Fix FixedUint8ClampedArray::SetValue.

src/objects-inl.h

Index: src/objects-inl.h
diff --git a/src/objects-inl.h b/src/objects-inl.h
index c358ee6584525e4415aacce8615efd687acda79e..95f52b194c5cf2f2d4e8dca4541dfe83db78b495 100644
--- a/src/objects-inl.h
+++ b/src/objects-inl.h
@@ -3744,21 +3744,69 @@ MaybeObject* FixedTypedArray<Traits>::get(int index) {
   return Traits::ToObject(GetHeap(), get_scalar(index));
 }
 
+
+inline uint8_t clampObjectToUint8(Object* value) {
+  uint8_t clamped_value = 0;
+  if (value->IsSmi()) {
+    int int_value = Smi::cast(value)->value();
+    if (int_value < 0) {
+      clamped_value = 0;
+    } else if (int_value > 255) {
+      clamped_value = 255;
+    } else {
+      clamped_value = static_cast<uint8_t>(int_value);
+    }
+  } else if (value->IsHeapNumber()) {
+    double double_value = HeapNumber::cast(value)->value();
+    if (!(double_value > 0)) {
+      // NaN and less than zero clamp to zero.
+      clamped_value = 0;
+    } else if (double_value > 255) {
+      // Greater than 255 clamp to 255.
+      clamped_value = 255;
+    } else {
+      // Other doubles are rounded to the nearest integer.
+      clamped_value = static_cast<uint8_t>(lrint(double_value));
+    }
+  } else {
+    // Clamp undefined to zero (default). All other types have been
+    // converted to a number type further up in the call chain.
+    ASSERT(value->IsUndefined());
+  }
+  return clamped_value;
+}
+
+
+template<> inline
+uint8_t FixedTypedArray<Uint8ClampedArrayTraits>::castObject(Object* value) {
+  return clampObjectToUint8(value);
+}
+
+
+template <class Traits>
+typename Traits::ElementType FixedTypedArray<Traits>::castObject(
+    Object* value) {
+  ElementType result = Traits::defaultValue();
+  if (value->IsSmi()) {
+    int int_value = Smi::cast(value)->value();
+    result = static_cast<ElementType>(int_value);
+  } else if (value->IsHeapNumber()) {
+    double double_value = HeapNumber::cast(value)->value();
+    result = static_cast<ElementType>(DoubleToInt32(double_value));
+  } else {
+    // Clamp undefined to the default value. All other types have been
+    // converted to a number type further up in the call chain.
+    ASSERT(value->IsUndefined());
+  }
+  return result;
+}
+
+
 template <class Traits>
 MaybeObject* FixedTypedArray<Traits>::SetValue(uint32_t index, Object* value) {
   ElementType cast_value = Traits::defaultValue();
   if (index < static_cast<uint32_t>(length())) {
-    if (value->IsSmi()) {
-      int int_value = Smi::cast(value)->value();
-      cast_value = static_cast<ElementType>(int_value);
-    } else if (value->IsHeapNumber()) {
-      double double_value = HeapNumber::cast(value)->value();
-      cast_value = static_cast<ElementType>(DoubleToInt32(double_value));
-    } else {
-      // Clamp undefined to the default value. All other types have been
-      // converted to a number type further up in the call chain.
-      ASSERT(value->IsUndefined());
-    }
+    cast_value = castObject(value);
     set(index, cast_value);
   }
   return Traits::ToObject(GetHeap(), cast_value);