1 | /* |
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2 | * (c) Copyright 1986 HEWLETT-PACKARD COMPANY |
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3 | * |
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4 | * To anyone who acknowledges that this file is provided "AS IS" |
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5 | * without any express or implied warranty: |
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6 | * permission to use, copy, modify, and distribute this file |
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7 | * for any purpose is hereby granted without fee, provided that |
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8 | * the above copyright notice and this notice appears in all |
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9 | * copies, and that the name of Hewlett-Packard Company not be |
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10 | * used in advertising or publicity pertaining to distribution |
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11 | * of the software without specific, written prior permission. |
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12 | * Hewlett-Packard Company makes no representations about the |
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13 | * suitability of this software for any purpose. |
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14 | */ |
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15 | |
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16 | /* SPECTRUM_ID: @(#)memchr.s 37.4 86/04/23 */ |
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17 | /* |
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18 | * memchr(s, c, n) |
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19 | * |
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20 | * returns pointer to first occurrence of char c |
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21 | * in first n characters of memory area s, |
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22 | * or null if c does not occur. |
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23 | */ |
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24 | |
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25 | #include "DEFS.h" |
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26 | |
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27 | #define FROM arg0 |
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28 | #define CHAR arg1 |
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29 | #define COUNT arg2 |
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30 | #define TEMP1 r19 |
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31 | |
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32 | ENTRY(memchr) |
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33 | comb,<= COUNT,r0,memchrexit /* return if count is zero */ |
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34 | copy r0,ret0 /* null if c not found in n chars */ |
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35 | depi 0,23,24,CHAR /* make char unsigned */ |
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36 | |
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37 | ldbs,ma 1(FROM),TEMP1 |
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38 | memchrloop: |
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39 | comb,=,n TEMP1,CHAR,memchrequal |
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40 | addib,<> -1,COUNT,memchrloop |
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41 | ldbs,ma 1(FROM),TEMP1 |
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42 | b,n memchrexit |
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43 | |
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44 | memchrequal: |
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45 | ldo -1(FROM),ret0 |
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46 | |
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47 | memchrexit: |
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48 | EXIT(memchr) |
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