Introduction of improved switch lowering.

src/IceTargetLoweringARM32.h

 //===- subzero/src/IceTargetLoweringARM32.h - ARM32 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 60 matching lines @@
   bool hasFramePointer() const override { return UsesFramePointer; }
   SizeT getFrameOrStackReg() const override {
     return UsesFramePointer ? RegARM32::Reg_fp : RegARM32::Reg_sp;
   }
   size_t typeWidthInBytesOnStack(Type Ty) const override {
     // Round up to the next multiple of 4 bytes.  In particular, i1,
     // i8, and i16 are rounded up to 4 bytes.
     return (typeWidthInBytes(Ty) + 3) & ~3;
   }
 
+  // TODO(ascull): what size is best for ARM?
+  SizeT getMinJumpTableSize() const override { return 3; }
+
   void emitVariable(const Variable *Var) const override;
 
   const char *getConstantPrefix() const final { return "#"; }
   void emit(const ConstantUndef *C) const final;
   void emit(const ConstantInteger32 *C) const final;
   void emit(const ConstantInteger64 *C) const final;
   void emit(const ConstantFloat *C) const final;
   void emit(const ConstantDouble *C) const final;
 
   void lowerArguments() override;
@@ skipping 367 matching lines @@
 
 private:
   ~TargetHeaderARM32() = default;
 
   TargetARM32Features CPUFeatures;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERINGARM32_H