Optimize identical-comparisons based on propagated type information.

runtime/vm/flow_graph_optimizer.cc

 // Copyright (c) 2013, 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.
 
 #include "vm/flow_graph_optimizer.h"
 
 #include "vm/bit_vector.h"
 #include "vm/cha.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_builder.h"
@@ skipping 3205 matching lines @@
   ComparisonInstr* comparison = instr->comparison();
   if (comparison->IsEqualityCompare()) {
     HandleEqualityCompare(comparison->AsEqualityCompare(), instr);
   } else {
     ASSERT(comparison->IsStrictCompare());
     // Nothing to do.
   }
 }
 
 
-static bool MayBeBoxableNumber(intptr_t cid) {
-  return (cid == kDynamicCid) ||
-         (cid == kMintCid) ||
-         (cid == kBigintCid) ||
-         (cid == kDoubleCid);
-}
-
-
-// Check if number check is not needed.
-void FlowGraphOptimizer::VisitStrictCompare(StrictCompareInstr* instr) {
-  if (!instr->needs_number_check()) return;
-
-  // If one of the input is not a boxable number (Mint, Double, Bigint), no
-  // need for number checks.
-  if (!MayBeBoxableNumber(instr->left()->Type()->ToCid()) ||
-      !MayBeBoxableNumber(instr->right()->Type()->ToCid()))  {
-    instr->set_needs_number_check(false);
-  }
-}
-
-
 // Range analysis for smi values.
 class RangeAnalysis : public ValueObject {
  public:
   explicit RangeAnalysis(FlowGraph* flow_graph)
       : flow_graph_(flow_graph),
         marked_defns_(NULL) { }
 
   // Infer ranges for all values and remove overflow checks from binary smi
   // operations when proven redundant.
   void Analyze();
@@ skipping 4496 matching lines @@
   }
 
   // Insert materializations at environment uses.
   for (intptr_t i = 0; i < exits.length(); i++) {
     CreateMaterializationAt(exits[i], alloc, alloc->cls(), *fields);
   }
 }
 
 
 }  // namespace dart