dnl  ARM mpn_rsh1add_n and mpn_rsh1sub_n.

dnl  Contributed to the GNU project by Torbjörn Granlund.

dnl  Copyright 2012 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 StrongARM	 ?

C XScale	 ?

C Cortex-A7	 ?

C Cortex-A8	 ?

C Cortex-A9	3.64-3.7

C Cortex-A15	 2.5

C TODO

C  * Not optimised.

define(`rp', `r0')

define(`up', `r1')

define(`vp', `r2')

define(`n',  `r3')

ifdef(`OPERATION_rsh1add_n', `

  define(`ADDSUB',	adds)

  define(`ADDSUBC',	adcs)

  define(`RSTCY',	`cmn	$1, $1')

  define(`func',	mpn_rsh1add_n)

  define(`func_nc',	mpn_rsh1add_nc)')

ifdef(`OPERATION_rsh1sub_n', `

  define(`ADDSUB',	subs)

  define(`ADDSUBC',	sbcs)

  define(`RSTCY',

	`mvn	$2, #0x80000000

	cmp	$2, $1')

  define(`func',	mpn_rsh1sub_n)

  define(`func_nc',	mpn_rsh1sub_nc)')

MULFUNC_PROLOGUE(mpn_rsh1add_n mpn_rsh1sub_n)

ASM_START()

PROLOGUE(func)

	push	{r4-r11}

	ldr	r4, [up], #4

	ldr	r8, [vp], #4

	ADDSUB	r4, r4, r8

	movs	r12, r7, rrx

	and	r11, r4, #1	C return value

	subs	n, n, #4

	blo	L(end)

L(top):	ldmia	up!, {r5,r6,r7}

	ldmia	vp!, {r8,r9,r10}

	cmn	r12, r12

	ADDSUBC	r5, r5, r8

	ADDSUBC	r6, r6, r9

	ADDSUBC	r7, r7, r10

	movs	r12, r7, rrx

	movs	r6, r6, rrx

	movs	r5, r5, rrx

	movs	r4, r4, rrx

	subs	n, n, #3

	stmia	rp!, {r4,r5,r6}

	mov	r4, r7

	bhs	L(top)

L(end):	cmn	n, #2

	bls	L(e2)

	ldm	up, {r5,r6}

	ldm	vp, {r8,r9}

	cmn	r12, r12

	ADDSUBC	r5, r5, r8

	ADDSUBC	r6, r6, r9

	movs	r12, r6, rrx

	movs	r5, r5, rrx

	movs	r4, r4, rrx

	stmia	rp!, {r4,r5}

	mov	r4, r6

	b	L(e1)

L(e2):	bne	L(e1)

	ldr	r5, [up, #0]

	ldr	r8, [vp, #0]

	cmn	r12, r12

	ADDSUBC	r5, r5, r8

	movs	r12, r5, rrx

	movs	r4, r4, rrx

	str	r4, [rp], #4

	mov	r4, r5

L(e1):	RSTCY(	r12, r1)

	mov	r4, r4, rrx

	str	r4, [rp, #0]

	mov	r0, r11

	pop	{r4-r11}

	ret	r14

EPILOGUE()