Remember all deopt reasons in ic_data, not just the last one.

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 35415)
+++ runtime/vm/object.h	(working copy)
@@ -3180,6 +3180,42 @@
 };
 
 
+#define DEOPT_REASONS(V)                                                       \
+  V(Unknown)                                                                   \
+  V(InstanceGetter)                                                            \
+  V(PolymorphicInstanceCallTestFail)                                           \
+  V(InstanceCallNoICData)                                                      \
+  V(IntegerToDouble)                                                           \
+  V(BinarySmiOp)                                                               \
+  V(BinaryMintOp)                                                              \
+  V(UnaryMintOp)                                                               \
+  V(ShiftMintOp)                                                               \
+  V(BinaryDoubleOp)                                                            \
+  V(InstanceSetter)                                                            \
+  V(Equality)                                                                  \
+  V(RelationalOp)                                                              \
+  V(EqualityClassCheck)                                                        \
+  V(NoTypeFeedback)                                                            \
+  V(UnaryOp)                                                                   \
+  V(UnboxInteger)                                                              \
+  V(CheckClass)                                                                \
+  V(HoistedCheckClass)                                                         \
+  V(CheckSmi)                                                                  \
+  V(CheckArrayBound)                                                           \
+  V(AtCall)                                                                    \
+  V(DoubleToSmi)                                                               \
+  V(Int32Load)                                                                 \
+  V(Uint32Load)                                                                \
+  V(GuardField)                                                                \
+  V(NumReasons)                                                                \
+
+enum DeoptReasonId {
+#define DEFINE_ENUM_LIST(name) kDeopt##name,
+DEOPT_REASONS(DEFINE_ENUM_LIST)
+#undef DEFINE_ENUM_LIST
+};
+
+
 class Code : public Object {
  public:
   RawInstructions* instructions() const { return raw_ptr()->instructions_; }
@@ -3257,7 +3293,7 @@
     return raw_ptr()->static_calls_target_table_;
   }
 
-  RawDeoptInfo* GetDeoptInfoAtPc(uword pc, intptr_t* deopt_reason) const;
+  RawDeoptInfo* GetDeoptInfoAtPc(uword pc, DeoptReasonId* deopt_reason) const;
 
   // Returns null if there is no static call at 'pc'.
   RawFunction* GetStaticCallTargetFunctionAt(uword pc) const;
@@ -3608,8 +3644,8 @@
 // corresponding targets.
 class ICData : public Object {
  public:
-  RawFunction* function() const {
-    return raw_ptr()->function_;
+  RawFunction* owner() const {
+    return raw_ptr()->owner_;
   }
 
   RawString* target_name() const {
@@ -3620,25 +3656,24 @@
     return raw_ptr()->args_descriptor_;
   }
 
-  intptr_t num_args_tested() const {
-    return raw_ptr()->num_args_tested_;
-  }
+  intptr_t NumArgsTested() const;
 
   intptr_t deopt_id() const {
     return raw_ptr()->deopt_id_;
   }
 
-  intptr_t deopt_reason() const {
-    return raw_ptr()->deopt_reason_;
-  }
+  bool HasDeoptReasons() const { return DeoptReasons() > 0; }
+  uint32_t DeoptReasons() const;
+  void SetDeoptReasons(uint32_t reasons) const;
 
-  void set_deopt_reason(intptr_t reason) const;
+  bool HasDeoptReason(DeoptReasonId reason) const;
+  void AddDeoptReason(DeoptReasonId reason) const;
 
-  bool is_closure_call() const {
-    return raw_ptr()->is_closure_call_ == 1;
-  }
+  bool IssuedJSWarning() const;
+  void SetIssuedJSWarning() const;
 
-  void set_is_closure_call(bool value) const;
+  bool IsClosureCall() const;
+  void SetIsClosureCall() const;
 
   intptr_t NumberOfChecks() const;
 
@@ -3650,10 +3685,14 @@
     return OFFSET_OF(RawICData, target_name_);
   }
 
-  static intptr_t num_args_tested_offset() {
-    return OFFSET_OF(RawICData, num_args_tested_);
+  static intptr_t state_bits_offset() {
+    return OFFSET_OF(RawICData, state_bits_);
   }
 
+  static intptr_t NumArgsTestedMask() {
+    return (1 << kNumArgsTestedSize) - 1;
+  }
+
   static intptr_t arguments_descriptor_offset() {
     return OFFSET_OF(RawICData, args_descriptor_);
   }
@@ -3662,14 +3701,10 @@
     return OFFSET_OF(RawICData, ic_data_);
   }
 
-  static intptr_t function_offset() {
-    return OFFSET_OF(RawICData, function_);
+  static intptr_t owner_offset() {
+    return OFFSET_OF(RawICData, owner_);
   }
 
-  static intptr_t is_closure_call_offset() {
-    return OFFSET_OF(RawICData, is_closure_call_);
-  }
-
   // Used for unoptimized static calls when no class-ids are checked.
   void AddTarget(const Function& target) const;
 
@@ -3720,7 +3755,7 @@
   bool HasOneTarget() const;
   bool HasReceiverClassId(intptr_t class_id) const;
 
-  static RawICData* New(const Function& caller_function,
+  static RawICData* New(const Function& owner,
                         const String& target_name,
                         const Array& arguments_descriptor,
                         intptr_t deopt_id,
@@ -3741,13 +3776,30 @@
     return raw_ptr()->ic_data_;
   }
 
-  void set_function(const Function& value) const;
+  void set_owner(const Function& value) const;
   void set_target_name(const String& value) const;
   void set_arguments_descriptor(const Array& value) const;
   void set_deopt_id(intptr_t value) const;
-  void set_num_args_tested(intptr_t value) const;
+  void SetNumArgsTested(intptr_t value) const;
   void set_ic_data(const Array& value) const;
+  void set_state_bits(uint32_t bits) const;
 
+  enum {
+    kNumArgsTestedBits = 0,
+    kNumArgsTestedSize = 2,
+    kDeoptReasonBits = kNumArgsTestedBits + kNumArgsTestedSize,
+    kDeoptReasonSize = kDeoptNumReasons,
+    kIssuedJSWarningBit = kDeoptReasonBits + kDeoptReasonSize,
+    kIsClosureCallBit = kIssuedJSWarningBit + 1,
+  };
+
+  class NumArgsTestedBits : public BitField<uint32_t,
+      kNumArgsTestedBits, kNumArgsTestedSize> {};  // NOLINT
+  class DeoptReasonBits : public BitField<uint32_t,
+      kDeoptReasonBits, kDeoptReasonSize> {};  // NOLINT
+  class IssuedJSWarningBit : public BitField<bool, kIssuedJSWarningBit, 1> {};
+  class IsClosureCallBit : public BitField<bool, kIsClosureCallBit, 1> {};
+
 #if defined(DEBUG)
   // Used in asserts to verify that a check is not added twice.
   bool HasCheck(const GrowableArray<intptr_t>& cids) const;