/* mpn_submul_1 -- multiply and subtract bignums.

   Copyright (C) 2013-2018 Free Software Foundation, Inc.

   This file is part of the GNU C Library.

   The GNU C Library is free software; you can redistribute it and/or

   modify it under the terms of the GNU Lesser General Public

   License as published by the Free Software Foundation; either

   version 2.1 of the License, or (at your option) any later version.

   The GNU C Library is distributed in the hope that it will be useful,

   but WITHOUT ANY WARRANTY; without even the implied warranty of

   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

   Lesser General Public License for more details.

   You should have received a copy of the GNU Lesser General Public

   License along with the GNU C Library.  If not, see

   <http://www.gnu.org/licenses/>.  */

#include <sysdep.h>

	.syntax unified

	.text

@		cycles/limb

@ StrongArm	   ?

@ Cortex-A8	   ?

@ Cortex-A9	   ?

@ Cortex-A15	   4

/* mp_limb_t mpn_submul_1(res_ptr, src1_ptr, size, s2_limb) */

ENTRY (__mpn_submul_1)

	push	{ r4, r5, r6, r7 }

	cfi_adjust_cfa_offset (16)

	cfi_rel_offset (r4, 0)

	cfi_rel_offset (r5, 4)

	cfi_rel_offset (r6, 8)

	cfi_rel_offset (r7, 12)

	ldr	r6, [r1], #4

	ldr	r7, [r0]

	mov	r4, #0			/* init carry in */

	b	1f

0:

	ldr	r6, [r1], #4		/* load next ul */

	adds	r5, r5, r4		/* (lpl, c) = lpl + cl */

	adc	r4, ip, #0		/* cl = hpl + c */

	subs	r5, r7, r5		/* (lpl, !c) = rl - lpl */

	ldr	r7, [r0, #4]		/* load next rl */

	it	cc

	addcc	r4, r4, #1		/* cl += !c */

	str	r5, [r0], #4

1:

	umull	r5, ip, r6, r3		/* (hpl, lpl) = ul * vl */

	subs	r2, r2, #1

	bne	0b

	adds	r5, r5, r4		/* (lpl, c) = lpl + cl */

	adc	r4, ip, #0		/* cl = hpl + c */

	subs	r5, r7, r5		/* (lpl, !c) = rl - lpl */

	str	r5, [r0], #4

	it	cc

	addcc	r4, r4, #1		/* cl += !c */

	mov	r0, r4			/* return carry */

	pop	{ r4, r5, r6, r7 }

	DO_RET	(lr)

END (__mpn_submul_1)