deps/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.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.
  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.
  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
  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(kMachUint32), base, zero);
  85     Node* inc = graph->NewNode(machine.Int32Add(), load, one);
  86     Node* store = graph->NewNode(
  87         machine.Store(StoreRepresentation(kMachUint32, kNoWriteBarrier)), base,
  88         zero, inc);
  89     // Insert the new nodes.
  90     static const int kArraySize = 6;
  91     Node* to_insert[kArraySize] = {zero, one, base, load, inc, store};
  92     int insertion_start = block_number == 0 ? 0 : 2;
  93     NodeVector::iterator insertion_point = FindInsertionPoint(block);
  94     block->InsertNodes(insertion_point, &to_insert[insertion_start],
  95                        &to_insert[kArraySize]);
  96     // Tell the scheduler about the new nodes.
  97     for (int i = insertion_start; i < kArraySize; ++i) {
  98       schedule->SetBlockForNode(block, to_insert[i]);
  99     }
 100   }
 101   return data;
 102 }
 103
 104 }  // namespace compiler
 105 }  // namespace internal
 106 }  // namespace v8