| /* Copyright (c) 2006, Carlos Lamas |
| |
| based on libc/pmstring/strncmp_P.S which is |
| Copyright (c) 2002, 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: strncmp_PF.S 2191 2010-11-05 13:45:57Z arcanum $ */ |
| |
| #if !defined(__AVR_TINY__) |
| |
| #include "macros.inc" |
| |
| #define s1_b1 r25 |
| #define s1_b0 r24 |
| #define s2_b3 r23 |
| #define s2_b2 r22 |
| #define s2_b1 r21 |
| #define s2_b0 r20 |
| #define len_b1 r19 |
| #define len_b0 r18 |
| |
| #define ret_b1 r25 |
| #define ret_b0 r24 |
| |
| /** \ingroup avr_pgmspace |
| \fn int strncmp_PF (const char *s1, uint_farptr_t s2, size_t n) |
| \brief Compare two strings with limited length |
| |
| The strncmp_PF() function is similar to strcmp_PF() except it only |
| compares the first (at most) \e n characters of \e s1 and \e s2 |
| |
| \param s1 A pointer to the first string in SRAM |
| \param s2 A far pointer to the second string in Flash |
| \param n The maximum number of bytes to compare |
| |
| \returns The strncmp_PF() function returns an integer less than, equal |
| to, or greater than zero if \e s1 (or the first \e n bytes thereof) is found, |
| respectively, to be less than, to match, or be greater than \e s2. The |
| contents of RAMPZ SFR are undefined when the function returns */ |
| |
| #if !defined(__DOXYGEN__) |
| |
| .text |
| .global _U(strncmp_PF) |
| .type _U(strncmp_PF), @function |
| |
| _U(strncmp_PF): |
| |
| X_movw ZL, s2_b0 |
| LPM_R0_ZPLUS_INIT s2_b2 |
| X_movw XL, s1_b0 |
| |
| .L_strncmp_PF_loop: |
| |
| subi len_b0, lo8(1) |
| sbci len_b1, hi8(1) |
| brcs .L_strncmp_PF_equal |
| ld ret_b0, X+ |
| LPM_R0_ZPLUS_NEXT s2_b2 |
| sub ret_b0, r0 |
| brne .L_strncmp_PF_done |
| tst r0 |
| brne .L_strncmp_PF_loop |
| |
| .L_strncmp_PF_equal: |
| |
| sub ret_b0, ret_b0 |
| |
| .L_strncmp_PF_done: |
| ; ret_hi = SREG.C ? 0xFF : 0 |
| |
| sbc ret_b1, ret_b1 |
| ret |
| |
| .L_strncmp_PF_end: |
| |
| .size _U(strncmp_PF), .L_strncmp_PF_end - _U(strncmp_PF) |
| |
| #endif /* not __DOXYGEN__ */ |
| |
| #endif /* !defined(__AVR_TINY__) */ |