[turbofan] Quit storing strings in types.

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 1509 matching lines @@
 
 Type* Typer::Visitor::TypeStringEqual(Node* node) { return Type::Boolean(); }
 
 Type* Typer::Visitor::TypeStringLessThan(Node* node) { return Type::Boolean(); }
 
 Type* Typer::Visitor::TypeStringLessThanOrEqual(Node* node) {
   return Type::Boolean();
 }
 
 Type* Typer::Visitor::StringFromCharCodeTyper(Type* type, Typer* t) {
-  type = NumberToUint32(ToNumber(type, t), t);
-  Factory* f = t->isolate()->factory();
-  double min = type->Min();
-  double max = type->Max();
-  if (min == max) {
-    uint32_t code = static_cast<uint32_t>(min) & String::kMaxUtf16CodeUnitU;
-    Handle<String> string = f->LookupSingleCharacterStringFromCode(code);
-    return Type::HeapConstant(string, t->zone());
-  }
   return Type::String();
 }
 
 Type* Typer::Visitor::StringFromCodePointTyper(Type* type, Typer* t) {
-  type = NumberToUint32(ToNumber(type, t), t);
-  Factory* f = t->isolate()->factory();
-  double min = type->Min();
-  double max = type->Max();
-  if (min == max) {
-    uint32_t code = static_cast<uint32_t>(min) & String::kMaxUtf16CodeUnitU;
-    Handle<String> string = f->LookupSingleCharacterStringFromCode(code);
-    return Type::HeapConstant(string, t->zone());
-  }
   return Type::String();
 }
 
 Type* Typer::Visitor::TypeStringCharCodeAt(Node* node) {
   // TODO(bmeurer): We could do better here based on inputs.
   return Type::Range(0, kMaxUInt16, zone());
 }
 
 Type* Typer::Visitor::TypeStringFromCharCode(Node* node) {
   return TypeUnaryOp(node, StringFromCharCodeTyper);
@@ skipping 159 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