[turbofan] Optimize typeof o === "object" checks.

src/compiler/typer.cc

 // 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.
 
 #include "src/compiler/typer.h"
 
 #include <iomanip>
 
 #include "src/base/flags.h"
 #include "src/bootstrapper.h"
@@ skipping 266 matching lines @@
 #undef DECLARE_METHOD
 #define DECLARE_METHOD(Name)                          \
   static Type* Name(Type* lhs, Type* rhs, Typer* t) { \
     return t->operation_typer_.Name(lhs, rhs);        \
   }
   SIMPLIFIED_NUMBER_BINOP_LIST(DECLARE_METHOD)
   SIMPLIFIED_SPECULATIVE_NUMBER_BINOP_LIST(DECLARE_METHOD)
 #undef DECLARE_METHOD
 
   static Type* ObjectIsCallable(Type*, Typer*);
+  static Type* ObjectIsNonCallable(Type*, Typer*);
   static Type* ObjectIsNumber(Type*, Typer*);
   static Type* ObjectIsReceiver(Type*, Typer*);
   static Type* ObjectIsSmi(Type*, Typer*);
   static Type* ObjectIsString(Type*, Typer*);
   static Type* ObjectIsUndetectable(Type*, Typer*);
 
   static ComparisonOutcome JSCompareTyper(Type*, Type*, Typer*);
 
 #define DECLARE_METHOD(x) static Type* x##Typer(Type*, Type*, Typer*);
   JS_SIMPLE_BINOP_LIST(DECLARE_METHOD)
@@ skipping 198 matching lines @@
 Type* Typer::Visitor::ToString(Type* type, Typer* t) {
   // ES6 section 7.1.12 ToString ( argument )
   type = ToPrimitive(type, t);
   if (type->Is(Type::String())) return type;
   return Type::String();
 }
 
 // Type checks.
 
 Type* Typer::Visitor::ObjectIsCallable(Type* type, Typer* t) {
-  if (type->Is(Type::Function())) return t->singleton_true_;
-  if (type->Is(Type::Primitive())) return t->singleton_false_;
+  if (type->Is(Type::Callable())) return t->singleton_true_;

[bakkot1, 2017/01/23 19:26:16]

Drive-by comment: document.all is "callable", in that `document.all()` succeeds
(and the 'Callable' type in types.h includes 'kOtherUndetectable', which I'm
guessing is the type of document.all), but `typeof document.all === 'function'`
should evaluate to false. At a glance it looks like this might cause it to
evaluate to true.

[Benedikt Meurer, 2017/02/14 10:18:24]

Aye, sorry for the delay, just discovered this comment. Can you file a bug
report please?

+  if (!type->Maybe(Type::Callable())) return t->singleton_false_;
   return Type::Boolean();
 }
 
+Type* Typer::Visitor::ObjectIsNonCallable(Type* type, Typer* t) {
+  if (type->Is(Type::NonCallable())) return t->singleton_true_;
+  if (!type->Maybe(Type::NonCallable())) return t->singleton_false_;
+  return Type::Boolean();
+}
+
 Type* Typer::Visitor::ObjectIsNumber(Type* type, Typer* t) {
   if (type->Is(Type::Number())) return t->singleton_true_;
   if (!type->Maybe(Type::Number())) return t->singleton_false_;
   return Type::Boolean();
 }
 
 
 Type* Typer::Visitor::ObjectIsReceiver(Type* type, Typer* t) {
   if (type->Is(Type::Receiver())) return t->singleton_true_;
   if (!type->Maybe(Type::Receiver())) return t->singleton_false_;
@@ skipping 1301 matching lines @@
 
 Type* Typer::Visitor::TypeStoreTypedElement(Node* node) {
   UNREACHABLE();
   return nullptr;
 }
 
 Type* Typer::Visitor::TypeObjectIsCallable(Node* node) {
   return TypeUnaryOp(node, ObjectIsCallable);
 }
 
+Type* Typer::Visitor::TypeObjectIsNonCallable(Node* node) {
+  return TypeUnaryOp(node, ObjectIsNonCallable);
+}
+
 Type* Typer::Visitor::TypeObjectIsNumber(Node* node) {
   return TypeUnaryOp(node, ObjectIsNumber);
 }
 
 
 Type* Typer::Visitor::TypeObjectIsReceiver(Node* node) {
   return TypeUnaryOp(node, ObjectIsReceiver);
 }
 
 
@@ skipping 26 matching lines @@
 Type* Typer::Visitor::TypeConstant(Handle<Object> value) {
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::NewConstant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8