The transformation in PromoteStatelessToBindless is performed for

all users of found buffer argument but there are places where such
transformation is illegal. The idea is to collect only instructions
which are related to an access (load/store) through the buffer and
make the transformation for collected instructions only.

Change-Id: I7344a3d5ec6a04fa91835b5b0b8490683826a37b

Author: itsimbal

IGC/Compiler/PromoteStatelessToBindless.cpp

@@ -101,7 +101,8 @@ void PromoteStatelessToBindless::GetAccessInstToSrcPointerMap(Instruction* inst,
             return;
     }
 
-    Value* srcPtr = IGC::TracePointerSource(resourcePtr);
+    std::vector<Value*> tempList;
+    Value* srcPtr = IGC::TracePointerSource(resourcePtr, false, true, true, tempList);
 
     if (!srcPtr ||
         !srcPtr->getType()->isPointerTy() ||
@@ -111,31 +112,41 @@ void PromoteStatelessToBindless::GetAccessInstToSrcPointerMap(Instruction* inst,
         IGC_ASSERT_MESSAGE(0, "Stateless buffer pointer not traceable, cannot promote stateless to bindless");
         return;
     }
-
+    // Save the instruction, which makes access (load/store/intrinsic) to the buffer
     m_AccessToSrcPtrMap[inst] = srcPtr;
+    // Save the instruction, which generate an address of the buffer. This is the
+    // instruction right before the last one. The last one has to be the buffer itself.
+    if (tempList.size() > 1)
+    {
+        m_AddressUsedSrcPtrMap[tempList[tempList.size()-2]] = srcPtr;
+    }
+    else
+    {
+        m_AddressUsedSrcPtrMap[inst] = srcPtr;
+    }
 }
 
 void PromoteStatelessToBindless::PromoteStatelessToBindlessBuffers(Function& F) const
 {
     ModuleMetaData* modMD = getAnalysis<MetaDataUtilsWrapper>().getModuleMetaData();
-    for (auto inst : m_AccessToSrcPtrMap)
+    // Modify the reference to the buffer not through all users but only in instructions
+    // which are used in accesing (load/store) the buffer.
+    for (auto inst : m_AddressUsedSrcPtrMap)
     {
+        Instruction* accessInst = cast<Instruction>(inst.first);
         Argument* srcPtr = cast<Argument>(inst.second);
-        if (!srcPtr->use_empty())
+        Value* nullSrcPtr = ConstantPointerNull::get(cast<PointerType>(srcPtr->getType()));
+        accessInst->replaceUsesOfWith(srcPtr, nullSrcPtr);
+        if (modMD->FuncMD.find(&F) != modMD->FuncMD.end())
         {
-            Value* nullSrcPtr = ConstantPointerNull::get(cast<PointerType>(srcPtr->getType()));
-            srcPtr->replaceAllUsesWith(nullSrcPtr);
-            if (modMD->FuncMD.find(&F) != modMD->FuncMD.end())
+            FunctionMetaData* funcMD = &modMD->FuncMD[&F];
+            ResourceAllocMD* resourceAlloc = &funcMD->resAllocMD;
+            ArgAllocMD* argInfo = &resourceAlloc->argAllocMDList[srcPtr->getArgNo()];
+            IGC_ASSERT_MESSAGE((size_t)srcPtr->getArgNo() < resourceAlloc->argAllocMDList.size(), "ArgAllocMD List Out of Bounds");
+            if (argInfo->type == ResourceTypeEnum::UAVResourceType)
             {
-                FunctionMetaData* funcMD = &modMD->FuncMD[&F];
-                ResourceAllocMD* resourceAlloc = &funcMD->resAllocMD;
-                ArgAllocMD* argInfo = &resourceAlloc->argAllocMDList[srcPtr->getArgNo()];
-                IGC_ASSERT_MESSAGE((size_t)srcPtr->getArgNo() < resourceAlloc->argAllocMDList.size(), "ArgAllocMD List Out of Bounds");
-                if (argInfo->type == ResourceTypeEnum::UAVResourceType)
-                {
-                    // Update metadata to show bindless resource type
-                    argInfo->type = ResourceTypeEnum::BindlessUAVResourceType;
-                }
+                // Update metadata to show bindless resource type
+                argInfo->type = ResourceTypeEnum::BindlessUAVResourceType;
             }
         }
     }

IGC/Compiler/PromoteStatelessToBindless.h

@@ -63,6 +63,7 @@ namespace IGC
         void PromoteStatelessToBindlessBuffers(llvm::Function& F) const;
 
         std::unordered_map<llvm::Value*, llvm::Value*> m_AccessToSrcPtrMap;
+        std::unordered_map<llvm::Value*, llvm::Value*> m_AddressUsedSrcPtrMap;
     };
 
 } // namespace IGC