Merge pull request 'improve dead code analysis' (#45) from dead_code_removing into master

sapfor/experts/Sapfor_2017/_src/CFGraph/DataFlow/data_flow.h

@@ -6,6 +6,8 @@
 #include "../CFGraph.h"
 #include "../IR.h"
 
+enum class DATA_FLOW_UPD_STATUS { NO_CHANGE = 0, PROPAGATED, GENERATED };
+
 template <class DataType>
 class DataFlowAnalysisNode {
     static const int CNT_NOTINIT = 0;
@@ -13,7 +15,6 @@ class DataFlowAnalysisNode {
     int in_cnt = CNT_NOTINIT, out_cnt = CNT_NOTINIT;
 
     std::set<int> rollback;
-    std::set<int> ignore_rollback;
 
     std::set<DataFlowAnalysisNode<DataType>*> prev_blocks;
 
@@ -30,7 +31,7 @@ public:
     virtual bool addOut(const DataType& data) = 0;
 
     virtual bool updateState() { return false; }
-    virtual bool forwardData(const DataType& data) = 0;
+    virtual DATA_FLOW_UPD_STATUS forwardData(const DataType& data) = 0;
 
     bool newerThan(const DataFlowAnalysisNode<DataType>* block) const { return out_cnt > block->in_cnt; }
 
@@ -42,7 +43,6 @@ public:
     static int getStartCounter() { return CNT_NOTINIT; }
 
     std::set<int>& getRollback() { return rollback; }
-    std::set<int>& getIgnoreRollback() { return ignore_rollback; }
 
     std::set<DataFlowAnalysisNode<DataType>*>& getPrevBlocks() { return prev_blocks; }
 

sapfor/experts/Sapfor_2017/_src/CFGraph/DataFlow/data_flow_impl.h

@@ -19,7 +19,6 @@ template <class DataType>
 DataFlowAnalysisNode<DataType>::DataFlowAnalysisNode()
 {
     getRollback() = {};
-    getIgnoreRollback() = {};
     prev_blocks = {};
 }
 
@@ -33,18 +32,21 @@ void DataFlowAnalysisNode<DataType>::doStep()
     {
         if (in_cnt < next->out_cnt)
         {
+            if (next->out_cnt > in_max_cnt)
+                in_max_cnt = next->out_cnt;
+
             const auto& byOut = next->getOut();
             bool inserted = addIn( byOut);
 
             if (inserted)
             {
-                if (next->out_cnt > in_max_cnt)
+                auto status = forwardData(byOut);
-                    in_max_cnt = next->out_cnt;
+                inserted = status != DATA_FLOW_UPD_STATUS::NO_CHANGE;
-
-                inserted = forwardData(byOut);
 
                 if (inserted && next->out_cnt > out_max_cnt)
                     out_max_cnt = next->out_cnt;
+
+                uniq_change |= status == DATA_FLOW_UPD_STATUS::GENERATED;
             }
         }
     }
@@ -81,12 +83,10 @@ void DataFlowAnalysis<NodeType>::analyze()
         const auto& jumps = curr_bb->getRollback();
         if (jumps.size() != 0)
         {
-            auto& ignored_jumps = curr_bb->getIgnoreRollback();
-
             bool jump = false;
             for (const auto& jump_to : jumps)
             {
-                if (ignored_jumps.insert(jump_to).second && curr_bb->newerThan(nodes[jump_to]))
+                if (curr_bb->newerThan(nodes[jump_to]))
                 {
                     jump = true;
                     curr = jump_to;
@@ -94,9 +94,7 @@ void DataFlowAnalysis<NodeType>::analyze()
                 }
             }
 
-            if (!jump)
+            if (jump)
-                curr_bb->getIgnoreRollback().clear();
-            else
                 continue;
         }
 

sapfor/experts/Sapfor_2017/_src/CFGraph/live_variable_analysis.cpp

@@ -107,8 +107,6 @@ namespace SAPFOR
 
         removed |= (current_set.erase(to_remove) != 0);
 
-        if (!removed)
-        {
         auto it = live_inout.find(to_remove);
 
         if (it != live_inout.end())
@@ -122,9 +120,9 @@ namespace SAPFOR
                     dest.insert(find_bb_from_dest, bb);
             }
 
+            live_inout.erase(to_remove);
             removed = true;
         }
-        }
 
         return removed;
     }
@@ -253,7 +251,7 @@ public:
         return getBlock()->addLiveIn(data);
     }
 
-    bool forwardData(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
+    DATA_FLOW_UPD_STATUS forwardData(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
     {
         bool inserted = false;
 
@@ -261,7 +259,7 @@ public:
             if (live.find(byArg.first) == live.end() && dead.find(byArg.first) == dead.end())
                 inserted |= getBlock()->addLiveIn({ byArg });
 
-        return inserted;
+        return inserted ? DATA_FLOW_UPD_STATUS::PROPAGATED : DATA_FLOW_UPD_STATUS::NO_CHANGE;
     }
 
     LiveVarAnalysisNode(SAPFOR::BasicBlock* block, vector<SAPFOR::Argument*>& formal_parameters,
@@ -740,7 +738,7 @@ void runLiveVariableAnalysis(const map<FuncInfo*, vector<SAPFOR::BasicBlock*>>&
                     if (exit->addIn(converted))
                     {
                         exit->setInCnt(max_cnt);
-                        if (exit->forwardData(converted))
+                        if (exit->forwardData(converted) != DATA_FLOW_UPD_STATUS::NO_CHANGE)
                             exit->setOutCnt(max_cnt);
                     }
                 }

sapfor/experts/Sapfor_2017/_src/Transformations/dead_code.cpp

@@ -235,6 +235,15 @@ public:
         if (!useful_block)
             updated |= updateNextNotEmpty();
 
+        if (!useful_block)
+        {
+            if (next_notempty_in != next_notempty_out)
+            {
+                updated = true;
+                next_notempty_out = next_notempty_in;
+            }
+        }
+
         updated |= updateJumpStatus();
 
         if(updated)
@@ -243,9 +252,10 @@ public:
         return updated;
     }
 
-    bool forwardData(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
+    DATA_FLOW_UPD_STATUS forwardData(const map<SAPFOR::Argument*, vector<SAPFOR::BasicBlock*>>& data)
     {
-        bool inserted = false;
+        bool inserted_prop = false, inserted_gen = false;
+
         SAPFOR::BasicBlock* bb = getBlock();
 
         set<SAPFOR::Argument*> use, def;
@@ -271,7 +281,7 @@ public:
                     if (data_it == data.end())
                         printInternalError(convertFileName(__FILE__).c_str(), __LINE__);
 
-                    inserted |= bb->addLiveIn({ *data_it });
+                    inserted_prop |= bb->addLiveIn({ *data_it });
                 }
                 else
                 {
@@ -285,7 +295,7 @@ public:
                             bb->removeLiveIn(arg);
                     }
                     if(!skip)
-                        inserted |= bb->addLiveIn({ { arg, { bb } } });
+                        inserted_gen |= bb->addLiveIn({ { arg, { bb } } });
                 }
             }
         }
@@ -298,23 +308,19 @@ public:
                 {
                     useful_block = true;
 
-                    inserted = true;
+                    inserted_gen = true;
                     next_notempty_out = { this };
                     break;
                 }
             }
         }
 
-        if (!useful_block)
+        if(inserted_gen)
-        {
+            return DATA_FLOW_UPD_STATUS::GENERATED;
-            if (next_notempty_in != next_notempty_out)
+        else if(inserted_prop)
-            {
+            return DATA_FLOW_UPD_STATUS::PROPAGATED;
-                inserted = true;
-                next_notempty_out = next_notempty_in;
-            }
-        }
 
-        return inserted;
+        return DATA_FLOW_UPD_STATUS::NO_CHANGE;
     }
 
     DeadCodeAnalysisNode(SAPFOR::BasicBlock* block,