1 // Copyright 2014 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/compiler/basic-block-instrumentor.h"
6
7 #include <sstream>
8
9 #include "src/compiler/common-operator.h"
10 #include "src/compiler/graph.h"
11 #include "src/compiler/machine-operator.h"
12 #include "src/compiler/node.h"
13 #include "src/compiler/operator-properties.h"
14 #include "src/compiler/schedule.h"
15 #include "src/objects-inl.h"
16 #include "src/optimized-compilation-info.h"
17
18 namespace v8 {
19 namespace internal {
20 namespace compiler {
21
22 // Find the first place to insert new nodes in a block that's already been
23 // scheduled that won't upset the register allocator.
FindInsertionPoint(BasicBlock * block)24 static NodeVector::iterator FindInsertionPoint(BasicBlock* block) {
25 NodeVector::iterator i = block->begin();
26 for (; i != block->end(); ++i) {
27 const Operator* op = (*i)->op();
28 if (OperatorProperties::IsBasicBlockBegin(op)) continue;
29 switch (op->opcode()) {
30 case IrOpcode::kParameter:
31 case IrOpcode::kPhi:
32 case IrOpcode::kEffectPhi:
33 continue;
34 }
35 break;
36 }
37 return i;
38 }
39
40
41 // TODO(dcarney): need to mark code as non-serializable.
PointerConstant(CommonOperatorBuilder * common,intptr_t ptr)42 static const Operator* PointerConstant(CommonOperatorBuilder* common,
43 intptr_t ptr) {
44 return kPointerSize == 8 ? common->Int64Constant(ptr)
45 : common->Int32Constant(static_cast<int32_t>(ptr));
46 }
47
Instrument(OptimizedCompilationInfo * info,Graph * graph,Schedule * schedule,Isolate * isolate)48 BasicBlockProfiler::Data* BasicBlockInstrumentor::Instrument(
49 OptimizedCompilationInfo* info, Graph* graph, Schedule* schedule,
50 Isolate* isolate) {
51 // Basic block profiling disables concurrent compilation, so handle deref is
52 // fine.
53 AllowHandleDereference allow_handle_dereference;
54 // Skip the exit block in profiles, since the register allocator can't handle
55 // it and entry into it means falling off the end of the function anyway.
56 size_t n_blocks = static_cast<size_t>(schedule->RpoBlockCount()) - 1;
57 BasicBlockProfiler::Data* data = BasicBlockProfiler::Get()->NewData(n_blocks);
58 // Set the function name.
59 data->SetFunctionName(info->GetDebugName());
60 // Capture the schedule string before instrumentation.
61 {
62 std::ostringstream os;
63 os << *schedule;
64 data->SetSchedule(&os);
65 }
66 // Add the increment instructions to the start of every block.
67 CommonOperatorBuilder common(graph->zone());
68 Node* zero = graph->NewNode(common.Int32Constant(0));
69 Node* one = graph->NewNode(common.Int32Constant(1));
70 MachineOperatorBuilder machine(graph->zone());
71 BasicBlockVector* blocks = schedule->rpo_order();
72 size_t block_number = 0;
73 for (BasicBlockVector::iterator it = blocks->begin(); block_number < n_blocks;
74 ++it, ++block_number) {
75 BasicBlock* block = (*it);
76 data->SetBlockRpoNumber(block_number, block->rpo_number());
77 // TODO(dcarney): wire effect and control deps for load and store.
78 // Construct increment operation.
79 Node* base = graph->NewNode(
80 PointerConstant(&common, data->GetCounterAddress(block_number)));
81 Node* load = graph->NewNode(machine.Load(MachineType::Uint32()), base, zero,
82 graph->start(), graph->start());
83 Node* inc = graph->NewNode(machine.Int32Add(), load, one);
84 Node* store =
85 graph->NewNode(machine.Store(StoreRepresentation(
86 MachineRepresentation::kWord32, kNoWriteBarrier)),
87 base, zero, inc, graph->start(), graph->start());
88 // Insert the new nodes.
89 static const int kArraySize = 6;
90 Node* to_insert[kArraySize] = {zero, one, base, load, inc, store};
91 int insertion_start = block_number == 0 ? 0 : 2;
92 NodeVector::iterator insertion_point = FindInsertionPoint(block);
93 block->InsertNodes(insertion_point, &to_insert[insertion_start],
94 &to_insert[kArraySize]);
95 // Tell the scheduler about the new nodes.
96 for (int i = insertion_start; i < kArraySize; ++i) {
97 schedule->SetBlockForNode(block, to_insert[i]);
98 }
99 }
100 return data;
101 }
102
103 } // namespace compiler
104 } // namespace internal
105 } // namespace v8
106