Subzero: Don't store std::string objects inside Variable.

src/IceOperand.cpp

 //===- subzero/src/IceOperand.cpp - High-level operand implementation -----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This file implements the Operand class and its target-independent
@@ skipping 113 matching lines @@
       return true;
   }
   return false;
 }
 
 void LiveRange::trim(InstNumberT Lower) {
   while (TrimmedBegin != Range.end() && TrimmedBegin->second <= Lower)
     ++TrimmedBegin;
 }
 
-IceString Variable::getName() const {
-  if (!Name.empty())
-    return Name;
+IceString Variable::getName(const Cfg *Func) const {
+  if (Func && NameIndex >= 0)
+    return Func->getIdentifierName(NameIndex);
   return "__" + std::to_string(getIndex());
 }
 
 Variable Variable::asType(Type Ty) {
   // Note: This returns a Variable, even if the "this" object is a
   // subclass of Variable.
-  Variable V(kVariable, Ty, Number, Name);
+  Variable V(kVariable, Ty, Number);
+  V.NameIndex = NameIndex;
   V.RegNum = RegNum;
   V.StackOffset = StackOffset;
   return V;
 }
 
 void VariableTracking::markUse(MetadataKind TrackingKind, const Inst *Instr,
                                const CfgNode *Node, bool IsFromDef,
                                bool IsImplicit) {
   (void)TrackingKind;
   if (MultiBlock == MBS_MultiBlock)
@@ skipping 244 matching lines @@
 
 void Variable::emit(const Cfg *Func) const {
   if (ALLOW_DUMP)
     Func->getTarget()->emitVariable(this);
 }
 
 void Variable::dump(const Cfg *Func, Ostream &Str) const {
   if (!ALLOW_DUMP)
     return;
   if (Func == NULL) {
-    Str << "%" << getName();
+    Str << "%" << getName(Func);
     return;
   }
   if (Func->getContext()->isVerbose(IceV_RegOrigins) ||
       (!hasReg() && !Func->getTarget()->hasComputedFrame()))
-    Str << "%" << getName();
+    Str << "%" << getName(Func);
   if (hasReg()) {
     if (Func->getContext()->isVerbose(IceV_RegOrigins))
       Str << ":";
     Str << Func->getTarget()->getRegName(RegNum, getType());
   } else if (Func->getTarget()->hasComputedFrame()) {
     if (Func->getContext()->isVerbose(IceV_RegOrigins))
       Str << ":";
     Str << "[" << Func->getTarget()->getRegName(
                       Func->getTarget()->getFrameOrStackReg(), IceType_i32);
     int32_t Offset = getStackOffset();
@@ skipping 66 matching lines @@
   if (!ALLOW_DUMP)
     return Str;
   if (W.getWeight() == RegWeight::Inf)
     Str << "Inf";
   else
     Str << W.getWeight();
   return Str;
 }
 
 } // end of namespace Ice