Last change
on this file was
444,
checked in by satin@…, 6 years ago
|
add newlib,libalmos-mkh, restructure shared_syscalls.h and mini-libc
|
File size:
1.5 KB
|
Line | |
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1 | #if defined __thumb__ || defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
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2 | |
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3 | #include "../../string/strlen.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 | size_t |
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11 | strlen (const char *str) |
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12 | { |
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13 | const char *start = str; |
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14 | |
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15 | /* Skip unaligned part. */ |
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16 | if ((long)str & 3) |
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17 | { |
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18 | str--; |
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19 | do |
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20 | { |
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21 | if (*++str == '\0') |
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22 | goto out; |
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23 | } |
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24 | while ((long)str & 3); |
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25 | } |
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26 | |
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27 | /* Load two constants: |
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28 | R4 = 0xfefefeff [ == ~(0x80808080 << 1) ] |
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29 | R5 = 0x80808080 */ |
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30 | |
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31 | asm ("mov r5, #0x80\n\ |
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32 | add r5, r5, #0x8000\n\ |
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33 | add r5, r5, r5, lsl #16\n\ |
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34 | mvn r4, r5, lsl #1\n\ |
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35 | " |
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36 | |
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37 | #if defined __ARM_ARCH_5__ || defined __ARM_ARCH_5T__ || defined __ARM_ARCH_5E__ || defined __ARM_ARCH_5TE__ |
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38 | |
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39 | " tst %0, #0x7\n\ |
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40 | ldreqd r6, [%0]\n\ |
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41 | beq 1f\n\ |
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42 | ldr r2, [%0]\n\ |
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43 | add r3, r2, r4\n\ |
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44 | bic r3, r3, r2\n\ |
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45 | ands r2, r3, r5\n\ |
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46 | bne 2f\n\ |
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47 | sub %0, %0, #4\n\ |
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48 | \n\ |
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49 | 0:\n\ |
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50 | ldrd r6, [%0, #8]!\n\ |
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51 | " |
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52 | PRELOADSTR ("%0") |
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53 | "\n\ |
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54 | 1:\n\ |
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55 | add r3, r6, r4\n\ |
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56 | add r2, r7, r4\n\ |
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57 | bic r3, r3, r6\n\ |
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58 | bic r2, r2, r7\n\ |
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59 | and r3, r3, r5\n\ |
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60 | and r2, r2, r5\n\ |
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61 | orrs r3, r2, r3\n\ |
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62 | beq 0b\n\ |
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63 | " |
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64 | #else |
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65 | |
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66 | " sub %0, %0, #4\n\ |
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67 | \n\ |
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68 | 0:\n\ |
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69 | ldr r6, [%0, #4]!\n\ |
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70 | " |
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71 | PRELOADSTR ("%0") |
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72 | "\n\ |
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73 | add r3, r6, r4\n\ |
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74 | bic r3, r3, r6\n\ |
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75 | ands r3, r3, r5\n\ |
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76 | beq 0b\n\ |
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77 | " |
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78 | #endif /* __ARM_ARCH_5[T][E]__ */ |
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79 | "\n\ |
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80 | 2:\n\ |
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81 | ldrb r3, [%0]\n\ |
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82 | cmp r3, #0x0\n\ |
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83 | beq 1f\n\ |
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84 | \n\ |
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85 | 0:\n\ |
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86 | ldrb r3, [%0, #1]!\n\ |
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87 | " |
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88 | PRELOADSTR ("%0") |
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89 | "\n\ |
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90 | cmp r3, #0x0\n\ |
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91 | bne 0b\n\ |
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92 | 1:\n\ |
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93 | " |
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94 | : "=r" (str) : "0" (str) : "r2", "r3", "r4", "r5", "r6", "r7"); |
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95 | |
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96 | out: |
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97 | return str - start; |
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98 | } |
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99 | |
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100 | #endif |
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