/* Copyright (C) 1996-2018 Free Software Foundation, Inc.

   Contributed by Richard Henderson (rth@tamu.edu)

   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/>.  */

/* Copy no more than COUNT bytes of the null-terminated string from

   SRC to DST.  If SRC does not cover all of COUNT, the balance is

   zeroed.  */

#include <sysdep.h>

	.set noat

	.set noreorder

	.text

ENTRY(strncpy)

	ldgp	gp, 0(pv)

#ifdef PROF

	lda	AT, _mcount

	jsr	AT, (AT), _mcount

#endif

	.prologue 1

	mov	a0, v0		# set return value now

	beq	a2, $zerocount

	jsr	t9, __stxncpy	# do the work of the copy

	bne	a2, $multiword	# do we have full words left?

	.align 3

	subq	t8, 1, t2	# e0    : guess not

	subq	t10, 1, t3	# .. e1 :

	or	t2, t8, t2	# e0    : clear the bits between the last

	or	t3, t10, t3	# .. e1 : written byte and the last byte in

	andnot	t3, t2, t3	# e0    : COUNT

	zap	t0, t3, t0	# e1    :

	stq_u	t0, 0(a0)	# e0    :

	ret			# .. e1 :

$multiword:

	subq	t8, 1, t7	# e0    : clear the final bits in the prev

	or	t7, t8, t7	# e1    : word

	zapnot	t0, t7, t0	# e0    :

	subq	a2, 1, a2	# .. e1 :

	stq_u	t0, 0(a0)	# e0    :

	addq	a0, 8, a0	# .. e1 :

	beq	a2, 1f		# e1    :

	blbc	a2, 0f		# e1    :

	stq_u	zero, 0(a0)	# e0    : zero one word

	subq	a2, 1, a2	# .. e1 :

	addq	a0, 8, a0	# e0    :

	beq	a2, 1f		# .. e1 :

0:	stq_u	zero, 0(a0)	# e0    : zero two words

	subq	a2, 2, a2	# .. e1 :

	stq_u	zero, 8(a0)	# e0    :

	addq	a0, 16, a0	# .. e1 :

	bne	a2, 0b		# e1    :

	unop

1:	ldq_u	t0, 0(a0)	# e0    : clear the leading bits in the final

	subq	t10, 1, t7	# .. e1 : word

	or	t7, t10, t7	# e0    :

	zap	t0, t7, t0	# e1 (stall)

	stq_u	t0, 0(a0)	# e0    :

$zerocount:

	ret			# .. e1 :

	END(strncpy)

libc_hidden_builtin_def (strncpy)