To remove one sync instruction

Change-Id: I685b8a2e82510ae113480bd6f577c708fb3ae84a

Author: bcheng0127

visa/LocalScheduler/SWSB_G4IR.cpp

@@ -2081,7 +2081,7 @@ G4_INST* SWSB::insertSyncAllWRInstruction(G4_BB* bb, unsigned int SBIDs, INST_LI
     return syncInst;
 }
 
-void SWSB::insertSyncToken(G4_BB* bb, SBNode* node, G4_INST* inst, INST_LIST_ITER inst_it, int newInstID, BitSet* dstTokens, BitSet* srcTokens, bool removeAllToken)
+bool SWSB::insertSyncToken(G4_BB *bb, SBNode *node, G4_INST *inst, INST_LIST_ITER inst_it, int newInstID, BitSet *dstTokens, BitSet *srcTokens, bool removeAllToken)
 {
     //Non-test instruction can only have
     // 1. non-send: one Dst Token with distance, or
@@ -2097,6 +2097,8 @@ void SWSB::insertSyncToken(G4_BB* bb, SBNode* node, G4_INST* inst, INST_LIST_ITE
     unsigned short dstToken = (unsigned short)-1;
     unsigned short srcToken = (unsigned short)-1;
     SWSBTokenType type = G4_INST::SWSBTokenType::TOKEN_NONE;
+    bool insertedSync = false;
+
     for (unsigned int i = 0; i < node->GetInstruction()->getDepTokenNum();)
     {
         G4_INST* synAllInst = nullptr;
@@ -2212,6 +2214,7 @@ void SWSB::insertSyncToken(G4_BB* bb, SBNode* node, G4_INST* inst, INST_LIST_ITE
             synInst->setDepToken(dstToken, SWSBTokenType::AFTER_WRITE);
         }
         synInst->setLexicalId(newInstID);
+        insertedSync = true;
     }
 
     if (src)
@@ -2230,23 +2233,31 @@ void SWSB::insertSyncToken(G4_BB* bb, SBNode* node, G4_INST* inst, INST_LIST_ITE
             synInst->setDepToken(srcToken, SWSBTokenType::AFTER_READ);
         }
         synInst->setLexicalId(newInstID);
+        insertedSync = true;
     }
 
-    return;
+    return insertedSync;
 }
 
 
 void SWSB::insertSync(G4_BB* bb, SBNode* node, G4_INST* inst, INST_LIST_ITER inst_it, int newInstID, BitSet* dstTokens, BitSet* srcTokens, bool hasDistOneAreg)
 {
-    G4_INST* syncInst = nullptr;
+    bool insertedSync = false;
+    INST_LIST_ITER prevIt = inst_it;
     if (hasDistOneAreg)
     {
-        syncInst = insertSyncInstructionAfter(bb, inst_it, inst->getCISAOff(), inst->getLineNo());
-        syncInst->setDistance(1);
+        prevIt--;
+    }
+
+    {
+        insertedSync = insertSyncToken(bb, node, inst, inst_it, newInstID, dstTokens, srcTokens, false);
     }
 
+    if (hasDistOneAreg && insertedSync)
     {
-        insertSyncToken(bb, node, inst, inst_it, newInstID, dstTokens, srcTokens, false);
+        G4_INST* syncInst = nullptr;
+        syncInst = insertSyncInstructionAfter(bb, prevIt, inst->getCISAOff(), inst->getLineNo());
+        syncInst->setDistance(1);
     }
 }
 
@@ -3348,6 +3359,7 @@ void G4_BB_SB::SBDDD(G4_BB* bb,
         if (hasFollowDistOneAReg)
         {
             node->setDistance(1);
+            node->setDistOneAReg();
             hasFollowDistOneAReg = false;
         }
 
@@ -3357,8 +3369,6 @@ void G4_BB_SB::SBDDD(G4_BB* bb,
         if (hasFollowDistOneAReg)
         {
             node->setDistance(1);
-            node->setDistOneAReg();
-
         }
 
 

visa/LocalScheduler/SWSB_G4IR.h

@@ -1040,7 +1040,7 @@ namespace vISA
         //Assign Token
         void assignToken(SBNode *node, unsigned short token, uint32_t &tokenReuseCount, uint32_t &AWTokenReuseCount, uint32_t &ARTokenReuseCount, uint32_t &AATokenReuseCount);
         void assignDepToken(SBNode *node);
-        void insertSyncToken(G4_BB *bb, SBNode *node, G4_INST *inst, INST_LIST_ITER inst_it, int newInstID, BitSet *dstTokens, BitSet *srcTokens, bool removeAllTokens);
+        bool insertSyncToken(G4_BB *bb, SBNode *node, G4_INST *inst, INST_LIST_ITER inst_it, int newInstID, BitSet *dstTokens, BitSet *srcTokens, bool removeAllTokens);
         void insertSync(G4_BB *bb, SBNode *node, G4_INST *inst, INST_LIST_ITER inst_it, int newInstID, BitSet *dstTokens, BitSet *srcTokens, bool hasDistOneAreg);
         void insertTest();