This change reverts both of the last changes to CVariable.

Change-Id: I5f390e2be541d1da1e2f694725eb30dac204d3ae

Author: trbauer

IGC/Compiler/CISACodeGen/CVariable.cpp

@@ -65,7 +65,6 @@ CVariable::CVariable(uint16_t nbElement, bool uniform, VISA_Type type,
     m_undef(false),
     m_isUnpacked(false)
 {
-    visaGenVariable[0] = visaGenVariable[1] = nullptr;
 }
 
 static unsigned
@@ -109,7 +108,6 @@ CVariable::CVariable(CVariable* var, VISA_Type type, uint16_t offset,
     m_undef(false),
     m_isUnpacked(false)
 {
-    visaGenVariable[0] = visaGenVariable[1] = nullptr;
     if (numElements)
     {
         m_nbElement = numElements;
@@ -141,15 +139,24 @@ CVariable::CVariable(uint64_t immediate, VISA_Type type) :
     m_undef(false),
     m_isUnpacked(false)
 {
-    visaGenVariable[0] = visaGenVariable[1] = nullptr;
+
 }
 
 /// CVariable constructor, for undef
 ///
-CVariable::CVariable(VISA_Type type)
-    : CVariable(0, type) // undef variable are represented as immediate
+CVariable::CVariable(VISA_Type type) :
+    m_immediateValue(0),
+    m_alias(nullptr),
+    m_nbElement(0),
+    m_numberOfInstance(1),
+    m_type(type),
+    m_varType(EVARTYPE_GENERAL),
+    m_uniform(true),
+    m_isImmediate(true),
+    m_subspanUse(false),
+    m_uniformVector(false),
+    m_undef(true),
+    m_isUnpacked(false)
 {
-    // fields are all the same as immediate except for these
-    m_nbElement = 0;
-    m_undef = true;
+    // undef variable are represented as immediate but can considered as trash data
 }

IGC/Compiler/CISACodeGen/CVariable.hpp

@@ -54,12 +54,10 @@ namespace IGC {
         // Copy Ctor
         CVariable(const CVariable& V)
         {
-            // the only differences
-            m_alias = nullptr;
-            m_aliasOffset = 0;
-            // everything else is the same
             m_immediateValue = V.m_immediateValue;
+            m_alias = nullptr;
             m_nbElement = V.m_nbElement;
+            m_aliasOffset = 0;
             m_numberOfInstance = V.m_numberOfInstance;
             m_type = V.m_type;
             m_varType = V.m_varType;
@@ -70,11 +68,10 @@ namespace IGC {
             m_uniformVector = V.m_uniformVector;
             m_undef = V.m_undef;
             m_isUnpacked = V.m_isUnpacked;
-            visaGenVariable[0] = V.visaGenVariable[0];
-            visaGenVariable[1] = V.visaGenVariable[1];
         }
 
-        e_alignment GetAlign() const {
+        e_alignment GetAlign() const
+        {
             assert(!m_isImmediate && "Calling GetAlign() on an immediate returns undefined result");
             return m_align;
         }
@@ -83,9 +80,9 @@ namespace IGC {
         uint16_t GetNumberElement() const { return m_nbElement; }
         bool IsUniform() const { return m_uniform; }
 
-        uint GetSize() const { return m_nbElement * CEncoder::GetCISADataTypeSize(m_type); }
+        uint GetSize() { return m_nbElement * CEncoder::GetCISADataTypeSize(m_type); }
 
-        uint GetElemSize() const { return CEncoder::GetCISADataTypeSize(m_type); }
+        uint GetElemSize() { return CEncoder::GetCISADataTypeSize(m_type); }
         CVariable* GetAlias() { return m_alias; }
         uint16_t GetAliasOffset() const { return m_aliasOffset; }
         VISA_Type GetType() const { return m_type; }
@@ -103,19 +100,20 @@ namespace IGC {
         bool IsVectorUniform() const { return m_uniformVector; }
         uint8_t GetNumberInstance() const { return m_numberOfInstance; }
         bool IsUndef() const { return m_undef; }
-        bool IsGRFAligned(e_alignment requiredAlign = EALIGN_GRF) const {
+        bool IsGRFAligned(e_alignment requiredAlign = EALIGN_GRF) const
+        {
             e_alignment align = GetAlign();
             if (requiredAlign == EALIGN_GRF)
                 return align == EALIGN_GRF || align == EALIGN_2GRF;
             return align == requiredAlign;
         }
 
         void setisUnpacked() { m_isUnpacked = true; }
-        bool isUnpacked() const { return m_isUnpacked; }
-        uint8_t getOffsetMultiplier() const { return (m_isUnpacked) ? 2 : 1; }
+        bool isUnpacked() { return m_isUnpacked; }
+        uint8_t getOffsetMultiplier() { return (m_isUnpacked) ? 2 : 1; }
         void ResolveAlias();
 
-        // two pointers wide
+        // 4 bytes
         union {
             VISA_GenVar* visaGenVariable[2];
             VISA_SurfaceVar* visaSurfVariable;
@@ -148,7 +146,7 @@ namespace IGC {
         // 8 bytes
         uint64_t m_immediateValue;
 
-        // 4 or 8 sizeof pointer
+        // 4 bytes - pointer
         CVariable* m_alias;
 
         // 2 bytes types