Calls to HCheckFunction can be eliminated if the value is an HConstant.

Reland "Calls to HCheckFunction can be eliminated if the value is an HConstant"
(https://codereview.chromium.org/18751003/).

The CL failed because of heap snapshot issues. alph@chromium.org just checked in
a fix for that (https://code.google.com/p/v8/source/detail?r=15694).

BUG=
R=danno@chromium.org

Review URL: https://codereview.chromium.org/19504007

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@15704 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

diff --git a/src/hydrogen-instructions.cc b/src/hydrogen-instructions.cc
index 5a9510f..e99f909 100644 (file)
--- a/src/hydrogen-instructions.cc
+++ b/src/hydrogen-instructions.cc
@@ -1690,6 +1690,14 @@ void HCheckFunction::PrintDataTo(StringStream* stream) {
 }
 
 
+HValue* HCheckFunction::Canonicalize() {
+  return (value()->IsConstant() &&
+          HConstant::cast(value())->UniqueValueIdsMatch(target_unique_id_))
+      ? NULL
+      : this;
+}
+
+
 const char* HCheckInstanceType::GetCheckName() {
   switch (check_) {
     case IS_SPEC_OBJECT: return "object";

diff --git a/src/hydrogen-instructions.h b/src/hydrogen-instructions.h
index 27c517a..2fb18fd 100644 (file)
--- a/src/hydrogen-instructions.h
+++ b/src/hydrogen-instructions.h
@@ -2837,6 +2837,8 @@ class HCheckFunction: public HUnaryOperation {
   virtual void PrintDataTo(StringStream* stream);
   virtual HType CalculateInferredType();
 
+  virtual HValue* Canonicalize();
+
 #ifdef DEBUG
   virtual void Verify();
 #endif
@@ -3410,6 +3412,10 @@ class HConstant: public HTemplateInstruction<0> {
     }
   }
 
+  bool UniqueValueIdsMatch(UniqueValueId other) {
+    return !has_double_value_ && unique_id_ == other;
+  }
+
 #ifdef DEBUG
   virtual void Verify() { }
 #endif

diff --git a/src/objects.cc b/src/objects.cc
index 7b06b87..0c31df3 100644 (file)
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -15899,7 +15899,8 @@ Type* PropertyCell::UpdateType(Handle<PropertyCell> cell,
                                Handle<Object> value) {
   Isolate* isolate = cell->GetIsolate();
   Handle<Type> old_type(cell->type(), isolate);
-  Handle<Type> new_type((value->IsSmi() || value->IsUndefined())
+  Handle<Type> new_type((value->IsSmi() || value->IsJSFunction() ||
+                         value->IsUndefined())
                         ? Type::Constant(value, isolate)
                         : Type::Any(), isolate);