Construct Range rather than Constant when typing integers.

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 "src/base/flags.h"
 #include "src/base/lazy-instance.h"
 #include "src/bootstrapper.h"
 #include "src/compiler/common-operator.h"
@@ skipping 30 matching lines @@
     : isolate_(isolate),
       graph_(graph),
       function_type_(function_type),
       decorator_(nullptr),
       cache_(kCache.Get()) {
   Zone* zone = this->zone();
   Factory* const factory = isolate->factory();
 
   Type* infinity = Type::Constant(factory->infinity_value(), zone);
   Type* minus_infinity = Type::Constant(factory->minus_infinity_value(), zone);
+  // TODO(neis): Unfortunately, the infinities created in other places might
+  // be different ones (eg the result of NewNumber in TypeNumberConstant).
   Type* truncating_to_zero =
       Type::Union(Type::Union(infinity, minus_infinity, zone),
                   Type::MinusZeroOrNaN(), zone);
 
   singleton_false_ = Type::Constant(factory->false_value(), zone);
   singleton_true_ = Type::Constant(factory->true_value(), zone);
   signed32ish_ = Type::Union(Type::Signed32(), truncating_to_zero, zone);
   unsigned32ish_ = Type::Union(Type::Unsigned32(), truncating_to_zero, zone);
   falsish_ = Type::Union(
       Type::Undetectable(),
@@ skipping 467 matching lines @@
 
 Bounds Typer::Visitor::TypeFloat64Constant(Node* node) {
   return Bounds(Type::Intersect(
       Type::Of(OpParameter<double>(node), zone()),
       Type::UntaggedFloat64(), zone()));
 }
 
 
 Bounds Typer::Visitor::TypeNumberConstant(Node* node) {
   Factory* f = isolate()->factory();
-  return Bounds(Type::Constant(
-      f->NewNumber(OpParameter<double>(node)), zone()));
+  double number = OpParameter<double>(node);
+  if (Type::IsInteger(number)) {
+    return Bounds(Type::Range(number, number, zone()));
+  }
+  return Bounds(Type::Constant(f->NewNumber(number), zone()));
 }
 
 
 Bounds Typer::Visitor::TypeHeapConstant(Node* node) {
   return Bounds(TypeConstant(OpParameter<Handle<HeapObject>>(node)));
 }
 
 
 Bounds Typer::Visitor::TypeExternalConstant(Node* node) {
   return Bounds(Type::None(zone()), Type::Internal(zone()));
@@ skipping 1731 matching lines @@
     }
   } else if (value->IsJSTypedArray()) {
     switch (JSTypedArray::cast(*value)->type()) {
 #define TYPED_ARRAY_CASE(Type, type, TYPE, ctype, size) \
   case kExternal##Type##Array:                          \
     return typer_->cache_.k##Type##Array;
       TYPED_ARRAYS(TYPED_ARRAY_CASE)
 #undef TYPED_ARRAY_CASE
     }
   }
+  if (Type::IsInteger(*value)) {
+    return Type::Range(value->Number(), value->Number(), zone());
+  }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8