[turbofan] Introduce dedicated ObjectIsNaN operator.

src/compiler/effect-control-linearizer.cc

 // Copyright 2015 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.
 
 #include "src/compiler/effect-control-linearizer.h"
 
 #include "src/code-factory.h"
 #include "src/compiler/access-builder.h"
 #include "src/compiler/compiler-source-position-table.h"
 #include "src/compiler/js-graph.h"
@@ skipping 703 matching lines @@
       break;
     case IrOpcode::kTruncateTaggedToWord32:
       result = LowerTruncateTaggedToWord32(node);
       break;
     case IrOpcode::kCheckedTruncateTaggedToWord32:
       result = LowerCheckedTruncateTaggedToWord32(node, frame_state);
       break;
     case IrOpcode::kObjectIsDetectableCallable:
       result = LowerObjectIsDetectableCallable(node);
       break;
+    case IrOpcode::kObjectIsNaN:
+      result = LowerObjectIsNaN(node);
+      break;
     case IrOpcode::kObjectIsNonCallable:
       result = LowerObjectIsNonCallable(node);
       break;
     case IrOpcode::kObjectIsNumber:
       result = LowerObjectIsNumber(node);
       break;
     case IrOpcode::kObjectIsReceiver:
       result = LowerObjectIsReceiver(node);
       break;
     case IrOpcode::kObjectIsSmi:
@@ skipping 974 matching lines @@
                                     (1 << Map::kIsUndetectable))));
   __ Goto(&done, vfalse);
 
   __ Bind(&if_smi);
   __ Goto(&done, __ Int32Constant(0));
 
   __ Bind(&done);
   return done.PhiAt(0);
 }
 
+Node* EffectControlLinearizer::LowerObjectIsNaN(Node* node) {
+  Node* value = node->InputAt(0);
+  Node* zero = __ Int32Constant(0);
+
+  auto done = __ MakeLabel<3>(MachineRepresentation::kBit);
+
+  // Check if {value} is a Smi.
+  __ GotoIf(ObjectIsSmi(value), &done, zero);
+
+  // Check if {value} is a HeapNumber.
+  Node* value_map = __ LoadField(AccessBuilder::ForMap(), value);
+  __ GotoUnless(__ WordEqual(value_map, __ HeapNumberMapConstant()), &done,
+                zero);
+
+  // Check if {value} contains a NaN.
+  Node* value_value = __ LoadField(AccessBuilder::ForHeapNumberValue(), value);
+  __ Goto(&done,
+          __ Word32Equal(__ Float64Equal(value_value, value_value), zero));
+
+  __ Bind(&done);
+  return done.PhiAt(0);
+}
+
 Node* EffectControlLinearizer::LowerObjectIsNonCallable(Node* node) {
   Node* value = node->InputAt(0);
 
   auto if_primitive = __ MakeDeferredLabel<2>();
   auto done = __ MakeLabel<2>(MachineRepresentation::kBit);
 
   Node* check0 = ObjectIsSmi(value);
   __ GotoIf(check0, &if_primitive);
 
   Node* value_map = __ LoadField(AccessBuilder::ForMap(), value);
@@ skipping 1059 matching lines @@
   return isolate()->factory();
 }
 
 Isolate* EffectControlLinearizer::isolate() const {
   return jsgraph()->isolate();
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8