Subzero: Prototype to make use of RegNumT::No Register more concise

src/IceInstX86BaseImpl.h

 //===- subzero/src/IceInstX86BaseImpl.h - Generic X86 instructions -*- C++ -*=//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 1969 matching lines @@
   Ostream &Str = Func->getContext()->getStrEmit();
   assert(this->getSrcSize() == 1);
   assert(this->getDest()->hasReg());
   Str << "\t"
          "lea" << this->getWidthString(this->getDest()->getType()) << "\t";
   Operand *Src0 = this->getSrc(0);
   if (const auto *Src0Var = llvm::dyn_cast<Variable>(Src0)) {
     Type Ty = Src0Var->getType();
     // lea on x86-32 doesn't accept mem128 operands, so cast VSrc0 to an
     // acceptable type.
-    Src0Var->asType(isVectorType(Ty) ? IceType_i32 : Ty, RegNumT::NoRegister)
-        ->emit(Func);
+    Src0Var->asType(isVectorType(Ty) ? IceType_i32 : Ty, RegNumT())->emit(Func);
   } else {
     Src0->emit(Func);
   }
   Str << ", ";
   this->getDest()->emit(Func);
 }
 
 template <typename TraitsType>
 void InstImpl<TraitsType>::InstX86Mov::emit(const Cfg *Func) const {
   if (!BuildDefs::dump())
@@ skipping 16 matching lines @@
   }
   // For an integer truncation operation, src is wider than dest. In this case,
   // we use a mov instruction whose data width matches the narrower dest.
   // TODO: This assert disallows usages such as copying a floating
   // point value between a vector and a scalar (which movss is used for). Clean
   // this up.
   assert(InstX86Base::getTarget(Func)->typeWidthInBytesOnStack(DestTy) ==
          InstX86Base::getTarget(Func)->typeWidthInBytesOnStack(SrcTy));
   const Operand *NewSrc = Src;
   if (auto *SrcVar = llvm::dyn_cast<Variable>(Src)) {
-    auto NewRegNum = RegNumT::NoRegister;
+    RegNumT NewRegNum;
     if (SrcVar->hasReg())
       NewRegNum = Traits::getGprForType(DestTy, SrcVar->getRegNum());
     if (SrcTy != DestTy)
       NewSrc = SrcVar->asType(DestTy, NewRegNum);
   }
   NewSrc->emit(Func);
   Str << ", ";
   this->getDest()->emit(Func);
 }
 
@@ skipping 850 matching lines @@
     return;
   Ostream &Str = Func->getContext()->getStrDump();
   Str << "IACA_END";
 }
 
 } // end of namespace X86NAMESPACE
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINSTX86BASEIMPL_H