[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/strlen.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 | #if defined(__ARC601__) || !defined (__ARC_BARREL_SHIFTER__) |
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| 39 | /* This code is optimized for the ARC601 pipeline without barrel shifter. */ |
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| 40 | |
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| 41 | ENTRY (strlen) |
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| 42 | or r3,r0,7 |
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| 43 | ld r2,[r3,-7] |
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| 44 | ld.a r6,[r3,-3] |
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| 45 | mov r4,0x01010101 |
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| 46 | ; uses long immediate |
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| 47 | #ifdef __LITTLE_ENDIAN__ |
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| 48 | bmsk.f 0,r0,1 |
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| 49 | mov_s r1,31 |
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| 50 | add3_s r1,r1,r0 |
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| 51 | bmsk r7,r4,r1 |
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| 52 | xor.ne r7,r7,r4 |
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| 53 | btst_s r0,2 |
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| 54 | ror r5,r4 |
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| 55 | sub r1,r2,r7 |
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| 56 | bic_s r1,r1,r2 |
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| 57 | mov.eq r7,r4 |
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| 58 | sub r12,r6,r7 |
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| 59 | bic r12,r12,r6 |
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| 60 | or.eq r12,r12,r1 |
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| 61 | and r12,r12,r5 |
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| 62 | brne r12,0,.Learly_end |
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| 63 | #else /* BIG ENDIAN */ |
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| 64 | add.f r1,r4,30 ; r1 mod 31 := -1; clear carry |
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| 65 | ror r5,r4 |
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| 66 | sub3 r7,r1,r0 |
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| 67 | btst_s r0,2 |
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| 68 | sub r1,r2,r4 |
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| 69 | bic_s r1,r1,r2 |
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| 70 | bmsk r1,r1,r7 |
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| 71 | sub r12,r6,r4 |
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| 72 | bic r12,r12,r6 |
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| 73 | bmsk.ne r12,r12,r7 |
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| 74 | or.eq r12,r12,r1 |
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| 75 | and r12,r12,r5 |
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| 76 | brne r12,0,.Learly_end |
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| 77 | #endif /* ENDIAN */ |
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| 78 | |
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| 79 | .Loop: |
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| 80 | ld_s r2,[r3,4] |
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| 81 | ld.a r6,[r3,8] |
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| 82 | ; stall for load result |
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| 83 | sub r1,r2,r4 |
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| 84 | bic_s r1,r1,r2 |
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| 85 | sub r12,r6,r4 |
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| 86 | bic r12,r12,r6 |
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| 87 | or_s r12,r12,r1 |
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| 88 | and r12,r12,r5 |
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| 89 | breq_s r12,0,.Loop |
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| 90 | .Lend: |
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| 91 | and.f r1,r1,r5 |
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| 92 | sub.ne r3,r3,4 |
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| 93 | #ifdef __LITTLE_ENDIAN__ |
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| 94 | mov.eq r1,r12 |
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| 95 | btst_s r1,7 |
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| 96 | sub r0,r3,r0 |
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| 97 | add.eq r0,r0,1 |
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| 98 | bmsk.f 0,r1,15 |
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| 99 | add.eq r0,r0,1 |
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| 100 | bmsk.f 0,r1,23 |
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| 101 | j_s.d [blink] |
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| 102 | add.eq r0,r0,1 |
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| 103 | #else /* BIG ENDIAN */ |
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| 104 | #ifdef __OPTIMIZE_SIZE__ |
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| 105 | 1: ldb_s r1,[r3] |
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| 106 | breq_s r1,0,0f |
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| 107 | ldb.a r1,[r3,1] |
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| 108 | breq_s r1,0,0f |
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| 109 | ldb.a r1,[r3,1] |
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| 110 | breq_s r1,0,0f |
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| 111 | add_s r3,r3,1 |
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| 112 | 0: j_s.d [blink] |
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| 113 | sub r0,r3,r0 |
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| 114 | |
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| 115 | #define SPECIAL_EARLY_END |
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| 116 | .Learly_end: |
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| 117 | mov_s r3,r0 |
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| 118 | b_s 1b |
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| 119 | #elif 0 /* Need more information about pipeline to assess if this is faster. */ |
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| 120 | mov.eq r2,r6 |
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| 121 | and r2,r2,r5 |
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| 122 | sub1 r2,r4,r2 |
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| 123 | mov.eq r1,r12 |
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| 124 | bic.f r1,r1,r2 |
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| 125 | sub r0,r3,r0 |
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| 126 | add.pl r0,r0,1 |
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| 127 | btst.pl r1,23 |
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| 128 | add.eq r0,r0,1 |
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| 129 | btst.eq r1,15 |
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| 130 | j_s.d [blink] |
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| 131 | add.eq r0,r0,1 |
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| 132 | #else /* !__OPTIMIZE_SIZE__ */ |
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| 133 | /* Need carry clear here. */ |
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| 134 | mov.eq r2,r6 |
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| 135 | 1: bmsk r1,r2,23 |
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| 136 | breq r1,r2,0f |
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| 137 | bmsk r2,r1,15 |
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| 138 | breq.d r1,r2,0f |
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| 139 | add_s r3,r3,1 |
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| 140 | cmp r2,0x100 |
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| 141 | add_s r3,r3,2 |
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| 142 | 0: j_s.d [blink] |
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| 143 | sbc r0,r3,r0 |
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| 144 | |
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| 145 | #define SPECIAL_EARLY_END |
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| 146 | .Learly_end: |
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| 147 | sub_s.ne r1,r1,r1 |
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| 148 | mov_s r12,0 |
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| 149 | bset r12,r12,r7 |
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| 150 | sub1 r2,r2,r12 |
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| 151 | b.d .Lend |
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| 152 | sub1.ne r6,r6,r12 |
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| 153 | #endif /* !__OPTIMIZE_SIZE__ */ |
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| 154 | #endif /* ENDIAN */ |
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| 155 | |
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| 156 | #ifndef SPECIAL_EARLY_END |
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| 157 | .balign 4 |
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| 158 | .Learly_end: |
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| 159 | b.d .Lend |
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| 160 | sub_s.ne r1,r1,r1 |
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| 161 | #endif /* !SPECIAL_EARLY_END */ |
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| 162 | ENDFUNC (strlen) |
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| 163 | #endif /* __ARC601__ || !__ARC_BARREL_SHIFTER__*/ |
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| 164 | |
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| 165 | #endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ |
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