| 1 | /* |
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| 2 | * memcmp routine for Z8000 |
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| 3 | * Copyright (C) 2004 Christian Groessler <chris@groessler.org> |
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| 4 | * |
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| 5 | * Permission to use, copy, modify, and distribute this file |
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| 6 | * for any purpose is hereby granted without fee, provided that |
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| 7 | * the above copyright notice and this notice appears in all |
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| 8 | * copies. |
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| 9 | * |
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| 10 | * This file is distributed WITHOUT ANY WARRANTY; without even the implied |
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| 11 | * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
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| 12 | */ |
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| 13 | |
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| 14 | /* int memcmp(const void *b1, const void *b2, size_t length); |
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| 15 | */ |
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| 16 | |
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| 17 | name "memcmp.S" |
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| 18 | |
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| 19 | .text |
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| 20 | even |
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| 21 | global _memcmp |
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| 22 | |
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| 23 | _memcmp: |
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| 24 | |
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| 25 | #ifdef __Z8001__ |
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| 26 | segm |
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| 27 | |
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| 28 | #ifdef __STD_CALL__ |
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| 29 | ldl rr6,rr14(#4) |
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| 30 | ldl rr4,rr14(#8) |
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| 31 | ldl rr2,rr14(#12) |
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| 32 | #endif |
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| 33 | |
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| 34 | /* rr2 - length (high word ignored) |
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| 35 | * rr4 - b2 |
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| 36 | * rr6 - b1 |
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| 37 | */ |
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| 38 | |
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| 39 | clr r1 /* initialize return value */ |
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| 40 | testl rr2 |
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| 41 | jr z,finish |
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| 42 | |
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| 43 | bitb rl7,#0 /* odd b1? */ |
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| 44 | jr nz,testb2 |
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| 45 | bitb rl5,#0 /* odd b2? */ |
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| 46 | jr nz,odd_cmp /* b1 even, b2 odd */ |
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| 47 | jr t,even_cmp |
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| 48 | |
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| 49 | testb2: |
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| 50 | bitb rl5,#0 |
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| 51 | jr z,odd_cmp /* b2 even, b1 odd */ |
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| 52 | |
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| 53 | cpsib @rr6,@rr4,r3,eq |
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| 54 | jr z,beq /* bytes are the same */ |
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| 55 | jr t,byte_diff |
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| 56 | |
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| 57 | beq: jr ov,finish /* jump if r3 is zero now */ |
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| 58 | |
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| 59 | /* compare words */ |
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| 60 | even_cmp: |
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| 61 | ld r2,r3 /* remember length */ |
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| 62 | srl r3,#1 |
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| 63 | jr z,no_words |
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| 64 | |
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| 65 | cpsir @rr6,@rr4,r3,ne |
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| 66 | jr nz,no_words |
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| 67 | |
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| 68 | dec r7,#2 |
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| 69 | dec r5,#2 /* point to different bytes */ |
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| 70 | ldk r3,#2 |
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| 71 | jr t,odd_cmp |
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| 72 | |
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| 73 | no_words: |
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| 74 | bitb rl2,#0 /* odd length? */ |
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| 75 | jr z,finish |
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| 76 | |
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| 77 | cpsib @rr6,@rr4,r3,eq |
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| 78 | jr z,finish /* last bytes are the same */ |
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| 79 | jr t,byte_diff |
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| 80 | |
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| 81 | /* compare bytes */ |
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| 82 | odd_cmp: |
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| 83 | cpsirb @rr6,@rr4,r3,ne |
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| 84 | jr nz,finish |
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| 85 | |
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| 86 | byte_diff: |
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| 87 | dec r7,#1 |
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| 88 | dec r5,#1 /* point to different bytes */ |
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| 89 | |
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| 90 | ldb rl1,@rr6 |
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| 91 | clr r0 |
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| 92 | ldb rl0,@rr4 |
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| 93 | sub r1,r0 |
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| 94 | |
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| 95 | finish: /* set return value */ |
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| 96 | #ifdef __STD_CALL__ |
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| 97 | ld r7,r1 |
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| 98 | #else |
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| 99 | ld r2,r1 |
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| 100 | #endif |
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| 101 | |
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| 102 | |
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| 103 | #else /* above Z8001, below Z8002 */ |
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| 104 | |
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| 105 | |
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| 106 | unsegm |
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| 107 | |
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| 108 | #ifdef __STD_CALL__ |
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| 109 | ld r7,r15(#2) |
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| 110 | ld r6,r15(#4) |
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| 111 | ld r5,r15(#6) |
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| 112 | #endif |
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| 113 | |
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| 114 | /* r5 - length |
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| 115 | * r6 - b2 |
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| 116 | * r7 - b1 |
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| 117 | */ |
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| 118 | |
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| 119 | clr r1 /* initialize return value */ |
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| 120 | test r5 |
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| 121 | jr z,finish |
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| 122 | |
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| 123 | bitb rl7,#0 /* odd destination address? */ |
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| 124 | jr nz,testb2 |
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| 125 | bitb rl6,#0 /* odd source address? */ |
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| 126 | jr nz,odd_cmp /* b1 even, b2 odd */ |
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| 127 | jr t,even_cmp |
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| 128 | |
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| 129 | testb2: |
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| 130 | bitb rl6,#0 |
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| 131 | jr z,odd_cmp /* b2 even, b1 odd */ |
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| 132 | |
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| 133 | cpsib @r7,@r6,r5,eq |
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| 134 | jr z,beq /* bytes are the same */ |
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| 135 | jr t,byte_diff |
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| 136 | |
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| 137 | beq: jr ov,finish /* jump if r3 is zero now */ |
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| 138 | |
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| 139 | /* compare words */ |
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| 140 | even_cmp: |
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| 141 | ld r4,r5 /* remember length */ |
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| 142 | srl r5,#1 |
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| 143 | jr z,no_words |
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| 144 | |
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| 145 | cpsir @r7,@r6,r5,ne |
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| 146 | jr nz,no_words |
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| 147 | |
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| 148 | dec r7,#2 |
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| 149 | dec r6,#2 /* point to different bytes */ |
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| 150 | ldk r5,#2 |
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| 151 | jr t,odd_cmp |
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| 152 | |
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| 153 | no_words: |
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| 154 | bitb rl4,#0 /* odd length? */ |
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| 155 | jr z,finish |
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| 156 | |
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| 157 | cpsib @r7,@r6,r4,eq |
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| 158 | jr z,finish /* last bytes are the same */ |
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| 159 | jr t,byte_diff |
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| 160 | |
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| 161 | /* compare bytes */ |
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| 162 | odd_cmp: |
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| 163 | cpsirb @r7,@r6,r5,ne |
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| 164 | jr nz,finish |
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| 165 | |
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| 166 | byte_diff: |
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| 167 | dec r7,#1 |
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| 168 | dec r6,#1 /* point to different bytes */ |
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| 169 | |
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| 170 | ldb rl1,@r7 |
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| 171 | clr r0 |
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| 172 | ldb rl0,@r6 |
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| 173 | sub r1,r0 |
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| 174 | |
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| 175 | finish: |
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| 176 | #ifdef __STD_CALL__ |
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| 177 | ld r7,r1 |
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| 178 | #else |
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| 179 | ld r2,r1 |
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| 180 | #endif |
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| 181 | |
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| 182 | #endif /* Z8002 */ |
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| 183 | |
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| 184 | ret |
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| 185 | .end |
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