Enable Local CSE by default

src/IceDefs.h

 //===- subzero/src/IceDefs.h - Common Subzero declarations ------*- C++ -*-===//
 //
 //                        The Subzero Code Generator
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
@@ skipping 290 matching lines @@
   /// live-out variables for each block. Identifies and deletes dead
   /// instructions (primarily stores).
   Liveness_Basic,
 
   /// In addition to Liveness_Basic, also calculate the complete live range for
   /// each variable in a form suitable for interference calculation and register
   /// allocation.
   Liveness_Intervals
 };
 
+enum LCSEOptions {
+  LCSE_Disabled,
+  LCSE_EnabledSSA,  // Default Mode, assumes SSA.
+  LCSE_EnabledNoSSA // Does not assume SSA, to be enabled if CSE is done later.
+};
+
 enum RegAllocKind {
   RAK_Unknown,
   RAK_Global,       /// full, global register allocation
   RAK_SecondChance, /// second-chance bin-packing after full regalloc attempt
   RAK_Phi,          /// infinite-weight Variables with active spilling/filling
   RAK_InfOnly       /// allocation only for infinite-weight Variables
 };
 
 enum VerboseItem {
   IceV_None = 0,
@@ skipping 113 matching lines @@
   RPE_PooledConstantReordering,
   RPE_RegAllocRandomization,
   RPE_num
 };
 
 using RelocOffsetArray = llvm::SmallVector<class RelocOffset *, 4>;
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICEDEFS_H