1 files changed, 17 insertions, 48 deletions

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 5cfbf4249e..6f4f3c9505 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -336,7 +336,7 @@ class HGraph : public ArenaObject<kArenaAllocGraph> {
   }
 
   // Acquires and stores RTI of inexact Object to be used when creating HNullConstant.
-  void InitializeInexactObjectRTI(StackHandleScopeCollection* handles);
+  void InitializeInexactObjectRTI(VariableSizedHandleScope* handles);
 
   ArenaAllocator* GetArena() const { return arena_; }
   const ArenaVector<HBasicBlock*>& GetBlocks() const { return blocks_; }
@@ -366,13 +366,6 @@ class HGraph : public ArenaObject<kArenaAllocGraph> {
   // is a throw-catch loop, i.e. the header is a catch block.
   GraphAnalysisResult AnalyzeLoops() const;
 
-  // Computes a linear order for the current graph (should be called before
-  // using HLinearOrderIterator). Linearizes the graph such that:
-  // (1): a block is always after its dominator,
-  // (2): blocks of loops are contiguous.
-  // This creates a natural and efficient ordering when visualizing live ranges.
-  void Linearize();
-
   // Iterate over blocks to compute try block membership. Needs reverse post
   // order and loop information.
   void ComputeTryBlockInformation();
@@ -1938,6 +1931,19 @@ class HInstruction : public ArenaObject<kArenaAllocInstruction> {
     return !HasEnvironmentUses() && GetUses().HasExactlyOneElement();
   }
 
+  bool IsDeadAndRemovable() const {
+    return
+        !HasSideEffects() &&
+        !CanThrow() &&
+        !IsSuspendCheck() &&
+        !IsControlFlow() &&
+        !IsNativeDebugInfo() &&
+        !IsParameterValue() &&
+        !HasUses() &&
+        // If we added an explicit barrier then we should keep it.
+        !IsMemoryBarrier();
+  }
+
   // Does this instruction strictly dominate `other_instruction`?
   // Returns false if this instruction and `other_instruction` are the same.
   // Aborts if this instruction and `other_instruction` are both phis.
@@ -2087,10 +2093,10 @@ class HInstruction : public ArenaObject<kArenaAllocInstruction> {
   // to the current method. Such instructions are:
   // (1): Instructions that require an environment, as calling the runtime requires
   //      to walk the stack and have the current method stored at a specific stack address.
-  // (2): Object literals like classes and strings, that are loaded from the dex cache
-  //      fields of the current method.
+  // (2): HCurrentMethod, potentially used by HInvokeStaticOrDirect, HLoadString, or HLoadClass
+  //      to access the dex cache.
   bool NeedsCurrentMethod() const {
-    return NeedsEnvironment() || IsLoadClass() || IsLoadString();
+    return NeedsEnvironment() || IsCurrentMethod();
   }
 
   // Returns whether the code generation of the instruction will require to have access
@@ -6661,43 +6667,6 @@ class HPostOrderIterator : public ValueObject {
   DISALLOW_COPY_AND_ASSIGN(HPostOrderIterator);
 };
 
-class HLinearPostOrderIterator : public ValueObject {
- public:
-  explicit HLinearPostOrderIterator(const HGraph& graph)
-      : order_(graph.GetLinearOrder()), index_(graph.GetLinearOrder().size()) {}
-
-  bool Done() const { return index_ == 0; }
-
-  HBasicBlock* Current() const { return order_[index_ - 1u]; }
-
-  void Advance() {
-    --index_;
-    DCHECK_GE(index_, 0U);
-  }
-
- private:
-  const ArenaVector<HBasicBlock*>& order_;
-  size_t index_;
-
-  DISALLOW_COPY_AND_ASSIGN(HLinearPostOrderIterator);
-};
-
-class HLinearOrderIterator : public ValueObject {
- public:
-  explicit HLinearOrderIterator(const HGraph& graph)
-      : order_(graph.GetLinearOrder()), index_(0) {}
-
-  bool Done() const { return index_ == order_.size(); }
-  HBasicBlock* Current() const { return order_[index_]; }
-  void Advance() { ++index_; }
-
- private:
-  const ArenaVector<HBasicBlock*>& order_;
-  size_t index_;
-
-  DISALLOW_COPY_AND_ASSIGN(HLinearOrderIterator);
-};
-
 // Iterator over the blocks that art part of the loop. Includes blocks part
 // of an inner loop. The order in which the blocks are iterated is on their
 // block id.