1 | /* |
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2 | (C) Copyright 2001,2006, |
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3 | International Business Machines Corporation, |
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4 | Sony Computer Entertainment, Incorporated, |
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5 | Toshiba Corporation, |
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6 | |
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7 | All rights reserved. |
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8 | |
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9 | Redistribution and use in source and binary forms, with or without |
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10 | modification, are permitted provided that the following conditions are met: |
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11 | |
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12 | * Redistributions of source code must retain the above copyright notice, |
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13 | this list of conditions and the following disclaimer. |
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14 | * Redistributions in binary form must reproduce the above copyright |
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15 | notice, this list of conditions and the following disclaimer in the |
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16 | documentation and/or other materials provided with the distribution. |
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17 | * Neither the names of the copyright holders nor the names of their |
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18 | contributors may be used to endorse or promote products derived from this |
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19 | software without specific prior written permission. |
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20 | |
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21 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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22 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE |
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25 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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26 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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27 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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28 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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29 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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30 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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31 | POSSIBILITY OF SUCH DAMAGE. |
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32 | */ |
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33 | #include <spu_intrinsics.h> |
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34 | #include <stddef.h> |
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35 | |
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36 | /* |
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37 | * Calculates the length of the string s, not including the terminating |
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38 | * \0 character. |
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39 | */ |
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40 | size_t strlen(const char *s) |
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41 | { |
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42 | unsigned int cnt, cmp, skip, mask; |
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43 | vec_uchar16 *ptr, data; |
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44 | |
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45 | /* |
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46 | * Compensate for initial mis-aligned string. |
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47 | */ |
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48 | ptr = (vec_uchar16 *)s; /* implicit 16 byte alignment when dereferenced */ |
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49 | skip = (unsigned int)(ptr) & 15; |
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50 | mask = 0xFFFF >> skip; |
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51 | |
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52 | data = *ptr; |
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53 | cmp = spu_extract(spu_gather(spu_cmpeq(data, 0)), 0); |
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54 | cmp &= mask; |
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55 | |
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56 | cnt = spu_extract(spu_cntlz(spu_promote(cmp, 0)), 0); |
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57 | |
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58 | while (cnt == 32) { |
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59 | data = *++ptr; |
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60 | cnt = spu_extract(spu_cntlz(spu_gather(spu_cmpeq(data, 0))), 0); |
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61 | } |
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62 | |
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63 | /* |
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64 | * The length is ptr aligned down to a 16 byte boundary, plus the offset |
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65 | * to the zero byte, minus the starting address s. |
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66 | */ |
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67 | return ((((int) ptr & ~0xf) + (cnt - 16)) - (int) s); |
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68 | } |
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