1/* Copyright (C) 2000-2022 Free Software Foundation, Inc.
2   This file is part of the GNU C Library.
3
4   The GNU C Library is free software; you can redistribute it and/or
5   modify it under the terms of the GNU Lesser General Public
6   License as published by the Free Software Foundation; either
7   version 2.1 of the License, or (at your option) any later version.
8
9   The GNU C Library is distributed in the hope that it will be useful,
10   but WITHOUT ANY WARRANTY; without even the implied warranty of
11   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12   Lesser General Public License for more details.
13
14   You should have received a copy of the GNU Lesser General Public
15   License along with the GNU C Library.  If not, see
16   <https://www.gnu.org/licenses/>.  */
17
18/* Copy no more than N bytes from SRC to DEST, returning the address of
19   the terminating '\0' in DEST.  */
20
21#include <sysdep.h>
22
23	.arch ev6
24	.set noat
25	.set noreorder
26	.text
27
28ENTRY(__stpncpy)
29	ldgp	gp, 0(pv)
30#ifdef PROF
31	lda	AT, _mcount
32	jsr	AT, (AT), _mcount
33#endif
34	.prologue 1
35
36	mov	a0, v0
37	beq	a2, $zerocount
38
39	.align 4
40	nop
41	nop
42	jsr	t9, __stxncpy	# do the work of the copy
43
44	cttz	t8, t4
45	zapnot	t0, t8, t5
46	andnot	a0, 7, a0
47	bne	a2, $multiword	# do we have full words left?
48
49	subq	t8, 1, t2
50	subq	t10, 1, t3
51	cmpult	zero, t5, t5
52	addq	a0, t4, v0
53
54	or	t2, t8, t2
55	or	t3, t10, t3
56	addq	v0, t5, v0
57	andnot	t3, t2, t3
58
59	zap	t0, t3, t0
60	nop
61	stq	t0, 0(a0)
62	ret
63
64$multiword:
65	subq	t8, 1, t7	# clear the final bits in the prev word
66	cmpult	zero, t5, t5
67	or	t7, t8, t7
68	zapnot	t0, t7, t0
69
70	subq	a2, 1, a2
71	stq	t0, 0(a0)
72	addq	a0, 8, a1
73	beq	a2, 1f		# loop over full words remaining
74
75	nop
76	nop
77	nop
78	blbc	a2, 0f
79
80	stq	zero, 0(a1)
81	subq	a2, 1, a2
82	addq	a1, 8, a1
83	beq	a2, 1f
84
850:	stq	zero, 0(a1)
86	subq	a2, 2, a2
87	nop
88	nop
89
90	stq	zero, 8(a1)
91	addq	a1, 16, a1
92	nop
93	bne	a2, 0b
94
951:	ldq	t0, 0(a1)	# clear the leading bits in the final word
96	subq	t10, 1, t7
97	addq	a0, t4, v0
98	nop
99
100	or	t7, t10, t7
101	addq	v0, t5, v0
102	zap	t0, t7, t0
103	stq	t0, 0(a1)
104
105$zerocount:
106	nop
107	nop
108	nop
109	ret
110
111	END(__stpncpy)
112
113libc_hidden_def (__stpncpy)
114weak_alias (__stpncpy, stpncpy)
115