Reland r38116: Improve receiver class check in polymorphic inlining.

runtime/vm/intermediate_language.h

Index: runtime/vm/intermediate_language.h
===================================================================
--- runtime/vm/intermediate_language.h	(revision 38118)
+++ runtime/vm/intermediate_language.h	(working copy)
@@ -724,6 +724,7 @@
   M(DoubleToFloat)                                                             \
   M(FloatToDouble)                                                             \
   M(CheckClass)                                                                \
+  M(CheckClassId)                                                              \
   M(CheckSmi)                                                                  \
   M(Constant)                                                                  \
   M(UnboxedConstant)                                                           \
@@ -1104,6 +1105,7 @@
   friend class MathUnaryInstr;
   friend class MathMinMaxInstr;
   friend class CheckClassInstr;
+  friend class CheckClassIdInstr;
   friend class GuardFieldInstr;
   friend class CheckSmiInstr;
   friend class CheckArrayBoundInstr;
@@ -7893,12 +7895,18 @@
 
   const ICData& unary_checks() const { return unary_checks_; }
 
+  const GrowableArray<intptr_t>& cids() const { return cids_; }
+
   virtual Instruction* Canonicalize(FlowGraph* flow_graph);
 
   virtual void PrintOperandsTo(BufferFormatter* f) const;
 
   bool IsNullCheck() const;
 
+  bool IsDenseSwitch() const;
+  intptr_t ComputeCidMask() const;
+  static bool IsDenseMask(intptr_t mask);
+
   virtual bool AllowsCSE() const { return true; }
   virtual EffectSet Effects() const { return EffectSet::None(); }
   virtual EffectSet Dependencies() const;
@@ -7910,6 +7918,7 @@
 
  private:
   const ICData& unary_checks_;
+  GrowableArray<intptr_t> cids_;  // Sorted, lowest first.
   bool licm_hoisted_;
   const intptr_t token_pos_;
 
@@ -7951,6 +7960,36 @@
 };
 
 
+class CheckClassIdInstr : public TemplateInstruction<2> {
+ public:
+  CheckClassIdInstr(Value* left, Value* right, intptr_t deopt_id) {
+    SetInputAt(0, left);
+    SetInputAt(1, right);
+    // Override generated deopt-id.
+    deopt_id_ = deopt_id;
+  }
+
+  Value* left() const { return inputs_[0]; }
+  Value* right() const { return inputs_[1]; }
+
+  DECLARE_INSTRUCTION(CheckClassId)
+
+  virtual intptr_t ArgumentCount() const { return 0; }
+
+  virtual bool CanDeoptimize() const { return true; }
+
+  virtual bool AllowsCSE() const { return true; }

[Florian Schneider, 2014/07/10 15:10:13]

Correct flags and dependencies to allow CSE/LICM (same as CheckClassInstr).

+  virtual EffectSet Effects() const { return EffectSet::None(); }
+  virtual EffectSet Dependencies() const;
+  virtual bool AttributesEqual(Instruction* other) const { return true; }
+
+  virtual bool MayThrow() const { return false; }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CheckClassIdInstr);
+};
+
+
 class CheckArrayBoundInstr : public TemplateInstruction<2> {
  public:
   CheckArrayBoundInstr(Value* length, Value* index, intptr_t deopt_id) {