submul_1.asm

a very popular packet of cryptography tools,it encloses the most common used algorithm and protocols

dnl  HP-PA 2.0 64-bit mpn_submul_1 -- Multiply a limb vector with a limb and
dnl  subtract the result from a second limb vector.

dnl  Copyright 1998, 1999, 2000, 2002, 2003 Free Software Foundation, Inc.

dnl  This file is part of the GNU MP Library.

dnl  The GNU MP Library is free software; you can redistribute it and/or modify
dnl  it under the terms of the GNU Lesser General Public License as published
dnl  by the Free Software Foundation; either version 2.1 of the License, or (at
dnl  your option) any later version.

dnl  The GNU MP Library is distributed in the hope that it will be useful, but
dnl  WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
dnl  or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
dnl  License for more details.

dnl  You should have received a copy of the GNU Lesser General Public License
dnl  along with the GNU MP Library; see the file COPYING.LIB.  If not, write to
dnl  the Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
dnl  MA 02111-1307, USA.


dnl  This approaches ?? cycles/limb on PA8000 and 6.75 cycles/limb on PA8500
dnl  for huge operands.

dnl  The feed-in and wind-down code has not yet been scheduled.  Many cycles
dnl  could be saved there per call.

dnl  DESCRIPTION:
dnl  The main loop "BIG" is 4-way unrolled, mainly to allow
dnl  effective use of ADD,DC.  Delays in moving data via the cache from the FP
dnl  registers to the IU registers, have demaned a deep software pipeline, and
dnl  a lot of stack slots for partial products in flight.
dnl
dnl  CODE STRUCTURE:
dnl  save-some-registers
dnl  do 0, 1, 2, or 3 limbs
dnl  if done, restore-some-regs and return
dnl  save-many-regs
dnl  do 4, 8, ... limb
dnl  restore-all-regs

dnl  STACK LAYOUT:
dnl  HP-PA stack grows upwards.  We could allocate 8 fewer slots by using the
dnl  slots marked FREE, as well as some slots in the caller's "frame marker".
dnl
dnl -00 <- r30
dnl -08  FREE
dnl -10  tmp
dnl -18  tmp
dnl -20  tmp
dnl -28  tmp
dnl -30  tmp
dnl -38  tmp
dnl -40  tmp
dnl -48  tmp
dnl -50  tmp
dnl -58  tmp
dnl -60  tmp
dnl -68  tmp
dnl -70  tmp
dnl -78  tmp
dnl -80  tmp
dnl -88  tmp
dnl -90  FREE
dnl -98  FREE
dnl -a0  FREE
dnl -a8  FREE
dnl -b0  r13
dnl -b8  r12
dnl -c0  r11
dnl -c8  r10
dnl -d0  r8
dnl -d8  r8
dnl -e0  r7
dnl -e8  r6
dnl -f0  r5
dnl -f8  r4
dnl -100 r3
dnl  Previous frame:
dnl  [unused area]
dnl -38/-138 vlimb home slot.  For 2.0N, the vlimb arg will arrive here.


include(`../config.m4')

dnl INPUT PARAMETERS:
define(`rp',`%r26')	dnl
define(`up',`%r25')	dnl
define(`n',`%r24')	dnl
define(`vlimb',`%r23')	dnl

define(`climb',`%r23')	dnl

ifdef(`HAVE_ABI_2_0w',
`	.level	2.0w
',`	.level	2.0
')
PROLOGUE(mpn_submul_1)

ifdef(`HAVE_ABI_2_0w',
`	std		vlimb, -0x38(%r30)	C store vlimb into "home" slot
')
	std,ma		%r3, 0x100(%r30)
	std		%r4, -0xf8(%r30)
	std		%r5, -0xf0(%r30)
	ldo		0(%r0), climb		C clear climb
	fldd		-0x138(%r30), %fr8	C put vlimb in fp register

define(`p032a1',`%r1')	dnl
define(`p032a2',`%r19')	dnl

define(`m032',`%r20')	dnl
define(`m096',`%r21')	dnl

define(`p000a',`%r22')	dnl
define(`p064a',`%r29')	dnl

define(`s000',`%r31')	dnl

define(`ma000',`%r4')	dnl
define(`ma064',`%r20')	dnl

define(`r000',`%r3')	dnl

	extrd,u		n, 63, 2, %r5
	cmpb,=		%r5, %r0, L(BIG)
	nop

	fldd		0(up), %fr4
	ldo		8(up), up
	xmpyu		%fr8R, %fr4L, %fr22
	xmpyu		%fr8L, %fr4R, %fr23
	fstd		%fr22, -0x78(%r30)	C mid product to  -0x78..-0x71
	xmpyu		%fr8R, %fr4R, %fr24
	xmpyu		%fr8L, %fr4L, %fr25
	fstd		%fr23, -0x70(%r30)	C mid product to  -0x70..-0x69
	fstd		%fr24, -0x80(%r30)	C low product to  -0x80..-0x79
	addib,<>	-1, %r5, L(two_or_more)
	fstd		%fr25, -0x68(%r30)	C high product to -0x68..-0x61
L(one)
	ldd		-0x78(%r30), p032a1
	ldd		-0x70(%r30), p032a2
	ldd		-0x80(%r30), p000a
	b		L(0_one_out)
	ldd		-0x68(%r30), p064a

L(two_or_more)
	fldd		0(up), %fr4
	ldo		8(up), up
	xmpyu		%fr8R, %fr4L, %fr22
	xmpyu		%fr8L, %fr4R, %fr23
	ldd		-0x78(%r30), p032a1
	fstd		%fr22, -0x78(%r30)	C mid product to  -0x78..-0x71
	xmpyu		%fr8R, %fr4R, %fr24
	xmpyu		%fr8L, %fr4L, %fr25
	ldd		-0x70(%r30), p032a2
	fstd		%fr23, -0x70(%r30)	C mid product to  -0x70..-0x69
	ldd		-0x80(%r30), p000a
	fstd		%fr24, -0x80(%r30)	C low product to  -0x80..-0x79
	ldd		-0x68(%r30), p064a
	addib,<>	-1, %r5, L(three_or_more)
	fstd		%fr25, -0x68(%r30)	C high product to -0x68..-0x61
L(two)
	add		p032a1, p032a2, m032
	add,dc		%r0, %r0, m096
	depd,z		m032, 31, 32, ma000
	extrd,u		m032, 31, 32, ma064
	ldd		0(rp), r000
	b		L(0_two_out)
	depd		m096, 31, 32, ma064

L(three_or_more)
	fldd		0(up), %fr4
	add		p032a1, p032a2, m032
	add,dc		%r0, %r0, m096
	depd,z		m032, 31, 32, ma000
	extrd,u		m032, 31, 32, ma064
	ldd		0(rp), r000
dnl	addib,=		-1, %r5, L(0_out)
	depd		m096, 31, 32, ma064
L(oop0)
dnl	xmpyu		%fr8R, %fr4L, %fr22
dnl	xmpyu		%fr8L, %fr4R, %fr23
dnl	ldd		-0x78(%r30), p032a1
dnl	fstd		%fr22, -0x78(%r30)	C mid product to  -0x78..-0x71
dnl
dnl	xmpyu		%fr8R, %fr4R, %fr24
dnl	xmpyu		%fr8L, %fr4L, %fr25
dnl	ldd		-0x70(%r30), p032a2
dnl	fstd		%fr23, -0x70(%r30)	C mid product to  -0x70..-0x69
dnl
dnl	ldo		8(rp), rp
dnl	add		climb, p000a, s000
dnl	ldd		-0x80(%r30), p000a
dnl	fstd		%fr24, -0x80(%r30)	C low product to  -0x80..-0x79
dnl
dnl	add,dc		p064a, %r0, climb
dnl	ldo		8(up), up
dnl	ldd		-0x68(%r30), p064a
dnl	fstd		%fr25, -0x68(%r30)	C high product to -0x68..-0x61
dnl
dnl	add		ma000, s000, s000
dnl	add,dc		ma064, climb, climb
dnl	fldd		0(up), %fr4
dnl
dnl	sub		r000, s000, s000
dnl	sub,db		%r0, climb, climb
dnl	sub		%r0, climb, climb
dnl	std		s000, -8(rp)
dnl
dnl	add		p032a1, p032a2, m032
dnl	add,dc		%r0, %r0, m096
dnl
dnl	depd,z		m032, 31, 32, ma000
dnl	extrd,u		m032, 31, 32, ma064
dnl	ldd		0(rp), r000
dnl	addib,<>	-1, %r5, L(oop0)
dnl	depd		m096, 31, 32, ma064
L(0_out)
	ldo		8(up), up
	xmpyu		%fr8R, %fr4L, %fr22
	xmpyu		%fr8L, %fr4R, %fr23
	ldd		-0x78(%r30), p032a1
	fstd		%fr22, -0x78(%r30)	C mid product to  -0x78..-0x71
	xmpyu		%fr8R, %fr4R, %fr24
	xmpyu		%fr8L, %fr4L, %fr25
	ldd		-0x70(%r30), p032a2
	fstd		%fr23, -0x70(%r30)	C mid product to  -0x70..-0x69
	ldo		8(rp), rp
	add		climb, p000a, s000
	ldd		-0x80(%r30), p000a
	fstd		%fr24, -0x80(%r30)	C low product to  -0x80..-0x79
	add,dc		p064a, %r0, climb
	ldd		-0x68(%r30), p064a
	fstd		%fr25, -0x68(%r30)	C high product to -0x68..-0x61
	add		ma000, s000, s000
	add,dc		ma064, climb, climb
	sub		r000, s000, s000
	sub,db		%r0, climb, climb
	sub		%r0, climb, climb
	std		s000, -8(rp)
	add		p032a1, p032a2, m032
	add,dc		%r0, %r0, m096
	depd,z		m032, 31, 32, ma000
	extrd,u		m032, 31, 32, ma064
	ldd		0(rp), r000
	depd		m096, 31, 32, ma064
L(0_two_out)
	ldd		-0x78(%r30), p032a1
	ldd		-0x70(%r30), p032a2
	ldo		8(rp), rp
	add		climb, p000a, s000
	ldd		-0x80(%r30), p000a
	add,dc		p064a, %r0, climb
	ldd		-0x68(%r30), p064a
	add		ma000, s000, s000
	add,dc		ma064, climb, climb
	sub		r000, s000, s000
	sub,db		%r0, climb, climb
	sub		%r0, climb, climb
	std		s000, -8(rp)
L(0_one_out)
	add		p032a1, p032a2, m032
	add,dc		%r0, %r0, m096
	depd,z		m032, 31, 32, ma000
	extrd,u		m032, 31, 32, ma064
	ldd		0(rp), r000
	depd		m096, 31, 32, ma064

	add		climb, p000a, s000
	add,dc		p064a, %r0, climb
	add		ma000, s000, s000
	add,dc		ma064, climb, climb
	sub		r000, s000, s000
	sub,db		%r0, climb, climb
	sub		%r0, climb, climb
	std		s000, 0(rp)

	cmpib,>=	4, n, L(done)
	ldo		8(rp), rp

dnl 4-way unrolled code.

L(BIG)

define(`p032a1',`%r1')	dnl
define(`p032a2',`%r19')	dnl
define(`p096b1',`%r20')	dnl
define(`p096b2',`%r21')	dnl
define(`p160c1',`%r22')	dnl
define(`p160c2',`%r29')	dnl
define(`p224d1',`%r31')	dnl
define(`p224d2',`%r3')	dnl
			dnl
define(`m032',`%r4')	dnl
define(`m096',`%r5')	dnl
define(`m160',`%r6')	dnl
define(`m224',`%r7')	dnl
define(`m288',`%r8')	dnl
			dnl
define(`p000a',`%r1')	dnl
define(`p064a',`%r19')	dnl
define(`p064b',`%r20')	dnl
define(`p128b',`%r21')	dnl
define(`p128c',`%r22')	dnl
define(`p192c',`%r29')	dnl
define(`p192d',`%r31')	dnl
define(`p256d',`%r3')	dnl
			dnl
define(`s000',`%r10')	dnl
define(`s064',`%r11')	dnl
define(`s128',`%r12')	dnl
define(`s192',`%r13')	dnl
			dnl
define(`ma000',`%r9')	dnl
define(`ma064',`%r4')	dnl
define(`ma128',`%r5')	dnl
define(`ma192',`%r6')	dnl
define(`ma256',`%r7')	dnl
			dnl
define(`r000',`%r1')	dnl
define(`r064',`%r19')	dnl
define(`r128',`%r20')	dnl
define(`r192',`%r21')	dnl

	std		%r6, -0xe8(%r30)
	std		%r7, -0xe0(%r30)
	std		%r8, -0xd8(%r30)
	std		%r9, -0xd0(%r30)
	std		%r10, -0xc8(%r30)
	std		%r11, -0xc0(%r30)
	std		%r12, -0xb8(%r30)
	std		%r13, -0xb0(%r30)

ifdef(`HAVE_ABI_2_0w',
`	extrd,u		n, 61, 62, n		C right shift 2
',`	extrd,u		n, 61, 30, n		C right shift 2, zero extend
')

L(4_or_more)
	fldd		0(up), %fr4
	fldd		8(up), %fr5
	fldd		16(up), %fr6