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 12 namespace v8 { 13 namespace internal { 14 namespace compiler { 15 16 // A helper to make it easier to build diamond-shaped control patterns. 17 struct 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& 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& that, bool if_true) { 43 if (if_true) { 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 57 } // namespace compiler 58 } // namespace internal 59 } // namespace v8 60 61 #endif // V8_COMPILER_DIAMOND_H_ 62