[turbofan] basic block profiler

src/compiler/basic-block-profiler.cc

+// Copyright 2014 the V8 project authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "src/compiler/basic-block-profiler.h"
+#include "src/compiler/common-operator.h"
+#include "src/compiler/graph.h"
+#include "src/compiler/machine-operator.h"
+#include "src/compiler/operator-properties-inl.h"
+#include "src/compiler/schedule.h"
+#include "src/global-handles.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+BasicBlockProfiler::Data::Data(int n_blocks, int* block_ids, uint32_t* counts,

[titzer, 2014/09/23 14:14:09]

Can you make the constructor allocate the block_ids and counts arrays? Thus the
ownership of those is entirely in this class.

+                               OStringStream* function_name,
+                               OStringStream* schedule_stream)
+    : n_blocks_(n_blocks),
+      block_ids_(block_ids),
+      counts_(counts),
+      function_name_(function_name),
+      schedule_stream_(schedule_stream),
+      code_stream_(NULL) {}
+
+
+BasicBlockProfiler::Data::~Data() {
+  delete[] block_ids_;
+  delete[] counts_;
+  delete function_name_;
+  delete schedule_stream_;
+  delete code_stream_;
+}
+
+
+void BasicBlockProfiler::Data::SetCode(Handle<Code> code) {
+  DCHECK_EQ(NULL, code_stream_);
+#if ENABLE_DISASSEMBLER
+// TODO(dcarney): reenable this once code printing is fixed.

[titzer, 2014/09/23 14:14:09]

What's broken with code printing?

+// code_stream_ = new OStringStream();
+// code->Disassemble(NULL, *code_stream_);
+#endif
+}
+
+
+void BasicBlockProfiler::Data::DumpProfilingData() {

[titzer, 2014/09/23 14:14:09]

Can you use OFStream here? It seems to be the way the winds are blowing.

+  const char* name = "unknown function";
+  if (function_name_ != NULL) {
+    name = function_name_->c_str();
+  }
+  fprintf(stderr, "schedule for %s:\n", name);
+  if (schedule_stream_ != NULL) {
+    fprintf(stderr, "%s\n", schedule_stream_->c_str());
+  }
+  fprintf(stderr, "block counts for %s:\n", name);
+  for (int i = 0; i < n_blocks_; ++i) {
+    fprintf(stderr, "block %d : %u\n", block_ids_[i], counts_[i]);
+  }
+  fprintf(stderr, "\n");
+  if (code_stream_ != NULL) {
+    fprintf(stderr, "%s\n", code_stream_->c_str());
+  }
+}
+
+
+void BasicBlockProfiler::Data::ResetCounts() {
+  for (int i = 0; i < n_blocks_; ++i) {
+    counts_[i] = 0;
+  }
+}
+
+
+BasicBlockProfiler::BasicBlockProfiler() {}
+
+
+BasicBlockProfiler::~BasicBlockProfiler() {
+  DumpProfilingData();
+  TearDown();
+}
+
+
+void BasicBlockProfiler::TearDown() {
+  for (DataList::iterator i = data_list_.begin(); i != data_list_.end(); ++i) {
+    delete (*i);
+  }
+  data_list_.clear();
+}
+
+
+void BasicBlockProfiler::ResetCounts() {
+  for (DataList::iterator i = data_list_.begin(); i != data_list_.end(); ++i) {
+    (*i)->ResetCounts();
+  }
+}
+
+
+void BasicBlockProfiler::DumpProfilingData() {
+  fprintf(stderr, "---- Start Profiling Data ----\n");
+  for (DataList::iterator i = data_list_.begin(); i != data_list_.end(); ++i) {
+    (*i)->DumpProfilingData();
+  }
+  fprintf(stderr, "---- End Profiling Data ----\n");
+}
+
+
+BasicBlockProfiler::Data* BasicBlockProfiler::Profile(CompilationInfo* info,
+                                                      Graph* graph,
+                                                      Schedule* schedule) {
+  OStringStream* schedule_stream = new OStringStream();
+  (*schedule_stream) << *schedule;
+  int n_blocks = schedule->RpoBlockCount();
+  // Create a backing store for the count data.
+  uint32_t* counts = new uint32_t[n_blocks];
+  for (int i = 0; i < n_blocks; ++i) {
+    counts[i] = 0;
+  }
+  // Add the increment instructions to the start of every block.
+  CommonOperatorBuilder common(graph->zone());
+  intptr_t base_address = reinterpret_cast<intptr_t>(counts);
+  // TODO(dcarney): need to mark code as non-serializable.
+  const Operator* base_op =
+      kPointerSize == 8 ? common.Int64Constant(base_address)
+                        : common.Int32Constant(static_cast<int>(base_address));
+  Node* base = graph->NewNode(base_op);
+  Node* one = graph->NewNode(common.Int32Constant(1));
+  MachineOperatorBuilder machine;
+  StoreRepresentation representation(kMachUint32, kNoWriteBarrier);
+  const Operator* load_op = machine.Load(kMachUint32);
+  const Operator* store_op = machine.Store(representation);
+  const Operator* add_op = machine.Int32Add();
+  BasicBlockVector* blocks = schedule->rpo_order();
+  int block_number = 0;
+  int* block_ids = new int[n_blocks];
+  for (BasicBlockVector::iterator it = blocks->begin(); it != blocks->end();
+       ++it, ++block_number) {
+    BasicBlock* block = (*it);
+    block_ids[block_number] = block->id();

[titzer, 2014/09/23 14:14:09]

Pull the body of this loop out into its own function. BTW you shouldn't have to
bother caching the load and store operators now. They are cached in the operator
builder now.

+    // Construct increment operation.
+    int index_value = sizeof(counts[0]) * block_number;
+    Node* index = graph->NewNode(common.Int32Constant(index_value));
+    // TODO(dcarney): wire effect and control deps for load and store.
+    Node* load = graph->NewNode(load_op, base, index);
+    Node* inc = graph->NewNode(add_op, load, one);
+    Node* store = graph->NewNode(store_op, base, index, inc);
+    // skip parameters and phis when inserting.
+    NodeVector& nodes = block->nodes_;
+    NodeVector::iterator j = nodes.begin();
+    for (; j != nodes.end(); ++j) {
+      const Operator* op = (*j)->op();
+      if (OperatorProperties::IsBasicBlockBegin(op)) continue;
+      switch (op->opcode()) {
+        case IrOpcode::kParameter:
+        case IrOpcode::kPhi:
+        case IrOpcode::kEffectPhi:
+          continue;
+      }
+      break;
+    }
+    static const int kArraySize = 6;
+    Node* to_insert[kArraySize] = {base, one, index, load, inc, store};
+    int insertion_start = block_number == 0 ? 0 : 2;
+    nodes.insert(j, &to_insert[insertion_start], &to_insert[kArraySize]);
+    for (int j = insertion_start; j < kArraySize; ++j) {
+      schedule->SetBlockForNode(block, to_insert[j]);
+    }
+  }
+  OStringStream* function_name = NULL;
+  if (!info->shared_info().is_null() &&
+      info->shared_info()->name()->IsString()) {
+    function_name = new OStringStream();
+    String::cast(info->shared_info()->name())->PrintUC16(*function_name);
+  }
+  Data* data =
+      new Data(n_blocks, block_ids, counts, function_name, schedule_stream);
+  data_list_.push_back(data);
+  return data;
+}
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8