Use same range info when emitting code and computing if instruction can deopt.

runtime/vm/flow_graph_range_analysis.h

 // Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef RUNTIME_VM_FLOW_GRAPH_RANGE_ANALYSIS_H_
 #define RUNTIME_VM_FLOW_GRAPH_RANGE_ANALYSIS_H_
 
 #include "vm/flow_graph.h"
 #include "vm/intermediate_language.h"
 
@@ skipping 378 matching lines @@
   }
 
   bool Fits(RangeBoundary::RangeSize size) const {
     return !min().LowerBound().Overflowed(size) &&
            !max().UpperBound().Overflowed(size);
   }
 
   // Clamp this to be within size.
   void Clamp(RangeBoundary::RangeSize size);
 
+  // Clamp this to be within size and eliminate symbols.
+  void ClampToConstant(RangeBoundary::RangeSize size);
+
   static void Add(const Range* left_range,
                   const Range* right_range,
                   RangeBoundary* min,
                   RangeBoundary* max,
                   Definition* left_defn);
 
   static void Sub(const Range* left_range,
                   const Range* right_range,
                   RangeBoundary* min,
                   RangeBoundary* max,
@@ skipping 53 matching lines @@
     return !Range::IsUnknown(range) && range->Fits(size);
   }
 
   static bool IsWithin(Range* range, int64_t min, int64_t max) {
     return !Range::IsUnknown(range) && range->IsWithin(min, max);
   }
 
   static bool IsPositive(Range* range) {
     return !Range::IsUnknown(range) && range->IsPositive();
   }
+
+  static bool Overlaps(Range* range, intptr_t min, intptr_t max) {
+    return Range::IsUnknown(range) || range->Overlaps(min, max);
+  }
+
+  static bool CanBeZero(Range* range) { return Overlaps(range, 0, 0); }
+
+  static bool OnlyLessThanOrEqualTo(Range* range, intptr_t value) {
+    return !Range::IsUnknown(range) && range->OnlyLessThanOrEqualTo(value);
+  }
 };
 
 
 // Range analysis for integer values.
 class RangeAnalysis : public ValueObject {
  public:
   explicit RangeAnalysis(FlowGraph* flow_graph)
       : flow_graph_(flow_graph),
         smi_range_(Range::Full(RangeBoundary::kRangeBoundarySmi)),
         int64_range_(Range::Full(RangeBoundary::kRangeBoundaryInt64)) {}
@@ skipping 139 matching lines @@
   BitVector* selected_uint32_defs_;
 
   FlowGraph* flow_graph_;
   Zone* zone_;
 };
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_FLOW_GRAPH_RANGE_ANALYSIS_H_