Support for mixed null/smi equality: do not deoptimize, emit same optimized code as if that was smi…

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 13236)
+++ runtime/vm/object.h	(working copy)
@@ -2735,6 +2735,8 @@
     return OFFSET_OF(RawICData, function_);
   }
 
+  // Adding checks.
+
   // Adds one more class test to ICData. Length of 'classes' must be equal to
   // the number of arguments tested. Use only for num_args_tested > 1.
   void AddCheck(const GrowableArray<intptr_t>& class_ids,
@@ -2743,19 +2745,27 @@
   // num_args_tested == 1.
   void AddReceiverCheck(intptr_t receiver_class_id,
                         const Function& target) const;
+
+  // Retrieving checks.
+
   void GetCheckAt(intptr_t index,
                   GrowableArray<intptr_t>* class_ids,
                   Function* target) const;
-  void GetOneClassCheckAt(
-      int index, intptr_t* class_id, Function* target) const;
+  void GetOneClassCheckAt(intptr_t index,
+                          intptr_t* class_id,
+                          Function* target) const;
+  intptr_t GetReceiverClassIdAt(intptr_t index) const;
+  intptr_t GetClassIdAt(intptr_t index, intptr_t arg_nr) const;
 
-  intptr_t GetReceiverClassIdAt(intptr_t index) const;
   RawFunction* GetTargetAt(intptr_t index) const;
   RawFunction* GetTargetForReceiverClassId(intptr_t class_id) const;
 
-  // Returns this->raw() if num_args_tested == 1, otherwise returns a new
-  // ICData object containing only unique arg0 checks.
-  RawICData* AsUnaryClassChecks() const;
+  // Returns this->raw() if num_args_tested == 1 and arg_nr == 1, otherwise
+  // returns a new ICData object containing only unique arg_nr checks.
+  RawICData* AsUnaryClassChecksForArgNr(intptr_t arg_nr) const;
+  RawICData* AsUnaryClassChecks() const {
+    return AsUnaryClassChecksForArgNr(0);
+  }
 
   bool AllTargetsHaveSameOwner(intptr_t owner_cid) const;
   bool AllReceiversAreNumbers() const;
@@ -2777,6 +2787,9 @@
   void set_num_args_tested(intptr_t value) const;
   void set_ic_data(const Array& value) const;
 
+  // Used in asserts to verify that a check is not added twice.
+  bool HasCheck(const GrowableArray<intptr_t>& cids) const;
+
   intptr_t TestEntryLength() const;
   void WriteSentinel() const;