Land the Fan (disabled)

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/graph-inl.h"
+#include "src/compiler/js-operator.h"
+#include "src/compiler/node.h"
+#include "src/compiler/node-properties-inl.h"
+#include "src/compiler/node-properties.h"
+#include "src/compiler/simplified-operator.h"
+#include "src/compiler/typer.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+Typer::Typer(Zone* zone) : zone_(zone) {
+  Type* number = Type::Number(zone);
+  Type* signed32 = Type::Signed32(zone);
+  Type* unsigned32 = Type::Unsigned32(zone);
+  Type* integral32 = Type::Integral32(zone);
+  Type* object = Type::Object(zone);
+  Type* undefined = Type::Undefined(zone);
+  number_fun0_ = Type::Function(number, zone);
+  number_fun1_ = Type::Function(number, number, zone);
+  number_fun2_ = Type::Function(number, number, number, zone);
+  imul_fun_ = Type::Function(signed32, integral32, integral32, zone);
+
+#define NATIVE_TYPE(sem, rep) \
+  Type::Intersect(Type::sem(zone), Type::rep(zone), zone)
+  // TODO(rossberg): Use range types for more precision, once we have them.
+  Type* int8 = NATIVE_TYPE(SignedSmall, UntaggedInt8);
+  Type* int16 = NATIVE_TYPE(SignedSmall, UntaggedInt16);
+  Type* int32 = NATIVE_TYPE(Signed32, UntaggedInt32);
+  Type* uint8 = NATIVE_TYPE(UnsignedSmall, UntaggedInt8);
+  Type* uint16 = NATIVE_TYPE(UnsignedSmall, UntaggedInt16);
+  Type* uint32 = NATIVE_TYPE(Unsigned32, UntaggedInt32);
+  Type* float32 = NATIVE_TYPE(Number, UntaggedFloat32);
+  Type* float64 = NATIVE_TYPE(Number, UntaggedFloat64);
+#undef NATIVE_TYPE
+  Type* buffer = Type::Buffer(zone);
+  Type* int8_array = Type::Array(int8, zone);
+  Type* int16_array = Type::Array(int16, zone);
+  Type* int32_array = Type::Array(int32, zone);
+  Type* uint8_array = Type::Array(uint8, zone);
+  Type* uint16_array = Type::Array(uint16, zone);
+  Type* uint32_array = Type::Array(uint32, zone);
+  Type* float32_array = Type::Array(float32, zone);
+  Type* float64_array = Type::Array(float64, zone);
+  Type* arg1 = Type::Union(unsigned32, object, zone);
+  Type* arg2 = Type::Union(unsigned32, undefined, zone);
+  Type* arg3 = arg2;
+  array_buffer_fun_ = Type::Function(buffer, unsigned32, zone);
+  int8_array_fun_ = Type::Function(int8_array, arg1, arg2, arg3, zone);
+  int16_array_fun_ = Type::Function(int16_array, arg1, arg2, arg3, zone);
+  int32_array_fun_ = Type::Function(int32_array, arg1, arg2, arg3, zone);
+  uint8_array_fun_ = Type::Function(uint8_array, arg1, arg2, arg3, zone);
+  uint16_array_fun_ = Type::Function(uint16_array, arg1, arg2, arg3, zone);
+  uint32_array_fun_ = Type::Function(uint32_array, arg1, arg2, arg3, zone);
+  float32_array_fun_ = Type::Function(float32_array, arg1, arg2, arg3, zone);
+  float64_array_fun_ = Type::Function(float64_array, arg1, arg2, arg3, zone);
+}
+
+
+class Typer::Visitor : public NullNodeVisitor {
+ public:
+  Visitor(Typer* typer, MaybeHandle<Context> context) :
+      typer_(typer), context_(context) {
+  }
+
+  Bounds TypeNode(Node* node) {
+    switch (node->opcode()) {
+      #define DECLARE_CASE(x) \
+        case IrOpcode::k##x: return Type##x(node);
+      VALUE_OP_LIST(DECLARE_CASE)
+      #undef DECLARE_CASE
+
+      #define DECLARE_CASE(x) \
+        case IrOpcode::k##x:
+      CONTROL_OP_LIST(DECLARE_CASE)
+      #undef DECLARE_CASE
+        break;
+    }
+    return Bounds(Type::None(zone()));
+  }
+
+  Type* TypeConstant(Handle<Object> value);
+
+ protected:
+  #define DECLARE_METHOD(x) \
+    inline Bounds Type##x(Node* node);
+  VALUE_OP_LIST(DECLARE_METHOD)
+  #undef DECLARE_METHOD
+
+  Bounds OperandType(Node* node, int i) {
+    return NodeProperties::GetBounds(NodeProperties::GetValueInput(node, i));
+  }
+
+  Type* ContextType(Node* node) {
+    Bounds result =
+        NodeProperties::GetBounds(NodeProperties::GetContextInput(node));
+    ASSERT(result.upper->Is(Type::Internal()));
+    ASSERT(result.lower->Equals(result.upper));
+    return result.upper;
+  }
+
+  Zone* zone() { return typer_->zone(); }
+  Isolate* isolate() { return typer_->isolate(); }
+  MaybeHandle<Context> context() { return context_; }
+
+ private:
+  Typer* typer_;
+  MaybeHandle<Context> context_;
+};
+
+
+class Typer::RunVisitor : public Typer::Visitor {
+ public:
+  RunVisitor(Typer* typer, MaybeHandle<Context> context)
+      : Visitor(typer, context),
+        phis(NodeSet::key_compare(), NodeSet::allocator_type(typer->zone())) {}
+
+  GenericGraphVisit::Control Pre(Node* node) {
+    return NodeProperties::IsControl(node)
+        && node->opcode() != IrOpcode::kEnd
+        && node->opcode() != IrOpcode::kMerge
+        && node->opcode() != IrOpcode::kReturn
+        ? GenericGraphVisit::SKIP : GenericGraphVisit::CONTINUE;
+  }
+
+  GenericGraphVisit::Control Post(Node* node) {
+    Bounds bounds = TypeNode(node);
+    if (node->opcode() == IrOpcode::kPhi) {
+      // Remember phis for least fixpoint iteration.
+      phis.insert(node);
+    } else {
+      NodeProperties::SetBounds(node, bounds);
+    }
+    return GenericGraphVisit::CONTINUE;
+  }
+
+  NodeSet phis;
+};
+
+
+class Typer::NarrowVisitor : public Typer::Visitor {
+ public:
+  NarrowVisitor(Typer* typer, MaybeHandle<Context> context)
+      : Visitor(typer, context) {}
+
+  GenericGraphVisit::Control Pre(Node* node) {
+    Bounds previous = NodeProperties::GetBounds(node);
+    Bounds bounds = TypeNode(node);
+    NodeProperties::SetBounds(node, Bounds::Both(bounds, previous, zone()));
+    ASSERT(bounds.Narrows(previous));
+    // Stop when nothing changed (but allow reentry in case it does later).
+    return previous.Narrows(bounds)
+        ? GenericGraphVisit::DEFER : GenericGraphVisit::REENTER;
+  }
+
+  GenericGraphVisit::Control Post(Node* node) {
+    return GenericGraphVisit::REENTER;
+  }
+};
+
+
+class Typer::WidenVisitor : public Typer::Visitor {
+ public:
+  WidenVisitor(Typer* typer, MaybeHandle<Context> context)
+      : Visitor(typer, context) {}
+
+  GenericGraphVisit::Control Pre(Node* node) {
+    Bounds previous = NodeProperties::GetBounds(node);
+    Bounds bounds = TypeNode(node);
+    ASSERT(previous.lower->Is(bounds.lower));
+    ASSERT(previous.upper->Is(bounds.upper));
+    NodeProperties::SetBounds(node, bounds);  // TODO(rossberg): Either?
+    // Stop when nothing changed (but allow reentry in case it does later).
+    return bounds.Narrows(previous)
+        ? GenericGraphVisit::DEFER : GenericGraphVisit::REENTER;
+  }
+
+  GenericGraphVisit::Control Post(Node* node) {
+    return GenericGraphVisit::REENTER;
+  }
+};
+
+
+void Typer::Run(Graph* graph, MaybeHandle<Context> context) {
+  RunVisitor typing(this, context);
+  graph->VisitNodeInputsFromEnd(&typing);
+  // Find least fixpoint.
+  for (NodeSetIter i = typing.phis.begin(); i != typing.phis.end(); ++i) {
+    Widen(graph, *i, context);
+  }
+}
+
+
+void Typer::Narrow(
+    Graph* graph, Node* start, MaybeHandle<Context> context) {
+  NarrowVisitor typing(this, context);
+  graph->VisitNodeUsesFrom(start, &typing);
+}
+
+
+void Typer::Widen(Graph* graph, Node* start, MaybeHandle<Context> context) {
+  WidenVisitor typing(this, context);
+  graph->VisitNodeUsesFrom(start, &typing);
+}
+
+
+void Typer::Init(Node* node) {
+  Visitor typing(this, MaybeHandle<Context>());
+  Bounds bounds = typing.TypeNode(node);
+  NodeProperties::SetBounds(node, bounds);
+}
+
+
+// Common operators.
+Bounds Typer::Visitor::TypeParameter(Node* node) {
+  return Bounds::Unbounded(zone());
+}
+
+
+Bounds Typer::Visitor::TypeInt32Constant(Node* node) {
+  // TODO(titzer): only call Type::Of() if the type is not already known.
+  return Bounds(Type::Of(ValueOf<int32_t>(node->op()), zone()));
+}
+
+
+Bounds Typer::Visitor::TypeInt64Constant(Node* node) {
+  // TODO(titzer): only call Type::Of() if the type is not already known.
+  return Bounds(
+      Type::Of(static_cast<double>(ValueOf<int64_t>(node->op())), zone()));
+}
+
+
+Bounds Typer::Visitor::TypeFloat64Constant(Node* node) {
+  // TODO(titzer): only call Type::Of() if the type is not already known.
+  return Bounds(Type::Of(ValueOf<double>(node->op()), zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberConstant(Node* node) {
+  // TODO(titzer): only call Type::Of() if the type is not already known.
+  return Bounds(Type::Of(ValueOf<double>(node->op()), zone()));
+}
+
+
+Bounds Typer::Visitor::TypeHeapConstant(Node* node) {
+  return Bounds(TypeConstant(ValueOf<Handle<Object> >(node->op())));
+}
+
+
+Bounds Typer::Visitor::TypeExternalConstant(Node* node) {
+  return Bounds(Type::Internal(zone()));
+}
+
+
+Bounds Typer::Visitor::TypePhi(Node* node) {
+  int arity = NodeProperties::GetValueInputCount(node);
+  Bounds bounds = OperandType(node, 0);
+  for (int i = 1; i < arity; ++i) {
+    bounds = Bounds::Either(bounds, OperandType(node, i), zone());
+  }
+  return bounds;
+}
+
+
+Bounds Typer::Visitor::TypeEffectPhi(Node* node) {
+  return Bounds(Type::None(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeFrameState(Node* node) {
+  return Bounds(Type::None(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeCall(Node* node) {
+  return Bounds::Unbounded(zone());
+}
+
+
+Bounds Typer::Visitor::TypeProjection(Node* node) {
+  // TODO(titzer): use the output type of the input to determine the bounds.
+  return Bounds::Unbounded(zone());
+}
+
+
+// JS comparison operators.
+
+#define DEFINE_METHOD(x) \
+  Bounds Typer::Visitor::Type##x(Node* node) { \
+    return Bounds(Type::Boolean(zone()));      \
+  }
+JS_COMPARE_BINOP_LIST(DEFINE_METHOD)
+#undef DEFINE_METHOD
+
+
+// JS bitwise operators.
+
+Bounds Typer::Visitor::TypeJSBitwiseOr(Node* node) {
+  Bounds left = OperandType(node, 0);
+  Bounds right = OperandType(node, 1);
+  Type* upper = Type::Union(left.upper, right.upper, zone());
+  if (!upper->Is(Type::Signed32())) upper = Type::Signed32(zone());
+  Type* lower = Type::Intersect(Type::SignedSmall(zone()), upper, zone());
+  return Bounds(lower, upper);
+}
+
+
+Bounds Typer::Visitor::TypeJSBitwiseAnd(Node* node) {
+  Bounds left = OperandType(node, 0);
+  Bounds right = OperandType(node, 1);
+  Type* upper = Type::Union(left.upper, right.upper, zone());
+  if (!upper->Is(Type::Signed32())) upper = Type::Signed32(zone());
+  Type* lower = Type::Intersect(Type::SignedSmall(zone()), upper, zone());
+  return Bounds(lower, upper);
+}
+
+
+Bounds Typer::Visitor::TypeJSBitwiseXor(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Signed32(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSShiftLeft(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Signed32(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSShiftRight(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Signed32(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSShiftRightLogical(Node* node) {
+  return Bounds(Type::UnsignedSmall(zone()), Type::Unsigned32(zone()));
+}
+
+
+// JS arithmetic operators.
+
+Bounds Typer::Visitor::TypeJSAdd(Node* node) {
+  Bounds left = OperandType(node, 0);
+  Bounds right = OperandType(node, 1);
+  Type* lower =
+      left.lower->Is(Type::None()) || right.lower->Is(Type::None()) ?
+          Type::None(zone()) :
+      left.lower->Is(Type::Number()) && right.lower->Is(Type::Number()) ?
+          Type::SignedSmall(zone()) :
+      left.lower->Is(Type::String()) || right.lower->Is(Type::String()) ?
+          Type::String(zone()) : Type::None(zone());
+  Type* upper =
+      left.upper->Is(Type::None()) && right.upper->Is(Type::None()) ?
+          Type::None(zone()) :
+      left.upper->Is(Type::Number()) && right.upper->Is(Type::Number()) ?
+          Type::Number(zone()) :
+      left.upper->Is(Type::String()) || right.upper->Is(Type::String()) ?
+          Type::String(zone()) : Type::NumberOrString(zone());
+  return Bounds(lower, upper);
+}
+
+
+Bounds Typer::Visitor::TypeJSSubtract(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSMultiply(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSDivide(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSModulus(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Number(zone()));
+}
+
+
+// JS unary operators.
+
+Bounds Typer::Visitor::TypeJSUnaryNot(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSTypeOf(Node* node) {
+  return Bounds(Type::InternalizedString(zone()));
+}
+
+
+// JS conversion operators.
+
+Bounds Typer::Visitor::TypeJSToBoolean(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSToNumber(Node* node) {
+  return Bounds(Type::SignedSmall(zone()), Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSToString(Node* node) {
+  return Bounds(Type::None(zone()), Type::String(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSToName(Node* node) {
+  return Bounds(Type::None(zone()), Type::Name(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSToObject(Node* node) {
+  return Bounds(Type::None(zone()), Type::Object(zone()));
+}
+
+
+// JS object operators.
+
+Bounds Typer::Visitor::TypeJSCreate(Node* node) {
+  return Bounds(Type::None(zone()), Type::Object(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSLoadProperty(Node* node) {
+  Bounds object = OperandType(node, 0);
+  Bounds name = OperandType(node, 1);
+  Bounds result = Bounds::Unbounded(zone());
+  // TODO(rossberg): Use range types and sized array types to filter undefined.
+  if (object.lower->IsArray() && name.lower->Is(Type::Integral32())) {
+    result.lower = Type::Union(
+        object.lower->AsArray()->Element(), Type::Undefined(zone()), zone());
+  }
+  if (object.upper->IsArray() && name.upper->Is(Type::Integral32())) {
+    result.upper = Type::Union(
+        object.upper->AsArray()->Element(), Type::Undefined(zone()), zone());
+  }
+  return result;
+}
+
+
+Bounds Typer::Visitor::TypeJSLoadNamed(Node* node) {
+  return Bounds::Unbounded(zone());
+}
+
+
+Bounds Typer::Visitor::TypeJSStoreProperty(Node* node) {
+  return Bounds(Type::None(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSStoreNamed(Node* node) {
+  return Bounds(Type::None(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSDeleteProperty(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSHasProperty(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSInstanceOf(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+// JS context operators.
+
+Bounds Typer::Visitor::TypeJSLoadContext(Node* node) {
+  Bounds outer = OperandType(node, 0);
+  ASSERT(outer.upper->Is(Type::Internal()));
+  ASSERT(outer.lower->Equals(outer.upper));
+  ContextAccess access = OpParameter<ContextAccess>(node);
+  Type* context_type = outer.upper;
+  MaybeHandle<Context> context;
+  if (context_type->IsConstant()) {
+    context = Handle<Context>::cast(context_type->AsConstant()->Value());
+  }
+  // Walk context chain (as far as known), mirroring dynamic lookup.
+  // Since contexts are mutable, the information is only useful as a lower
+  // bound.
+  // TODO(rossberg): Could use scope info to fix upper bounds for constant
+  // bindings if we know that this code is never shared.
+  for (int i = access.depth(); i > 0; --i) {
+    if (context_type->IsContext()) {
+      context_type = context_type->AsContext()->Outer();
+      if (context_type->IsConstant()) {
+        context = Handle<Context>::cast(context_type->AsConstant()->Value());
+      }
+    } else {
+      context = handle(context.ToHandleChecked()->previous(), isolate());
+    }
+  }
+  if (context.is_null()) {
+    return Bounds::Unbounded(zone());
+  } else {
+    Handle<Object> value =
+        handle(context.ToHandleChecked()->get(access.index()), isolate());
+    Type* lower = TypeConstant(value);
+    return Bounds(lower, Type::Any(zone()));
+  }
+}
+
+
+Bounds Typer::Visitor::TypeJSStoreContext(Node* node) {
+  return Bounds(Type::None(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCreateFunctionContext(Node* node) {
+  Type* outer = ContextType(node);
+  return Bounds(Type::Context(outer, zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCreateCatchContext(Node* node) {
+  Type* outer = ContextType(node);
+  return Bounds(Type::Context(outer, zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCreateWithContext(Node* node) {
+  Type* outer = ContextType(node);
+  return Bounds(Type::Context(outer, zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCreateBlockContext(Node* node) {
+  Type* outer = ContextType(node);
+  return Bounds(Type::Context(outer, zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCreateModuleContext(Node* node) {
+  // TODO(rossberg): this is probably incorrect
+  Type* outer = ContextType(node);
+  return Bounds(Type::Context(outer, zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCreateGlobalContext(Node* node) {
+  Type* outer = ContextType(node);
+  return Bounds(Type::Context(outer, zone()));
+}
+
+
+// JS other operators.
+
+Bounds Typer::Visitor::TypeJSYield(Node* node) {
+  return Bounds::Unbounded(zone());
+}
+
+
+Bounds Typer::Visitor::TypeJSCallConstruct(Node* node) {
+  return Bounds(Type::None(zone()), Type::Receiver(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeJSCallFunction(Node* node) {
+  Bounds fun = OperandType(node, 0);
+  Type* lower = fun.lower->IsFunction() ?
+      fun.lower->AsFunction()->Result() : Type::None(zone());
+  Type* upper = fun.upper->IsFunction() ?
+      fun.upper->AsFunction()->Result() : Type::Any(zone());
+  return Bounds(lower, upper);
+}
+
+
+Bounds Typer::Visitor::TypeJSCallRuntime(Node* node) {
+  return Bounds::Unbounded(zone());
+}
+
+
+Bounds Typer::Visitor::TypeJSDebugger(Node* node) {
+  return Bounds::Unbounded(zone());
+}
+
+
+// Simplified operators.
+
+Bounds Typer::Visitor::TypeBooleanNot(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberEqual(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberLessThan(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberLessThanOrEqual(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberAdd(Node* node) {
+  return Bounds(Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberSubtract(Node* node) {
+  return Bounds(Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberMultiply(Node* node) {
+  return Bounds(Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberDivide(Node* node) {
+  return Bounds(Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberModulus(Node* node) {
+  return Bounds(Type::Number(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeNumberToInt32(Node* node) {
+  Bounds arg = OperandType(node, 0);
+  Type* s32 = Type::Signed32(zone());
+  Type* lower = arg.lower->Is(s32) ? arg.lower : s32;
+  Type* upper = arg.upper->Is(s32) ? arg.upper : s32;
+  return Bounds(lower, upper);
+}
+
+
+Bounds Typer::Visitor::TypeNumberToUint32(Node* node) {
+  Bounds arg = OperandType(node, 0);
+  Type* u32 = Type::Unsigned32(zone());
+  Type* lower = arg.lower->Is(u32) ? arg.lower : u32;
+  Type* upper = arg.upper->Is(u32) ? arg.upper : u32;
+  return Bounds(lower, upper);
+}
+
+
+Bounds Typer::Visitor::TypeReferenceEqual(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeStringEqual(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeStringLessThan(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeStringLessThanOrEqual(Node* node) {
+  return Bounds(Type::Boolean(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeStringAdd(Node* node) {
+  return Bounds(Type::String(zone()));
+}
+
+
+Bounds Typer::Visitor::TypeChangeTaggedToInt32(Node* node) {
+  // TODO(titzer): type is type of input, representation is Word32.
+  return Bounds(Type::Integral32());
+}
+
+
+Bounds Typer::Visitor::TypeChangeTaggedToUint32(Node* node) {
+  return Bounds(Type::Integral32());  // TODO(titzer): add appropriate rep
+}
+
+
+Bounds Typer::Visitor::TypeChangeTaggedToFloat64(Node* node) {
+  // TODO(titzer): type is type of input, representation is Float64.
+  return Bounds(Type::Number());
+}
+
+
+Bounds Typer::Visitor::TypeChangeInt32ToTagged(Node* node) {
+  // TODO(titzer): type is type of input, representation is Tagged.
+  return Bounds(Type::Integral32());
+}
+
+
+Bounds Typer::Visitor::TypeChangeUint32ToTagged(Node* node) {
+  // TODO(titzer): type is type of input, representation is Tagged.
+  return Bounds(Type::Unsigned32());
+}
+
+
+Bounds Typer::Visitor::TypeChangeFloat64ToTagged(Node* node) {
+  // TODO(titzer): type is type of input, representation is Tagged.
+  return Bounds(Type::Number());
+}
+
+
+Bounds Typer::Visitor::TypeChangeBoolToBit(Node* node) {
+  // TODO(titzer): type is type of input, representation is Bit.
+  return Bounds(Type::Boolean());
+}
+
+
+Bounds Typer::Visitor::TypeChangeBitToBool(Node* node) {
+  // TODO(titzer): type is type of input, representation is Tagged.
+  return Bounds(Type::Boolean());
+}
+
+
+Bounds Typer::Visitor::TypeLoadField(Node* node) {
+  return Bounds(FieldAccessOf(node->op()).type);
+}
+
+
+Bounds Typer::Visitor::TypeLoadElement(Node* node) {
+  return Bounds(ElementAccessOf(node->op()).type);
+}
+
+
+Bounds Typer::Visitor::TypeStoreField(Node* node) {
+  return Bounds(Type::None());
+}
+
+
+Bounds Typer::Visitor::TypeStoreElement(Node* node) {
+  return Bounds(Type::None());
+}
+
+
+// Machine operators.
+
+// TODO(rossberg): implement
+#define DEFINE_METHOD(x) \
+  Bounds Typer::Visitor::Type##x(Node* node) { return Bounds(Type::None()); }
+MACHINE_OP_LIST(DEFINE_METHOD)
+#undef DEFINE_METHOD
+
+
+// Heap constants.
+
+Type* Typer::Visitor::TypeConstant(Handle<Object> value) {
+  if (value->IsJSFunction() && JSFunction::cast(*value)->IsBuiltin() &&
+      !context().is_null()) {
+    Handle<Context> native =
+        handle(context().ToHandleChecked()->native_context(), isolate());
+    if (*value == native->math_abs_fun()) {
+      return typer_->number_fun1_;  // TODO(rossberg): can't express overloading
+    } else if (*value == native->math_acos_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_asin_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_atan_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_atan2_fun()) {
+      return typer_->number_fun2_;
+    } else if (*value == native->math_ceil_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_cos_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_exp_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_floor_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_imul_fun()) {
+      return typer_->imul_fun_;
+    } else if (*value == native->math_log_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_pow_fun()) {
+      return typer_->number_fun2_;
+    } else if (*value == native->math_random_fun()) {
+      return typer_->number_fun0_;
+    } else if (*value == native->math_round_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_sin_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_sqrt_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->math_tan_fun()) {
+      return typer_->number_fun1_;
+    } else if (*value == native->array_buffer_fun()) {
+      return typer_->array_buffer_fun_;
+    } else if (*value == native->int8_array_fun()) {
+      return typer_->int8_array_fun_;
+    } else if (*value == native->int16_array_fun()) {
+      return typer_->int16_array_fun_;
+    } else if (*value == native->int32_array_fun()) {
+      return typer_->int32_array_fun_;
+    } else if (*value == native->uint8_array_fun()) {
+      return typer_->uint8_array_fun_;
+    } else if (*value == native->uint16_array_fun()) {
+      return typer_->uint16_array_fun_;
+    } else if (*value == native->uint32_array_fun()) {
+      return typer_->uint32_array_fun_;
+    } else if (*value == native->float32_array_fun()) {
+      return typer_->float32_array_fun_;
+    } else if (*value == native->float64_array_fun()) {
+      return typer_->float64_array_fun_;
+    }
+  }
+  return Type::Constant(value, zone());
+}
+
+
+namespace {
+
+class TyperDecorator : public GraphDecorator {
+ public:
+  explicit TyperDecorator(Typer* typer) : typer_(typer) {}
+  virtual void Decorate(Node* node) { typer_->Init(node); }
+
+ private:
+  Typer* typer_;
+};
+}
+
+
+void Typer::DecorateGraph(Graph* graph) {
+  graph->AddDecorator(new (zone()) TyperDecorator(this));
+}
+} } }  // namespace v8::internal::compiler