[WIP] NumberToString operator in TF.

src/compiler/operation-typer.cc

 // Copyright 2016 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/operation-typer.h"
 
 #include "src/compiler/common-operator.h"
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/type-cache.h"
 #include "src/types.h"
 
 #include "src/objects-inl.h"
 
 namespace v8 {
 namespace internal {
 namespace compiler {
 
 OperationTyper::OperationTyper(Isolate* isolate, Zone* zone)
-    : zone_(zone), cache_(TypeCache::Get()) {
+    : isolate_(isolate), zone_(zone), cache_(TypeCache::Get()) {
   Factory* factory = isolate->factory();
   infinity_ = Type::Constant(factory->infinity_value(), zone);
   minus_infinity_ = Type::Constant(factory->minus_infinity_value(), zone);
   // 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);
   DCHECK(!truncating_to_zero->Maybe(Type::Integral32()));
 
@@ skipping 446 matching lines @@
 
   if (type->Is(Type::Unsigned32())) return type;
   if (type->Is(cache_.kZeroish)) return cache_.kSingletonZero;
   if (type->Is(unsigned32ish_)) {
     return Type::Intersect(Type::Union(type, cache_.kSingletonZero, zone()),
                            Type::Unsigned32(), zone());
   }
   return Type::Unsigned32();
 }
 
+Type* OperationTyper::NumberToString(Type* lhs, Type* rhs) {
+  DCHECK(lhs->Is(Type::Number()));
+  DCHECK(rhs->Is(Type::Unsigned30()));
+  if (!lhs->IsInhabited()) return Type::None();
+  if (lhs->Is(Type::NaN())) {
+    return Type::Constant(factory()->nan_string(), zone());
+  }
+  if (lhs->Is(cache_.kZeroish)) {
+    return Type::Constant(factory()->zero_string(), zone());
+  }
+  if (lhs->Is(infinity_)) {
+    return Type::Constant(factory()->infinity_string(), zone());
+  }
+  if (lhs->Is(minus_infinity_)) {
+    return Type::Constant(factory()->minus_infinity_string(), zone());
+  }
+  return Type::String();
+}
+
 Type* OperationTyper::NumberSilenceNaN(Type* type) {
   DCHECK(type->Is(Type::Number()));
   // TODO(jarin): This is a terrible hack; we definitely need a dedicated type
   // for the hole (tagged and/or double). Otherwise if the input is the hole
   // NaN constant, we'd just eliminate this node in JSTypedLowering.
   if (type->Maybe(Type::NaN())) return Type::Number();
   return type;
 }
 
 Type* OperationTyper::NumberAdd(Type* lhs, Type* rhs) {
@@ skipping 459 matching lines @@
   }
   // Type should be non empty, so we know it should be true.
   DCHECK((outcome & kComparisonTrue) != 0);
   return singleton_true();
 }
 
 Type* OperationTyper::TypeTypeGuard(const Operator* sigma_op, Type* input) {
   return Type::Intersect(input, TypeGuardTypeOf(sigma_op), zone());
 }
 
+Factory* OperationTyper::factory() const { return isolate()->factory(); }
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8