Fixed numeric relations on HPhi instances.

src/hydrogen-instructions.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 101 matching lines @@
   V(FastLiteral)                               \
   V(FixedArrayBaseLength)                      \
   V(ForceRepresentation)                       \
   V(FunctionLiteral)                           \
   V(GetCachedArrayIndex)                       \
   V(GlobalObject)                              \
   V(GlobalReceiver)                            \
   V(Goto)                                      \
   V(HasCachedArrayIndexAndBranch)              \
   V(HasInstanceTypeAndBranch)                  \
+  V(InductionVariable)                         \
   V(In)                                        \
   V(InstanceOf)                                \
   V(InstanceOfKnownGlobal)                     \
   V(InvokeFunction)                            \
   V(IsConstructCallAndBranch)                  \
   V(IsNilAndBranch)                            \
   V(IsObjectAndBranch)                         \
   V(IsStringAndBranch)                         \
   V(IsSmiAndBranch)                            \
   V(IsUndetectableAndBranch)                   \
@@ skipping 565 matching lines @@
     kIsArguments,
     kTruncatingToInt32,
     kIsDead,
     // Instructions that are allowed to produce full range unsigned integer
     // values are marked with kUint32 flag. If arithmetic shift or a load from
     // EXTERNAL_UNSIGNED_INT_ELEMENTS array is not marked with this flag
     // it will deoptimize if result does not fit into signed integer range.
     // HGraph::ComputeSafeUint32Operations is responsible for setting this
     // flag.
     kUint32,
+    // If a phi is involved in the evaluation of a numeric constraints the

[Jakob Kummerow, 2013/02/20 10:46:47]

"a numeric constraints" -> singular or plural?

[Massi, 2013/02/21 07:40:32]

Done.

+    // recursion can cause an endless cycle: we use this flag to exit the loop.
+    kNumericConstraintEvaluationInProgress,
     // This flag is set to true after the SetupInformativeDefinitions() pass
     // has processed this instruction.
     kIDefsProcessingDone,
     kLastFlag = kIDefsProcessingDone
   };
 
   STATIC_ASSERT(kLastFlag < kBitsPerInt);
 
   static const int kChangesToDependsFlagsLeftShift = 1;
 
@@ skipping 2224 matching lines @@
     }
     return true;
   }
 
  protected:
   virtual void DeleteFromGraph();
   virtual void InternalSetOperandAt(int index, HValue* value) {
     inputs_[index] = value;
   }
 
+  virtual bool IsRelationTrueInternal(NumericRelation relation, HValue* other);
+
  private:
   ZoneList<HValue*> inputs_;
   int merged_index_;
 
   int non_phi_uses_[Representation::kNumRepresentations];
   int indirect_uses_[Representation::kNumRepresentations];
   int phi_id_;
   bool is_live_;
   bool is_convertible_to_integer_;
 };
 
 
+class HInductionVariable : public HUnaryOperation {

[Jakob Kummerow, 2013/02/20 10:46:47]

The name is misleading, as this instruction *isn't* an induction variable, it's
just an idef. Maybe "InductionVariableAnnotation"?

[Massi, 2013/02/21 07:40:32]

Done.

+ public:
+  static HInductionVariable* AddToGraph(HPhi* phi,
+                                        NumericRelation relation,
+                                        int operand_index);
+
+  NumericRelation relation() { return relation_; }
+  HValue* induction_base() { return phi_->OperandAt(operand_index_); }
+
+  virtual int RedefinedOperandIndex() { return 0; }
+  virtual bool IsPurelyInformativeDefinition() { return true; }
+  virtual Representation RequiredInputRepresentation(int index) {
+    return representation();
+  }
+
+  virtual void PrintDataTo(StringStream* stream);
+
+  virtual bool IsRelationTrueInternal(NumericRelation other_relation,
+                                      HValue* other_related_value) {
+    if (induction_base() == other_related_value) {
+      return relation().Implies(other_relation);
+    } else {
+      return false;
+    }
+  }
+
+  DECLARE_CONCRETE_INSTRUCTION(InductionVariable)
+
+ private:
+  HInductionVariable(HPhi* phi, NumericRelation relation, int operand_index)
+      : HUnaryOperation(phi),
+    phi_(phi), relation_(relation), operand_index_(operand_index) {
+    set_representation(phi->representation());
+  }
+
+  HPhi* phi_;

[Jakob Kummerow, 2013/02/20 10:46:47]

No need to store this -- the UnaryOperation base class stores it for us as
"value()".

[Massi, 2013/02/21 07:40:32]

Actually it is needed, adding a comment to clarify why.

+  NumericRelation relation_;
+  int operand_index_;
+};
+
+
 class HArgumentsObject: public HTemplateInstruction<0> {
  public:
   HArgumentsObject() {
     set_representation(Representation::Tagged());
     SetFlag(kIsArguments);
   }
 
   virtual Representation RequiredInputRepresentation(int index) {
     return Representation::None();
   }
@@ skipping 3052 matching lines @@
   virtual bool IsDeletable() const { return true; }
 };
 
 
 #undef DECLARE_INSTRUCTION
 #undef DECLARE_CONCRETE_INSTRUCTION
 
 } }  // namespace v8::internal
 
 #endif  // V8_HYDROGEN_INSTRUCTIONS_H_