/* Copyright (C) 2012-2018 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>

#include "ucontext_i.h"

	.syntax unified

	.text

/* int swapcontext (ucontext_t *oucp, const ucontext_t *ucp) */

ENTRY(swapcontext)

	/* Have getcontext() do most of the work then fix up

	   LR afterwards.  Save R3 to keep the stack aligned.  */

	push	{r0,r1,r3,r14}

	cfi_adjust_cfa_offset (16)

	cfi_rel_offset (r0,0)

	cfi_rel_offset (r1,4)

	cfi_rel_offset (r3,8)

	cfi_rel_offset (r14,12)

	bl	__getcontext

	mov	r4, r0

	pop	{r0,r1,r3,r14}

	cfi_adjust_cfa_offset (-16)

	cfi_restore (r0)

	cfi_restore (r1)

	cfi_restore (r3)

	cfi_restore (r14)

	/* Exit if getcontext() failed.  */

	cmp 	r4, #0

	itt	ne

	movne	r0, r4

	RETINSTR(ne, r14)

	/* Fix up LR and the PC.  */

	str	r13,[r0, #MCONTEXT_ARM_SP]

	str	r14,[r0, #MCONTEXT_ARM_LR]

	str	r14,[r0, #MCONTEXT_ARM_PC]

	/* And swap using swapcontext().  */

	mov	r0, r1

	b	__setcontext

END(swapcontext)