addmul_3.asm

RSA 大整数运算源码

dnl  Alpha ev6 nails mpn_addmul_3.

dnl  Copyright 2002, 2006 Free Software Foundation, Inc.
dnl
dnl  This file is part of the GNU MP Library.
dnl
dnl  The GNU MP Library is free software; you can redistribute it and/or
dnl  modify it under the terms of the GNU Lesser General Public License as
dnl  published by the Free Software Foundation; either version 3 of the
dnl  License, or (at your option) any later version.
dnl
dnl  The GNU MP Library is distributed in the hope that it will be useful,
dnl  but WITHOUT ANY WARRANTY; without even the implied warranty of
dnl  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
dnl  Lesser General Public License for more details.
dnl
dnl  You should have received a copy of the GNU Lesser General Public License
dnl  along with the GNU MP Library.  If not, see http://www.gnu.org/licenses/.


dnl  Runs at 3.0 cycles/limb.  With unrolling, the ulimb load and the 3
dnl  bookkeeping increments and the `bis' that copies from r22 to r6 could be
dnl  removed and the instruction count reduced from 26 to to 21.  We could
dnl  thereby probably reach 2 cycles/limb, the IMUL bandwidth.

include(`../config.m4')

dnl  INPUT PARAMETERS
define(`rp',`r16')
define(`up',`r17')
define(`n',`r18')
define(`vp',`r19')

dnl  Useful register aliases
define(`numb_mask',`r24')
define(`ulimb',`r25')
define(`rlimb',`r27')

define(`m0a',`r0')
define(`m0b',`r1')
define(`m1a',`r2')
define(`m1b',`r3')
define(`m2a',`r20')
define(`m2b',`r21')

define(`acc0',`r4')
define(`acc1',`r5')
define(`acc2',`r22')

define(`v0',`r6')
define(`v1',`r7')
define(`v2',`r23')

dnl Used for temps: r8 r19 r28

define(`NAIL_BITS',`GMP_NAIL_BITS')
define(`NUMB_BITS',`GMP_NUMB_BITS')

dnl  This declaration is munged by configure
NAILS_SUPPORT(3-63)

ASM_START()
PROLOGUE(mpn_addmul_3)
	lda	numb_mask,-1(r31)
	srl	numb_mask,NAIL_BITS,numb_mask

	ldq	v0,	0(vp)
	ldq	v1,	8(vp)
	ldq	v2,	16(vp)

	bis	r31,	r31,	acc0		C	zero acc0
	sll	v0,NAIL_BITS,	v0
	bis	r31,	r31,	acc1		C	zero acc1
	sll	v1,NAIL_BITS,	v1
	bis	r31,	r31,	acc2		C	zero acc2
	sll	v2,NAIL_BITS,	v2
	bis	r31,	r31,	r19

	ldq	ulimb,	0(up)
	lda	up,	8(up)
	mulq	v0,	ulimb,	m0a		C U1
	umulh	v0,	ulimb,	m0b		C U1
	mulq	v1,	ulimb,	m1a		C U1
	umulh	v1,	ulimb,	m1b		C U1
	lda	n,	-1(n)
	mulq	v2,	ulimb,	m2a		C U1
	umulh	v2,	ulimb,	m2b		C U1
	beq	n,	L(end)			C U0
	ALIGN(16)
L(top):	bis	r31,	r31,	r31		C	nop
	ldq	rlimb,	0(rp)
	ldq	ulimb,	0(up)
	addq	r19,	acc0,	acc0		C	propagate nail

	lda	rp,	8(rp)
	srl	m0a,NAIL_BITS,	r8		C U0
	lda	up,	8(up)
	mulq	v0,	ulimb,	m0a		C U1

	addq	r8,	acc0,	r19
	addq	m0b,	acc1,	acc0
	umulh	v0,	ulimb,	m0b		C U1
	bis	r31,	r31,	r31		C	nop

	addq	rlimb,	r19,	r19
	srl	m1a,NAIL_BITS,	r8		C U0
	bis	r31,	r31,	r31		C	nop
	mulq	v1,	ulimb,	m1a		C U1

	addq	r8,	acc0,	acc0
	addq	m1b,	acc2,	acc1
	umulh	v1,	ulimb,	m1b		C U1
	and	r19,numb_mask,	r28		C	extract numb part

	bis	r31,	r31,	r31		C	nop
	srl	m2a,NAIL_BITS,	r8		C U0
	lda	n,	-1(n)
	mulq	v2,	ulimb,	m2a		C U1

	addq	r8,	acc1,	acc1
	bis	r31,	m2b,	acc2
	umulh	v2,	ulimb,	m2b		C U1
	srl	r19,NUMB_BITS,	r19		C	extract nail part

	bis	r31,	r31,	r31		C	nop
	stq	r28,	-8(rp)

	bne	n,	L(top)			C U0

L(end):	ldq	rlimb,	0(rp)
	addq	r19,	acc0,	acc0		C	propagate nail
	lda	rp,	8(rp)
	srl	m0a,NAIL_BITS,	r8		C U0
	addq	r8,	acc0,	r19
	addq	m0b,	acc1,	acc0
	addq	rlimb,	r19,	r19
	srl	m1a,NAIL_BITS,	r8		C U0
	addq	r8,	acc0,	acc0
	addq	m1b,	acc2,	acc1
	and	r19,numb_mask,	r28		C extract limb
	srl	m2a,NAIL_BITS,	r8		C U0
	addq	r8,	acc1,	acc1
	bis	r31,	m2b,	acc2
	srl	r19,NUMB_BITS,	r19		C extract nail
	stq	r28,	-8(rp)

	addq	r19,	acc0,	acc0		C propagate nail
	and	acc0,numb_mask,	r28
	stq	r28,	0(rp)
	srl	acc0,NUMB_BITS,	r19
	addq	r19,	acc1,	acc1

	and	acc1,numb_mask,	r28
	stq	r28,	8(rp)
	srl	acc1,NUMB_BITS,	r19
	addq	r19,	acc2,	m0a

	ret	r31,	(r26),	1
EPILOGUE()
ASM_END()