Minor Refactoring

Change-Id: I53ec3cedc8c7131c184da1fe9ae25fe43d0d31a8

Author: jgu222

IGC/Compiler/CISACodeGen/DriverInfo.hpp

@@ -259,6 +259,9 @@ namespace IGC
         /// Allow aggressive vector value aliasing
         virtual bool EnableVecAliasing() const { return false; }
 
+        /// Restrict dessa aliasing level. -1 : no restriction; max level otherwise.
+        virtual int DessaAliasLevel() const { return -1; }
+
         /// Rounding mode used for DP emulated function, defaults to Round to nearest
         virtual unsigned DPEmulationRoundingMode() const { return 0; }
 

IGC/Compiler/CodeGenContext.cpp

@@ -675,6 +675,15 @@ namespace IGC
             "IGC::PositionOnlyVertexShader") != nullptr;
     }
 
+    void CodeGenContext::setFlagsPerCtx()
+    {
+        if (m_DriverInfo.DessaAliasLevel() != -1) {
+            if ((int)IGC_GET_FLAG_VALUE(EnableDeSSAAlias) > m_DriverInfo.DessaAliasLevel())
+            {
+                IGC_SET_FLAG_VALUE(EnableDeSSAAlias, m_DriverInfo.DessaAliasLevel());
+            }
+        }
+    }
 
 
 }

IGC/Compiler/CodeGenPublic.h

@@ -777,6 +777,8 @@ namespace IGC
         /// input: IGC MetaData Utils
         IGC::IGCMD::MetaDataUtils* m_pMdUtils = nullptr;
         IGC::ModuleMetaData* modMD = nullptr;
+
+        virtual void setFlagsPerCtx();
     public:
         CodeGenContext(
             ShaderType          _type,      ///< shader type
@@ -805,6 +807,9 @@ namespace IGC
                     instrStat[i][j] = 0;
                 }
             }
+
+            // Per context flag adjustment
+            setFlagsPerCtx();
         }
 
         CodeGenContext(CodeGenContext&) = delete;