Training courses

Kernel and Embedded Linux

Bootlin training courses

Embedded Linux, kernel,
Yocto Project, Buildroot, real-time,
graphics, boot time, debugging...

Bootlin logo

Elixir Cross Referencer

dnl  ARM64 mpn_mul_1

dnl  Contributed to the GNU project by Torbjörn Granlund.

dnl  Copyright 2013 Free Software Foundation, Inc.

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 modify
dnl  it under the terms of either:
dnl
dnl    * the GNU Lesser General Public License as published by the Free
dnl      Software Foundation; either version 3 of the License, or (at your
dnl      option) any later version.
dnl
dnl  or
dnl
dnl    * the GNU General Public License as published by the Free Software
dnl      Foundation; either version 2 of the License, or (at your option) any
dnl      later version.
dnl
dnl  or both in parallel, as here.
dnl
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 General Public License
dnl  for more details.
dnl
dnl  You should have received copies of the GNU General Public License and the
dnl  GNU Lesser General Public License along with the GNU MP Library.  If not,
dnl  see https://www.gnu.org/licenses/.

include(`../config.m4')

C	     cycles/limb
C Cortex-A53	 ?
C Cortex-A57	 ?

define(`rp', `x0')
define(`up', `x1')
define(`n',  `x2')
define(`v0', `x3')

ASM_START()
PROLOGUE(mpn_mul_1)
	ldr	x12, [up], #8
	and	x6, n, #3
	and	n, n, #-4
	cbz	x6, L(fi0)
	cmp	x6, #2
	b.cc	L(fi1)
	b.eq	L(fi2)

L(fi3):	mul	x8, x12, v0
	umulh	x13, x12, v0
	cmn	xzr, xzr
	b	L(L3)
L(fi2):	mul	x7, x12, v0
	umulh	x5, x12, v0
	cmn	xzr, xzr
	b	L(L2)
L(fi0):	mul	x9, x12, v0
	umulh	x5, x12, v0
	sub	n, n, #4
	cmn	xzr, xzr
	b	L(L0)
L(fi1):	mul	x10, x12, v0
	umulh	x13, x12, v0
	cmn	xzr, xzr
	cbz	n, L(end)

L(top):	sub	n, n, #4
	ldr	x12, [up], #8
	mul	x6, x12, v0
	umulh	x5, x12, v0
	str	x10, [rp], #8
	adcs	x9, x6, x13
L(L0):	ldr	x12, [up], #8
	mul	x6, x12, v0
	umulh	x13, x12, v0
	str	x9, [rp] ,#8
	adcs	x8, x6, x5
L(L3):	ldr	x12, [up], #8
	mul	x6, x12, v0
	umulh	x5, x12, v0
	str	x8, [rp], #8
	adcs	x7, x6, x13
L(L2):	ldr	x12, [up], #8
	mul	x6, x12, v0
	umulh	x13, x12, v0
	str	x7, [rp], #8
	adcs	x10, x6, x5
	cbnz	n, L(top)

L(end):	str	x10, [rp]
	adc	x0, x13, xzr
	ret
EPILOGUE()