1 | /* |
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2 | * This program is free software; you can redistribute it and/or modify |
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3 | * it under the terms of the GNU General Public License as published by |
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4 | * the Free Software Foundation; either version 2 of the License, or |
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5 | * (at your option) any later version. |
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6 | * |
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7 | * This program is distributed in the hope that it will be useful, |
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8 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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9 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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10 | * GNU General Public License for more details. |
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11 | * |
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12 | * You should have received a copy of the GNU General Public License |
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13 | * along with this program; if not, write to the Free Software |
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14 | * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. |
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15 | * |
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16 | * Copyright (C) IBM Corp. 2005 |
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17 | * |
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18 | * Authors: Jimi Xenidis <jimix@watson.ibm.com> |
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19 | */ |
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20 | |
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21 | #include <xen/string.h> |
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22 | |
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23 | void * |
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24 | memset(void *s, int c, size_t n) |
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25 | { |
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26 | uint8_t *ss = (uint8_t *)s; |
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27 | |
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28 | if (n == 0) { |
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29 | return s; |
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30 | } |
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31 | |
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32 | /* yes, I pulled the 2 out of this air */ |
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33 | if (n >= (2 * sizeof (ulong))) { |
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34 | ulong val = 0; |
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35 | ulong i; |
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36 | |
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37 | /* construct val assignment from c */ |
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38 | if (c != 0) { |
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39 | for (i = 0; i < sizeof (ulong); i++) { |
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40 | val = (val << 8) | c; |
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41 | } |
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42 | } |
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43 | |
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44 | /* do by character until aligned */ |
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45 | while (((ulong)ss & (sizeof (ulong) - 1)) > 0) { |
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46 | *ss = c; |
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47 | ++ss; |
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48 | --n; |
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49 | } |
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50 | |
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51 | /* now do the aligned stores */ |
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52 | while (n >= sizeof (ulong)) { |
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53 | *(ulong *)ss = val; |
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54 | ss += sizeof (ulong); |
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55 | n -= sizeof (ulong); |
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56 | } |
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57 | } |
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58 | /* do that last unaligned bit */ |
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59 | while (n > 0) { |
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60 | *ss = c; |
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61 | ++ss; |
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62 | --n; |
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63 | |
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64 | } |
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65 | |
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66 | return s; |
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67 | } |
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