Change == into an instance call to allow polymorphic inlining of ==.

runtime/vm/intermediate_language.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/intermediate_language.h"
 
 #include "vm/bigint_operations.h"
 #include "vm/bit_vector.h"
 #include "vm/dart_entry.h"
 #include "vm/flow_graph_allocator.h"
 #include "vm/flow_graph_builder.h"
 #include "vm/flow_graph_compiler.h"
 #include "vm/flow_graph_optimizer.h"
 #include "vm/locations.h"
 #include "vm/object.h"
 #include "vm/object_store.h"
 #include "vm/os.h"
 #include "vm/resolver.h"
 #include "vm/scopes.h"
 #include "vm/stub_code.h"
 #include "vm/symbols.h"
 
 #include "vm/il_printer.h"
 
 namespace dart {
 
-DEFINE_FLAG(int, max_equality_polymorphic_checks, 32,
-    "Maximum number of polymorphic checks in equality operator,"
-    " otherwise use megamorphic dispatch.");
 DEFINE_FLAG(bool, new_identity_spec, true,
     "Use new identity check rules for numbers.");
 DEFINE_FLAG(bool, propagate_ic_data, true,
     "Propagate IC data from unoptimized to optimized IC calls.");
 DECLARE_FLAG(bool, enable_type_checks);
 DECLARE_FLAG(bool, eliminate_type_checks);
-DECLARE_FLAG(int, max_polymorphic_checks);
 DECLARE_FLAG(bool, trace_optimization);
 DECLARE_FLAG(bool, trace_constant_propagation);
 DECLARE_FLAG(bool, throw_on_javascript_int_overflow);
 
 Definition::Definition()
     : range_(NULL),
       type_(NULL),
       temp_index_(-1),
       ssa_temp_index_(-1),
       input_use_list_(NULL),
@@ skipping 116 matching lines @@
 }
 
 
 bool MathMinMaxInstr::AttributesEqual(Instruction* other) const {
   MathMinMaxInstr* other_op = other->AsMathMinMax();
   ASSERT(other_op != NULL);
   return (op_kind() == other_op->op_kind()) &&
       (result_cid() == other_op->result_cid());
 }
 
+
 bool BinarySmiOpInstr::AttributesEqual(Instruction* other) const {
   BinarySmiOpInstr* other_op = other->AsBinarySmiOp();
   ASSERT(other_op != NULL);
   return (op_kind() == other_op->op_kind()) &&
       (overflow_ == other_op->overflow_) &&
       (is_truncating_ == other_op->is_truncating_);
 }
 
 
 EffectSet LoadFieldInstr::Dependencies() const {
@@ skipping 929 matching lines @@
   ASSERT(index == 0);
   return successor();
 }
 
 
 void Instruction::Goto(JoinEntryInstr* entry) {
   LinkTo(new GotoInstr(entry));
 }
 
 
-bool EqualityCompareInstr::IsPolymorphic() const {
-  return HasICData() &&
-      (ic_data()->NumberOfChecks() > 0) &&
-      (ic_data()->NumberOfChecks() <= FLAG_max_polymorphic_checks);
-}
-
-
-bool EqualityCompareInstr::IsCheckedStrictEqual() const {
-  if (!HasICData()) return false;
-  return ic_data()->AllTargetsHaveSameOwner(kInstanceCid) &&
-         (unary_ic_data_->NumberOfChecks() <=
-             FLAG_max_equality_polymorphic_checks);
-}
-
-
 bool BinarySmiOpInstr::CanDeoptimize() const {
   if (FLAG_throw_on_javascript_int_overflow && (Smi::kBits > 32)) {
     // If Smi's are bigger than 32-bits, then the instruction could deoptimize
     // if the result is too big.
     return true;
   }
   switch (op_kind()) {
     case Token::kBIT_AND:
     case Token::kBIT_OR:
     case Token::kBIT_XOR:
@@ skipping 388 matching lines @@
 
 Definition* UnboxUint32x4Instr::Canonicalize(FlowGraph* flow_graph) {
   // Fold away UnboxUint32x4(BoxUint32x4(v)).
   BoxUint32x4Instr* defn = value()->definition()->AsBoxUint32x4();
   return (defn != NULL) ? defn->value()->definition() : this;
 }
 
 
 Definition* BooleanNegateInstr::Canonicalize(FlowGraph* flow_graph) {
   Definition* defn = value()->definition();
-  if (defn->IsComparison() &&
-      (value()->Type()->ToCid() == kBoolCid) &&
-      defn->HasOnlyUse(value())) {
+  if (defn->IsComparison() && defn->HasOnlyUse(value())) {
+    // Comparisons always have a bool result.
+    ASSERT(value()->Type()->ToCid() == kBoolCid);
     defn->AsComparison()->NegateComparison();
     return defn;
   }
   return this;
 }
 
 
 static bool MayBeBoxableNumber(intptr_t cid) {
   return (cid == kDynamicCid) ||
          (cid == kMintCid) ||
@@ skipping 48 matching lines @@
       (constant.raw() == Bool::True().raw()) &&
       (other->Type()->ToCid() == kBoolCid)) {
     return other_defn;
   }
   // Handle e !== false.
   if ((kind == Token::kNE_STRICT) &&
       (constant.raw() == Bool::False().raw()) &&
       (other->Type()->ToCid() == kBoolCid)) {
     return other_defn;
   }
-  // Handle e !== true
+  // Handle e !== true.
   if ((kind == Token::kNE_STRICT) &&
       (constant.raw() == Bool::True().raw()) &&
       other_defn->IsComparison() &&
       (other->Type()->ToCid() == kBoolCid) &&
       other_defn->HasOnlyUse(other)) {
     *negated = true;
     return other_defn;
   }
+  // Handle e === false.
   if ((kind == Token::kEQ_STRICT) &&
       (constant.raw() == Bool::False().raw()) &&
       other_defn->IsComparison() &&
       (other->Type()->ToCid() == kBoolCid) &&
       other_defn->HasOnlyUse(other)) {
     *negated = true;
     return other_defn;
   }
   return compare;
 }
@@ skipping 24 matching lines @@
 
     // Replace the comparison if the replacement is used at this branch,
     // and has exactly one use.
     Value* use = comp->input_use_list();
     if ((use->instruction() == this) && comp->HasOnlyUse(use)) {
       if (negated) {
         comp->NegateComparison();
       }
       RemoveEnvironment();
       flow_graph->CopyDeoptTarget(this, comp);
+      // Unlink environment from the comparison since it is copied to the
+      // branch instruction.
+      comp->RemoveEnvironment();
 
       comp->RemoveFromGraph();
       SetComparison(comp);
       if (FLAG_trace_optimization) {
         OS::Print("Merging comparison v%" Pd "\n", comp->ssa_temp_index());
       }
       // Clear the comparison's temp index and ssa temp index since the
       // value of the comparison is not used outside the branch anymore.
       ASSERT(comp->input_use_list() == NULL);
       comp->ClearSSATempIndex();
@@ skipping 1212 matching lines @@
       return kCosRuntimeEntry;
     default:
       UNREACHABLE();
   }
   return kSinRuntimeEntry;
 }
 
 #undef __
 
 }  // namespace dart