Selectively invert ICMP operands for better address optimization

src/IceTargetLowering.h

 //===- subzero/src/IceTargetLowering.h - Lowering interface -----*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 378 matching lines @@
   virtual void lowerSelect(const InstSelect *Instr) = 0;
   virtual void lowerShuffleVector(const InstShuffleVector *Instr) = 0;
   virtual void lowerStore(const InstStore *Instr) = 0;
   virtual void lowerSwitch(const InstSwitch *Instr) = 0;
   virtual void lowerUnreachable(const InstUnreachable *Instr) = 0;
   virtual void lowerOther(const Inst *Instr);
 
   virtual void genTargetHelperCallFor(Inst *Instr) = 0;
   virtual uint32_t getCallStackArgumentsSizeBytes(const InstCall *Instr) = 0;
 
+  /// Opportunity to modify other instructions to help Address Optimization
+  virtual void doAddressOptOther() {}
   virtual void doAddressOptLoad() {}
   virtual void doAddressOptStore() {}
   virtual void doMockBoundsCheck(Operand *) {}
   virtual void randomlyInsertNop(float Probability,
                                  RandomNumberGenerator &RNG) = 0;
   /// This gives the target an opportunity to post-process the lowered expansion
   /// before returning.
   virtual void postLower() {}
 
   /// When the SkipUnimplemented flag is set, addFakeDefUses() gets invoked by
@@ skipping 210 matching lines @@
   virtual void lower() {}
 
 protected:
   explicit TargetHeaderLowering(GlobalContext *Ctx) : Ctx(Ctx) {}
   GlobalContext *Ctx;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERING_H