1/* Copyright (c) 2007  Dmitry Xmelkov
2   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   * Redistributions of source code must retain the above copyright
8     notice, this list of conditions and the following disclaimer.
9   * Redistributions in binary form must reproduce the above copyright
10     notice, this list of conditions and the following disclaimer in
11     the documentation and/or other materials provided with the
12     distribution.
13   * Neither the name of the copyright holders nor the names of
14     contributors may be used to endorse or promote products derived
15     from this software without specific prior written permission.
16
17  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
18  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
21  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
22  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
23  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
24  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
25  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
26  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
27  POSSIBILITY OF SUCH DAMAGE. */
28
29/* $Id: strspn.S 2191 2010-11-05 13:45:57Z arcanum $ */
30
31/** \file */
32/** \ingroup avr_string
33    \fn size_t strspn(const char *s, const char *accept)
34
35    The strspn() function calculates the length of the initial segment
36    of \p s which consists entirely of characters in \p accept.
37
38    \return  The strspn() function returns the number of characters in
39    the initial segment of \p s which consist only of characters from \p
40    accept. The terminating zero is not considered as a part of string.	*/
41
42#if !defined(__AVR_TINY__)
43
44#ifndef	__DOXYGEN__
45
46#include "macros.inc"
47
48#define str_lo	r24
49#define str_hi	r25
50#define acc_lo	r22
51#define acc_hi	r23
52
53#define chs	r21	/* char from s[]	*/
54
55/* This realization is compact, but is not very fast: an accept string
56   is not cashed.	*/
57
58	ASSEMBLY_CLIB_SECTION
59	.global _U(strspn)
60	.type   _U(strspn), @function
61
62_U(strspn):
63	X_movw	XL, str_lo
64  ; get next symbol from s[]
651:	ld	chs, X+		; *s++
66	tst	chs
67	breq	3f
68  ; check an occurance
69	X_movw	ZL, acc_lo
702:	ld	r0, Z+
71	cp	r0, chs
72	cpse	r0, __zero_reg__
73	brne	2b
74	breq	1b		; branch if chs is present in accept[]
75  ; end of scanning: chs is not found or end of s[] is reached
76  ; Return: X - 1 - str == X + ~str
773:	com	str_lo
78	com	str_hi
79	add	str_lo, XL
80	adc	str_hi, XH
81	ret
82
83	.size _U(strspn), . - _U(strspn)
84
85#endif	/* !__DOXYGEN__ */
86
87#endif /* !defined(__AVR_TINY__) */
88