Don't make a copy in a foreach loop.

Don't make a copy in a foreach loop.

Author: mateuszchudyk

IGC/AdaptorCommon/AddImplicitArgs.cpp

@@ -134,15 +134,15 @@ bool AddImplicitArgs::runOnModule(Module &M)
 
     if (!IGC::ForceAlwaysInline(ctx))
     {
-        for (auto I : funcsMappingForReplacement)
+        for (const auto& I : funcsMappingForReplacement)
         {
             replaceAllUsesWithNewOCLBuiltinFunction(I.first, I.second);
         }
     }
 
     // Update IGC Metadata
     // Function declarations are changing, this needs to be reflected in the metadata.
-    for (auto i : funcsMapping)
+    for (const auto& i : funcsMapping)
     {
         IGCMD::IGCMetaDataHelper::moveFunction(
             *m_pMdUtils, *ctx->getModuleMetaData(), i.first, i.second);
@@ -275,7 +275,7 @@ void AddImplicitArgs::updateNewFuncArgs(llvm::Function* pFunc, llvm::Function* p
     // byval. Bug#GD-429 had this exact issue. If we don't do this then we lose
     // mapping of argument to dbg.declare and elf file comes up with empty
     // storage location for the variable.
-    for (auto toReplace : newAddr)
+    for (const auto& toReplace : newAddr)
     {
         auto d = dyn_cast<DbgDeclareInst>(toReplace.first);
 
@@ -600,7 +600,7 @@ void BuiltinCallGraphAnalysis::traverseCallGraphSCC(const std::vector<CallGraphN
         // calculate args from sub-routine.
         // This function have not been processed yet, therefore no map-entry for it yet
         IGC_ASSERT(argMap.count(f) == 0);
-        for (auto N : (*CGN))
+        for (const auto& N : (*CGN))
         {
             Function *sub = N.second->getFunction();
             // if callee has not been visited

IGC/AdaptorCommon/LegalizeFunctionSignatures.cpp

@@ -350,7 +350,7 @@ void LegalizeFunctionSignatures::FixFunctionSignatures(Module& M)
 
 void LegalizeFunctionSignatures::FixFunctionBody(Module& M)
 {
-    for (auto iter : oldToNewFuncMap)
+    for (const auto& iter : oldToNewFuncMap)
     {
         Function* pFunc = iter.first;
         Function* pNewFunc = iter.second;
@@ -483,7 +483,7 @@ void LegalizeFunctionSignatures::FixFunctionUsers(Module& M)
     std::vector<CallInst*> callsToFix;
 
     // Check for all users of the old function and replace with the new signature
-    for (auto it : oldToNewFuncMap)
+    for (const auto& it : oldToNewFuncMap)
     {
         Function* pFunc = it.first;
         Function* pNewFunc = it.second;

IGC/AdaptorCommon/ProcessFuncAttributes.cpp

@@ -190,7 +190,7 @@ static bool convertRecursionToStackCall(CallGraph& CG)
         {
             // Check self-recursion.
             auto Node = SCCNodes.back();
-            for (auto Callee : *Node)
+            for (const auto& Callee : *Node)
             {
                 if (Callee.second == Node)
                 {