Added high level structure of the BasePredictor

Author: dragon540

core/fetch/BPU.cpp

@@ -21,7 +21,8 @@ namespace olympia
             tage_tagged_table_num_(p->tage_tagged_table_num),
             logical_table_num_(p->logical_table_num),
             loop_pred_table_size_(p->loop_pred_table_size),
-            loop_pred_table_way_(p->loop_pred_table_way)
+            loop_pred_table_way_(p->loop_pred_table_way),
+            base_predictor_(pht_size_, ctr_bits_, btb_size_, ras_size_)
         {
             in_fetch_predictionRequest_.registerConsumerHandler(
                 CREATE_SPARTA_HANDLER_WITH_DATA(BPU, recievePredictionRequest_, PredictionRequest));

core/fetch/BPU.hpp

@@ -8,6 +8,7 @@
 #include "sparta/utils/LogUtils.hpp"
 
 #include "BranchPredIF.hpp"
+#include "BasePredictor.hpp"
 
 #include <list>
 
@@ -126,6 +127,8 @@ namespace olympia
             uint32_t predictionRequestCredits_ = 0;
             uint32_t predictionOutputCredits_ = 0;
 
+            BasePredictor base_predictor_;
+
             ///////////////////////////////////////////////////////////////////////////////
             // Ports
             ///////////////////////////////////////////////////////////////////////////////

core/fetch/BasePredictor.cpp

@@ -0,0 +1,26 @@
+#include "BasePredictor.hpp"
+
+namespace olympia
+{
+    namespace BranchPredictor
+    {
+        BasePredictor::BasePredictor(uint32_t pht_size, uint8_t ctr_bits, uint32_t btb_size,
+                                     uint32_t ras_size) :
+            pattern_history_table(pht_size, ctr_bits),
+            branch_target_buffer(btb_size),
+            return_address_stack(ras_size)
+        {
+        }
+
+        PatternHistoryTable::PatternHistoryTable(uint32_t pht_size, uint8_t ctr_bits) :
+            pht_size_(pht_size),
+            ctr_bits_(ctr_bits),
+            ctr_bits_val_(pow(2, ctr_bits))
+        {
+        }
+
+        BranchTargetBuffer::BranchTargetBuffer(uint32_t btb_size) : btb_size_(btb_size) {}
+
+        ReturnAddressStack::ReturnAddressStack(uint32_t ras_size) : ras_size_(ras_size) {}
+    } // namespace BranchPredictor
+} // namespace olympia

core/fetch/BasePredictor.hpp

@@ -0,0 +1,68 @@
+#pragma once
+
+#include <cstdint>
+#include <cmath>
+#include <map>
+#include <stack>
+
+namespace olympia
+{
+    namespace BranchPredictor
+    {
+        class PatternHistoryTable
+        {
+          public:
+            PatternHistoryTable(uint32_t pht_size, uint8_t ctr_bits);
+
+            void incrementCounter(uint32_t idx);
+            void decrementCounter(uint32_t idx);
+            uint8_t getPrediction(uint32_t idx);
+
+          private:
+            const uint32_t pht_size_;
+            const uint8_t ctr_bits_;
+            const uint8_t ctr_bits_val_;
+            std::map<uint64_t, uint8_t> pht_;
+        };
+
+        class BranchTargetBuffer
+        {
+          public:
+            BranchTargetBuffer(uint32_t btb_size);
+
+            bool addEntry(uint64_t PC, uint64_t targetPC);
+            bool removeEntry(uint64_t PC);
+            uint64_t getPredictedPC(uint64_t PC);
+            bool isHit(uint64_t PC);
+
+          private:
+            const uint32_t btb_size_;
+            std::map<uint64_t, uint64_t> btb_;
+        };
+
+        class ReturnAddressStack
+        {
+          public:
+            ReturnAddressStack(uint32_t ras_size);
+
+            void pushAddress();
+            uint64_t popAddress();
+
+          private:
+            const uint32_t ras_size_;
+            std::stack<uint64_t> ras_;
+        };
+
+        class BasePredictor
+        {
+          public:
+            BasePredictor(uint32_t pht_size, uint8_t ctr_bits, uint32_t btb_size,
+                          uint32_t ras_size);
+
+          private:
+            PatternHistoryTable pattern_history_table;
+            BranchTargetBuffer branch_target_buffer;
+            ReturnAddressStack return_address_stack;
+        };
+    } // namespace BranchPredictor
+} // namespace olympia

test/core/bpu/CMakeLists.txt

@@ -11,7 +11,7 @@ set(BPUDir ../../../core/fetch)
 
 project(${PRJ})
 
-add_executable(${EXE} BPU_testbench.cpp ${BPUDir}/BPU.cpp ${BPUDir}/BPU.hpp BPUSource.hpp BPUSink.hpp)
+add_executable(${EXE} BPU_testbench.cpp ${BPUDir}/BPU.cpp ${BPUDir}/BPU.hpp ${BPUDir}/BasePredictor.cpp ${BPUDir}/BasePredictor.hpp BPUSource.hpp BPUSink.hpp)
 target_include_directories(${EXE} PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
 
 target_link_libraries(${EXE} core common_test ${STF_LINK_LIBS} mavis SPARTA::sparta)