcs $a6,$a6,$t2
+ sbcs $a7,$a7,$t3
+ sbc $ff,$ff,$ff @ broadcast borrow bit
+ ldr lr,[sp],#4 @ pop lr
+
+.Lreduce_by_add:
+
+ @ if a-b borrows, add modulus.
+ @
+ @ Note that because mod has special form, i.e. consists of
+ @ 0xffffffff, 1 and 0s, we can conditionally synthesize it by
+ @ broadcasting borrow bit to a register, $ff, and using it as
+ @ a whole or extracting single bit.
+
+ adds $a0,$a0,$ff @ add synthesized modulus
+ adcs $a1,$a1,$ff
+ str $a0,[$r_ptr,#0]
+ adcs $a2,$a2,$ff
+ str $a1,[$r_ptr,#4]
+ adcs $a3,$a3,#0
+ str $a2,[$r_ptr,#8]
+ adcs $a4,$a4,#0
+ str $a3,[$r_ptr,#12]
+ adcs $a5,$a5,#0
+ str $a4,[$r_ptr,#16]
+ adcs $a6,$a6,$ff,lsr#31
+ str $a5,[$r_ptr,#20]
+ adcs $a7,$a7,$ff
+ str $a6,[$r_ptr,#24]
+ str $a7,[$r_ptr,#28]
+
+ mov pc,lr
+.size _ecp_nistz256_sub,.-_ecp_nistz256_sub
+
+@ void ecp_nistz256_neg(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_neg
+.type ecp_nistz256_neg,%function
+.align 4
+ecp_nistz256_neg:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_neg
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_neg,.-ecp_nistz256_neg
+
+.type _ecp_nistz256_neg,%function
+.align 4
+_ecp_nistz256_neg:
+ ldr $a0,[$a_ptr,#0]
+ eor $ff,$ff,$ff
+ ldr $a1,[$a_ptr,#4]
+ ldr $a2,[$a_ptr,#8]
+ subs $a0,$ff,$a0
+ ldr $a3,[$a_ptr,#12]
+ sbcs $a1,$ff,$a1
+ ldr $a4,[$a_ptr,#16]
+ sbcs $a2,$ff,$a2
+ ldr $a5,[$a_ptr,#20]
+ sbcs $a3,$ff,$a3
+ ldr $a6,[$a_ptr,#24]
+ sbcs $a4,$ff,$a4
+ ldr $a7,[$a_ptr,#28]
+ sbcs $a5,$ff,$a5
+ sbcs $a6,$ff,$a6
+ sbcs $a7,$ff,$a7
+ sbc $ff,$ff,$ff
+
+ b .Lreduce_by_add
+.size _ecp_nistz256_neg,.-_ecp_nistz256_neg
+___
+{
+my @acc=map("r$_",(3..11));
+my ($t0,$t1,$bj,$t2,$t3)=map("r$_",(0,1,2,12,14));
+
+$code.=<<___;
+@ void ecp_nistz256_sqr_mont(BN_ULONG r0[8],const BN_ULONG r1[8]);
+.globl ecp_nistz256_sqr_mont
+.type ecp_nistz256_sqr_mont,%function
+.align 4
+ecp_nistz256_sqr_mont:
+ mov $b_ptr,$a_ptr
+ b .Lecp_nistz256_mul_mont
+.size ecp_nistz256_sqr_mont,.-ecp_nistz256_sqr_mont
+
+@ void ecp_nistz256_mul_mont(BN_ULONG r0[8],const BN_ULONG r1[8],
+@ const BN_ULONG r2[8]);
+.globl ecp_nistz256_mul_mont
+.type ecp_nistz256_mul_mont,%function
+.align 4
+ecp_nistz256_mul_mont:
+.Lecp_nistz256_mul_mont:
+ stmdb sp!,{r4-r12,lr}
+ bl _ecp_nistz256_mul_mont
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_mul_mont,.-ecp_nistz256_mul_mont
+
+.type _ecp_nistz256_mul_mont,%function
+.align 4
+_ecp_nistz256_mul_mont:
+ stmdb sp!,{r0-r2,lr} @ make a copy of arguments too
+
+ ldr $bj,[$b_ptr,#0] @ b[0]
+ ldmia $a_ptr,{@acc[1]-@acc[8]}
+
+ umull @acc[0],$t3,@acc[1],$bj @ r[0]=a[0]*b[0]
+ stmdb sp!,{$acc[1]-@acc[8]} @ copy a[0-7] to stack, so
+ @ that it can be addressed
+ @ without spending register
+ @ on address
+ umull @acc[1],$t0,@acc[2],$bj @ r[1]=a[1]*b[0]
+ umull @acc[2],$t1,@acc[3],$bj
+ adds @acc[1],@acc[1],$t3 @ accumulate high part of mult
+ umull @acc[3],$t2,@acc[4],$bj
+ adcs @acc[2],@acc[2],$t0
+ umull @acc[4],$t3,@acc[5],$bj
+ adcs @acc[3],@acc[3],$t1
+ umull @acc[5],$t0,@acc[6],$bj
+ adcs @acc[4],@acc[4],$t2
+ umull @acc[6],$t1,@acc[7],$bj
+ adcs @acc[5],@acc[5],$t3
+ umull @acc[7],$t2,@acc[8],$bj
+ adcs @acc[6],@acc[6],$t0
+ adcs @acc[7],@acc[7],$t1
+ eor $t3,$t3,$t3 @ first overflow bit is zero
+ adc @acc[8],$t2,#0
+___
+for(my $i=1;$i<8;$i++) {
+my $t4=@acc[0];
+
+ # Reduction iteration is normally performed by accumulating
+ # result of multiplication of modulus by "magic" digit [and
+ # omitting least significant word, which is guaranteed to
+ # be 0], but thanks to special form of modulus and "magic"
+ # digit being equal to least significant word, it can be
+ # performed with additions and subtractions alone. Indeed:
+ #
+ # ffff.0001.0000.0000.0000.ffff.ffff.ffff
+ # * abcd
+ # + xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.abcd
+ #
+ # Now observing that ff..ff*x = (2^n-1)*x = 2^n*x-x, we
+ # rewrite above as:
+ #
+ # xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.abcd
+ # + abcd.0000.abcd.0000.0000.abcd.0000.0000.0000
+ # - abcd.0000.0000.0000.0000.0000.0000.abcd
+ #
+ # or marking redundant operations:
+ #
+ # xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.xxxx.----
+ # + abcd.0000.abcd.0000.0000.abcd.----.----.----
+ # - abcd.----.----.----.----.----.----.----
+
+$code.=<<___;
+ @ multiplication-less reduction $i
+ adds @acc[3],@acc[3],@acc[0] @ r[3]+=r[0]
+ ldr $bj,[sp,#40] @ restore b_ptr
+ adcs @acc[4],@acc[4],#0 @ r[4]+=0
+ adcs @acc[5],@acc[5],#0 @ r[5]+=0
+ adcs @acc[6],@acc[6],@acc[0] @ r[6]+=r[0]
+ ldr $t1,[sp,#0] @ load a[0]
+ adcs @acc[7],@acc[7],#0 @ r[7]+=0
+ ldr $bj,[$bj,#4*$i] @ load b[i]
+ adcs @acc[8],@acc[8],@acc[0] @ r[8]+=r[0]
+ eor $t0,$t0,$t0
+ adc $t3,$t3,#0 @ overflow bit
+ subs @acc[7],@acc[7],@acc[0] @ r[7]-=r[0]
+ ldr $t2,[sp,#4] @ a[1]
+ sbcs @acc[8],@acc[8],#0 @ r[8]-=0
+ umlal @acc[1],$t0,$t1,$bj @ "r[0]"+=a[0]*b[i]
+ eor $t1,$t1,$t1
+ sbc @acc[0],$t3,#0 @ overflow bit, keep in mind
+ @ that netto result is
+ @ addition of a value which
+ @ makes underflow impossible
+
+ ldr $t3,[sp,#8] @ a[2]
+ umlal @acc[2],$t1,$t2,$bj @ "r[1]"+=a[1]*b[i]
+ str @acc[0],[sp,#36] @ temporarily offload overflow
+ eor $t2,$t2,$t2
+ ldr $t4,[sp,#12] @ a[3], $t4 is alias @acc[0]
+ umlal @acc[3],$t2,$t3,$bj @ "r[2]"+=a[2]*b[i]
+ eor $t3,$t3,$t3
+ adds @acc[2],@acc[2],$t0 @ accumulate high part of mult
+ ldr $t0,[sp,#16] @ a[4]
+ umlal @acc[4],$t3,$t4,$bj @ "r[3]"+=a[3]*b[i]
+ eor $t4,$t4,$t4
+ adcs @acc[3],@acc[3],$t1
+ ldr $t1,[sp,#20] @ a[5]
+ umlal @acc[5],$t4,$t0,$bj @ "r[4]"+=a[4]*b[i]
+ eor $t0,$t0,$t0
+ adcs @acc[4],@acc[4],$t2
+ ldr $t2,[sp,#24] @ a[6]
+ umlal @acc[6],$t0,$t1,$bj @ "r[5]"+=a[5]*b[i]
+ eor $t1,$t1,$t1
+ adcs @acc[5],@acc[5],$t3
+ ldr $t3,[sp,#28] @ a[7]
+ umlal @acc[7],$t1,$t2,$bj @ "r[6]"+=a[6]*b[i]
+ eor $t2,$t2,$t2
+ adcs @acc[6],@acc[6],$t4
+ ldr @acc[0],[sp,#36] @ restore overflow bit
+ umlal @acc[8],$t2,$t3,$bj @ "r[7]"+=a[7]*b[i]
+ eor $t3,$t3,$t3
+ adcs @acc[7],@acc[7],$t0
+ adcs @acc[8],@acc[8],$t1
+ adcs @acc[0],$acc[0],$t2
+ adc $t3,$t3,#0 @ new overflow bit
+___
+ push(@acc,shift(@acc)); # rotate registers, so that
+ # "r[i]" becomes r[i]
+}
+$code.=<<___;
+ @ last multiplication-less reduction
+ adds @acc[3],@acc[3],@acc[0]
+ ldr $r_ptr,[sp,#32] @ restore r_ptr
+ adcs @acc[4],@acc[4],#0
+ adcs @acc[5],@acc[5],#0
+ adcs @acc[6],@acc[6],@acc[0]
+ adcs @acc[7],@acc[7],#0
+ adcs @acc[8],@acc[8],@acc[0]
+ adc $t3,$t3,#0
+ subs @acc[7],@acc[7],@acc[0]
+ sbcs @acc[8],@acc[8],#0
+ sbc @acc[0],$t3,#0 @ overflow bit
+
+ @ Final step is "if result > mod, subtract mod", but we do it
+ @ "other way around", namely subtract modulus from result
+ @ and if it borrowed, add modulus back.
+
+ subs @acc[1],@acc[1],#-1 @ compare to modulus
+ sbcs @acc[2],@acc[2],#-1
+ sbcs @acc[3],@acc[3],#-1
+ sbcs @acc[4],@acc[4],#0
+ sbcs @acc[5],@acc[5],#0
+ sbcs @acc[6],@acc[6],#0
+ sbcs @acc[7],@acc[7],#1
+ sbcs @acc[8],@acc[8],#-1
+ ldr lr,[sp,#44] @ restore lr
+ sbc @acc[0],@acc[0],#0 @ broadcast borrow bit
+ add sp,sp,#48
+
+ @ Note that because mod has special form, i.e. consists of
+ @ 0xffffffff, 1 and 0s, we can conditionally synthesize it by
+ @ broadcasting borrow bit to a register, @acc[0], and using it as
+ @ a whole or extracting single bit.
+
+ adds @acc[1],@acc[1],@acc[0] @ add modulus or zero
+ adcs @acc[2],@acc[2],@acc[0]
+ str @acc[1],[$r_ptr,#0]
+ adcs @acc[3],@acc[3],@acc[0]
+ str @acc[2],[$r_ptr,#4]
+ adcs @acc[4],@acc[4],#0
+ str @acc[3],[$r_ptr,#8]
+ adcs @acc[5],@acc[5],#0
+ str @acc[4],[$r_ptr,#12]
+ adcs @acc[6],@acc[6],#0
+ str @acc[5],[$r_ptr,#16]
+ adcs @acc[7],@acc[7],@acc[0],lsr#31
+ str @acc[6],[$r_ptr,#20]
+ adc @acc[8],@acc[8],@acc[0]
+ str @acc[7],[$r_ptr,#24]
+ str @acc[8],[$r_ptr,#28]
+
+ mov pc,lr
+.size _ecp_nistz256_mul_mont,.-_ecp_nistz256_mul_mont
+___
+}
+
+{
+my ($out,$inp,$index,$mask)=map("r$_",(0..3));
+$code.=<<___;
+@ void ecp_nistz256_scatter_w5(void *r0,const P256_POINT *r1,
+@ int r2);
+.globl ecp_nistz256_scatter_w5
+.type ecp_nistz256_scatter_w5,%function
+.align 5
+ecp_nistz256_scatter_w5:
+ stmdb sp!,{r4-r11}
+
+ add $out,$out,$index,lsl#2
+
+ ldmia $inp!,{r4-r11} @ X
+ str r4,[$out,#64*0-4]
+ str r5,[$out,#64*1-4]
+ str r6,[$out,#64*2-4]
+ str r7,[$out,#64*3-4]
+ str r8,[$out,#64*4-4]
+ str r9,[$out,#64*5-4]
+ str r10,[$out,#64*6-4]
+ str r11,[$out,#64*7-4]
+ add $out,$out,#64*8
+
+ ldmia $inp!,{r4-r11} @ Y
+ str r4,[$out,#64*0-4]
+ str r5,[$out,#64*1-4]
+ str r6,[$out,#64*2-4]
+ str r7,[$out,#64*3-4]
+ str r8,[$out,#64*4-4]
+ str r9,[$out,#64*5-4]
+ str r10,[$out,#64*6-4]
+ str r11,[$out,#64*7-4]
+ add $out,$out,#64*8
+
+ ldmia $inp,{r4-r11} @ Z
+ str r4,[$out,#64*0-4]
+ str r5,[$out,#64*1-4]
+ str r6,[$out,#64*2-4]
+ str r7,[$out,#64*3-4]
+ str r8,[$out,#64*4-4]
+ str r9,[$out,#64*5-4]
+ str r10,[$out,#64*6-4]
+ str r11,[$out,#64*7-4]
+
+ ldmia sp!,{r4-r11}
+#if __ARM_ARCH__>=5 || defined(__thumb__)
+ bx lr
+#else
+ mov pc,lr
+#endif
+.size ecp_nistz256_scatter_w5,.-ecp_nistz256_scatter_w5
+
+@ void ecp_nistz256_gather_w5(P256_POINT *r0,const void *r1,
+@ int r2);
+.globl ecp_nistz256_gather_w5
+.type ecp_nistz256_gather_w5,%function
+.align 5
+ecp_nistz256_gather_w5:
+ stmdb sp!,{r4-r11}
+
+ cmp $index,#0
+ mov $mask,#0
+ subne $index,$index,#1
+ movne $mask,#-1
+ add $inp,$inp,$index,lsl#2
+
+ ldr r4,[$inp,#64*0]
+ ldr r5,[$inp,#64*1]
+ ldr r6,[$inp,#64*2]
+ and r4,r4,$mask
+ ldr r7,[$inp,#64*3]
+ and r5,r5,$mask
+ ldr r8,[$inp,#64*4]
+ and r6,r6,$mask
+ ldr r9,[$inp,#64*5]
+ and r7,r7,$mask
+ ldr r10,[$inp,#64*6]
+ and r8,r8,$mask
+ ldr r11,[$inp,#64*7]
+ add $inp,$inp,#64*8
+ and r9,r9,$mask
+ and r10,r10,$mask
+ and r11,r11,$mask
+ stmia $out!,{r4-r11} @ X
+
+ ldr r4,[$inp,#64*0]
+ ldr r5,[$inp,#64*1]
+ ldr r6,[$inp,#64*2]
+ and r4,r4,$mask
+ ldr r7,[$inp,#64*3]
+ and r5,r5,$mask
+ ldr r8,[$inp,#64*4]
+ and r6,r6,$mask
+ ldr r9,[$inp,#64*5]
+ and r7,r7,$mask
+ ldr r10,[$inp,#64*6]
+ and r8,r8,$mask
+ ldr r11,[$inp,#64*7]
+ add $inp,$inp,#64*8
+ and r9,r9,$mask
+ and r10,r10,$mask
+ and r11,r11,$mask
+ stmia $out!,{r4-r11} @ Y
+
+ ldr r4,[$inp,#64*0]
+ ldr r5,[$inp,#64*1]
+ ldr r6,[$inp,#64*2]
+ and r4,r4,$mask
+ ldr r7,[$inp,#64*3]
+ and r5,r5,$mask
+ ldr r8,[$inp,#64*4]
+ and r6,r6,$mask
+ ldr r9,[$inp,#64*5]
+ and r7,r7,$mask
+ ldr r10,[$inp,#64*6]
+ and r8,r8,$mask
+ ldr r11,[$inp,#64*7]
+ and r9,r9,$mask
+ and r10,r10,$mask
+ and r11,r11,$mask
+ stmia $out,{r4-r11} @ Z
+
+ ldmia sp!,{r4-r11}
+#if __ARM_ARCH__>=5 || defined(__thumb__)
+ bx lr
+#else
+ mov pc,lr
+#endif
+.size ecp_nistz256_gather_w5,.-ecp_nistz256_gather_w5
+
+@ void ecp_nistz256_scatter_w7(void *r0,const P256_POINT_AFFINE *r1,
+@ int r2);
+.globl ecp_nistz256_scatter_w7
+.type ecp_nistz256_scatter_w7,%function
+.align 5
+ecp_nistz256_scatter_w7:
+ add $out,$out,$index
+ mov $index,#64/4
+.Loop_scatter_w7:
+ ldr $mask,[$inp],#4
+ subs $index,$index,#1
+ strb $mask,[$out,#64*0-1]
+ mov $mask,$mask,lsr#8
+ strb $mask,[$out,#64*1-1]
+ mov $mask,$mask,lsr#8
+ strb $mask,[$out,#64*2-1]
+ mov $mask,$mask,lsr#8
+ strb $mask,[$out,#64*3-1]
+ add $out,$out,#64*4
+ bne .Loop_scatter_w7
+
+#if __ARM_ARCH__>=5 || defined(__thumb__)
+ bx lr
+#else
+ mov pc,lr
+#endif
+.size ecp_nistz256_scatter_w7,.-ecp_nistz256_scatter_w7
+
+@ void ecp_nistz256_gather_w7(P256_POINT_AFFINE *r0,const void *r1,
+@ int r2);
+.globl ecp_nistz256_gather_w7
+.type ecp_nistz256_gather_w7,%function
+.align 5
+ecp_nistz256_gather_w7:
+ stmdb sp!,{r4-r7}
+
+ cmp $index,#0
+ mov $mask,#0
+ subne $index,$index,#1
+ movne $mask,#-1
+ add $inp,$inp,$index
+ mov $index,#64/4
+ nop
+.Loop_gather_w7:
+ ldrb r4,[$inp,#64*0]
+ subs $index,$index,#1
+ ldrb r5,[$inp,#64*1]
+ ldrb r6,[$inp,#64*2]
+ ldrb r7,[$inp,#64*3]
+ add $inp,$inp,#64*4
+ orr r4,r4,r5,lsl#8
+ orr r4,r4,r6,lsl#16
+ orr r4,r4,r7,lsl#24
+ and r4,r4,$mask
+ str r4,[$out],#4
+ bne .Loop_gather_w7
+
+ ldmia sp!,{r4-r7}
+#if __ARM_ARCH__>=5 || defined(__thumb__)
+ bx lr
+#else
+ mov pc,lr
+#endif
+.size ecp_nistz256_gather_w7,.-ecp_nistz256_gather_w7
+___
+}
+if (0) {
+# In comparison to integer-only equivalent of below subroutine:
+#
+# Cortex-A8 +10%
+# Cortex-A9 -10%
+# Snapdragon S4 +5%
+#
+# As not all time is spent in multiplication, overall impact is deemed
+# too low to care about.
+
+my ($A0,$A1,$A2,$A3,$Bi,$zero,$temp)=map("d$_",(0..7));
+my $mask="q4";
+my $mult="q5";
+my @AxB=map("q$_",(8..15));
+
+my ($rptr,$aptr,$bptr,$toutptr)=map("r$_",(0..3));
+
+$code.=<<___;
+#if __ARM_ARCH__>=7
+.fpu neon
+
+.globl ecp_nistz256_mul_mont_neon
+.type ecp_nistz256_mul_mont_neon,%function
+.align 5
+ecp_nistz256_mul_mont_neon:
+ mov ip,sp
+ stmdb sp!,{r4-r9}
+ vstmdb sp!,{q4-q5} @ ABI specification says so
+
+ sub $toutptr,sp,#40
+ vld1.32 {${Bi}[0]},[$bptr,:32]!
+ veor $zero,$zero,$zero
+ vld1.32 {$A0-$A3}, [$aptr] @ can't specify :32 :-(
+ vzip.16 $Bi,$zero
+ mov sp,$toutptr @ alloca
+ vmov.i64 $mask,#0xffff
+
+ vmull.u32 @AxB[0],$Bi,${A0}[0]
+ vmull.u32 @AxB[1],$Bi,${A0}[1]
+ vmull.u32 @AxB[2],$Bi,${A1}[0]
+ vmull.u32 @AxB[3],$Bi,${A1}[1]
+ vshr.u64 $temp,@AxB[0]#lo,#16
+ vmull.u32 @AxB[4],$Bi,${A2}[0]
+ vadd.u64 @AxB[0]#hi,@AxB[0]#hi,$temp
+ vmull.u32 @AxB[5],$Bi,${A2}[1]
+ vshr.u64 $temp,@AxB[0]#hi,#16 @ upper 32 bits of a[0]*b[0]
+ vmull.u32 @AxB[6],$Bi,${A3}[0]
+ vand.u64 @AxB[0],@AxB[0],$mask @ lower 32 bits of a[0]*b[0]
+ vmull.u32 @AxB[7],$Bi,${A3}[1]
+___
+for($i=1;$i<8;$i++) {
+$code.=<<___;
+ vld1.32 {${Bi}[0]},[$bptr,:32]!
+ veor $zero,$zero,$zero
+ vadd.u64 @AxB[1]#lo,@AxB[1]#lo,$temp @ reduction
+ vshl.u64 $mult,@AxB[0],#32
+ vadd.u64 @AxB[3],@AxB[3],@AxB[0]
+ vsub.u64 $mult,$mult,@AxB[0]
+ vzip.16 $Bi,$zero
+ vadd.u64 @AxB[6],@AxB[6],@AxB[0]
+ vadd.u64 @AxB[7],@AxB[7],$mult
+___
+ push(@AxB,shift(@AxB));
+$code.=<<___;
+ vmlal.u32 @AxB[0],$Bi,${A0}[0]
+ vmlal.u32 @AxB[1],$Bi,${A0}[1]
+ vmlal.u32 @AxB[2],$Bi,${A1}[0]
+ vmlal.u32 @AxB[3],$Bi,${A1}[1]
+ vshr.u64 $temp,@AxB[0]#lo,#16
+ vmlal.u32 @AxB[4],$Bi,${A2}[0]
+ vadd.u64 @AxB[0]#hi,@AxB[0]#hi,$temp
+ vmlal.u32 @AxB[5],$Bi,${A2}[1]
+ vshr.u64 $temp,@AxB[0]#hi,#16 @ upper 33 bits of a[0]*b[i]+t[0]
+ vmlal.u32 @AxB[6],$Bi,${A3}[0]
+ vand.u64 @AxB[0],@AxB[0],$mask @ lower 32 bits of a[0]*b[0]
+ vmull.u32 @AxB[7],$Bi,${A3}[1]
+___
+}
+$code.=<<___;
+ vadd.u64 @AxB[1]#lo,@AxB[1]#lo,$temp @ last reduction
+ vshl.u64 $mult,@AxB[0],#32
+ vadd.u64 @AxB[3],@AxB[3],@AxB[0]
+ vsub.u64 $mult,$mult,@AxB[0]
+ vadd.u64 @AxB[6],@AxB[6],@AxB[0]
+ vadd.u64 @AxB[7],@AxB[7],$mult
+
+ vshr.u64 $temp,@AxB[1]#lo,#16 @ convert
+ vadd.u64 @AxB[1]#hi,@AxB[1]#hi,$temp
+ vshr.u64 $temp,@AxB[1]#hi,#16
+ vzip.16 @AxB[1]#lo,@AxB[1]#hi
+___
+foreach (2..7) {
+$code.=<<___;
+ vadd.u64 @AxB[$_]#lo,@AxB[$_]#lo,$temp
+ vst1.32 {@AxB[$_-1]#lo[0]},[$toutptr,:32]!
+ vshr.u64 $temp,@AxB[$_]#lo,#16
+ vadd.u64 @AxB[$_]#hi,@AxB[$_]#hi,$temp
+ vshr.u64 $temp,@AxB[$_]#hi,#16
+ vzip.16 @AxB[$_]#lo,@AxB[$_]#hi
+___
+}
+$code.=<<___;
+ vst1.32 {@AxB[7]#lo[0]},[$toutptr,:32]!
+ vst1.32 {$temp},[$toutptr] @ upper 33 bits
+
+ ldr r1,[sp,#0]
+ ldr r2,[sp,#4]
+ ldr r3,[sp,#8]
+ subs r1,r1,#-1
+ ldr r4,[sp,#12]
+ sbcs r2,r2,#-1
+ ldr r5,[sp,#16]
+ sbcs r3,r3,#-1
+ ldr r6,[sp,#20]
+ sbcs r4,r4,#0
+ ldr r7,[sp,#24]
+ sbcs r5,r5,#0
+ ldr r8,[sp,#28]
+ sbcs r6,r6,#0
+ ldr r9,[sp,#32] @ top-most bit
+ sbcs r7,r7,#1
+ sub sp,ip,#40+16
+ sbcs r8,r8,#-1
+ sbc r9,r9,#0
+ vldmia sp!,{q4-q5}
+
+ adds r1,r1,r9
+ adcs r2,r2,r9
+ str r1,[$rptr,#0]
+ adcs r3,r3,r9
+ str r2,[$rptr,#4]
+ adcs r4,r4,#0
+ str r3,[$rptr,#8]
+ adcs r5,r5,#0
+ str r4,[$rptr,#12]
+ adcs r6,r6,#0
+ str r5,[$rptr,#16]
+ adcs r7,r7,r9,lsr#31
+ str r6,[$rptr,#20]
+ adcs r8,r8,r9
+ str r7,[$rptr,#24]
+ str r8,[$rptr,#28]
+
+ ldmia sp!,{r4-r9}
+ bx lr
+.size ecp_nistz256_mul_mont_neon,.-ecp_nistz256_mul_mont_neon
+#endif
+___
+}
+
+{{{
+########################################################################
+# Below $aN assignment matches order in which 256-bit result appears in
+# register bank at return from _ecp_nistz256_mul_mont, so that we can
+# skip over reloading it from memory. This means that below functions
+# use custom calling sequence accepting 256-bit input in registers,
+# output pointer in r0, $r_ptr, and optional pointer in r2, $b_ptr.
+#
+# See their "normal" counterparts for insights on calculations.
+
+my ($a0,$a1,$a2,$a3,$a4,$a5,$a6,$a7,
+ $t0,$t1,$t2,$t3)=map("r$_",(11,3..10,12,14,1));
+my $ff=$b_ptr;
+
+$code.=<<___;
+.type __ecp_nistz256_sub_from,%function
+.align 5
+__ecp_nistz256_sub_from:
+ str lr,[sp,#-4]! @ push lr
+
+ ldr $t0,[$b_ptr,#0]
+ ldr $t1,[$b_ptr,#4]
+ ldr $t2,[$b_ptr,#8]
+ ldr $t3,[$b_ptr,#12]
+ subs $a0,$a0,$t0
+ ldr $t0,[$b_ptr,#16]
+ sbcs $a1,$a1,$t1
+ ldr $t1,[$b_ptr,#20]
+ sbcs $a2,$a2,$t2
+ ldr $t2,[$b_ptr,#24]
+ sbcs $a3,$a3,$t3
+ ldr $t3,[$b_ptr,#28]
+ sbcs $a4,$a4,$t0
+ sbcs $a5,$a5,$t1
+ sbcs $a6,$a6,$t2
+ sbcs $a7,$a7,$t3
+ sbc $ff,$ff,$ff @ broadcast borrow bit
+ ldr lr,[sp],#4 @ pop lr
+
+ adds $a0,$a0,$ff @ add synthesized modulus
+ adcs $a1,$a1,$ff
+ str $a0,[$r_ptr,#0]
+ adcs $a2,$a2,$ff
+ str $a1,[$r_ptr,#4]
+ adcs $a3,$a3,#0
+ str $a2,[$r_ptr,#8]
+ adcs $a4,$a4,#0
+ str $a3,[$r_ptr,#12]
+ adcs $a5,$a5,#0
+ str $a4,[$r_ptr,#16]
+ adcs $a6,$a6,$ff,lsr#31
+ str $a5,[$r_ptr,#20]
+ adcs $a7,$a7,$ff
+ str $a6,[$r_ptr,#24]
+ str $a7,[$r_ptr,#28]
+
+ mov pc,lr
+.size __ecp_nistz256_sub_from,.-__ecp_nistz256_sub_from
+
+.type __ecp_nistz256_sub_morf,%function
+.align 5
+__ecp_nistz256_sub_morf:
+ str lr,[sp,#-4]! @ push lr
+
+ ldr $t0,[$b_ptr,#0]
+ ldr $t1,[$b_ptr,#4]
+ ldr $t2,[$b_ptr,#8]
+ ldr $t3,[$b_ptr,#12]
+ subs $a0,$t0,$a0
+ ldr $t0,[$b_ptr,#16]
+ sbcs $a1,$t1,$a1
+ ldr $t1,[$b_ptr,#20]
+ sbcs $a2,$t2,$a2
+ ldr $t2,[$b_ptr,#24]
+ sbcs $a3,$t3,$a3
+ ldr $t3,[$b_ptr,#28]
+ sbcs $a4,$t0,$a4
+ sbcs $a5,$t1,$a5
+ sbcs $a6,$t2,$a6
+ sbcs $a7,$t3,$a7
+ sbc $ff,$ff,$ff @ broadcast borrow bit
+ ldr lr,[sp],#4 @ pop lr
+
+ adds $a0,$a0,$ff @ add synthesized modulus
+ adcs $a1,$a1,$ff
+ str $a0,[$r_ptr,#0]
+ adcs $a2,$a2,$ff
+ str $a1,[$r_ptr,#4]
+ adcs $a3,$a3,#0
+ str $a2,[$r_ptr,#8]
+ adcs $a4,$a4,#0
+ str $a3,[$r_ptr,#12]
+ adcs $a5,$a5,#0
+ str $a4,[$r_ptr,#16]
+ adcs $a6,$a6,$ff,lsr#31
+ str $a5,[$r_ptr,#20]
+ adcs $a7,$a7,$ff
+ str $a6,[$r_ptr,#24]
+ str $a7,[$r_ptr,#28]
+
+ mov pc,lr
+.size __ecp_nistz256_sub_morf,.-__ecp_nistz256_sub_morf
+
+.type __ecp_nistz256_mul_by_2,%function
+.align 4
+__ecp_nistz256_mul_by_2:
+ adds $a0,$a0,$a0 @ a[0:7]+=a[0:7]
+ adcs $a1,$a1,$a1
+ adcs $a2,$a2,$a2
+ adcs $a3,$a3,$a3
+ adcs $a4,$a4,$a4
+ adcs $a5,$a5,$a5
+ adcs $a6,$a6,$a6
+ mov $ff,#0
+ adcs $a7,$a7,$a7
+ movcs $ff,#-1 @ $ff = carry ? -1 : 0
+
+ subs $a0,$a0,$ff @ subtract synthesized modulus
+ sbcs $a1,$a1,$ff
+ str $a0,[$r_ptr,#0]
+ sbcs $a2,$a2,$ff
+ str $a1,[$r_ptr,#4]
+ sbcs $a3,$a3,#0
+ str $a2,[$r_ptr,#8]
+ sbcs $a4,$a4,#0
+ str $a3,[$r_ptr,#12]
+ sbcs $a5,$a5,#0
+ str $a4,[$r_ptr,#16]
+ sbcs $a6,$a6,$ff,lsr#31
+ str $a5,[$r_ptr,#20]
+ sbcs $a7,$a7,$ff
+ str $a6,[$r_ptr,#24]
+ str $a7,[$r_ptr,#28]
+
+ mov pc,lr
+.size __ecp_nistz256_mul_by_2,.-__ecp_nistz256_mul_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,$Zsqr,$in_x,$tmp0)=map(32*$_,(0..4));
+# above map() describes stack layout with 5 temporary
+# 256-bit vectors on top. Then note that we push
+# starting from r0, which means that we have copy of
+# input arguments just below these temporary vectors.
+
+$code.=<<___;
+.globl ecp_nistz256_point_double
+.type ecp_nistz256_point_double,%function
+.align 5
+ecp_nistz256_point_double:
+ stmdb sp!,{r0-r12,lr} @ push from r0, unusual, but intentional
+ sub sp,sp,#32*5
+
+ add r3,sp,#$in_x
+ ldmia $a_ptr!,{r4-r11} @ copy in_x
+ stmia r3,{r4-r11}
+
+ add $r_ptr,sp,#$S
+ bl _ecp_nistz256_mul_by_2 @ p256_mul_by_2(S, in_y);
+
+ add $b_ptr,$a_ptr,#32
+ add $a_ptr,$a_ptr,#32
+ add $r_ptr,sp,#$Zsqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Zsqr, in_z);
+
+ add $a_ptr,sp,#$S
+ add $b_ptr,sp,#$S
+ add $r_ptr,sp,#$S
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(S, S);
+
+ ldr $b_ptr,[sp,#32*5+4]
+ add $a_ptr,$b_ptr,#32
+ add $b_ptr,$b_ptr,#64
+ add $r_ptr,sp,#$tmp0
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(tmp0, in_z, in_y);
+
+ ldr $r_ptr,[sp,#32*5]
+ add $r_ptr,$r_ptr,#64
+ bl __ecp_nistz256_mul_by_2 @ p256_mul_by_2(res_z, tmp0);
+
+ add $a_ptr,sp,#$in_x
+ add $b_ptr,sp,#$Zsqr
+ add $r_ptr,sp,#$M
+ bl _ecp_nistz256_add @ p256_add(M, in_x, Zsqr);
+
+ add $a_ptr,sp,#$in_x
+ add $b_ptr,sp,#$Zsqr
+ add $r_ptr,sp,#$Zsqr
+ bl _ecp_nistz256_sub @ p256_sub(Zsqr, in_x, Zsqr);
+
+ add $a_ptr,sp,#$S
+ add $b_ptr,sp,#$S
+ add $r_ptr,sp,#$tmp0
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(tmp0, S);
+
+ add $a_ptr,sp,#$Zsqr
+ add $b_ptr,sp,#$M
+ add $r_ptr,sp,#$M
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(M, M, Zsqr);
+
+ ldr $r_ptr,[sp,#32*5]
+ add $a_ptr,sp,#$tmp0
+ add $r_ptr,$r_ptr,#32
+ bl _ecp_nistz256_div_by_2 @ p256_div_by_2(res_y, tmp0);
+
+ add $a_ptr,sp,#$M
+ add $r_ptr,sp,#$M
+ bl _ecp_nistz256_mul_by_3 @ p256_mul_by_3(M, M);
+
+ add $a_ptr,sp,#$in_x
+ add $b_ptr,sp,#$S
+ add $r_ptr,sp,#$S
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S, S, in_x);
+
+ add $r_ptr,sp,#$tmp0
+ bl __ecp_nistz256_mul_by_2 @ p256_mul_by_2(tmp0, S);
+
+ ldr $r_ptr,[sp,#32*5]
+ add $a_ptr,sp,#$M
+ add $b_ptr,sp,#$M
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(res_x, M);
+
+ add $b_ptr,sp,#$tmp0
+ bl __ecp_nistz256_sub_from @ p256_sub(res_x, res_x, tmp0);
+
+ add $b_ptr,sp,#$S
+ add $r_ptr,sp,#$S
+ bl __ecp_nistz256_sub_morf @ p256_sub(S, S, res_x);
+
+ add $a_ptr,sp,#$M
+ add $b_ptr,sp,#$S
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S, S, M);
+
+ ldr $r_ptr,[sp,#32*5]
+ add $b_ptr,$r_ptr,#32
+ add $r_ptr,$r_ptr,#32
+ bl __ecp_nistz256_sub_from @ p256_sub(res_y, S, res_y);
+
+ add sp,sp,#32*5+16 @ +16 means "skip even over saved r0-r3"
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.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,
+ $in1_x,$in1_y,$in1_z,
+ $in2_x,$in2_y,$in2_z,
+ $H,$Hsqr,$R,$Rsqr,$Hcub,
+ $U1,$U2,$S1,$S2)=map(32*$_,(0..17));
+my ($Z1sqr, $Z2sqr) = ($Hsqr, $Rsqr);
+# above map() describes stack layout with 18 temporary
+# 256-bit vectors on top. Then note that we push
+# starting from r0, which means that we have copy of
+# input arguments just below these temporary vectors.
+# We use three of them for !in1infty, !in2intfy and
+# result of check for zero.
+
+$code.=<<___;
+.globl ecp_nistz256_point_add
+.type ecp_nistz256_point_add,%function
+.align 5
+ecp_nistz256_point_add:
+ stmdb sp!,{r0-r12,lr} @ push from r0, unusual, but intentional
+ sub sp,sp,#32*18
+
+ ldmia $b_ptr!,{r4-r11} @ copy in2
+ add r3,sp,#$in2_x
+ orr r12,r4,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $b_ptr!,{r4-r11}
+ orr r12,r12,r4
+ orr r12,r12,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $b_ptr,{r4-r11}
+ cmp r12,#0
+ movne r12,#-1
+ stmia r3,{r4-r11}
+ str r12,[sp,#32*18+8] @ !in2infty
+
+ ldmia $a_ptr!,{r4-r11} @ copy in1
+ add r3,sp,#$in1_x
+ orr r12,r4,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $a_ptr!,{r4-r11}
+ orr r12,r12,r4
+ orr r12,r12,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $a_ptr,{r4-r11}
+ cmp r12,#0
+ movne r12,#-1
+ stmia r3,{r4-r11}
+ str r12,[sp,#32*18+4] @ !in1infty
+
+ add $a_ptr,sp,#$in2_z
+ add $b_ptr,sp,#$in2_z
+ add $r_ptr,sp,#$Z2sqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Z2sqr, in2_z);
+
+ add $a_ptr,sp,#$in1_z
+ add $b_ptr,sp,#$in1_z
+ add $r_ptr,sp,#$Z1sqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Z1sqr, in1_z);
+
+ add $a_ptr,sp,#$in2_z
+ add $b_ptr,sp,#$Z2sqr
+ add $r_ptr,sp,#$S1
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S1, Z2sqr, in2_z);
+
+ add $a_ptr,sp,#$in1_z
+ add $b_ptr,sp,#$Z1sqr
+ add $r_ptr,sp,#$S2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S2, Z1sqr, in1_z);
+
+ add $a_ptr,sp,#$in1_y
+ add $b_ptr,sp,#$S1
+ add $r_ptr,sp,#$S1
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S1, S1, in1_y);
+
+ add $a_ptr,sp,#$in2_y
+ add $b_ptr,sp,#$S2
+ add $r_ptr,sp,#$S2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S2, S2, in2_y);
+
+ add $b_ptr,sp,#$S1
+ add $r_ptr,sp,#$R
+ bl __ecp_nistz256_sub_from @ p256_sub(R, S2, S1);
+
+ orr $a0,$a0,$a1 @ see if result is zero
+ orr $a2,$a2,$a3
+ orr $a4,$a4,$a5
+ orr $a0,$a0,$a2
+ orr $a4,$a4,$a6
+ orr $a0,$a0,$a7
+ add $a_ptr,sp,#$in1_x
+ orr $a0,$a0,$a4
+ add $b_ptr,sp,#$Z2sqr
+ str $a0,[sp,#32*18+12]
+
+ add $r_ptr,sp,#$U1
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(U1, in1_x, Z2sqr);
+
+ add $a_ptr,sp,#$in2_x
+ add $b_ptr,sp,#$Z1sqr
+ add $r_ptr,sp,#$U2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(U2, in2_x, Z1sqr);
+
+ add $b_ptr,sp,#$U1
+ add $r_ptr,sp,#$H
+ bl __ecp_nistz256_sub_from @ p256_sub(H, U2, U1);
+
+ orr $a0,$a0,$a1 @ see if result is zero
+ orr $a2,$a2,$a3
+ orr $a4,$a4,$a5
+ orr $a0,$a0,$a2
+ orr $a4,$a4,$a6
+ orr $a0,$a0,$a7
+ orrs $a0,$a0,$a4
+
+ bne .Ladd_proceed @ is_equal(U1,U2)?
+
+ ldr $t0,[sp,#32*18+4]
+ ldr $t1,[sp,#32*18+8]
+ ldr $t2,[sp,#32*18+12]
+ tst $t0,$t1
+ beq .Ladd_proceed @ (in1infty || in2infty)?
+ tst $t2,$t2
+ beq .Ladd_proceed @ is_equal(S1,S2)?
+
+ ldr $r_ptr,[sp,#32*18]
+ eor r4,r4,r4
+ eor r5,r5,r5
+ eor r6,r6,r6
+ eor r7,r7,r7
+ eor r8,r8,r8
+ eor r9,r9,r9
+ eor r10,r10,r10
+ eor r11,r11,r11
+ stmia $r_ptr!,{r4-r11}
+ stmia $r_ptr!,{r4-r11}
+ stmia $r_ptr!,{r4-r11}
+ b .Ladd_done
+
+.align 4
+.Ladd_proceed:
+ add $a_ptr,sp,#$R
+ add $b_ptr,sp,#$R
+ add $r_ptr,sp,#$Rsqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Rsqr, R);
+
+ add $a_ptr,sp,#$H
+ add $b_ptr,sp,#$in1_z
+ add $r_ptr,sp,#$res_z
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(res_z, H, in1_z);
+
+ add $a_ptr,sp,#$H
+ add $b_ptr,sp,#$H
+ add $r_ptr,sp,#$Hsqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Hsqr, H);
+
+ add $a_ptr,sp,#$in2_z
+ add $b_ptr,sp,#$res_z
+ add $r_ptr,sp,#$res_z
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(res_z, res_z, in2_z);
+
+ add $a_ptr,sp,#$H
+ add $b_ptr,sp,#$Hsqr
+ add $r_ptr,sp,#$Hcub
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(Hcub, Hsqr, H);
+
+ add $a_ptr,sp,#$Hsqr
+ add $b_ptr,sp,#$U1
+ add $r_ptr,sp,#$U2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(U2, U1, Hsqr);
+
+ add $r_ptr,sp,#$Hsqr
+ bl __ecp_nistz256_mul_by_2 @ p256_mul_by_2(Hsqr, U2);
+
+ add $b_ptr,sp,#$Rsqr
+ add $r_ptr,sp,#$res_x
+ bl __ecp_nistz256_sub_morf @ p256_sub(res_x, Rsqr, Hsqr);
+
+ add $b_ptr,sp,#$Hcub
+ bl __ecp_nistz256_sub_from @ p256_sub(res_x, res_x, Hcub);
+
+ add $b_ptr,sp,#$U2
+ add $r_ptr,sp,#$res_y
+ bl __ecp_nistz256_sub_morf @ p256_sub(res_y, U2, res_x);
+
+ add $a_ptr,sp,#$Hcub
+ add $b_ptr,sp,#$S1
+ add $r_ptr,sp,#$S2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S2, S1, Hcub);
+
+ add $a_ptr,sp,#$R
+ add $b_ptr,sp,#$res_y
+ add $r_ptr,sp,#$res_y
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(res_y, res_y, R);
+
+ add $b_ptr,sp,#$S2
+ bl __ecp_nistz256_sub_from @ p256_sub(res_y, res_y, S2);
+
+ ldr r11,[sp,#32*18+4] @ !in1intfy
+ ldr r12,[sp,#32*18+8] @ !in2intfy
+ add r1,sp,#$res_x
+ add r2,sp,#$in2_x
+ and r10,r11,r12
+ mvn r11,r11
+ add r3,sp,#$in1_x
+ and r11,r11,r12
+ mvn r12,r12
+ ldr $r_ptr,[sp,#32*18]
+___
+for($i=0;$i<96;$i+=8) { # conditional moves
+$code.=<<___;
+ ldmia r1!,{r4-r5} @ res_x
+ ldmia r2!,{r6-r7} @ in2_x
+ ldmia r3!,{r8-r9} @ in1_x
+ and r4,r4,r10
+ and r5,r5,r10
+ and r6,r6,r11
+ and r7,r7,r11
+ and r8,r8,r12
+ and r9,r9,r12
+ orr r4,r4,r6
+ orr r5,r5,r7
+ orr r4,r4,r8
+ orr r5,r5,r9
+ stmia $r_ptr!,{r4-r5}
+___
+}
+$code.=<<___;
+.Ladd_done:
+ add sp,sp,#32*18+16 @ +16 means "skip even over saved r0-r3"
+#if __ARM_ARCH__>=5 || defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.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,
+ $in1_x,$in1_y,$in1_z,
+ $in2_x,$in2_y,
+ $U2,$S2,$H,$R,$Hsqr,$Hcub,$Rsqr)=map(32*$_,(0..14));
+my $Z1sqr = $S2;
+# above map() describes stack layout with 18 temporary
+# 256-bit vectors on top. Then note that we push
+# starting from r0, which means that we have copy of
+# input arguments just below these temporary vectors.
+# We use two of them for !in1infty, !in2intfy.
+
+my @ONE_mont=(1,0,0,-1,-1,-1,-2,0);
+
+$code.=<<___;
+.globl ecp_nistz256_point_add_affine
+.type ecp_nistz256_point_add_affine,%function
+.align 5
+ecp_nistz256_point_add_affine:
+ stmdb sp!,{r0-r12,lr} @ push from r0, unusual, but intentional
+ sub sp,sp,#32*15
+
+ ldmia $a_ptr!,{r4-r11} @ copy in1
+ add r3,sp,#$in1_x
+ orr r12,r4,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $a_ptr!,{r4-r11}
+ orr r12,r12,r4
+ orr r12,r12,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $a_ptr,{r4-r11}
+ cmp r12,#0
+ movne r12,#-1
+ stmia r3,{r4-r11}
+ str r12,[sp,#32*15+4] @ !in1infty
+
+ ldmia $b_ptr!,{r4-r11} @ copy in2
+ add r3,sp,#$in2_x
+ orr r12,r4,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ ldmia $b_ptr!,{r4-r11}
+ orr r12,r12,r4
+ orr r12,r12,r5
+ orr r12,r12,r6
+ orr r12,r12,r7
+ orr r12,r12,r8
+ orr r12,r12,r9
+ orr r12,r12,r10
+ orr r12,r12,r11
+ stmia r3!,{r4-r11}
+ cmp r12,#0
+ movne r12,#-1
+ str r12,[sp,#32*15+8] @ !in2infty
+
+ add $a_ptr,sp,#$in1_z
+ add $b_ptr,sp,#$in1_z
+ add $r_ptr,sp,#$Z1sqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Z1sqr, in1_z);
+
+ add $a_ptr,sp,#$Z1sqr
+ add $b_ptr,sp,#$in2_x
+ add $r_ptr,sp,#$U2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(U2, Z1sqr, in2_x);
+
+ add $b_ptr,sp,#$in1_x
+ add $r_ptr,sp,#$H
+ bl __ecp_nistz256_sub_from @ p256_sub(H, U2, in1_x);
+
+ add $a_ptr,sp,#$Z1sqr
+ add $b_ptr,sp,#$in1_z
+ add $r_ptr,sp,#$S2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S2, Z1sqr, in1_z);
+
+ add $a_ptr,sp,#$H
+ add $b_ptr,sp,#$in1_z
+ add $r_ptr,sp,#$res_z
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(res_z, H, in1_z);
+
+ add $a_ptr,sp,#$in2_y
+ add $b_ptr,sp,#$S2
+ add $r_ptr,sp,#$S2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S2, S2, in2_y);
+
+ add $b_ptr,sp,#$in1_y
+ add $r_ptr,sp,#$R
+ bl __ecp_nistz256_sub_from @ p256_sub(R, S2, in1_y);
+
+ add $a_ptr,sp,#$H
+ add $b_ptr,sp,#$H
+ add $r_ptr,sp,#$Hsqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Hsqr, H);
+
+ add $a_ptr,sp,#$R
+ add $b_ptr,sp,#$R
+ add $r_ptr,sp,#$Rsqr
+ bl _ecp_nistz256_mul_mont @ p256_sqr_mont(Rsqr, R);
+
+ add $a_ptr,sp,#$H
+ add $b_ptr,sp,#$Hsqr
+ add $r_ptr,sp,#$Hcub
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(Hcub, Hsqr, H);
+
+ add $a_ptr,sp,#$Hsqr
+ add $b_ptr,sp,#$in1_x
+ add $r_ptr,sp,#$U2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(U2, in1_x, Hsqr);
+
+ add $r_ptr,sp,#$Hsqr
+ bl __ecp_nistz256_mul_by_2 @ p256_mul_by_2(Hsqr, U2);
+
+ add $b_ptr,sp,#$Rsqr
+ add $r_ptr,sp,#$res_x
+ bl __ecp_nistz256_sub_morf @ p256_sub(res_x, Rsqr, Hsqr);
+
+ add $b_ptr,sp,#$Hcub
+ bl __ecp_nistz256_sub_from @ p256_sub(res_x, res_x, Hcub);
+
+ add $b_ptr,sp,#$U2
+ add $r_ptr,sp,#$res_y
+ bl __ecp_nistz256_sub_morf @ p256_sub(res_y, U2, res_x);
+
+ add $a_ptr,sp,#$Hcub
+ add $b_ptr,sp,#$in1_y
+ add $r_ptr,sp,#$S2
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(S2, in1_y, Hcub);
+
+ add $a_ptr,sp,#$R
+ add $b_ptr,sp,#$res_y
+ add $r_ptr,sp,#$res_y
+ bl _ecp_nistz256_mul_mont @ p256_mul_mont(res_y, res_y, R);
+
+ add $b_ptr,sp,#$S2
+ bl __ecp_nistz256_sub_from @ p256_sub(res_y, res_y, S2);
+
+ ldr r11,[sp,#32*15+4] @ !in1intfy
+ ldr r12,[sp,#32*15+8] @ !in2intfy
+ add r1,sp,#$res_x
+ add r2,sp,#$in2_x
+ and r10,r11,r12
+ mvn r11,r11
+ add r3,sp,#$in1_x
+ and r11,r11,r12
+ mvn r12,r12
+ ldr $r_ptr,[sp,#32*15]
+___
+for($i=0;$i<64;$i+=8) { # conditional moves
+$code.=<<___;
+ ldmia r1!,{r4-r5} @ res_x
+ ldmia r2!,{r6-r7} @ in2_x
+ ldmia r3!,{r8-r9} @ in1_x
+ and r4,r4,r10
+ and r5,r5,r10
+ and r6,r6,r11
+ and r7,r7,r11
+ and r8,r8,r12
+ and r9,r9,r12
+ orr r4,r4,r6
+ orr r5,r5,r7
+ orr r4,r4,r8
+ orr r5,r5,r9
+ stmia $r_ptr!,{r4-r5}
+___
+}
+for(;$i<96;$i+=8) {
+my $j=($i-64)/4;
+$code.=<<___;
+ ldmia r1!,{r4-r5} @ res_z
+ ldmia r3!,{r8-r9} @ in1_z
+ and r4,r4,r10
+ and r5,r5,r10
+ and r6,r11,#@ONE_mont[$j]
+ and r7,r11,#@ONE_mont[$j+1]
+ and r8,r8,r12
+ and r9,r9,r12
+ orr r4,r4,r6
+ orr r5,r5,r7
+ orr r4,r4,r8
+ orr r5,r5,r9
+ stmia $r_ptr!,{r4-r5}
+___
+}
+$code.=<<___;
+ add sp,sp,#32*15+16 @ +16 means "skip even over saved r0-r3"
+#if __ARM_ARCH__>=5 || !defined(__thumb__)
+ ldmia sp!,{r4-r12,pc}
+#else
+ ldmia sp!,{r4-r12,lr}
+ bx lr @ interoperable with Thumb ISA:-)
+#endif
+.size ecp_nistz256_point_add_affine,.-ecp_nistz256_point_add_affine
+___
+} }}}
+
+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; # enforce flush
projects / openssl.git / commitdiff