Montgomery multiplication for MIPS III/IV. Not engaged.

crypto/bn/asm/mips3-mont.pl

+#!/usr/bin/env perl
+#
+# ====================================================================
+# Written by Andy Polyakov <appro@fy.chalmers.se> 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/.
+# ====================================================================
+
+# This module doesn't present direct interest for OpenSSL, because it
+# doesn't provide better performance for longer keys. While 512-bit
+# RSA private key operations are 40% faster, 1024-bit ones are hardly
+# faster at all, while longer key operations are slower by up to 20%.
+# It might be of interest to embedded system developers though, as
+# it's smaller than 1KB, yet offers ~3x improvement over compiler
+# generated code.
+#
+# The module targets N32 and N64 MIPS ABIs and currently is a bit
+# IRIX-centric, i.e. is likely to require adaptation for other OSes.
+
+# int bn_mul_mont(
+$rp="a0";	# BN_ULONG *rp,
+$ap="a1";	# const BN_ULONG *ap,
+$bp="a2";	# const BN_ULONG *bp,
+$np="a3";	# const BN_ULONG *np,
+$n0="a4";	# const BN_ULONG *n0,
+$num="a5";	# int num);
+
+$lo0="a6";
+$hi0="a7";
+$lo1="v0";
+$hi1="v1";
+$aj="t0";
+$bi="t1";
+$nj="t2";
+$tp="t3";
+$alo="s0";
+$ahi="s1";
+$nlo="s2";
+$nhi="s3";
+$tj="s4";
+$i="s5";
+$j="s6";
+$fp="t8";
+$m1="t9";
+
+$FRAME=8*(2+8);
+
+$code=<<___;
+#include <asm.h>
+#include <regdef.h>
+
+.text
+
+.set	noat
+.set	reorder
+
+.align	5
+.globl	bn_mul_mont
+.ent	bn_mul_mont
+bn_mul_mont:
+	.set	noreorder
+	PTR_SUB	sp,64
+	move	$fp,sp
+	.frame	$fp,64,ra
+	slt	AT,$num,4
+	li	v0,0
+	beqzl	AT,.Lproceed
+	nop
+	jr	ra
+	PTR_ADD	sp,$fp,64
+	.set	reorder
+.align	5
+.Lproceed:
+	ld	$n0,0($n0)
+	ld	$bi,0($bp)	# bp[0]
+	ld	$aj,0($ap)	# ap[0]
+	ld	$nj,0($np)	# np[0]
+	PTR_SUB	sp,16		# place for two extra words
+	sll	$num,3
+	li	AT,-4096
+	PTR_SUB	sp,$num
+	and	sp,AT
+
+	sd	s0,0($fp)
+	sd	s1,8($fp)
+	sd	s2,16($fp)
+	sd	s3,24($fp)
+	sd	s4,32($fp)
+	sd	s5,40($fp)
+	sd	s6,48($fp)
+	sd	s7,56($fp)
+
+	dmultu	$aj,$bi
+	ld	$alo,8($ap)
+	ld	$nlo,8($np)
+	mflo	$lo0
+	mfhi	$hi0
+	dmultu	$lo0,$n0
+	mflo	$m1
+
+	dmultu	$alo,$bi
+	mflo	$alo
+	mfhi	$ahi
+
+	dmultu	$nj,$m1
+	mflo	$lo1
+	mfhi	$hi1
+	dmultu	$nlo,$m1
+	daddu	$lo1,$lo0
+	sltu	AT,$lo1,$lo0
+	daddu	$hi1,AT
+	mflo	$nlo
+	mfhi	$nhi
+
+	move	$tp,sp
+	li	$j,16
+.align	4
+.L1st:
+	.set	noreorder
+	PTR_ADD	$aj,$ap,$j
+	ld	$aj,($aj)
+	PTR_ADD	$nj,$np,$j
+	ld	$nj,($nj)
+
+	dmultu	$aj,$bi
+	daddu	$lo0,$alo,$hi0
+	daddu	$lo1,$nlo,$hi1
+	sltu	AT,$lo0,$hi0
+	sltu	s7,$lo1,$hi1
+	daddu	$hi0,$ahi,AT
+	daddu	$hi1,$nhi,s7
+	mflo	$alo
+	mfhi	$ahi
+
+	daddu	$lo1,$lo0
+	sltu	AT,$lo1,$lo0
+	dmultu	$nj,$m1
+	daddu	$hi1,AT
+	addu	$j,8
+	sd	$lo1,($tp)
+	sltu	s7,$j,$num
+	mflo	$nlo
+	mfhi	$nhi
+
+	bnez	s7,.L1st
+	PTR_ADD	$tp,8
+	.set	reorder
+
+	daddu	$lo0,$alo,$hi0
+	sltu	AT,$lo0,$hi0
+	daddu	$hi0,$ahi,AT
+
+	daddu	$lo1,$nlo,$hi1
+	sltu	s7,$lo1,$hi1
+	daddu	$hi1,$nhi,s7
+	daddu	$lo1,$lo0
+	sltu	AT,$lo1,$lo0
+	daddu	$hi1,AT
+
+	sd	$lo1,($tp)
+
+	daddu	$hi1,$hi0
+	sltu	AT,$hi1,$hi0
+	sd	$hi1,8($tp)
+	sd	AT,16($tp)
+
+	li	$i,8
+.align	4
+.Louter:
+	PTR_ADD	$bi,$bp,$i
+	ld	$bi,($bi)
+	ld	$aj,($ap)
+	ld	$alo,8($ap)
+	ld	$tj,(sp)
+
+	dmultu	$aj,$bi
+	ld	$nj,($np)
+	ld	$nlo,8($np)
+	mflo	$lo0
+	mfhi	$hi0
+	daddu	$lo0,$tj
+	dmultu	$lo0,$n0
+	sltu	AT,$lo0,$tj
+	daddu	$hi0,AT
+	mflo	$m1
+
+	dmultu	$alo,$bi
+	mflo	$alo
+	mfhi	$ahi
+
+	dmultu	$nj,$m1
+	mflo	$lo1
+	mfhi	$hi1
+
+	dmultu	$nlo,$m1
+	daddu	$lo1,$lo0
+	sltu	AT,$lo1,$lo0
+	daddu	$hi1,AT
+	mflo	$nlo
+	mfhi	$nhi
+
+	move	$tp,sp
+	li	$j,16
+	ld	$tj,8($tp)
+.align	4
+.Linner:
+	.set	noreorder
+	PTR_ADD	$aj,$ap,$j
+	ld	$aj,($aj)
+	PTR_ADD	$nj,$np,$j
+	ld	$nj,($nj)
+
+	dmultu	$aj,$bi
+	daddu	$lo0,$alo,$hi0
+	daddu	$lo1,$nlo,$hi1
+	sltu	AT,$lo0,$hi0
+	sltu	s7,$lo1,$hi1
+	daddu	$hi0,$ahi,AT
+	daddu	$hi1,$nhi,s7
+	mflo	$alo
+	mfhi	$ahi
+
+	daddu	$lo0,$tj
+	addu	$j,8
+	dmultu	$nj,$m1
+	sltu	AT,$lo0,$tj
+	daddu	$lo1,$lo0
+	daddu	$hi0,AT
+	sltu	s7,$lo1,$lo0
+	ld	$tj,16($tp)
+	daddu	$hi1,s7
+	sltu	AT,$j,$num
+	mflo	$nlo
+	mfhi	$nhi
+	sd	$lo1,($tp)
+	bnez	AT,.Linner
+	PTR_ADD	$tp,8
+	.set	reorder
+
+	daddu	$lo0,$alo,$hi0
+	sltu	AT,$lo0,$hi0
+	daddu	$hi0,$ahi,AT
+	daddu	$lo0,$tj
+	sltu	s7,$lo0,$tj
+	daddu	$hi0,s7
+
+	ld	$tj,16($tp)
+	daddu	$lo1,$nlo,$hi1
+	sltu	AT,$lo1,$hi1
+	daddu	$hi1,$nhi,AT
+	daddu	$lo1,$lo0
+	sltu	s7,$lo1,$lo0
+	daddu	$hi1,s7
+	sd	$lo1,($tp)
+
+	daddu	$lo1,$hi1,$hi0
+	sltu	$hi1,$lo1,$hi0
+	daddu	$lo1,$tj
+	sltu	AT,$lo1,$tj
+	daddu	$hi1,AT
+	sd	$lo1,8($tp)
+	sd	$hi1,16($tp)
+
+	addu	$i,8
+	sltu	s7,$i,$num
+	bnez	s7,.Louter
+
+	.set	noreorder
+	PTR_ADD	$ap,sp,$num
+	move	$tp,sp
+
+	bnez	$hi1,.Lsub
+	li	$hi0,0
+	sgeu	AT,$lo1,$nj
+	beqz	AT,.Lsub
+	nop
+
+.align	4
+.Lcopy:	ld	AT,($tp)
+	PTR_ADD	$tp,8
+	sd	AT,($rp)
+	sltu	AT,$tp,$ap
+	sd	zero,-8($tp)
+	bnez	AT,.Lcopy
+	PTR_ADD	$rp,8
+
+.Lexit:
+	ld	s0,0($fp)
+	ld	s1,8($fp)
+	ld	s2,16($fp)
+	ld	s3,24($fp)
+	ld	s4,32($fp)
+	ld	s5,40($fp)
+	ld	s6,48($fp)
+	ld	s7,56($fp)
+	li	v0,1
+	jr	ra
+	PTR_ADD	sp,$fp,64
+
+.align	4
+.Lsub:	ld	$lo0,($tp)
+	ld	$lo1,($np)
+	dsubu	$lo1,$lo0,$lo1
+	sgtu	AT,$lo1,$lo0
+	dsubu	$lo0,$lo1,$hi0
+	sgtu	$hi0,$lo0,$lo1
+	PTR_ADD	$tp,8
+	or	$hi0,AT
+	PTR_ADD	$np,8
+	sd	$lo0,($rp)
+	sltu	AT,$tp,$ap
+	bnez	AT,.Lsub
+	PTR_ADD	$rp,8
+
+	dsubu	$hi0,$hi1,$hi0
+	move	$tp,sp
+	sgtu	AT,$hi0,$hi1
+	bnez	AT,.Lcopy
+	PTR_SUB	$rp,$num
+.align	4
+.Lzap:	sd	zero,($tp)
+	sltu	AT,$tp,$ap
+	bnez	AT,.Lzap
+	PTR_ADD	$tp,8
+	b	.Lexit
+	nop
+	.set	reorder
+END(bn_mul_mont)
+.rdata
+.asciiz	"Montgomery Multiplication for MIPS III/IV, CRYPTOGAMS by <appro\@openssl.org>"
+___
+
+print $code;
+close STDOUT;