blob: df4eac97a93ba69daf1693935d0f4d8700c0a40d [file] [log] [blame]
// Copyright 2015 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/node.h"
namespace v8 {
namespace internal {
namespace compiler {
// Forward declarations.
class Graph;
// Base class for templatized NodeMarkers.
class NodeMarkerBase {
NodeMarkerBase(Graph* graph, uint32_t num_states);
NodeMarkerBase(const NodeMarkerBase&) = delete;
NodeMarkerBase& operator=(const NodeMarkerBase&) = delete;
V8_INLINE Mark Get(const Node* node) {
Mark mark = node->mark();
if (mark < mark_min_) {
return 0;
DCHECK_LT(mark, mark_max_);
return mark - mark_min_;
V8_INLINE void Set(Node* node, Mark mark) {
DCHECK_LT(mark, mark_max_ - mark_min_);
DCHECK_LT(node->mark(), mark_max_);
node->set_mark(mark + mark_min_);
Mark const mark_min_;
Mark const mark_max_;
// A NodeMarker assigns a local "state" to every node of a graph in constant
// memory. Only one NodeMarker per graph is valid at a given time, that is,
// after you create a NodeMarker you should no longer use NodeMarkers that
// were created earlier. Internally, the local state is stored in the Node
// structure.
// When you initialize a NodeMarker, all the local states are conceptually
// set to State(0) in constant time.
// In its current implementation, in debug mode NodeMarker will try to
// (efficiently) detect invalid use of an older NodeMarker. Namely, if you set a
// node with a NodeMarker, and then get or set that node with an older
// NodeMarker you will get a crash.
// GraphReducer uses a NodeMarker, so individual Reducers cannot use a
// NodeMarker.
template <typename State>
class NodeMarker : public NodeMarkerBase {
V8_INLINE NodeMarker(Graph* graph, uint32_t num_states)
: NodeMarkerBase(graph, num_states) {}
V8_INLINE State Get(const Node* node) {
return static_cast<State>(NodeMarkerBase::Get(node));
V8_INLINE void Set(Node* node, State state) {
NodeMarkerBase::Set(node, static_cast<Mark>(state));
} // namespace compiler
} // namespace internal
} // namespace v8