/* Copyright (c) 2002, 2007 Philip Soeberg Copyright (c) 2007 Dmitry Xmelkov 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. */ /* $Id$ */ /* strstr.S Search string contained in a string Contributed by: Philip Soeberg <philip@soeberg.net> */ #if !defined(__AVR_TINY__) #if !defined(__DOXYGEN__) #include "macros.inc" #define s1_hi r25 #define s1_lo r24 #define s2_hi r23 #define s2_lo r22 #define chr1 r20 #define beg2 r21 /* begin of s2: s2[0] */ #define chr2 r0 ASSEMBLY_CLIB_SECTION .global _U(strstr) .type _U(strstr), @function _U(strstr): X_movw ZL, s2_lo ld beg2, Z+ tst beg2 ; is str2 empty? breq .L_ret ; return original string (req'd by standard) X_movw s2_lo, ZL ; save: address of second s2 byte 0: X_movw XL, s1_lo 1: ld chr1, X+ ; Find first char cp chr1, beg2 cpse chr1, __zero_reg__ brne 1b brne .L_no_match ; end of s1 X_movw s1_lo, XL ; store return value 2: ld chr2, Z+ ; compare strings tst chr2 breq .L_match ; end of s2 ld chr1, X+ cp chr1, chr2 cpse chr1, __zero_reg__ ; break, if end of s1 breq 2b X_movw ZL, s2_lo ; restore s2+1 cpse chr1, __zero_reg__ rjmp 0b .L_no_match: ldi s1_lo, lo8(1) ldi s1_hi, hi8(1) .L_match: sbiw s1_lo, 1 ; restore after post-increment .L_ret: ret .size _U(strstr), . - _U(strstr) #endif /* not __DOXYGEN__ */ #endif /* !defined(__AVR_TINY__) */