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/strncpy.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 dst and src are 4 byte aligned, copy 8 bytes at a time. |
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39 | If the src is 4, but not 8 byte aligned, we first read 4 bytes to get |
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40 | it 8 byte aligned. Thus, we can do a little read-ahead, without |
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41 | dereferencing a cache line that we should not touch. |
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42 | Note that short and long instructions have been scheduled to avoid |
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43 | branch stalls. |
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44 | The beq_s to r3z could be made unaligned & long to avoid a stall |
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45 | there, but the it is not likely to be taken often, and it |
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46 | would also be likey to cost an unaligned mispredict at the next call. */ |
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47 | |
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48 | #if !defined (__ARC601__) && defined (__ARC_BARREL_SHIFTER__) |
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49 | |
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50 | #if defined (__ARC700___) || defined (__ARCEM__) || defined (__ARCHS__) |
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51 | #define BRand(a,b,l) tst a,b ` bne_l l |
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52 | #else |
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53 | #define BRand(a,b,l) and a,a,b ` brne_s a,0,l |
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54 | #endif |
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55 | |
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56 | ENTRY (strncpy) |
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57 | cmp_s r2,8 |
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58 | or r12,r0,r1 |
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59 | bmsk.cc.f r12,r12,1 |
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60 | brne.d r12,0,.Lbytewise |
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61 | mov_s r10,r0 |
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62 | ld_s r3,[r1,0] |
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63 | mov r8,0x01010101 |
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64 | sub lp_count,r2,1 |
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65 | bbit0.d r1,2,.Loop_start |
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66 | ror r11,r8 |
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67 | sub r12,r3,r8 |
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68 | bic_l r12,r12,r3 |
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69 | BRand (r12,r11,.Lr3z) |
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70 | mov_s r4,r3 |
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71 | ld.a r3,[r1,4] |
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72 | sub lp_count,lp_count,4 |
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73 | st.ab r4,[r10,4] |
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74 | .balign 4 |
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75 | .Loop_start: |
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76 | lsr.f lp_count,lp_count,3 |
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77 | lpne .Loop_end |
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78 | ld.a r4,[r1,4] |
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79 | sub r12,r3,r8 |
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80 | bic_s r12,r12,r3 |
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81 | BRand (r12,r11,.Lr3z) |
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82 | st.ab r3,[r10,4] |
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83 | sub r12,r4,r8 |
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84 | bic r12,r12,r4 |
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85 | BRand (r12,r11,.Lr4z) |
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86 | ld.a r3,[r1,4] |
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87 | st.ab r4,[r10,4] |
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88 | .Loop_end: |
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89 | bcc_s .Lastword |
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90 | ld.a r4,[r1,4] |
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91 | sub r12,r3,r8 |
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92 | bic_s r12,r12,r3 |
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93 | BRand (r12,r11,.Lr3z) |
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94 | st.ab r3,[r10,4] |
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95 | mov_s r3,r4 |
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96 | .Lastword: |
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97 | and.f lp_count,r2,3 |
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98 | mov.eq lp_count,4 |
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99 | lp .Last_byte_end |
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100 | #ifdef __LITTLE_ENDIAN__ |
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101 | bmsk.f r1,r3,7 |
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102 | lsr.ne r3,r3,8 |
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103 | #else |
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104 | lsr.f r1,r3,24 |
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105 | asl.ne r3,r3,8 |
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106 | #endif |
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107 | stb.ab r1,[r10,1] |
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108 | .Last_byte_end: |
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109 | j_s [blink] |
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110 | |
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111 | .balign 4 |
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112 | .Lr4z: |
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113 | mov_l r3,r4 |
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114 | .Lr3z: |
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115 | #if defined (__ARC700__) || defined (__ARCEM__) || defined (__ARCHS__) |
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116 | #ifdef __LITTLE_ENDIAN__ |
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117 | bmsk.f r1,r3,7 |
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118 | lsr_s r3,r3,8 |
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119 | #else |
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120 | lsr.f r1,r3,24 |
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121 | asl_s r3,r3,8 |
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122 | #endif |
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123 | bne.d .Lr3z |
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124 | stb.ab r1,[r10,1] |
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125 | #else /* ! __ARC700__ */ |
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126 | #ifdef __LITTLE_ENDIAN__ |
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127 | bmsk.f r1,r3,7 |
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128 | .Lr3z_loop: |
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129 | lsr_s r3,r3,8 |
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130 | stb.ab r1,[r10,1] |
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131 | bne.d .Lr3z_loop |
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132 | bmsk.f r1,r3,7 |
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133 | #else |
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134 | lsr.f r1,r3,24 |
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135 | .Lr3z_loop: |
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136 | asl_s r3,r3,8 |
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137 | stb.ab r1,[r10,1] |
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138 | bne.d .Lr3z_loop |
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139 | lsr.f r1,r3,24 |
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140 | #endif /* ENDIAN */ |
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141 | #endif /* ! __ARC700__ */ |
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142 | .Lzero_rest: |
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143 | ; __strncpy_bzero requires: |
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144 | ; return value in r0 |
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145 | ; zeroing length in r2 |
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146 | ; zeroing start address in r3 |
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147 | mov_s r3,r10 |
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148 | add_s r2,r2,r0 |
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149 | b.d __strncpy_bzero |
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150 | sub_s r2,r2,r3 |
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151 | |
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152 | .balign 4 |
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153 | .Lbytewise: |
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154 | sub.f r2,r2,1 |
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155 | mov_l r3,r0 |
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156 | jcs [blink] |
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157 | .Lcharloop: |
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158 | ldb.ab r12,[r1,1] |
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159 | beq.d .Last_byte |
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160 | sub.f r2,r2,1 |
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161 | brne.d r12,0,.Lcharloop |
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162 | stb.ab r12,[r3,1] |
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163 | b.d __strncpy_bzero |
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164 | stb.ab r12,[r3,1] |
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165 | .Last_byte: |
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166 | j_s.d [blink] |
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167 | stb_l r12,[r3] |
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168 | ENDFUNC (strncpy) |
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169 | #endif /* !__ARC601__ && __ARC_BARREL_SHIFTER__ */ |
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170 | |
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171 | #endif /* !__OPTIMIZE_SIZE__ && !PREFER_SIZE_OVER_SPEED */ |
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