AOT: Enable branch merging for checked smi comparisons

runtime/vm/intermediate_language.h

 // 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.
 
 #ifndef RUNTIME_VM_INTERMEDIATE_LANGUAGE_H_
 #define RUNTIME_VM_INTERMEDIATE_LANGUAGE_H_
 
 #include "vm/allocation.h"
 #include "vm/ast.h"
 #include "vm/growable_array.h"
@@ skipping 459 matching lines @@
   M(AllocateObject)                                                            \
   M(LoadField)                                                                 \
   M(LoadUntagged)                                                              \
   M(LoadClassId)                                                               \
   M(InstantiateType)                                                           \
   M(InstantiateTypeArguments)                                                  \
   M(AllocateContext)                                                           \
   M(AllocateUninitializedContext)                                              \
   M(CloneContext)                                                              \
   M(BinarySmiOp)                                                               \
+  M(CheckedSmiComparison)                                                      \
   M(CheckedSmiOp)                                                              \
   M(BinaryInt32Op)                                                             \
   M(UnarySmiOp)                                                                \
   M(UnaryDoubleOp)                                                             \
   M(CheckStackOverflow)                                                        \
   M(SmiToDouble)                                                               \
   M(Int32ToDouble)                                                             \
   M(MintToDouble)                                                              \
   M(DoubleToInteger)                                                           \
   M(DoubleToSmi)                                                               \
@@ skipping 1884 matching lines @@
                                        BranchLabels labels) = 0;
 
   void SetDeoptId(const Instruction& instr) {
     CopyDeoptIdFrom(instr);
   }
 
   // Operation class id is computed from collected ICData.
   void set_operation_cid(intptr_t value) { operation_cid_ = value; }
   intptr_t operation_cid() const { return operation_cid_; }
 
-  void NegateComparison() {
+  virtual void NegateComparison() {
     kind_ = Token::NegateComparison(kind_);
   }
 
   virtual bool CanBecomeDeoptimizationTarget() const { return true; }
   virtual intptr_t DeoptimizationTarget() const { return GetDeoptId(); }
 
   virtual bool AttributesEqual(Instruction* other) const {
     ComparisonInstr* other_comparison = other->AsComparison();
     return kind() == other_comparison->kind() &&
         (operation_cid() == other_comparison->operation_cid());
@@ skipping 4595 matching lines @@
         op_kind_(op_kind) {
     SetInputAt(0, left);
     SetInputAt(1, right);
   }
 
   InstanceCallInstr* call() const { return call_; }
   Token::Kind op_kind() const { return op_kind_; }
   Value* left() const { return inputs_[0]; }
   Value* right() const { return inputs_[1]; }
 
-  virtual bool CanDeoptimize() const { return true; }
+  virtual bool CanDeoptimize() const { return false; }
 
   virtual EffectSet Effects() const { return EffectSet::All(); }
 
   virtual Definition* Canonicalize(FlowGraph* flow_graph);
 
   PRINT_OPERANDS_TO_SUPPORT
 
   DECLARE_INSTRUCTION(CheckedSmiOp)
 
  private:
   InstanceCallInstr* call_;
   const Token::Kind op_kind_;
   DISALLOW_COPY_AND_ASSIGN(CheckedSmiOpInstr);
 };
 
 
+class CheckedSmiComparisonInstr : public TemplateComparison<2, Throws> {
+ public:
+  CheckedSmiComparisonInstr(Token::Kind op_kind,
+                            Value* left,
+                            Value* right,
+                            InstanceCallInstr* call)
+      : TemplateComparison(call->token_pos(), op_kind, call->deopt_id()),
+        call_(call),
+        is_negated_(false) {
+    SetInputAt(0, left);
+    SetInputAt(1, right);
+  }
+
+  InstanceCallInstr* call() const { return call_; }
+
+  virtual bool CanDeoptimize() const { return false; }
+
+  virtual Definition* Canonicalize(FlowGraph* flow_graph);
+
+  virtual void NegateComparison() {
+    ComparisonInstr::NegateComparison();
+    is_negated_ = true;
+  }

[Vyacheslav Egorov (Google), 2016/11/01 13:19:07]

If this function is called twice then is_negated_ gets out of sync. Maybe do:

is_negated_ = !is_negated_;

[Florian Schneider, 2016/11/01 15:26:25]

Yes, thanks.

Done.

+
+  bool is_negated() const { return is_negated_; }
+
+  virtual EffectSet Effects() const { return EffectSet::All(); }
+
+  PRINT_OPERANDS_TO_SUPPORT
+
+  DECLARE_INSTRUCTION(CheckedSmiComparison)
+
+  virtual void EmitBranchCode(FlowGraphCompiler* compiler,
+                              BranchInstr* branch);
+
+  virtual Condition EmitComparisonCode(FlowGraphCompiler* compiler,
+                                       BranchLabels labels);
+
+  virtual ComparisonInstr* CopyWithNewOperands(Value* left, Value* right);
+
+ private:
+  InstanceCallInstr* call_;
+  bool is_negated_;
+  DISALLOW_COPY_AND_ASSIGN(CheckedSmiComparisonInstr);
+};
+
+
 class BinaryIntegerOpInstr : public TemplateDefinition<2, NoThrow, Pure> {
  public:
   BinaryIntegerOpInstr(Token::Kind op_kind,
                        Value* left,
                        Value* right,
                        intptr_t deopt_id)
       : TemplateDefinition(deopt_id),
         op_kind_(op_kind),
         can_overflow_(true),
         is_truncating_(false) {
@@ skipping 1388 matching lines @@
   LocationSummary* Name::MakeLocationSummary(Zone* zone, bool opt) const {    \
     UNIMPLEMENTED();                                                          \
     return NULL;                                                              \
   }                                                                           \
   void Name::EmitNativeCode(FlowGraphCompiler* compiler) { UNIMPLEMENTED(); }
 
 
 }  // namespace dart
 
 #endif  // RUNTIME_VM_INTERMEDIATE_LANGUAGE_H_