1 | #ifdef SYSTEMC |
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2 | /* |
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3 | * $Id$ |
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4 | * |
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5 | * [ Description ] |
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6 | * |
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7 | */ |
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8 | |
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9 | #include "Behavioural/Core/Multi_Front_end/Front_end/Prediction_unit/Prediction_unit_Glue/include/Prediction_unit_Glue.h" |
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10 | |
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11 | namespace morpheo { |
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12 | namespace behavioural { |
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13 | namespace core { |
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14 | namespace multi_front_end { |
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15 | namespace front_end { |
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16 | namespace prediction_unit { |
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17 | namespace prediction_unit_glue { |
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18 | |
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19 | |
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20 | #undef FUNCTION |
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21 | #define FUNCTION "Prediction_unit_Glue::genMealy_predict" |
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22 | void Prediction_unit_Glue::genMealy_predict (void) |
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23 | { |
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24 | log_printf(FUNC,Prediction_unit_Glue,FUNCTION,"Begin"); |
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25 | |
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26 | Tcontrol_t ack [_param->_nb_context]; |
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27 | for (uint32_t i=0; i<_param->_nb_context; i++) |
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28 | { |
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29 | ack [i] = 0; |
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30 | |
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31 | if (_param->_have_port_depth[i]) |
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32 | { |
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33 | PORT_WRITE(out_DEPTH_TAIL [i],PORT_READ(in_DEPTH_UPT_TAIL [i])); |
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34 | } |
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35 | PORT_WRITE(out_DEPTH_NB_BRANCH [i],PORT_READ(in_DEPTH_UPT_NB_BRANCH [i])); |
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36 | } |
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37 | |
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38 | for (uint32_t i=0; i<_param->_nb_inst_branch_predict; i++) |
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39 | { |
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40 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION,"PREDICT [%d]",i); |
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41 | |
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42 | Tcontrol_t btb_val; |
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43 | Tcontrol_t dir_val; |
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44 | Tcontrol_t ras_val; |
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45 | Tcontrol_t upt_val; |
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46 | |
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47 | Tcontext_t context = (reg_PREDICT_PRIORITY+i)%_param->_nb_context; |
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48 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * context : %d",context); |
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49 | |
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50 | ack [context] = 1; |
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51 | |
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52 | if (PORT_READ(in_PREDICT_VAL[context]) == 0) |
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53 | { |
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54 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * not valid ..."); |
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55 | |
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56 | btb_val = false; |
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57 | dir_val = false; |
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58 | ras_val = false; |
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59 | upt_val = false; |
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60 | } |
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61 | else |
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62 | { |
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63 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * valid ..."); |
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64 | |
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65 | Taddress_t pc_previous = PORT_READ(in_PREDICT_PC_PREVIOUS [context]); |
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66 | Taddress_t pc_current = PORT_READ(in_PREDICT_PC_CURRENT [context]); |
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67 | Tcontrol_t pc_current_is_ds_take = PORT_READ(in_PREDICT_PC_CURRENT_IS_DS_TAKE [context]); |
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68 | |
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69 | Taddress_t pc_next ; |
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70 | Tcontrol_t pc_next_is_ds_take ; |
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71 | Tbranch_state_t branch_state ; |
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72 | Tprediction_ptr_t branch_update_prediction_id ; |
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73 | Tinst_ifetch_ptr_t inst_ifetch_ptr ; |
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74 | |
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75 | // STEP (1) - Compute the address source |
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76 | Taddress_t address = (pc_current_is_ds_take)?pc_previous:pc_current; |
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77 | Taddress_t address_lsb = pc_current%_param->_nb_instruction [context]; //if pc_current_is_ds_take, then pc_current%_param->_nb_instruction [context] == 0 |
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78 | Taddress_t address_msb; |
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79 | |
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80 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * address : 0x%x",address); |
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81 | |
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82 | // STEP (2) - Test if branch (access at branch_target_buffer) |
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83 | btb_val = true; |
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84 | ack [context] &= PORT_READ(in_PREDICT_BTB_ACK [i]); |
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85 | |
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86 | if (_param->_have_port_context_id) |
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87 | PORT_WRITE(out_PREDICT_BTB_CONTEXT_ID [i],context); |
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88 | PORT_WRITE(out_PREDICT_BTB_ADDRESS [i],address); |
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89 | |
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90 | // special case : |
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91 | // if pc_current_is_ds, then pc_previous have branch, also hit must be set. |
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92 | // else : a another branch have eject this branch : can't accurate |
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93 | Tcontrol_t hit = PORT_READ(in_PREDICT_BTB_HIT[i]); |
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94 | Tcontrol_t is_accurate = PORT_READ(in_PREDICT_BTB_IS_ACCURATE [i]) and not (pc_current_is_ds_take and not hit); |
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95 | |
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96 | // STEP (3) : Test if have branch in the packet |
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97 | if (hit == 1) |
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98 | { |
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99 | // STEP (3a) : branch - test condition |
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100 | |
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101 | bool use_dir = false; |
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102 | bool use_ras = false; |
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103 | bool use_upt = false; |
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104 | |
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105 | Tbranch_condition_t cond = PORT_READ(in_PREDICT_BTB_CONDITION [i]); |
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106 | Taddress_t address_src = PORT_READ(in_PREDICT_BTB_ADDRESS_SRC [i]); |
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107 | Taddress_t address_dest = PORT_READ(in_PREDICT_BTB_ADDRESS_DEST [i]); |
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108 | Tcontrol_t push; |
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109 | Tcontrol_t direction; |
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110 | |
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111 | switch (cond) |
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112 | { |
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113 | case BRANCH_CONDITION_NONE_WITHOUT_WRITE_STACK : // l.j |
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114 | { |
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115 | // use none unit (dir, upt and ras) |
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116 | direction = true; |
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117 | pc_next = address_dest; |
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118 | branch_state = BRANCH_STATE_NSPEC_TAKE; |
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119 | break; |
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120 | } |
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121 | case BRANCH_CONDITION_NONE_WITH_WRITE_STACK : // l.jal |
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122 | { |
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123 | use_upt = true; |
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124 | use_ras = true; |
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125 | push = true; |
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126 | direction = true; |
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127 | pc_next = address_dest; |
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128 | branch_state = BRANCH_STATE_NSPEC_TAKE; |
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129 | break; |
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130 | } |
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131 | case BRANCH_CONDITION_FLAG_UNSET : // l.bnf |
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132 | case BRANCH_CONDITION_FLAG_SET : // l.bf |
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133 | { |
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134 | use_upt = true; |
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135 | use_dir = true; |
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136 | // Test direction |
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137 | direction = PORT_READ(in_PREDICT_DIR_DIRECTION [i]); // Direction is not the "flag predict" ... also flag_unset and flag_set is the same |
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138 | if (direction = 1) |
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139 | { |
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140 | branch_state = BRANCH_STATE_SPEC_TAKE; |
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141 | pc_next = address_dest; |
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142 | } |
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143 | else |
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144 | { |
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145 | branch_state = BRANCH_STATE_SPEC_NTAKE; |
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146 | pc_next = address_src+2; // +1 = delay slot |
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147 | } |
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148 | break; |
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149 | } |
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150 | case BRANCH_CONDITION_READ_REGISTER_WITHOUT_WRITE_STACK : // l.jr (rb!=9) |
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151 | { |
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152 | use_upt = true; |
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153 | use_ras = true; |
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154 | push = true; |
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155 | direction = true; |
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156 | pc_next = address_dest; |
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157 | branch_state = BRANCH_STATE_SPEC_TAKE; |
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158 | break; |
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159 | } |
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160 | case BRANCH_CONDITION_READ_REGISTER_WITH_WRITE_STACK : // l.jalr |
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161 | { |
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162 | use_upt = true; |
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163 | use_ras = true; |
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164 | push = true; |
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165 | direction = true; |
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166 | pc_next = address_dest; |
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167 | branch_state = BRANCH_STATE_NSPEC_TAKE; |
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168 | break; |
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169 | } |
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170 | case BRANCH_CONDITION_READ_STACK : // l.jr (rb==9) |
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171 | { |
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172 | use_upt = true; |
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173 | use_ras = true; |
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174 | push = false; |
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175 | direction = true; |
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176 | pc_next = PORT_READ(in_PREDICT_RAS_ADDRESS_POP [i]); |
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177 | branch_state = BRANCH_STATE_SPEC_TAKE; |
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178 | break; |
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179 | } |
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180 | default : |
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181 | { |
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182 | ERRORMORPHEO(FUNCTION,"Unknow Condition"); |
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183 | break; |
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184 | } |
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185 | } |
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186 | |
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187 | if (use_dir) |
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188 | { |
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189 | ack[context] &= PORT_READ(in_PREDICT_DIR_ACK [i]); |
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190 | PORT_WRITE(out_PREDICT_DIR_ADDRESS_SRC [i], address_src); |
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191 | PORT_WRITE(out_PREDICT_DIR_STATIC [i], address_dest<address_src); // if destination is previous : the static direction is take |
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192 | // PORT_WRITE(out_PREDICT_DIR_LAST_TAKE [i], PORT_READ(in_PREDICT_BTB_LAST_TAKE [i])); |
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193 | } |
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194 | |
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195 | if (use_ras) |
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196 | { |
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197 | ack[context] &= PORT_READ(in_PREDICT_RAS_ACK [i]); |
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198 | if (_param->_have_port_context_id) |
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199 | PORT_WRITE(out_PREDICT_RAS_CONTEXT_ID [i], context); |
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200 | PORT_WRITE(out_PREDICT_RAS_PUSH [i], push); |
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201 | PORT_WRITE(out_PREDICT_RAS_ADDRESS_PUSH [i], address_src+2); |
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202 | |
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203 | is_accurate &= PORT_READ(in_PREDICT_RAS_HIT [i]); // if miss - prediction is not accurate |
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204 | } |
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205 | |
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206 | if (use_upt) |
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207 | { |
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208 | ack[context] &= PORT_READ(in_PREDICT_UPT_ACK [i]); |
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209 | |
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210 | PORT_WRITE(out_PREDICT_UPT_CONTEXT_ID [i],context); |
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211 | PORT_WRITE(out_PREDICT_UPT_BTB_ADDRESS_SRC [i],address_src); |
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212 | PORT_WRITE(out_PREDICT_UPT_BTB_ADDRESS_DEST [i],address_dest); |
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213 | PORT_WRITE(out_PREDICT_UPT_BTB_CONDITION [i],cond); |
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214 | PORT_WRITE(out_PREDICT_UPT_BTB_LAST_TAKE [i],direction); |
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215 | PORT_WRITE(out_PREDICT_UPT_BTB_IS_ACCURATE [i],is_accurate); |
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216 | // PORT_WRITE(out_PREDICT_UPT_DIR_HISTORY [i],PORT_READ(in_PREDICT_DIR_HISTORY [i])); |
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217 | PORT_WRITE(out_PREDICT_UPT_RAS_ADDRESS [i],PORT_READ(in_PREDICT_RAS_ADDRESS_POP [i])); |
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218 | // PORT_WRITE(out_PREDICT_UPT_RAS_INDEX [i],PORT_READ(in_PREDICT_RAS_INDEX [i])); |
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219 | } |
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220 | |
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221 | // ack = 1 if : |
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222 | // * btb_ack |
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223 | // * use_dir and dir_ack |
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224 | // * use_ras and ras_ack |
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225 | // * use_upt and upt_ack |
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226 | // ack [context] = (PORT_READ(in_PREDICT_BTB_ACK [i]) and |
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227 | // (use_dir and PORT_READ(in_PREDICT_DIR_ACK [i])) and |
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228 | // (use_ras and PORT_READ(in_PREDICT_RAS_ACK [i])) and |
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229 | // (use_upt and PORT_READ(in_PREDICT_UPT_ACK [i]))); |
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230 | |
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231 | dir_val = (use_dir and |
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232 | PORT_READ(in_PREDICT_BTB_ACK [i]) and |
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233 | (not use_ras or (use_ras and PORT_READ(in_PREDICT_RAS_ACK [i]))) and |
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234 | (not use_upt or (use_upt and PORT_READ(in_PREDICT_UPT_ACK [i])))); |
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235 | |
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236 | ras_val = (use_ras and |
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237 | PORT_READ(in_PREDICT_BTB_ACK [i]) and |
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238 | (not use_dir or (use_dir and PORT_READ(in_PREDICT_DIR_ACK [i]))) and |
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239 | (not use_upt or (use_upt and PORT_READ(in_PREDICT_UPT_ACK [i])))); |
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240 | |
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241 | upt_val = (use_upt and |
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242 | PORT_READ(in_PREDICT_BTB_ACK [i]) and |
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243 | (not use_dir or (use_dir and PORT_READ(in_PREDICT_DIR_ACK [i]))) and |
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244 | (not use_ras or (use_ras and PORT_READ(in_PREDICT_RAS_ACK [i])))); |
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245 | |
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246 | // pc_next - is previously computed |
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247 | // branch_state - is previously computed |
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248 | |
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249 | Taddress_t address_src_lsb = address_src%_param->_nb_instruction [context]; |
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250 | |
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251 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * address_src : 0x%x",address_src); |
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252 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * address_src_lsb : %d",address_src_lsb); |
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253 | if (address_src_lsb == (_param->_nb_instruction [context]-1)) |
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254 | { |
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255 | // branch is in the last slot of the packet |
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256 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * branch is in the last slot of the packet"); |
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257 | |
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258 | address_msb = _param->_nb_instruction [context]; // == (address_src_lsb+1) |
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259 | pc_next_is_ds_take = 1; |
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260 | } |
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261 | else |
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262 | { |
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263 | // branch is in the last slot of the packet |
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264 | address_msb = (address_src_lsb+2); // +1 == delayed slot |
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265 | pc_next_is_ds_take = 0; |
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266 | } |
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267 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * address_msb : %d",address_msb); |
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268 | |
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269 | inst_ifetch_ptr = address_src_lsb; |
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270 | branch_update_prediction_id = (_param->_have_port_depth[context])?((PORT_READ(in_DEPTH_UPT_TAIL[context])+PORT_READ(in_DEPTH_UPT_NB_BRANCH [context]))%_param->_size_depth[context]):0; |
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271 | } |
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272 | else |
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273 | { |
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274 | // STEP (3b) : Sequential order : compute next paquet |
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275 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * BTB miss : sequential order"); |
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276 | |
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277 | pc_next = address-address_lsb+_param->_nb_instruction [context]; // sequencial |
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278 | pc_next_is_ds_take = 0; // no branch, also no delay slot |
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279 | inst_ifetch_ptr = 0; |
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280 | branch_state = BRANCH_STATE_NONE; |
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281 | branch_update_prediction_id = 0; |
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282 | |
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283 | address_msb = _param->_nb_instruction [context]; |
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284 | } |
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285 | |
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286 | PORT_WRITE(out_PREDICT_PC_NEXT [context] , pc_next ); |
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287 | PORT_WRITE(out_PREDICT_PC_NEXT_IS_DS_TAKE [context] , pc_next_is_ds_take ); |
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288 | |
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289 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * instruction enable :"); |
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290 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * nb_inst : %d",_param->_nb_instruction [context]); |
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291 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * [0:%d[ = 0",address_lsb); |
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292 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * [%d:%d[ = 1",address_lsb,((pc_current_is_ds_take)?1:address_msb)); |
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293 | log_printf(TRACE,Prediction_unit_Glue,FUNCTION," * [%d:%d[ = 0",((pc_current_is_ds_take)?1:address_msb),_param->_nb_instruction [context]); |
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294 | |
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295 | for (uint32_t j=0; j<address_lsb; j++) |
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296 | PORT_WRITE(out_PREDICT_INSTRUCTION_ENABLE [context][j], 0); // Before the address : not valid |
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297 | for (uint32_t j=address_lsb; j<((pc_current_is_ds_take)?1:address_msb); j++) |
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298 | PORT_WRITE(out_PREDICT_INSTRUCTION_ENABLE [context][j], 1); // Vald packet |
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299 | for (uint32_t j=((pc_current_is_ds_take)?1:address_msb); j<_param->_nb_instruction [context]; j++) |
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300 | PORT_WRITE(out_PREDICT_INSTRUCTION_ENABLE [context][j], 0); // After last address (branch) : not valid |
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301 | if (_param->_have_port_inst_ifetch_ptr[context]) |
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302 | PORT_WRITE(out_PREDICT_INST_IFETCH_PTR [context] , inst_ifetch_ptr ); |
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303 | PORT_WRITE(out_PREDICT_BRANCH_STATE [context] , branch_state ); |
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304 | if (_param->_have_port_depth[context]) |
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305 | PORT_WRITE(out_PREDICT_BRANCH_UPDATE_PREDICTION_ID [context] , branch_update_prediction_id); |
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306 | } |
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307 | |
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308 | // Write output |
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309 | PORT_WRITE(out_PREDICT_BTB_VAL [i], btb_val); |
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310 | PORT_WRITE(out_PREDICT_DIR_VAL [i], dir_val); |
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311 | PORT_WRITE(out_PREDICT_RAS_VAL [i], ras_val); |
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312 | PORT_WRITE(out_PREDICT_UPT_VAL [i], upt_val); |
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313 | } |
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314 | |
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315 | for (uint32_t i=0; i<_param->_nb_context; i++) |
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316 | PORT_WRITE(out_PREDICT_ACK[i],ack[i]); |
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317 | |
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318 | log_printf(FUNC,Prediction_unit_Glue,FUNCTION,"End"); |
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319 | }; |
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320 | |
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321 | }; // end namespace prediction_unit_glue |
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322 | }; // end namespace prediction_unit |
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323 | }; // end namespace front_end |
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324 | }; // end namespace multi_front_end |
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325 | }; // end namespace core |
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326 | |
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327 | }; // end namespace behavioural |
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328 | }; // end namespace morpheo |
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329 | #endif |
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