1/*
2Copyright (c) 2013 Andes Technology Corporation.
3All rights reserved.
4
5Redistribution and use in source and binary forms, with or without
6modification, are permitted provided that the following conditions are met:
7
8    Redistributions of source code must retain the above copyright
9    notice, this list of conditions and the following disclaimer.
10
11    Redistributions in binary form must reproduce the above copyright
12    notice, this list of conditions and the following disclaimer in the
13    documentation and/or other materials provided with the distribution.
14
15    The name of the company may not be used to endorse or promote
16    products derived from this software without specific prior written
17    permission.
18
19THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
20AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
22DISCLAIMED.  IN NO EVENT SHALL RED HAT INCORPORATED BE LIABLE FOR ANY
23DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
24(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
25LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
26ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
27(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
28SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
29
30
31    Function:
32       strcpy - copy a string.
33    Syntax:
34       char *strcpy(char *dest, const char *src);
35    Description:
36       This function copies the string pointed to by src into the array
37       point to by dest (include the teminating null character).
38    Return value:
39       strcpy returns the dest as given.
40*/
41	.text
42	.align	2
43	.globl	strcpy
44	.type	strcpy, @function
45strcpy:
46	move	$r3, $r0	/* Keep r0 as reture value.  */
47	/* If SRC or DEST is unaligned, then copy bytes.  */
48	or	$r2, $r1, $r0
49	andi	$r2, $r2, #3
50	bnez	$r2, .Lbyte_mode
51
52.Lword_mode:
53	/* SRC and DEST are both "long int" aligned, try to do "long int"
54	   sized copies.  */
55	/* #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
56	   DETECTNULL returns nonzero if (long)X contains a NULL byte.  */
57	lwi	$r2, [$r1+(0)]		/* r2 is X */
58	sethi	$r4, hi20(0xFEFEFEFF)
59	ori	$r4, $r4, lo12(0xFEFEFEFF)
60	add	$r4, $r2, $r4		/* r4 = ((X) - 0x01010101) */
61	nor	$r5, $r2, $r2		/* r5 = ~(X) */
62	and	$r4, $r5, $r4		/* r4 = ~(X) & ((X) - 0x01010101) */
63	sethi	$r5, hi20(0x80808080)
64	ori	$r5, $r5, lo12(0x80808080)
65	and	$r4, $r4, $r5		/* r4 = r4 & 0x80808080 */
66	bnez	$r4, .Lbyte_mode	/* Contains a NULL byte.  */
67	swi.bi	$r2, [$r3], #4
68	addi	$r1, $r1, #4
69	b	.Lword_mode
70
71.Lbyte_mode:
72	lbi.bi	$r4, [$r1], #1		/* r4  <- *src++ */
73	sbi.bi	$r4, [$r3], #1		/* r4  -> *dest++ */
74	bnez	$r4, .Lbyte_mode
75	ret
76	.size	strcpy, .-strcpy
77