ARM: Add a postRA pass to legalize stack offsets. Greedy approach (reserve IP).

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 73 matching lines @@
   InstList::iterator Next;
   /// Begin is a copy of Insts.begin(), used if iterators are moved backward.
   InstList::iterator Begin;
   /// End is a copy of Insts.end(), used if Next needs to be advanced.
   InstList::iterator End;
 
   void skipDeleted(InstList::iterator &I) const;
   void advanceForward(InstList::iterator &I) const;
 };
 
+/// A helper class to advance the LoweringContext at each loop iteration.
+class PostIncrLoweringContext {
+  PostIncrLoweringContext() = delete;
+  PostIncrLoweringContext(const PostIncrLoweringContext &) = delete;
+  PostIncrLoweringContext &operator=(const PostIncrLoweringContext &) = delete;
+
+public:
+  explicit PostIncrLoweringContext(LoweringContext &Context)
+      : Context(Context) {}
+  ~PostIncrLoweringContext() {
+    Context.advanceCur();
+    Context.advanceNext();
+  }
+
+private:
+  LoweringContext &Context;
+};
+
 class TargetLowering {
   TargetLowering() = delete;
   TargetLowering(const TargetLowering &) = delete;
   TargetLowering &operator=(const TargetLowering &) = delete;
 
 public:
   // TODO(jvoung): return a unique_ptr like the other factory functions.
   static TargetLowering *createLowering(TargetArch Target, Cfg *Func);
   static std::unique_ptr<Assembler> createAssembler(TargetArch Target,
                                                     Cfg *Func);
@@ skipping 322 matching lines @@
   virtual void lower() {}
 
 protected:
   explicit TargetHeaderLowering(GlobalContext *Ctx) : Ctx(Ctx) {}
   GlobalContext *Ctx;
 };
 
 } // end of namespace Ice
 
 #endif // SUBZERO_SRC_ICETARGETLOWERING_H