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

src/IceInstMIPS32.h

 //===- subzero/src/IceInstMIPS32.h - MIPS32 machine instrs --*- C++ -*-----===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 1182 matching lines @@
 using InstMIPS32Xor = InstMIPS32ThreeAddrGPR<InstMIPS32::Xor>;
 using InstMIPS32Xori = InstMIPS32Imm16<InstMIPS32::Xori>;
 
 /// Handles (some of) vmov's various formats.
 class InstMIPS32Mov final : public InstMIPS32 {
   InstMIPS32Mov() = delete;
   InstMIPS32Mov(const InstMIPS32Mov &) = delete;
   InstMIPS32Mov &operator=(const InstMIPS32Mov &) = delete;
 
 public:
-  static InstMIPS32Mov *create(Cfg *Func, Variable *Dest, Operand *Src) {
-    return new (Func->allocate<InstMIPS32Mov>()) InstMIPS32Mov(Func, Dest, Src);
+  static InstMIPS32Mov *create(Cfg *Func, Variable *Dest, Operand *Src,
+                               Operand *Src2) {
+    return new (Func->allocate<InstMIPS32Mov>())
+        InstMIPS32Mov(Func, Dest, Src, Src2);
   }
+
   bool isRedundantAssign() const override {
     return !isMultiDest() && !isMultiSource() &&
            checkForRedundantAssign(getDest(), getSrc(0));
   }
   // bool isSimpleAssign() const override { return true; }
   void emit(const Cfg *Func) const override;
   void emitIAS(const Cfg *Func) const override;
   void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Inst) { return isClassof(Inst, Mov); }
 
-  bool isMultiDest() const { return DestHi != nullptr; }
+  bool isMultiDest() const { return false; }

[Jim Stichnoth, 2016/10/10 17:07:49]

Are these meant to be permanent changes?  (i.e. isMultiDest() and
isMultiSource() always return false)
If so, can you just remove these functions and change their users accordingly?

[sagar.thakur, 2016/10/12 06:07:06]

Yes, a mov instruction will always have single destination and source.
Removed these functions and their uses.

 
-  bool isMultiSource() const {
-    assert(getSrcSize() == 1 || getSrcSize() == 2);
-    return getSrcSize() == 2;
-  }
+  bool isMultiSource() const { return false; }
 
   Variable *getDestHi() const { return DestHi; }
 
 private:
-  InstMIPS32Mov(Cfg *Func, Variable *Dest, Operand *Src);
+  InstMIPS32Mov(Cfg *Func, Variable *Dest, Operand *Src, Operand *Src2);
 
   void emitMultiDestSingleSource(const Cfg *Func) const;
   void emitSingleDestMultiSource(const Cfg *Func) const;
   void emitSingleDestSingleSource(const Cfg *Func) const;
 
   Variable *DestHi = nullptr;
 };
 
 // Declare partial template specializations of emit() methods that already have
 // default implementations. Without this, there is the possibility of ODR
@@ skipping 86 matching lines @@
 template <> void InstMIPS32Trunc_l_s::emitIAS(const Cfg *Func) const;
 template <> void InstMIPS32Trunc_w_d::emitIAS(const Cfg *Func) const;
 template <> void InstMIPS32Trunc_w_s::emitIAS(const Cfg *Func) const;
 template <> void InstMIPS32Xor::emitIAS(const Cfg *Func) const;
 template <> void InstMIPS32Xori::emitIAS(const Cfg *Func) const;
 
 } // end of namespace MIPS32
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINSTMIPS32_H