1 | #if defined __thumb__ |
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2 | |
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3 | #include "../../string/memset.c" |
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4 | |
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5 | #else |
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6 | |
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7 | #include <string.h> |
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8 | #include "xscale.h" |
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9 | |
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10 | void * |
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11 | memset (void *dst, int c, size_t len) |
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12 | { |
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13 | int dummy; |
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14 | |
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15 | asm volatile ("tst %0, #0x3" |
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16 | #ifndef __OPTIMIZE_SIZE__ |
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17 | "\n\ |
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18 | beq 1f\n\ |
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19 | b 2f\n\ |
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20 | 0:\n\ |
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21 | strb %1, [%0], #1\n\ |
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22 | tst %0, #0x3\n\ |
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23 | beq 1f\n\ |
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24 | 2:\n\ |
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25 | movs r3, %2\n\ |
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26 | sub %2, %2, #1\n\ |
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27 | bne 0b\n\ |
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28 | # At this point we know that %2 == len == -1 (since the SUB has already taken\n\ |
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29 | # place). If we fall through to the 1: label (as the code used to do), the\n\ |
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30 | # CMP will detect this negative value and branch to the 2: label. This will\n\ |
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31 | # test %2 again, but this time against 0. The test will fail and the loop\n\ |
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32 | # at 2: will go on for (almost) ever. Hence the explicit branch to the end\n\ |
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33 | # of the hand written assembly code.\n\ |
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34 | b 4f\n\ |
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35 | 1:\n\ |
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36 | cmp %2, #0x3\n\ |
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37 | bls 2f\n\ |
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38 | and %1, %1, #0xff\n\ |
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39 | orr lr, %1, %1, asl #8\n\ |
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40 | cmp %2, #0xf\n\ |
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41 | orr lr, lr, lr, asl #16\n\ |
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42 | bls 1f\n\ |
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43 | mov r3, lr\n\ |
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44 | mov r4, lr\n\ |
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45 | mov r5, lr\n\ |
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46 | 0:\n\ |
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47 | sub %2, %2, #16\n\ |
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48 | stmia %0!, { r3, r4, r5, lr }\n\ |
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49 | cmp %2, #0xf\n\ |
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50 | bhi 0b\n\ |
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51 | 1:\n\ |
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52 | cmp %2, #0x7\n\ |
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53 | bls 1f\n\ |
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54 | mov r3, lr\n\ |
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55 | 0:\n\ |
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56 | sub %2, %2, #8\n\ |
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57 | stmia %0!, { r3, lr }\n\ |
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58 | cmp %2, #0x7\n\ |
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59 | bhi 0b\n\ |
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60 | 1:\n\ |
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61 | cmp %2, #0x3\n\ |
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62 | bls 2f\n\ |
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63 | 0:\n\ |
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64 | sub %2, %2, #4\n\ |
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65 | str lr, [%0], #4\n\ |
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66 | cmp %2, #0x3\n\ |
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67 | bhi 0b\n\ |
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68 | " |
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69 | #endif /* !__OPTIMIZE_SIZE__ */ |
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70 | "\n\ |
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71 | 2:\n\ |
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72 | movs r3, %2\n\ |
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73 | sub %2, %2, #1\n\ |
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74 | beq 4f\n\ |
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75 | 0:\n\ |
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76 | movs r3, %2\n\ |
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77 | sub %2, %2, #1\n\ |
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78 | strb %1, [%0], #1\n\ |
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79 | bne 0b\n\ |
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80 | 4:" |
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81 | |
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82 | : "=&r" (dummy), "=&r" (c), "=&r" (len) |
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83 | : "0" (dst), "1" (c), "2" (len) |
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84 | : "memory", "r3", "r4", "r5", "lr"); |
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85 | |
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86 | return dst; |
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87 | } |
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88 | |
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89 | #endif |
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