Range feedback for binary integer operations.

runtime/vm/object.h

Index: runtime/vm/object.h
diff --git a/runtime/vm/object.h b/runtime/vm/object.h
index cdf9ddb515c0212cd24dd0a2446c5f6802c7f57b..f6599f5b082601a7a91a41959b46e49a89b8cec4 100644
--- a/runtime/vm/object.h
+++ b/runtime/vm/object.h
@@ -3547,6 +3547,10 @@ class ICData : public Object {
     return raw_ptr()->deopt_id_;
   }
 
+  uint32_t range_feedback() const {
+    return raw_ptr()->range_feedback_;
+  }
+
   #define DEOPT_REASONS(V)                                                     \
     V(Unknown)                                                                 \
     V(InstanceGetter)                                                          \
@@ -3641,6 +3645,10 @@ class ICData : public Object {
     return OFFSET_OF(RawICData, owner_);
   }
 
+  static intptr_t range_feedback_offset() {
+    return OFFSET_OF(RawICData, range_feedback_);
+  }
+
   // Used for unoptimized static calls when no class-ids are checked.
   void AddTarget(const Function& target) const;
 
@@ -3715,6 +3723,38 @@ class ICData : public Object {
   void GetUsedCidsForTwoArgs(GrowableArray<intptr_t>* first,
                              GrowableArray<intptr_t>* second) const;
 
+  enum RangeFeedback {
+    kSmiRange, kInt32Range, kUint32Range, kInt64Range
+  };
+
+  enum {
+    kSignBit = 1 << 0,
+    kInt32Bit = 1 << 1,
+    kUint32Bit = 1 << 2,
+    kInt64Bit = 1 << 3,
+    kBitsPerRangeFeedback = 4,
+    kRangeFeedbackMask = (1 << kBitsPerRangeFeedback) - 1
+  };

[srdjan, 2014/12/15 16:39:01]

I think it would be more readable to say, e.g., kInt32RangeBit.

[Vyacheslav Egorov (Google), 2014/12/15 17:20:05]

Done.

+
+  static const char* RangeFeedbackToString(RangeFeedback feedback) {
+    switch (feedback) {
+      case kSmiRange:
+        return "smi";
+      case kInt32Range:
+        return "int32";
+      case kUint32Range:
+        return "uint32";
+      case kInt64Range:
+        return "int64";
+      default:
+        UNREACHABLE();
+        return "?";
+    }
+  }
+
+  bool HasRangeFeedback() const;
+  RangeFeedback DecodeRangeFeedbackAt(intptr_t idx) const;
+
  private:
   RawArray* ic_data() const {
     return raw_ptr()->ic_data_;
@@ -3727,6 +3767,7 @@ class ICData : public Object {
   void SetNumArgsTested(intptr_t value) const;
   void set_ic_data(const Array& value) const;
   void set_state_bits(uint32_t bits) const;
+  void set_range_feedback(uint32_t feedback);
 
   enum {
     kNumArgsTestedPos = 0,