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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