Introduction of uniform private memory block

This change is to reduce the private memory space if uniform allocas are used. This should improve cachability in some case due to increased packing.

Author: krystian-andrzejewski

IGC/Compiler/CISACodeGen/DriverInfo.hpp

@@ -380,6 +380,8 @@ namespace IGC
 
         // Informs if the UMD understands atomic pull tile walk for raytracing
         virtual bool supportsAtomicPullSWTileWalk() const { return false; }
+
+        virtual bool supportsUniformPrivateMemorySpace() const { return false; }
 protected:
     bool autoGRFSelection = false;
     };

IGC/Compiler/CISACodeGen/LowerGEPForPrivMem.cpp

@@ -559,6 +559,11 @@ bool SOALayoutChecker::checkStruct(StructType* StTy)
 // TODO: Consider a worklist-based implementation instead.
 bool SOALayoutChecker::checkUsers(Instruction& I)
 {
+    if (IGC_IS_FLAG_ENABLED(DisableSOAPromotion))
+    {
+        return false;
+    }
+
     parentLevelInst = &I;
     for (Value::user_iterator userIt = I.user_begin(), userE = I.user_end(); userIt != userE; ++userIt)
     {