| /* Copyright (c) 2002, 2007 Marek Michalkiewicz |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions are met: |
| |
| * Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| * Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in |
| the documentation and/or other materials provided with the |
| distribution. |
| * Neither the name of the copyright holders nor the names of |
| contributors may be used to endorse or promote products derived |
| from this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
| LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
| CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
| SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
| INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
| CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
| ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
| POSSIBILITY OF SUCH DAMAGE. */ |
| |
| /* $Id: memchr.S 2191 2010-11-05 13:45:57Z arcanum $ */ |
| |
| /** \file */ |
| /** \ingroup avr_string |
| \fn void *memchr(const void *src, int val, size_t len) |
| \brief Scan memory for a character. |
| |
| The memchr() function scans the first len bytes of the memory area pointed |
| to by src for the character val. The first byte to match val (interpreted |
| as an unsigned character) stops the operation. |
| |
| \returns The memchr() function returns a pointer to the matching byte or |
| NULL if the character does not occur in the given memory area. */ |
| |
| #if !defined(__AVR_TINY__) |
| |
| #if !defined(__DOXYGEN__) |
| |
| #include "macros.inc" |
| |
| #define src_hi r25 |
| #define src_lo r24 |
| ; #define val_hi r23 |
| #define val_lo r22 |
| #define len_hi r21 |
| #define len_lo r20 |
| |
| #define ret_hi r25 |
| #define ret_lo r24 |
| |
| ASSEMBLY_CLIB_SECTION |
| .global _U(memchr) |
| .type _U(memchr), @function |
| _U(memchr): |
| X_movw ZL, src_lo |
| .L_memchr_loop: |
| subi len_lo, lo8(1) |
| sbci len_hi, hi8(1) |
| brcs .L_memchr_notfound |
| ld __tmp_reg__, Z+ |
| cp __tmp_reg__, val_lo |
| brne .L_memchr_loop |
| sbiw ZL, 1 ; undo post-increment |
| X_movw ret_lo, ZL |
| ret |
| .L_memchr_notfound: |
| clr ret_lo |
| clr ret_hi |
| ret |
| .L_memchr_end: |
| .size _U(memchr), .L_memchr_end - _U(memchr) |
| |
| #endif /* not __DOXYGEN__ */ |
| |
| #endif /* !defined(__AVR_TINY__) */ |