try to repair the unexpected code pattern in Duplicate Tracker

Author: VyacheslavLevytskyy

llvm/lib/Target/SPIRV/SPIRVDuplicatesTracker.cpp

@@ -69,16 +69,31 @@ void SPIRVGeneralDuplicatesTracker::buildDepsGraph(
         MachineOperand *RegOp = &VRegDef->getOperand(0);
         if (Reg2Entry.count(RegOp) == 0 &&
             (MI->getOpcode() != SPIRV::OpVariable || i != 3)) {
-          std::string DiagMsg;
-          raw_string_ostream OS(DiagMsg);
-          OS << "Unexpected pattern while building a dependency "
-                "graph.\nInstruction: ";
-          MI->print(OS);
-          OS << "Operand: ";
-          Op.print(OS);
-          OS << "\nOperand definition: ";
-          VRegDef->print(OS);
-          report_fatal_error(DiagMsg.c_str());
+          // try to repair the unexpected code pattern
+          bool IsFixed = false;
+          if (VRegDef->getOpcode() == TargetOpcode::G_CONSTANT &&
+              RegOp->isReg() && MRI.getType(RegOp->getReg()).isScalar()) {
+            const Constant *C = VRegDef->getOperand(1).getCImm();
+            add(C, MI->getParent()->getParent(), RegOp->getReg());
+            auto Iter = CT.Storage.find(C);
+            if (Iter != CT.Storage.end()) {
+              SPIRV::DTSortableEntry &MissedEntry = Iter->second;
+              Reg2Entry[RegOp] = &MissedEntry;
+              IsFixed = true;
+            }
+          }
+          if (!IsFixed) {
+            std::string DiagMsg;
+            raw_string_ostream OS(DiagMsg);
+            OS << "Unexpected pattern while building a dependency "
+                  "graph.\nInstruction: ";
+            MI->print(OS);
+            OS << "Operand: ";
+            Op.print(OS);
+            OS << "\nOperand definition: ";
+            VRegDef->print(OS);
+            report_fatal_error(DiagMsg.c_str());
+          }
         }
         if (Reg2Entry.count(RegOp))
           E->addDep(Reg2Entry[RegOp]);