Move some Pop/Drop calls directly to the places where they are needed.

src/hydrogen.cc

Index: src/hydrogen.cc
diff --git a/src/hydrogen.cc b/src/hydrogen.cc
index 752a7482540b7a4e747429046b847a29453b8989..7df91d2e81648cd1bb1b45240c9a3d068a425f76 100644
--- a/src/hydrogen.cc
+++ b/src/hydrogen.cc
@@ -5070,6 +5070,7 @@ void HGraphBuilder::HandlePolymorphicLoadNamedField(Property* expr,
                                                     HValue* object,
                                                     SmallMapList* types,
                                                     Handle<String> name) {
+  AddInstruction(new(zone()) HCheckNonSmi(object));

[Michael Starzinger, 2012/07/27 12:26:03]

Can we move this down right in front of the block where instructions are
actually emitted? Because this first block is just checking some optimistic
assumptions but not generating any instructions.

[Sven Panne, 2012/07/27 12:35:30]

Done.

   int count = 0;
   int previous_field_offset = 0;
   bool previous_field_is_in_object = false;
@@ -5202,45 +5203,52 @@ void HGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
   expr->RecordTypeFeedback(oracle(), zone());
   CHECK_ALIVE(VisitForValue(prop->obj()));
 
-  HValue* value = NULL;
-  HInstruction* instr = NULL;
-
   if (prop->key()->IsPropertyName()) {
     // Named store.
     CHECK_ALIVE(VisitForValue(expr->value()));
-    value = Pop();
-    HValue* object = Pop();
+    HValue* value = environment()->ExpressionStackAt(0);
+    HValue* object = environment()->ExpressionStackAt(1);
 
     Literal* key = prop->key()->AsLiteral();
     Handle<String> name = Handle<String>::cast(key->handle());
     ASSERT(!name.is_null());
 
+    HInstruction* instr = NULL;
     SmallMapList* types = expr->GetReceiverTypes();
     if (expr->IsMonomorphic()) {
       Handle<Map> map = types->first();
       Handle<AccessorPair> accessors;
       Handle<JSObject> holder;
       if (LookupAccessorPair(map, name, &accessors, &holder)) {
+        Drop(2);
         instr = BuildCallSetter(object, value, map, accessors, holder);
       } else {
+        Drop(2);
         CHECK_ALIVE(instr = BuildStoreNamedMonomorphic(object,
                                                        name,
                                                        value,
                                                        map));
       }
-    } else if (types != NULL && types->length() > 1) {
-      HandlePolymorphicStoreNamedField(expr, object, value, types, name);
-      return;
 
+    } else if (types != NULL && types->length() > 1) {
+      Drop(2);
+      return HandlePolymorphicStoreNamedField(expr, object, value, types, name);
     } else {
+      Drop(2);
       instr = BuildStoreNamedGeneric(object, name, value);
     }
 
+    Push(value);
+    instr->set_position(expr->position());
+    AddInstruction(instr);
+    if (instr->HasObservableSideEffects()) AddSimulate(expr->AssignmentId());
+    return ast_context()->ReturnValue(Pop());
+
   } else {
     // Keyed store.
     CHECK_ALIVE(VisitForValue(prop->key()));
     CHECK_ALIVE(VisitForValue(expr->value()));
-    value = Pop();
+    HValue* value = Pop();
     HValue* key = Pop();
     HValue* object = Pop();
     bool has_side_effects = false;
@@ -5253,11 +5261,6 @@ void HGraphBuilder::HandlePropertyAssignment(Assignment* expr) {
     AddSimulate(expr->AssignmentId());
     return ast_context()->ReturnValue(Pop());
   }
-  Push(value);
-  instr->set_position(expr->position());
-  AddInstruction(instr);
-  if (instr->HasObservableSideEffects()) AddSimulate(expr->AssignmentId());
-  return ast_context()->ReturnValue(Pop());
 }
 
 
@@ -6344,22 +6347,19 @@ void HGraphBuilder::VisitProperty(Property* expr) {
     Handle<String> name = expr->key()->AsLiteral()->AsPropertyName();
     SmallMapList* types = expr->GetReceiverTypes();
 
-    HValue* obj = Pop();
     if (expr->IsMonomorphic()) {
       Handle<Map> map = types->first();
       Handle<AccessorPair> accessors;
       Handle<JSObject> holder;
       if (LookupAccessorPair(map, name, &accessors, &holder)) {
-        instr = BuildCallGetter(obj, map, accessors, holder);
+        instr = BuildCallGetter(Pop(), map, accessors, holder);
       } else {
-        instr = BuildLoadNamedMonomorphic(obj, name, expr, map);
+        instr = BuildLoadNamedMonomorphic(Pop(), name, expr, map);
       }
     } else if (types != NULL && types->length() > 1) {
-      AddInstruction(new(zone()) HCheckNonSmi(obj));
-      HandlePolymorphicLoadNamedField(expr, obj, types, name);
-      return;
+      return HandlePolymorphicLoadNamedField(expr, Pop(), types, name);
     } else {
-      instr = BuildLoadNamedGeneric(obj, name, expr);
+      instr = BuildLoadNamedGeneric(Pop(), name, expr);
     }
 
   } else {