| 1 | /* Copyright (c) 2009 Xilinx, Inc. All rights reserved. |
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| 2 | |
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| 3 | Redistribution and use in source and binary forms, with or without |
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| 4 | modification, are permitted provided that the following conditions are |
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| 5 | met: |
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| 6 | |
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| 7 | 1. Redistributions source code must retain the above copyright notice, |
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| 8 | this list of conditions and the following disclaimer. |
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| 9 | |
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| 10 | 2. Redistributions in binary form must reproduce the above copyright |
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| 11 | notice, this list of conditions and the following disclaimer in the |
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| 12 | documentation and/or other materials provided with the distribution. |
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| 13 | |
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| 14 | 3. Neither the name of Xilinx nor the names of its contributors may be |
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| 15 | used to endorse or promote products derived from this software without |
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| 16 | specific prior written permission. |
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| 17 | |
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| 18 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS "AS |
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| 19 | IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED |
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| 20 | TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A |
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| 21 | PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
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| 22 | HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
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| 23 | SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED |
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| 24 | TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
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| 25 | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
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| 26 | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
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| 27 | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
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| 28 | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
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| 29 | |
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| 30 | |
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| 31 | FUNCTION |
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| 32 | <<strcmp>>---character string compare |
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| 33 | |
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| 34 | INDEX |
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| 35 | strcmp |
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| 36 | |
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| 37 | SYNOPSIS |
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| 38 | #include <string.h> |
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| 39 | int strcmp(const char *<[a]>, const char *<[b]>); |
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| 40 | |
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| 41 | DESCRIPTION |
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| 42 | <<strcmp>> compares the string at <[a]> to |
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| 43 | the string at <[b]>. |
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| 44 | |
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| 45 | RETURNS |
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| 46 | If <<*<[a]>>> sorts lexicographically after <<*<[b]>>>, |
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| 47 | <<strcmp>> returns a number greater than zero. If the two |
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| 48 | strings match, <<strcmp>> returns zero. If <<*<[a]>>> |
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| 49 | sorts lexicographically before <<*<[b]>>>, <<strcmp>> returns a |
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| 50 | number less than zero. |
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| 51 | |
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| 52 | PORTABILITY |
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| 53 | <<strcmp>> is ANSI C. |
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| 54 | |
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| 55 | <<strcmp>> requires no supporting OS subroutines. |
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| 56 | |
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| 57 | QUICKREF |
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| 58 | strcmp ansi pure |
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| 59 | */ |
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| 60 | |
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| 61 | #include <string.h> |
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| 62 | #include <limits.h> |
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| 63 | |
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| 64 | /* Nonzero if either X or Y is not aligned on a "long" boundary. */ |
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| 65 | #define UNALIGNED(X, Y) \ |
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| 66 | (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1))) |
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| 67 | |
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| 68 | /* DETECTNULL returns nonzero if (long)X contains a NULL byte. */ |
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| 69 | #if LONG_MAX == 2147483647L |
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| 70 | #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080) |
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| 71 | #else |
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| 72 | #if LONG_MAX == 9223372036854775807L |
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| 73 | #define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080) |
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| 74 | #else |
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| 75 | #error long int is not a 32bit or 64bit type. |
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| 76 | #endif |
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| 77 | #endif |
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| 78 | |
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| 79 | #ifndef DETECTNULL |
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| 80 | #error long int is not a 32bit or 64bit byte |
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| 81 | #endif |
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| 82 | |
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| 83 | int |
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| 84 | strcmp (const char *s1, |
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| 85 | const char *s2) |
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| 86 | { |
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| 87 | |
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| 88 | #ifndef HAVE_HW_PCMP |
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| 89 | |
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| 90 | #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__) |
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| 91 | while (*s1 != '\0' && *s1 == *s2) |
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| 92 | { |
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| 93 | s1++; |
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| 94 | s2++; |
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| 95 | } |
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| 96 | |
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| 97 | return (*(unsigned char *) s1) - (*(unsigned char *) s2); |
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| 98 | #else |
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| 99 | unsigned long *a1; |
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| 100 | unsigned long *a2; |
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| 101 | |
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| 102 | /* If s1 or s2 are unaligned, then compare bytes. */ |
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| 103 | if (!UNALIGNED (s1, s2)) |
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| 104 | { |
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| 105 | /* If s1 and s2 are word-aligned, compare them a word at a time. */ |
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| 106 | a1 = (unsigned long*)s1; |
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| 107 | a2 = (unsigned long*)s2; |
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| 108 | while (*a1 == *a2) |
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| 109 | { |
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| 110 | /* To get here, *a1 == *a2, thus if we find a null in *a1, |
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| 111 | then the strings must be equal, so return zero. */ |
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| 112 | if (DETECTNULL (*a1)) |
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| 113 | return 0; |
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| 114 | |
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| 115 | a1++; |
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| 116 | a2++; |
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| 117 | } |
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| 118 | |
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| 119 | /* A difference was detected in last few bytes of s1, so search bytewise */ |
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| 120 | s1 = (char*)a1; |
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| 121 | s2 = (char*)a2; |
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| 122 | } |
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| 123 | |
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| 124 | while (*s1 != '\0' && *s1 == *s2) |
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| 125 | { |
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| 126 | s1++; |
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| 127 | s2++; |
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| 128 | } |
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| 129 | return (*(unsigned char *) s1) - (*(unsigned char *) s2); |
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| 130 | #endif /* not PREFER_SIZE_OVER_SPEED */ |
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| 131 | |
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| 132 | #else |
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| 133 | |
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| 134 | #include "mb_endian.h" |
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| 135 | |
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| 136 | asm volatile (" \n\ |
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| 137 | or r9, r0, r0 /* Index register */\n\ |
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| 138 | check_alignment: \n\ |
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| 139 | andi r3, r5, 3 \n\ |
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| 140 | andi r4, r6, 3 \n\ |
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| 141 | bnei r3, try_align_args \n\ |
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| 142 | bnei r4, regular_strcmp /* At this point we don't have a choice */ \n\ |
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| 143 | cmp_loop: \n" |
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| 144 | LOAD4BYTES("r3", "r5", "r9") |
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| 145 | LOAD4BYTES("r4", "r6", "r9") |
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| 146 | " \n\ |
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| 147 | pcmpbf r7, r3, r0 /* See if there is Null byte */ \n\ |
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| 148 | bnei r7, end_cmp_loop /* IF yes (r7 > 0) use byte compares in end_cmp_loop */ \n\ |
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| 149 | cmpu r7, r4, r3 /* ELSE compare whole word */ \n\ |
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| 150 | bnei r7, end_cmp \n\ |
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| 151 | brid cmp_loop \n\ |
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| 152 | addik r9, r9, 4 /* delay slot */ \n\ |
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| 153 | end_cmp_loop: \n\ |
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| 154 | lbu r3, r5, r9 /* byte compare loop */ \n\ |
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| 155 | lbu r4, r6, r9 \n\ |
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| 156 | cmpu r7, r4, r3 /* Compare bytes */ \n\ |
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| 157 | bnei r7, end_cmp_early \n\ |
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| 158 | bneid r3, end_cmp_loop /* If reached null on one string, terminate */ \n\ |
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| 159 | addik r9, r9, 1 /* delay slot */ \n\ |
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| 160 | end_cmp_early: \n\ |
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| 161 | rtsd r15, 8 \n\ |
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| 162 | or r3, r0, r7 \n\ |
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| 163 | try_align_args: \n\ |
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| 164 | xor r7, r4, r3 \n\ |
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| 165 | bnei r7, regular_strcmp /* cannot align args */ \n\ |
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| 166 | rsubik r10, r3, 4 /* Number of initial bytes to align */ \n\ |
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| 167 | align_loop: \n\ |
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| 168 | lbu r3, r5, r9 \n\ |
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| 169 | lbu r4, r6, r9 \n\ |
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| 170 | cmpu r7, r4, r3 \n\ |
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| 171 | bnei r7, end_cmp \n\ |
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| 172 | beqi r3, end_cmp \n\ |
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| 173 | addik r10, r10, -1 \n\ |
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| 174 | beqid r10, cmp_loop \n\ |
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| 175 | addik r9, r9, 1 \n\ |
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| 176 | bri align_loop \n\ |
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| 177 | regular_strcmp: \n\ |
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| 178 | lbu r3, r5, r9 \n\ |
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| 179 | lbu r4, r6, r9 \n\ |
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| 180 | cmpu r7, r4, r3 \n\ |
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| 181 | bnei r7, end_cmp \n\ |
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| 182 | beqi r3, end_cmp \n\ |
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| 183 | brid regular_strcmp \n\ |
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| 184 | addik r9, r9, 1 \n\ |
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| 185 | end_cmp: \n\ |
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| 186 | rtsd r15, 8 \n\ |
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| 187 | or r3, r0, r7 /* Return strcmp result */"); |
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| 188 | |
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| 189 | #endif /* ! HAVE_HW_PCMP */ |
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| 190 | } |
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| 191 | |
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