1/* Copyright (c) 2002, 2007 Marek Michalkiewicz 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: strchr.S 2191 2010-11-05 13:45:57Z arcanum $ */ 30 31/** \file */ 32 33/** \ingroup avr_string 34 \fn char *strchr(const char *src, int val) 35 \brief Locate character in string. 36 37 The strchr() function returns a pointer to the first occurrence of 38 the character \p val in the string \p src. 39 40 Here "character" means "byte" - these functions do not work with 41 wide or multi-byte characters. 42 43 \returns The strchr() function returns a pointer to the matched 44 character or \c NULL if the character is not found. */ 45 46#if !defined(__AVR_TINY__) 47 48#if !defined(__DOXYGEN__) 49 50#include "macros.inc" 51 52#define src_hi r25 53#define src_lo r24 54; #define val_hi r23 55#define val_lo r22 56 57#define ret_hi r25 58#define ret_lo r24 59 60 ASSEMBLY_CLIB_SECTION 61 .global _U(strchr) 62 .type _U(strchr), @function 63_U(strchr): 64 X_movw ZL, src_lo 65.L_strchr_loop: 66 ld ret_lo, Z+ 67 cp ret_lo, val_lo 68 breq .L_strchr_found 69 tst ret_lo 70 brne .L_strchr_loop 71; not found, return NULL pointer 72 clr ret_hi 73 ret 74.L_strchr_found: 75 sbiw ZL, 1 ; undo post-increment 76 X_movw ret_lo, ZL 77 ret 78.L_strchr_end: 79 .size _U(strchr), .L_strchr_end - _U(strchr) 80 81#endif /* not __DOXYGEN__ */ 82 83#endif /* !defined(__AVR_TINY__) */ 84