src/v8/src/compiler/basic-block-instrumentor.cc

   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/operator-properties-inl.h"
  13 #include "src/compiler/schedule.h"
  14
  15 namespace v8 {
  16 namespace internal {
  17 namespace compiler {
  18
  19 // Find the first place to insert new nodes in a block that's already been
  20 // scheduled that won't upset the register allocator.
  21 static NodeVector::iterator FindInsertionPoint(BasicBlock* block) {
  22   NodeVector::iterator i = block->begin();
  23   for (; i != block->end(); ++i) {
  24     const Operator* op = (*i)->op();
  25     if (OperatorProperties::IsBasicBlockBegin(op)) continue;
  26     switch (op->opcode()) {
  27       case IrOpcode::kParameter:
  28       case IrOpcode::kPhi:
  29       case IrOpcode::kEffectPhi:
  30         continue;
  31     }
  32     break;
  33   }
  34   return i;
  35 }
  36
  37
  38 // TODO(dcarney): need to mark code as non-serializable.
  39 static const Operator* PointerConstant(CommonOperatorBuilder* common,
  40                                        void* ptr) {
  41   return kPointerSize == 8
  42              ? common->Int64Constant(reinterpret_cast<intptr_t>(ptr))
  43              : common->Int32Constant(
  44                    static_cast<int32_t>(reinterpret_cast<intptr_t>(ptr)));
  45 }
  46
  47
  48 BasicBlockProfiler::Data* BasicBlockInstrumentor::Instrument(
  49     CompilationInfo* info, Graph* graph, Schedule* schedule) {
  50   // Skip the exit block in profiles, since the register allocator can't handle
  51   // it and entry into it means falling off the end of the function anyway.
  52   size_t n_blocks = static_cast<size_t>(schedule->RpoBlockCount()) - 1;
  53   BasicBlockProfiler::Data* data =
  54       info->isolate()->GetOrCreateBasicBlockProfiler()->NewData(n_blocks);
  55   // Set the function name.
  56   if (!info->shared_info().is_null() &&
  57       info->shared_info()->name()->IsString()) {
  58     std::ostringstream os;
  59     String::cast(info->shared_info()->name())->PrintUC16(os);
  60     data->SetFunctionName(&os);
  61   }
  62   // Capture the schedule string before instrumentation.
  63   {
  64     std::ostringstream os;
  65     os << *schedule;
  66     data->SetSchedule(&os);
  67   }
  68   // Add the increment instructions to the start of every block.
  69   CommonOperatorBuilder common(graph->zone());
  70   Node* zero = graph->NewNode(common.Int32Constant(0));
  71   Node* one = graph->NewNode(common.Int32Constant(1));
  72   MachineOperatorBuilder machine;
  73   BasicBlockVector* blocks = schedule->rpo_order();
  74   size_t block_number = 0;
  75   for (BasicBlockVector::iterator it = blocks->begin(); block_number < n_blocks;
  76        ++it, ++block_number) {
  77     BasicBlock* block = (*it);
  78     data->SetBlockId(block_number, block->id().ToSize());
  79     // TODO(dcarney): wire effect and control deps for load and store.
  80     // Construct increment operation.
  81     Node* base = graph->NewNode(
  82         PointerConstant(&common, data->GetCounterAddress(block_number)));
  83     Node* load = graph->NewNode(machine.Load(kMachUint32), base, zero);
  84     Node* inc = graph->NewNode(machine.Int32Add(), load, one);
  85     Node* store = graph->NewNode(
  86         machine.Store(StoreRepresentation(kMachUint32, kNoWriteBarrier)), base,
  87         zero, inc);
  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