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.h"
10 #include "src/compiler/common-operator.h"
11 #include "src/compiler/graph.h"
12 #include "src/compiler/machine-operator.h"
13 #include "src/compiler/node.h"
14 #include "src/compiler/operator-properties.h"
15 #include "src/compiler/schedule.h"
16
17 namespace v8 {
18 namespace internal {
19 namespace compiler {
20
21 // Find the first place to insert new nodes in a block that's already been
22 // scheduled that won't upset the register allocator.
FindInsertionPoint(BasicBlock * block)23 static NodeVector::iterator FindInsertionPoint(BasicBlock* block) {
24 NodeVector::iterator i = block->begin();
25 for (; i != block->end(); ++i) {
26 const Operator* op = (*i)->op();
27 if (OperatorProperties::IsBasicBlockBegin(op)) continue;
28 switch (op->opcode()) {
29 case IrOpcode::kParameter:
30 case IrOpcode::kPhi:
31 case IrOpcode::kEffectPhi:
32 continue;
33 }
34 break;
35 }
36 return i;
37 }
38
39
40 // TODO(dcarney): need to mark code as non-serializable.
PointerConstant(CommonOperatorBuilder * common,void * ptr)41 static const Operator* PointerConstant(CommonOperatorBuilder* common,
42 void* ptr) {
43 return kPointerSize == 8
44 ? common->Int64Constant(reinterpret_cast<intptr_t>(ptr))
45 : common->Int32Constant(
46 static_cast<int32_t>(reinterpret_cast<intptr_t>(ptr)));
47 }
48
49
Instrument(CompilationInfo * info,Graph * graph,Schedule * schedule)50 BasicBlockProfiler::Data* BasicBlockInstrumentor::Instrument(
51 CompilationInfo* info, Graph* graph, Schedule* schedule) {
52 // Skip the exit block in profiles, since the register allocator can't handle
53 // it and entry into it means falling off the end of the function anyway.
54 size_t n_blocks = static_cast<size_t>(schedule->RpoBlockCount()) - 1;
55 BasicBlockProfiler::Data* data =
56 info->isolate()->GetOrCreateBasicBlockProfiler()->NewData(n_blocks);
57 // Set the function name.
58 if (info->has_shared_info() && info->shared_info()->name()->IsString()) {
59 std::ostringstream os;
60 String::cast(info->shared_info()->name())->PrintUC16(os);
61 data->SetFunctionName(&os);
62 }
63 // Capture the schedule string before instrumentation.
64 {
65 std::ostringstream os;
66 os << *schedule;
67 data->SetSchedule(&os);
68 }
69 // Add the increment instructions to the start of every block.
70 CommonOperatorBuilder common(graph->zone());
71 Node* zero = graph->NewNode(common.Int32Constant(0));
72 Node* one = graph->NewNode(common.Int32Constant(1));
73 MachineOperatorBuilder machine(graph->zone());
74 BasicBlockVector* blocks = schedule->rpo_order();
75 size_t block_number = 0;
76 for (BasicBlockVector::iterator it = blocks->begin(); block_number < n_blocks;
77 ++it, ++block_number) {
78 BasicBlock* block = (*it);
79 data->SetBlockId(block_number, block->id().ToSize());
80 // TODO(dcarney): wire effect and control deps for load and store.
81 // Construct increment operation.
82 Node* base = graph->NewNode(
83 PointerConstant(&common, data->GetCounterAddress(block_number)));
84 Node* load = graph->NewNode(machine.Load(MachineType::Uint32()), base, zero,
85 graph->start(), graph->start());
86 Node* inc = graph->NewNode(machine.Int32Add(), load, one);
87 Node* store =
88 graph->NewNode(machine.Store(StoreRepresentation(
89 MachineRepresentation::kWord32, kNoWriteBarrier)),
90 base, zero, inc, graph->start(), graph->start());
91 // Insert the new nodes.
92 static const int kArraySize = 6;
93 Node* to_insert[kArraySize] = {zero, one, base, load, inc, store};
94 int insertion_start = block_number == 0 ? 0 : 2;
95 NodeVector::iterator insertion_point = FindInsertionPoint(block);
96 block->InsertNodes(insertion_point, &to_insert[insertion_start],
97 &to_insert[kArraySize]);
98 // Tell the scheduler about the new nodes.
99 for (int i = insertion_start; i < kArraySize; ++i) {
100 schedule->SetBlockForNode(block, to_insert[i]);
101 }
102 }
103 return data;
104 }
105
106 } // namespace compiler
107 } // namespace internal
108 } // namespace v8
109