[Subzero][MIPS32] Implement bitcast operation for both 32-bit and 64-bit operands

src/IceTargetLoweringMIPS32.h

 //===- subzero/src/IceTargetLoweringMIPS32.h - MIPS32 lowering ---*- C++-*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 323 matching lines @@
   }
 
   void _mfhi(Variable *Dest, Operand *Src) {
     Context.insert<InstMIPS32Mfhi>(Dest, Src);
   }
 
   void _mflo(Variable *Dest, Operand *Src) {
     Context.insert<InstMIPS32Mflo>(Dest, Src);
   }
 
-  void _mov(Variable *Dest, Operand *Src0) {
+  void _mov(Variable *Dest, Operand *Src0, Operand *Src1 = nullptr) {
     assert(Dest != nullptr);
     // Variable* Src0_ = llvm::dyn_cast<Variable>(Src0);
     if (llvm::isa<ConstantRelocatable>(Src0)) {
       Context.insert<InstMIPS32La>(Dest, Src0);
     } else {
-      auto *Instr = Context.insert<InstMIPS32Mov>(Dest, Src0);
-      if (Instr->isMultiDest()) {
-        // If Instr is multi-dest, then Dest must be a Variable64On32. We add a
+      auto *Instr = Context.insert<InstMIPS32Mov>(Dest, Src0, Src1);
+      if (Instr->getDestHi() != nullptr) {
+        // If DestHi is available, then Dest must be a Variable64On32. We add a
         // fake-def for Instr.DestHi here.
         assert(llvm::isa<Variable64On32>(Dest));
         Context.insert<InstFakeDef>(Instr->getDestHi());
       }
     }
   }
 
   void _mov_d(Variable *Dest, Variable *Src) {
     Context.insert<InstMIPS32Mov_d>(Dest, Src);
   }
@@ skipping 505 matching lines @@
   explicit TargetHeaderMIPS32(GlobalContext *Ctx);
 
 private:
   ~TargetHeaderMIPS32() = default;
 };
 
 } // end of namespace MIPS32
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGMIPS32_H