[444] | 1 | /* |
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| 2 | Copyright (c) 2015, Synopsys, Inc. All rights reserved. |
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| 3 | |
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| 4 | Redistribution and use in source and binary forms, with or without |
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| 5 | modification, are permitted provided that the following conditions are met: |
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| 6 | |
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| 7 | 1) Redistributions of 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 notice, |
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| 11 | this list of conditions and the following disclaimer in the documentation |
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| 12 | and/or other materials provided with the distribution. |
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| 13 | |
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| 14 | 3) Neither the name of the Synopsys, Inc., nor the names of its contributors |
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| 15 | may be used to endorse or promote products derived from this software |
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| 16 | without specific prior written permission. |
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| 17 | |
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| 18 | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
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| 19 | AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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| 20 | IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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| 21 | ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE |
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| 22 | LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR |
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| 23 | CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF |
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| 24 | SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS |
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| 25 | INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN |
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| 26 | CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) |
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| 27 | ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE |
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| 28 | POSSIBILITY OF SUCH DAMAGE. |
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| 29 | */ |
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| 30 | |
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| 31 | /* This implementation is optimized for performance. For code size a generic |
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| 32 | implementation of this function from newlib/libc/string/strchr.c will be |
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| 33 | used. */ |
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| 34 | #if !defined (__OPTIMIZE_SIZE__) && !defined (PREFER_SIZE_OVER_SPEED) |
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| 35 | |
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| 36 | #include "asm.h" |
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| 37 | |
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| 38 | /* In order to search for a zero in a W, we calculate |
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| 39 | X := (W - 0x01010101) & ~W & 0x80808080; |
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| 40 | In the little endian case: |
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| 41 | If no byte in W is zero, X will be zero; otherwise, the least significant |
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| 42 | byte of X which is nonzero indicates the least significant byte of W that |
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| 43 | is zero. |
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| 44 | In the big endian case: |
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| 45 | X will be zero iff no byte in W is zero. |
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| 46 | If X is nonzero, to find out which is the most significant zero byte |
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| 47 | in W, we calculate: |
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| 48 | Y := ~(((W | 0x80808080) - 0x01010101) | W) & 0x80808080; |
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| 49 | Each byte in Y is 0x80 if the the corresponding byte in |
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| 50 | W is zero, otherwise that byte of Y is 0. */ |
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| 51 | |
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| 52 | #if defined (__ARC_BARREL_SHIFTER__) && \ |
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| 53 | (defined (__ARC600__) || (!defined (__ARC_NORM__) && !defined (__ARC601__))) |
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| 54 | |
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| 55 | ENTRY (strchr) |
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| 56 | bmsk.f r2,r0,1 |
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| 57 | mov_s r3,0x01010101 |
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| 58 | extb_s r1,r1 |
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| 59 | asl r5,r1,8 |
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| 60 | or r5,r5,r1 |
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| 61 | beq.d .Laligned |
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| 62 | asl r4,r5,16 |
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| 63 | sub_s r0,r0,r2 |
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| 64 | asl_s r2,r2,3 |
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| 65 | #ifdef __LITTLE_ENDIAN__ |
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| 66 | asl r7,r3,r2 |
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| 67 | #else |
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| 68 | lsr r7,r3,r2 |
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| 69 | #endif |
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| 70 | ld_s r2,[r0] |
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| 71 | or r5,r5,r4 |
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| 72 | ror r4,r3 |
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| 73 | sub r12,r2,r7 |
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| 74 | bic_s r12,r12,r2 |
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| 75 | and r12,r12,r4 |
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| 76 | |
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| 77 | brne.d r12,0,.Lfound0_ua |
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| 78 | xor r6,r2,r5 |
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| 79 | ld.a r2,[r0,4] |
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| 80 | sub r12,r6,r7 |
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| 81 | bic r12,r12,r6 |
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| 82 | #ifdef __LITTLE_ENDIAN__ |
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| 83 | and.f r7,r12,r4 |
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| 84 | sub r12,r2,r3 |
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| 85 | bic_s r12,r12,r2 |
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| 86 | beq.d .Loop |
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| 87 | and r12,r12,r4 |
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| 88 | b.d .Lfound_char_ua |
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| 89 | btst r7,7 |
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| 90 | #else |
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| 91 | and.f r8,r12,r4 |
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| 92 | sub r12,r2,r3 |
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| 93 | bic_s r12,r12,r2 |
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| 94 | beq.d .Loop |
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| 95 | and r12,r12,r4 |
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| 96 | bic r12,r7,r6 |
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| 97 | asl_s r12,r12,7 |
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| 98 | and.f r2,r8,r12 |
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| 99 | b.d .Lfound_char_ua |
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| 100 | sub_s r0,r0,4 |
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| 101 | #endif |
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| 102 | |
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| 103 | .balign 4 |
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| 104 | .Laligned: |
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| 105 | ld_s r2,[r0] |
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| 106 | or r5,r5,r4 |
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| 107 | ror r4,r3 |
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| 108 | sub r12,r2,r3 |
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| 109 | bic_s r12,r12,r2 |
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| 110 | and r12,r12,r4 |
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| 111 | .Loop: |
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| 112 | |
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| 113 | brne.d r12,0,.Lfound0 |
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| 114 | xor r6,r2,r5 |
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| 115 | ld.a r2,[r0,4] |
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| 116 | sub r12,r6,r3 |
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| 117 | bic r12,r12,r6 |
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| 118 | and.f r7,r12,r4 |
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| 119 | sub r12,r2,r3 |
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| 120 | bic_s r12,r12,r2 |
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| 121 | beq.d .Loop |
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| 122 | and r12,r12,r4 |
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| 123 | ; Found searched-for character. r0 has already advanced to next word. |
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| 124 | #ifdef __LITTLE_ENDIAN__ |
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| 125 | /* We only need the information about the first matching byte |
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| 126 | (i.e. the least significant matching byte) to be exact, |
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| 127 | hence there is no problem with carry effects. */ |
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| 128 | .Lfound_char: |
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| 129 | btst r7,7 |
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| 130 | .Lfound_char_ua: |
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| 131 | sub_s r0,r0,4 |
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| 132 | add.eq r0,r0,1 |
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| 133 | btst.eq r7,15 |
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| 134 | add.eq r0,r0,1 |
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| 135 | btst.eq r7,23 |
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| 136 | j_s.d [blink] |
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| 137 | add.eq r0,r0,1 |
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| 138 | |
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| 139 | .balign 4 |
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| 140 | .Lfound0_ua: |
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| 141 | mov_l r3,r7 |
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| 142 | .Lfound0: |
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| 143 | sub r2,r6,r3 |
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| 144 | bic r2,r2,r6 |
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| 145 | and r2,r2,r4 |
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| 146 | or r3,r12,r2 |
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| 147 | sub_s r12,r3,1 |
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| 148 | xor_s r3,r3,r12 |
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| 149 | tst_s r2,r3 |
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| 150 | lsr r2,r3,31 |
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| 151 | lsr r12,r3,16 |
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| 152 | jeq.d [blink] |
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| 153 | mov.eq r0,0 |
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| 154 | lsr r3,r3,8 |
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| 155 | sub_s r2,r2,r12 |
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| 156 | sub_s r2,r2,r3 |
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| 157 | bmsk_s r2,r2,1 |
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| 158 | j_s.d [blink] |
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| 159 | add_s r0,r0,r2 |
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| 160 | #else /* BIG ENDIAN */ |
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| 161 | .Lfound_char: |
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| 162 | asl r6,r6,7 |
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| 163 | sub_s r0,r0,4 |
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| 164 | bic.f r2,r7,r6 |
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| 165 | .Lfound_char_ua: |
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| 166 | add.pl r0,r0,1 |
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| 167 | jmi.d [blink] |
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| 168 | btst_s r2,23 |
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| 169 | add.eq r0,r0,1 |
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| 170 | btst.eq r2,15 |
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| 171 | j_s.d [blink] |
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| 172 | add.eq r0,r0,1 |
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| 173 | |
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| 174 | ; N.B. if we searched for a char zero and found it in the MSB, |
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| 175 | ; and ignored matches are identical, we will take the early exit |
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| 176 | ; like for an ordinary found zero - except for the extra stalls at jhi - |
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| 177 | ; but still compute the right result. |
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| 178 | .Lfound0_ua: |
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| 179 | mov_s r3,r7 |
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| 180 | .Lfound0: |
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| 181 | asl_s r2,r2,7 |
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| 182 | or r7,r6,r4 |
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| 183 | bic_s r12,r12,r2 |
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| 184 | sub r2,r7,r3 |
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| 185 | or r2,r2,r6 |
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| 186 | bic r2,r4,r2 |
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| 187 | cmp r12,r2 |
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| 188 | mov.hi r0,0 |
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| 189 | btst.ls r2,31 |
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| 190 | jhi.d [blink] |
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| 191 | add.eq r0,r0,1 |
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| 192 | btst.eq r2,23 |
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| 193 | add.eq r0,r0,1 |
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| 194 | btst.eq r2,15 |
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| 195 | j_s.d [blink] |
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| 196 | add.eq r0,r0,1 |
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| 197 | #endif /* ENDIAN */ |
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| 198 | ENDFUNC (strchr) |
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| 199 | #endif /* __ARC_BARREL_SHIFTER__ && |
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| 200 | (__ARC600__ || (!__ARC_NORM__ && !__ARC601__)) */ |
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| 201 | |
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| 202 | #endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ |
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