1/*
2   Copyright (c) 2015, Synopsys, Inc. All rights reserved.
3
4   Redistribution and use in source and binary forms, with or without
5   modification, are permitted provided that the following conditions are met:
6
7   1) Redistributions of source code must retain the above copyright notice,
8   this list of conditions and the following disclaimer.
9
10   2) Redistributions in binary form must reproduce the above copyright notice,
11   this list of conditions and the following disclaimer in the documentation
12   and/or other materials provided with the distribution.
13
14   3) Neither the name of the Synopsys, Inc., nor the names of its contributors
15   may be used to endorse or promote products derived from this software
16   without specific prior written permission.
17
18   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
19   AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20   IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21   ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
22   LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
23   CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
24   SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
25   INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
26   CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
27   ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
28   POSSIBILITY OF SUCH DAMAGE.
29*/
30
31/* This implementation is optimized for performance.  For code size a generic
32   implementation of this function from newlib/libc/string/memset.c will be
33   used.  */
34#if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED)
35
36#include "asm.h"
37
38#if defined (__ARC601__) \
39    || (!defined (__ARC_BARREL_SHIFTER__) && !defined (__ARCHS__))
40
41/* To deal with alignment/loop issues, SMALL must be at least 2.  */
42#define SMALL 8 /* Even faster if aligned.  */
43
44	.global	__strncpy_bzero
45	.hidden __strncpy_bzero
46/* __strncpy_bzero provides the following interface to strncpy:
47   r0: return value
48   r2: zeroing length
49   r3: zeroing start address
50   No attempt is made here for __strncpy_memset to speed up aligned
51   cases, because the copying of a string presumably leaves start address
52   and length alignment for the zeroing randomly distributed.  */
53
54ENTRY (memset)
55	brls.d	r2,SMALL,.Ltiny
56	mov_s	r3,r0
57	or	r12,r0,r2
58	bmsk.f	r12,r12,1
59	breq_s	r1,0,.Lbzero
60	mov	r4,0
61	stb.a	r1,[sp,-4]
62	stb	r1,[sp,1]
63	stb	r1,[sp,2]
64	stb	r1,[sp,3]
65	ld.ab	r1,[sp,4]
66.Lbzero:
67	beq.d	.Laligned
68.Lbzero2:
69	add	r6,r2,r3
70.Lnot_tiny:
71	stb	r1,[r6,-1]
72	bclr	r12,r6,0
73	stw	r1,[r12,-2]
74	stb.ab	r1,[r3,1]
75	bclr_s	r3,r3,0
76	stw.ab	r1,[r3,2]
77	bclr_s	r3,r3,1
78.Laligned:	; This code address should be aligned for speed.
79	sub	r6,r6,8
80	brlo.d	r6,r3,.Loop_end
81	sub	r6,r6,8
823:
83	st_l	r1,[r3,4]
84	brhs.d	r6,r3,3b
85	st.ab	r1,[r3,8]
86.Loop_end:
87	bic	r12,r6,3
88	j_s.d	[blink]
89	st_s	r1,[r12,12]
90	.balign	4
91__strncpy_bzero:
92	brhi.d	r2,8,.Lbzero2
93	mov_s	r1,0
94.Ltiny:
95	sub_s	r2,r2,11
96	sub1	r12,pcl,r2
97	j_s	[r12]
98	stb_s	r1,[r3,7]
99	stb_s	r1,[r3,6]
100	stb_s	r1,[r3,5]
101	stb_s	r1,[r3,4]
102	stb_s	r1,[r3,3]
103	stb_s	r1,[r3,2]
104	stb_s	r1,[r3,1]
105	stb_s	r1,[r3]
106	j_s	[blink]
107ENDFUNC (memset)
108#endif /* __ARC601__ || (!__ARC_BARREL_SHIFTER__ && !__ARCHS__)  */
109
110#endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */
111