[turbofan] Introduce NumberFloor simplified operator.

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/bootstrapper.h"
 #include "src/compilation-dependencies.h"
 #include "src/compiler/common-operator.h"
@@ skipping 222 matching lines @@
   static Type* Rangify(Type*, Typer*);
 
   static Type* ToPrimitive(Type*, Typer*);
   static Type* ToBoolean(Type*, Typer*);
   static Type* ToInteger(Type*, Typer*);
   static Type* ToLength(Type*, Typer*);
   static Type* ToName(Type*, Typer*);
   static Type* ToNumber(Type*, Typer*);
   static Type* ToObject(Type*, Typer*);
   static Type* ToString(Type*, Typer*);
+  static Type* NumberFloor(Type*, Typer*);
   static Type* NumberToInt32(Type*, Typer*);
   static Type* NumberToUint32(Type*, Typer*);
 
   static Type* ObjectIsNumber(Type*, Typer*);
   static Type* ObjectIsReceiver(Type*, Typer*);
   static Type* ObjectIsSmi(Type*, Typer*);
   static Type* ObjectIsUndetectable(Type*, Typer*);
 
   static Type* JSAddRanger(RangeType*, RangeType*, Typer*);
   static Type* JSSubtractRanger(RangeType*, RangeType*, Typer*);
@@ skipping 227 matching lines @@
 
 
 // static
 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();
 }
 
+// static
+Type* Typer::Visitor::NumberFloor(Type* type, Typer* t) {
+  DCHECK(type->Is(Type::Number()));
+  if (type->Is(t->cache_.kIntegerOrMinusZeroOrNaN)) return type;
+  return t->cache_.kIntegerOrMinusZeroOrNaN;
+}
 
 Type* Typer::Visitor::NumberToInt32(Type* type, Typer* t) {
   // TODO(neis): DCHECK(type->Is(Type::Number()));
   if (type->Is(Type::Signed32())) return type;
   if (type->Is(t->cache_.kZeroish)) return t->cache_.kSingletonZero;
   if (type->Is(t->signed32ish_)) {
     return Type::Intersect(
         Type::Union(type, t->cache_.kSingletonZero, t->zone()),
         Type::Signed32(), t->zone());
   }
@@ skipping 1208 matching lines @@
 
 Type* Typer::Visitor::TypeNumberShiftRight(Node* node) {
   return Type::Signed32();
 }
 
 
 Type* Typer::Visitor::TypeNumberShiftRightLogical(Node* node) {
   return Type::Unsigned32();
 }
 
+Type* Typer::Visitor::TypeNumberFloor(Node* node) {
+  return TypeUnaryOp(node, NumberFloor);
+}
 
 Type* Typer::Visitor::TypeNumberToInt32(Node* node) {
   return TypeUnaryOp(node, NumberToInt32);
 }
 
 
 Type* Typer::Visitor::TypeNumberToUint32(Node* node) {
   return TypeUnaryOp(node, NumberToUint32);
 }
 
@@ skipping 739 matching lines @@
   }
   if (Type::IsInteger(*value)) {
     return Type::Range(value->Number(), value->Number(), zone());
   }
   return Type::Constant(value, zone());
 }
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8