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 #include "src/crankshaft/hydrogen-osr.h"
6
7 #include "src/crankshaft/hydrogen.h"
8
9 namespace v8 {
10 namespace internal {
11
12 // True iff. we are compiling for OSR and the statement is the entry.
HasOsrEntryAt(IterationStatement * statement)13 bool HOsrBuilder::HasOsrEntryAt(IterationStatement* statement) {
14 return statement->OsrEntryId() == builder_->current_info()->osr_ast_id();
15 }
16
17
BuildOsrLoopEntry(IterationStatement * statement)18 HBasicBlock* HOsrBuilder::BuildOsrLoopEntry(IterationStatement* statement) {
19 DCHECK(HasOsrEntryAt(statement));
20
21 Zone* zone = builder_->zone();
22 HGraph* graph = builder_->graph();
23
24 // only one OSR point per compile is allowed.
25 DCHECK(graph->osr() == NULL);
26
27 // remember this builder as the one OSR builder in the graph.
28 graph->set_osr(this);
29
30 HBasicBlock* non_osr_entry = graph->CreateBasicBlock();
31 osr_entry_ = graph->CreateBasicBlock();
32 HValue* true_value = graph->GetConstantTrue();
33 HBranch* test = builder_->New<HBranch>(true_value, ToBooleanICStub::Types(),
34 non_osr_entry, osr_entry_);
35 builder_->FinishCurrentBlock(test);
36
37 HBasicBlock* loop_predecessor = graph->CreateBasicBlock();
38 builder_->Goto(non_osr_entry, loop_predecessor);
39
40 builder_->set_current_block(osr_entry_);
41 osr_entry_->set_osr_entry();
42 BailoutId osr_entry_id = statement->OsrEntryId();
43
44 HEnvironment *environment = builder_->environment();
45 int first_expression_index = environment->first_expression_index();
46 int length = environment->length();
47 osr_values_ = new(zone) ZoneList<HUnknownOSRValue*>(length, zone);
48
49 for (int i = 0; i < first_expression_index; ++i) {
50 HUnknownOSRValue* osr_value
51 = builder_->Add<HUnknownOSRValue>(environment, i);
52 environment->Bind(i, osr_value);
53 osr_values_->Add(osr_value, zone);
54 }
55
56 if (first_expression_index != length) {
57 environment->Drop(length - first_expression_index);
58 for (int i = first_expression_index; i < length; ++i) {
59 HUnknownOSRValue* osr_value
60 = builder_->Add<HUnknownOSRValue>(environment, i);
61 environment->Push(osr_value);
62 osr_values_->Add(osr_value, zone);
63 }
64 }
65
66 unoptimized_frame_slots_ =
67 environment->local_count() + environment->push_count();
68
69 // Keep a copy of the old environment, since the OSR values need it
70 // to figure out where exactly they are located in the unoptimized frame.
71 environment = environment->Copy();
72 builder_->current_block()->UpdateEnvironment(environment);
73
74 builder_->Add<HSimulate>(osr_entry_id);
75 builder_->Add<HOsrEntry>(osr_entry_id);
76 HContext* context = builder_->Add<HContext>();
77 environment->BindContext(context);
78 builder_->Goto(loop_predecessor);
79 loop_predecessor->SetJoinId(statement->EntryId());
80 builder_->set_current_block(loop_predecessor);
81
82 // Create the final loop entry
83 osr_loop_entry_ = builder_->BuildLoopEntry();
84 return osr_loop_entry_;
85 }
86
87
FinishGraph()88 void HOsrBuilder::FinishGraph() {
89 // do nothing for now.
90 }
91
92
FinishOsrValues()93 void HOsrBuilder::FinishOsrValues() {
94 const ZoneList<HPhi*>* phis = osr_loop_entry_->phis();
95 for (int j = 0; j < phis->length(); j++) {
96 HPhi* phi = phis->at(j);
97 if (phi->HasMergedIndex()) {
98 osr_values_->at(phi->merged_index())->set_incoming_value(phi);
99 }
100 }
101 }
102
103 } // namespace internal
104 } // namespace v8
105