Mark HChange that convert to int32 with truncation with the appropiate flag.

Before we would compute the flag by iterating over all uses. The truncating
flag is always determined at construction time since we already computed
the flag for all other instructions before inserting HChange instructions.

Review URL: http://codereview.chromium.org/6615012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7047 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 22916f5034586e15cc0f384384d30a8db6807b26..371bc4a0b0cdaa5fa9c06cdb47606c0230093757 100644 (file)
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -940,13 +940,14 @@ class HChange: public HUnaryOperation {
  public:
   HChange(HValue* value,
           Representation from,
-          Representation to)
+          Representation to,
+          bool is_truncating)
       : HUnaryOperation(value), from_(from), to_(to) {
     ASSERT(!from.IsNone() && !to.IsNone());
     ASSERT(!from.Equals(to));
     set_representation(to);
     SetFlag(kUseGVN);
-
+    if (is_truncating) SetFlag(kTruncatingToInt32);
     if (from.IsInteger32() && to.IsTagged() && value->range() != NULL &&
         value->range()->IsInSmiRange()) {
       set_type(HType::Smi());
@@ -961,12 +962,7 @@ class HChange: public HUnaryOperation {
     return from_;
   }
 
-  bool CanTruncateToInt32() const {
-    for (int i = 0; i < uses()->length(); ++i) {
-      if (!uses()->at(i)->CheckFlag(HValue::kTruncatingToInt32)) return false;
-    }
-    return true;
-  }
+  bool CanTruncateToInt32() const { return CheckFlag(kTruncatingToInt32); }
 
   virtual void PrintDataTo(StringStream* stream);
 
@@ -978,8 +974,7 @@ class HChange: public HUnaryOperation {
     if (!other->IsChange()) return false;
     HChange* change = HChange::cast(other);
     return value() == change->value()
-        && to().Equals(change->to())
-        && CanTruncateToInt32() == change->CanTruncateToInt32();
+        && to().Equals(change->to());
   }
 
  private:

diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 30cc08839a5dd64a31cf795f822bf34be0232c8b..50ab7b236fe5e36d43dee11b201ed522857c07bc 100644 (file)
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -1663,8 +1663,7 @@ void HGraph::PropagateMinusZeroChecks(HValue* value, BitVector* visited) {
 
 void HGraph::InsertRepresentationChangeForUse(HValue* value,
                                               HValue* use,
-                                              Representation to,
-                                              bool is_truncating) {
+                                              Representation to) {
   // Insert the representation change right before its use. For phi-uses we
   // insert at the end of the corresponding predecessor.
   HInstruction* next = NULL;
@@ -1681,6 +1680,7 @@ void HGraph::InsertRepresentationChangeForUse(HValue* value,
   // information we treat constants like normal instructions and insert the
   // change instructions for them.
   HInstruction* new_value = NULL;
+  bool is_truncating = use->CheckFlag(HValue::kTruncatingToInt32);
   if (value->IsConstant()) {
     HConstant* constant = HConstant::cast(value);
     // Try to create a new copy of the constant with the new representation.
@@ -1690,7 +1690,7 @@ void HGraph::InsertRepresentationChangeForUse(HValue* value,
   }
 
   if (new_value == NULL) {
-    new_value = new HChange(value, value->representation(), to);
+    new_value = new HChange(value, value->representation(), to, is_truncating);
   }
 
   new_value->InsertBefore(next);
@@ -1765,8 +1765,7 @@ void HGraph::InsertRepresentationChanges(HValue* current) {
   for (int i = 0; i < to_convert.length(); ++i) {
     HValue* use = to_convert[i];
     Representation r_to = to_convert_reps[i];
-    bool is_truncating = use->CheckFlag(HValue::kTruncatingToInt32);
-    InsertRepresentationChangeForUse(current, use, r_to, is_truncating);
+    InsertRepresentationChangeForUse(current, use, r_to);
   }
 
   if (current->uses()->is_empty()) {

diff --git a/src/hydrogen.h b/src/hydrogen.h
index 185d2cbffee7b6470b611855bbb1e0ae2cad6dfb..9bb3f8cd790f8bef1989090f9b01c13ae1a34bc9 100644 (file)
--- a/src/hydrogen.h
+++ b/src/hydrogen.h
@@ -302,8 +302,7 @@ class HGraph: public HSubgraph {
   void PropagateMinusZeroChecks(HValue* value, BitVector* visited);
   void InsertRepresentationChangeForUse(HValue* value,
                                         HValue* use,
-                                        Representation to,
-                                        bool truncating);
+                                        Representation to);
   void InsertRepresentationChanges(HValue* current);
   void InferTypes(ZoneList<HValue*>* worklist);
   void InitializeInferredTypes(int from_inclusive, int to_inclusive);