Drop null/undefined check if we already check for IsUndetectable in BuildCompareNil

src/code-stubs.cc

 // Copyright 2012 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/code-stubs.h"
 
 #include <sstream>
 
 #include "src/bootstrapper.h"
 #include "src/compiler/code-stub-assembler.h"
@@ skipping 441 matching lines @@
 
 
 void CompareNilICStub::UpdateStatus(Handle<Object> object) {
   State state = this->state();
   DCHECK(!state.Contains(GENERIC));
   State old_state = state;
   if (object->IsNull()) {
     state.Add(NULL_TYPE);
   } else if (object->IsUndefined()) {
     state.Add(UNDEFINED);
-  } else if (object->IsUndetectableObject() ||
-             object->IsOddball() ||
-             !object->IsHeapObject()) {
+  } else if (object->IsUndetectableObject() || object->IsSmi()) {
     state.RemoveAll();
     state.Add(GENERIC);
   } else if (IsMonomorphic()) {
     state.RemoveAll();
     state.Add(GENERIC);
   } else {
     state.Add(MONOMORPHIC_MAP);
   }
   TraceTransition(old_state, state);
   set_sub_minor_key(TypesBits::update(sub_minor_key(), state.ToIntegral()));
@@ skipping 458 matching lines @@
   } else if (object->IsNull()) {
     Add(NULL_TYPE);
     return false;
   } else if (object->IsSmi()) {
     Add(SMI);
     return Smi::cast(*object)->value() != 0;
   } else if (object->IsJSReceiver()) {
     Add(SPEC_OBJECT);
     return !object->IsUndetectableObject();
   } else if (object->IsString()) {
+    DCHECK(!object->IsUndetectableObject());
     Add(STRING);
-    return !object->IsUndetectableObject() &&
-        String::cast(*object)->length() != 0;
+    return String::cast(*object)->length() != 0;
   } else if (object->IsSymbol()) {
     Add(SYMBOL);
     return true;
   } else if (object->IsHeapNumber()) {
     DCHECK(!object->IsUndetectableObject());
     Add(HEAP_NUMBER);
     double value = HeapNumber::cast(*object)->value();
     return value != 0 && !std::isnan(value);
   } else if (object->IsSimd128Value()) {
     Add(SIMD_VALUE);
@@ skipping 72 matching lines @@
   if (type->Is(Type::UntaggedPointer())) {
     return Representation::External();
   }
 
   DCHECK(!type->Is(Type::Untagged()));
   return Representation::Tagged();
 }
 
 }  // namespace internal
 }  // namespace v8