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1 // Copyright 2019 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/codegen/pending-optimization-table.h"
6 
7 #include "src/base/flags.h"
8 #include "src/execution/isolate-inl.h"
9 #include "src/heap/heap-inl.h"
10 #include "src/objects/hash-table.h"
11 #include "src/objects/js-objects.h"
12 
13 namespace v8 {
14 namespace internal {
15 
16 enum class FunctionStatus : int {
17   kPrepareForOptimize = 1 << 0,
18   kMarkForOptimize = 1 << 1,
19   kAllowHeuristicOptimization = 1 << 2,
20 };
21 
22 using FunctionStatusFlags = base::Flags<FunctionStatus>;
23 
PreparedForOptimization(Isolate * isolate,Handle<JSFunction> function,bool allow_heuristic_optimization)24 void PendingOptimizationTable::PreparedForOptimization(
25     Isolate* isolate, Handle<JSFunction> function,
26     bool allow_heuristic_optimization) {
27   DCHECK(FLAG_testing_d8_test_runner);
28 
29   FunctionStatusFlags status = FunctionStatus::kPrepareForOptimize;
30   if (allow_heuristic_optimization) {
31     status |= FunctionStatus::kAllowHeuristicOptimization;
32   }
33 
34   Handle<ObjectHashTable> table =
35       isolate->heap()->pending_optimize_for_test_bytecode().IsUndefined()
36           ? ObjectHashTable::New(isolate, 1)
37           : handle(ObjectHashTable::cast(
38                        isolate->heap()->pending_optimize_for_test_bytecode()),
39                    isolate);
40   Handle<Tuple2> tuple = isolate->factory()->NewTuple2(
41       handle(function->shared().GetBytecodeArray(), isolate),
42       handle(Smi::FromInt(status), isolate), AllocationType::kYoung);
43   table =
44       ObjectHashTable::Put(table, handle(function->shared(), isolate), tuple);
45   isolate->heap()->SetPendingOptimizeForTestBytecode(*table);
46 }
47 
IsHeuristicOptimizationAllowed(Isolate * isolate,JSFunction function)48 bool PendingOptimizationTable::IsHeuristicOptimizationAllowed(
49     Isolate* isolate, JSFunction function) {
50   DCHECK(FLAG_testing_d8_test_runner);
51 
52   Handle<Object> table =
53       handle(isolate->heap()->pending_optimize_for_test_bytecode(), isolate);
54   Handle<Object> entry =
55       table->IsUndefined()
56           ? handle(ReadOnlyRoots(isolate).the_hole_value(), isolate)
57           : handle(Handle<ObjectHashTable>::cast(table)->Lookup(
58                        handle(function.shared(), isolate)),
59                    isolate);
60   if (entry->IsTheHole()) {
61     return true;
62   }
63   DCHECK(entry->IsTuple2());
64   DCHECK(Handle<Tuple2>::cast(entry)->value2().IsSmi());
65   FunctionStatusFlags status(Smi::ToInt(Handle<Tuple2>::cast(entry)->value2()));
66   return status & FunctionStatus::kAllowHeuristicOptimization;
67 }
68 
MarkedForOptimization(Isolate * isolate,Handle<JSFunction> function)69 void PendingOptimizationTable::MarkedForOptimization(
70     Isolate* isolate, Handle<JSFunction> function) {
71   DCHECK(FLAG_testing_d8_test_runner);
72 
73   Handle<Object> table =
74       handle(isolate->heap()->pending_optimize_for_test_bytecode(), isolate);
75   Handle<Object> entry =
76       table->IsUndefined()
77           ? handle(ReadOnlyRoots(isolate).the_hole_value(), isolate)
78           : handle(Handle<ObjectHashTable>::cast(table)->Lookup(
79                        handle(function->shared(), isolate)),
80                    isolate);
81   if (entry->IsTheHole()) {
82     PrintF("Error: Function ");
83     function->ShortPrint();
84     PrintF(
85         " should be prepared for optimization with "
86         "%%PrepareFunctionForOptimization before  "
87         "%%OptimizeFunctionOnNextCall / %%OptimizeOSR ");
88     UNREACHABLE();
89   }
90 
91   DCHECK(entry->IsTuple2());
92   DCHECK(Handle<Tuple2>::cast(entry)->value2().IsSmi());
93   FunctionStatusFlags status(Smi::ToInt(Handle<Tuple2>::cast(entry)->value2()));
94   status = status.without(FunctionStatus::kPrepareForOptimize) |
95            FunctionStatus::kMarkForOptimize;
96   Handle<Tuple2>::cast(entry)->set_value2(Smi::FromInt(status));
97   table = ObjectHashTable::Put(Handle<ObjectHashTable>::cast(table),
98                                handle(function->shared(), isolate), entry);
99   isolate->heap()->SetPendingOptimizeForTestBytecode(*table);
100 }
101 
FunctionWasOptimized(Isolate * isolate,Handle<JSFunction> function)102 void PendingOptimizationTable::FunctionWasOptimized(
103     Isolate* isolate, Handle<JSFunction> function) {
104   DCHECK(FLAG_testing_d8_test_runner);
105 
106   if (isolate->heap()->pending_optimize_for_test_bytecode().IsUndefined()) {
107     return;
108   }
109 
110   Handle<ObjectHashTable> table =
111       handle(ObjectHashTable::cast(
112                  isolate->heap()->pending_optimize_for_test_bytecode()),
113              isolate);
114   Handle<Object> value(table->Lookup(handle(function->shared(), isolate)),
115                        isolate);
116   // Remove only if we have already seen %OptimizeFunctionOnNextCall. If it is
117   // optimized for other reasons, still keep holding the bytecode since we may
118   // optimize it later.
119   if (!value->IsTheHole() &&
120       Smi::cast(Handle<Tuple2>::cast(value)->value2()).value() ==
121           static_cast<int>(FunctionStatus::kMarkForOptimize)) {
122     bool was_present;
123     table = table->Remove(isolate, table, handle(function->shared(), isolate),
124                           &was_present);
125     DCHECK(was_present);
126     isolate->heap()->SetPendingOptimizeForTestBytecode(*table);
127   }
128 }
129 
130 }  // namespace internal
131 }  // namespace v8
132