Move private memory usage detection to PrivateMemoryResolution

Previously detection was placed in LowerGEPForPrivMem, which could be not
correct if PromoteMemoryToRegister menaged to promote given alloca. This
could cause situation where PromoteMemoryToRegister removed last alloca
in shader, meaning potential later spill/fill should be stored in slot0
instead of slot1, but detection mechanism still would force using slot1.
This would lead to situation where UMD programs only slot0, but spills
are written to slot1, causing crash.

IGC/Compiler/CISACodeGen/LowerGEPForPrivMem.cpp

@@ -522,19 +522,6 @@ void LowerGEPForPrivMem::MarkNotPromtedAllocas(llvm::AllocaInst& I, IGC::StatusP
         I.getContext(),
         MDString::get(I.getContext(), reason));
 
-
-    auto allocationSize = I.getAllocationSizeInBits(m_ctx->getModule()->getDataLayout());
-
-    if (allocationSize)
-    {
-        auto scratchUsage_i = m_ctx->m_ScratchSpaceUsage.find(I.getFunction());
-        if (scratchUsage_i == m_ctx->m_ScratchSpaceUsage.end())
-        {
-            m_ctx->m_ScratchSpaceUsage.insert({ I.getFunction(), 0 });
-        }
-        m_ctx->m_ScratchSpaceUsage[I.getFunction()] += allocationSize.getValue() / 8;
-    }
-
     UserAddrSpaceMD& userASMD = m_ctx->m_UserAddrSpaceMD;
     std::function<void(Instruction*, MDNode*)> markAS_PRIV;
     markAS_PRIV = [&markAS_PRIV, &userASMD](Instruction* instr, MDNode* node) -> void

IGC/Compiler/Optimizer/OpenCLPasses/PrivateMemory/PrivateMemoryResolution.cpp

@@ -730,6 +730,21 @@ bool PrivateMemoryResolution::resolveAllocaInstructions(bool privateOnStack)
         return false;
     }
 
+    for (AllocaInst* aInst : allocaInsts)
+    {
+        auto allocationSize = aInst->getAllocationSizeInBits(m_currFunction->getParent()->getDataLayout());
+
+        if (allocationSize)
+        {
+            auto scratchUsage_i = Ctx.m_ScratchSpaceUsage.find(m_currFunction);
+            if (scratchUsage_i == Ctx.m_ScratchSpaceUsage.end())
+            {
+                Ctx.m_ScratchSpaceUsage.insert({ m_currFunction, 0 });
+            }
+            Ctx.m_ScratchSpaceUsage[m_currFunction] += allocationSize.getValue() / 8;
+        }
+    }
+
     if (Ctx.m_instrTypes.numAllocaInsts > IGC_GET_FLAG_VALUE(AllocaRAPressureThreshold))
     {
         sinkAllocaSingleUse(allocaInsts);