Fixed inlining of constant values

Use CopyToRepresentation to elide HForceRepresentation of HConstant

BUG=v8:3529
LOG=y
R=bmeurer@chromium.org

Review URL: https://codereview.chromium.org/507613002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@23397 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/hydrogen-instructions.cc

@@ -1512,17 +1512,8 @@ HInstruction* HForceRepresentation::New(Zone* zone, HValue* context,
        HValue* value, Representation representation) {
   if (FLAG_fold_constants && value->IsConstant()) {
     HConstant* c = HConstant::cast(value);
-    if (c->HasNumberValue()) {
-      double double_res = c->DoubleValue();
-      if (representation.IsDouble()) {
-        return HConstant::New(zone, context, double_res);
-
-      } else if (representation.CanContainDouble(double_res)) {
-        return HConstant::New(zone, context,
-                              static_cast<int32_t>(double_res),
-                              representation);
-      }
-    }
+    c = c->CopyToRepresentation(representation, zone);
+    if (c != NULL) return c;
   }
   return new(zone) HForceRepresentation(value, representation);
 }

src/property-details-inl.h

@@ -13,18 +13,6 @@
 namespace v8 {
 namespace internal {
 
-inline bool Representation::CanContainDouble(double value) {
-  if (IsDouble() || is_more_general_than(Representation::Double())) {
-    return true;
-  }
-  if (IsInt32Double(value)) {
-    if (IsInteger32()) return true;
-    if (IsSmi()) return Smi::IsValid(static_cast<int32_t>(value));
-  }
-  return false;
-}
-
-
 Representation Representation::FromType(Type* type) {
   DisallowHeapAllocation no_allocation;
   if (type->Is(Type::None())) return Representation::None();

src/property-details.h

@@ -122,8 +122,6 @@ class Representation {
     return other.is_more_general_than(*this) || other.Equals(*this);
   }
 
-  bool CanContainDouble(double value);
-
   Representation generalize(Representation other) {
     if (other.fits_into(*this)) return *this;
     if (other.is_more_general_than(*this)) return other;

test/mjsunit/regress/regress-force-constant-representation.js

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Flags: --allow-natives-syntax
+
+// Test push double as tagged.
+var a = [{}];
+function f(a) {
+  a.push(Infinity);
+}
+
+f(a);
+f(a);
+f(a);
+%OptimizeFunctionOnNextCall(f);
+f(a);
+assertEquals([{}, Infinity, Infinity, Infinity, Infinity], a);