Selectively invert ICMP operands for better address optimization

src/IceInst.h

 //===- subzero/src/IceInst.h - High-level 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 520 matching lines @@
 
 /// Integer comparison instruction. The source operands are captured in
 /// getSrc(0) and getSrc(1).
 class InstIcmp : public InstHighLevel {
   InstIcmp() = delete;
   InstIcmp(const InstIcmp &) = delete;
   InstIcmp &operator=(const InstIcmp &) = delete;
 
 public:
   enum ICond {
-#define X(tag, str) tag,
+#define X(tag, inverse, str) tag,
     ICEINSTICMP_TABLE
 #undef X
         _num
   };
 
   static InstIcmp *create(Cfg *Func, ICond Condition, Variable *Dest,
                           Operand *Source1, Operand *Source2) {
     return new (Func->allocate<InstIcmp>())
         InstIcmp(Func, Condition, Dest, Source1, Source2);
   }
   ICond getCondition() const { return Condition; }
+  void reverseConditionAndOperands();
   bool isMemoryWrite() const override { return false; }
   void dump(const Cfg *Func) const override;
   static bool classof(const Inst *Instr) { return Instr->getKind() == Icmp; }
 
 private:
   InstIcmp(Cfg *Func, ICond Condition, Variable *Dest, Operand *Source1,
            Operand *Source2);
 
-  const ICond Condition;
+  ICond Condition;
 };
 
 /// InsertElement instruction.
 class InstInsertElement : public InstHighLevel {
   InstInsertElement() = delete;
   InstInsertElement(const InstInsertElement &) = delete;
   InstInsertElement &operator=(const InstInsertElement &) = delete;
 
 public:
   static InstInsertElement *create(Cfg *Func, Variable *Dest, Operand *Source1,
@@ skipping 574 matching lines @@
 
 inline Inst *iteratorToInst(InstList::iterator Iter) { return &*Iter; }
 
 inline const Inst *iteratorToInst(InstList::const_iterator Iter) {
   return &*Iter;
 }
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEINST_H