xref: /third_party/node/deps/v8/src/compiler/diamond.h (revision 1cb0ef41) 
1// Copyright 2013 the V8 project authors. All rights reserved.
2// Use of this source code is governed by a BSD-style license that can be
3// found in the LICENSE file.
4
5#ifndef V8_COMPILER_DIAMOND_H_
6#define V8_COMPILER_DIAMOND_H_
7
8#include "src/compiler/common-operator.h"
9#include "src/compiler/graph.h"
10#include "src/compiler/node.h"
11
12namespace v8 {
13namespace internal {
14namespace compiler {
15
16// A helper to make it easier to build diamond-shaped control patterns.
17struct Diamond {
18  Graph* graph;
19  CommonOperatorBuilder* common;
20  Node* branch;
21  Node* if_true;
22  Node* if_false;
23  Node* merge;
24
25  Diamond(Graph* g, CommonOperatorBuilder* b, Node* cond,
26          BranchHint hint = BranchHint::kNone) {
27    graph = g;
28    common = b;
29    branch = graph->NewNode(common->Branch(hint), cond, graph->start());
30    if_true = graph->NewNode(common->IfTrue(), branch);
31    if_false = graph->NewNode(common->IfFalse(), branch);
32    merge = graph->NewNode(common->Merge(2), if_true, if_false);
33  }
34
35  // Place {this} after {that} in control flow order.
36  void Chain(Diamond const& that) { branch->ReplaceInput(1, that.merge); }
37
38  // Place {this} after {that} in control flow order.
39  void Chain(Node* that) { branch->ReplaceInput(1, that); }
40
41  // Nest {this} into either the if_true or if_false branch of {that}.
42  void Nest(Diamond const& that, bool cond) {
43    if (cond) {
44      branch->ReplaceInput(1, that.if_true);
45      that.merge->ReplaceInput(0, merge);
46    } else {
47      branch->ReplaceInput(1, that.if_false);
48      that.merge->ReplaceInput(1, merge);
49    }
50  }
51
52  Node* Phi(MachineRepresentation rep, Node* tv, Node* fv) {
53    return graph->NewNode(common->Phi(rep, 2), tv, fv, merge);
54  }
55
56  Node* EffectPhi(Node* tv, Node* fv) {
57    return graph->NewNode(common->EffectPhi(2), tv, fv, merge);
58  }
59};
60
61}  // namespace compiler
62}  // namespace internal
63}  // namespace v8
64
65#endif  // V8_COMPILER_DIAMOND_H_
66