Uniformly handle 'undefined' store to Float64Array and Float32Array.

Previous behavior diverged in ICs and Crankshaft. When storing to a Float32Array or Float64Array, the ICs treated undefined as zero while Crankshaft treated it as NaN. Now both ICs and Crankshaft treat it as NaN, which is consistent with the WebGL & ECMAScript spec.

R=mstarzinger@chromium.org

Review URL: https://chromiumcodereview.appspot.com/9402008

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@10714 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/objects.cc

@@ -11757,7 +11757,7 @@ MaybeObject* ExternalUnsignedIntArray::SetValue(uint32_t index, Object* value) {
 
 
 MaybeObject* ExternalFloatArray::SetValue(uint32_t index, Object* value) {
-  float cast_value = 0;
+  float cast_value = OS::nan_value();
   Heap* heap = GetHeap();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
@@ -11767,7 +11767,7 @@ MaybeObject* ExternalFloatArray::SetValue(uint32_t index, Object* value) {
       double double_value = HeapNumber::cast(value)->value();
       cast_value = static_cast<float>(double_value);
     } else {
-      // Clamp undefined to zero (default). All other types have been
+      // Clamp undefined to NaN (default). All other types have been
       // converted to a number type further up in the call chain.
       ASSERT(value->IsUndefined());
     }
@@ -11778,7 +11778,7 @@ MaybeObject* ExternalFloatArray::SetValue(uint32_t index, Object* value) {
 
 
 MaybeObject* ExternalDoubleArray::SetValue(uint32_t index, Object* value) {
-  double double_value = 0;
+  double double_value = OS::nan_value();
   Heap* heap = GetHeap();
   if (index < static_cast<uint32_t>(length())) {
     if (value->IsSmi()) {
@@ -11787,7 +11787,7 @@ MaybeObject* ExternalDoubleArray::SetValue(uint32_t index, Object* value) {
     } else if (value->IsHeapNumber()) {
       double_value = HeapNumber::cast(value)->value();
     } else {
-      // Clamp undefined to zero (default). All other types have been
+      // Clamp undefined to NaN (default). All other types have been
       // converted to a number type further up in the call chain.
       ASSERT(value->IsUndefined());
     }

test/cctest/test-api.cc

@@ -12902,8 +12902,15 @@ static void ExternalArrayTestHelper(v8::ExternalArrayType array_type,
                       "}"
                       "ext_array[7];");
   CHECK_EQ(0, result->Int32Value());
-  CHECK_EQ(
-      0, static_cast<int>(jsobj->GetElement(7)->ToObjectChecked()->Number()));
+  if (array_type == kExternalDoubleArray ||
+      array_type == kExternalFloatArray) {
+    CHECK_EQ(
+        static_cast<int>(0x80000000),
+        static_cast<int>(jsobj->GetElement(7)->ToObjectChecked()->Number()));
+  } else {
+    CHECK_EQ(0, static_cast<int>(
+        jsobj->GetElement(7)->ToObjectChecked()->Number()));
+  }
 
   result = CompileRun("for (var i = 0; i < 8; i++) {"
                       "  ext_array[6] = '2.3';"

test/mjsunit/external-array.js

@@ -317,3 +317,37 @@ for (var t = 0; t < types.length; t++) {
   %DeoptimizeFunction(array_load_set_smi_check2);
   gc();  // Makes V8 forget about type information for array_load_set_smi_check.
 }
+
+// Check handling of undefined in 32- and 64-bit external float arrays.
+
+function store_float32_undefined(ext_array) {
+  ext_array[0] = undefined;
+}
+
+var float32_array = new Float32Array(1);
+// Make sure runtime does it right
+store_float32_undefined(float32_array);
+assertTrue(isNaN(float32_array[0]));
+// Make sure the ICs do it right
+store_float32_undefined(float32_array);
+assertTrue(isNaN(float32_array[0]));
+// Make sure that Cranskshft does it right.
+%OptimizeFunctionOnNextCall(store_float32_undefined);
+store_float32_undefined(float32_array);
+assertTrue(isNaN(float32_array[0]));
+
+function store_float64_undefined(ext_array) {
+  ext_array[0] = undefined;
+}
+
+var float64_array = new Float64Array(1);
+// Make sure runtime does it right
+store_float64_undefined(float64_array);
+assertTrue(isNaN(float64_array[0]));
+// Make sure the ICs do it right
+store_float64_undefined(float64_array);
+assertTrue(isNaN(float64_array[0]));
+// Make sure that Cranskshft does it right.
+%OptimizeFunctionOnNextCall(store_float64_undefined);
+store_float64_undefined(float64_array);
+assertTrue(isNaN(float64_array[0]));