[turbofan] Deopt support for escape analysis

src/compiler/frame-states.cc

Index: src/compiler/frame-states.cc
diff --git a/src/compiler/frame-states.cc b/src/compiler/frame-states.cc
index b9ea010cccdb38e7caf98b337879db996d497e36..fb3740d06256b551fc383ca8df3dd6e4745fe204 100644
--- a/src/compiler/frame-states.cc
+++ b/src/compiler/frame-states.cc
@@ -2,8 +2,13 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#include "src/base/functional.h"
 #include "src/compiler/frame-states.h"
+
+#include "src/base/functional.h"
+#include "src/compiler/code-generator.h"
+#include "src/compiler/instruction-selector-impl.h"
+#include "src/compiler/node.h"
+#include "src/compiler/state-values-utils.h"
 #include "src/handles-inl.h"
 
 namespace v8 {
@@ -72,6 +77,225 @@ std::ostream& operator<<(std::ostream& os, FrameStateInfo const& info) {
   return os;
 }
 
+
+FrameStateDescriptor::FrameStateDescriptor(
+    Zone* zone, FrameStateType type, BailoutId bailout_id,
+    OutputFrameStateCombine state_combine, size_t parameters_count,
+    size_t locals_count, size_t stack_count,
+    MaybeHandle<SharedFunctionInfo> shared_info,
+    FrameStateDescriptor* outer_state)
+    : type_(type),
+      bailout_id_(bailout_id),
+      frame_state_combine_(state_combine),
+      parameters_count_(parameters_count),
+      locals_count_(locals_count),
+      stack_count_(stack_count),
+      values_(zone, kMachAnyTagged),
+      shared_info_(shared_info),
+      outer_state_(outer_state) {}
+
+
+size_t FrameStateDescriptor::GetSize(OutputFrameStateCombine combine) const {
+  size_t size = 1 + parameters_count() + locals_count() + stack_count() +
+                (HasContext() ? 1 : 0);
+  switch (combine.kind()) {
+    case OutputFrameStateCombine::kPushOutput:
+      size += combine.GetPushCount();
+      break;
+    case OutputFrameStateCombine::kPokeAt:
+      break;
+  }
+  return size;
+}
+
+
+size_t FrameStateDescriptor::GetTotalSize() const {
+  size_t total_size = 0;
+  for (const FrameStateDescriptor* iter = this; iter != NULL;
+       iter = iter->outer_state_) {
+    total_size += iter->GetSize();
+  }
+  return total_size;
+}
+
+
+size_t FrameStateDescriptor::GetFrameCount() const {
+  size_t count = 0;
+  for (const FrameStateDescriptor* iter = this; iter != NULL;
+       iter = iter->outer_state_) {
+    ++count;
+  }
+  return count;
+}
+
+
+size_t FrameStateDescriptor::GetJSFrameCount() const {
+  size_t count = 0;
+  for (const FrameStateDescriptor* iter = this; iter != NULL;
+       iter = iter->outer_state_) {
+    if (iter->type_ == FrameStateType::kJavaScriptFunction) {
+      ++count;
+    }
+  }
+  return count;
+}
+
+
+size_t StateValueDescriptor::AddOperand(InstructionOperandVector* inputs,

[Jarin, 2015/12/02 12:24:34]

Could we have a comment explaining what the return values are? (I tlooks like
the number of added entries, only used for debug checks.)

[sigurds, 2015/12/02 16:35:13]

Done.

+                                        OperandGenerator* g,
+                                        StateObjectCache* cache, Node* input,
+                                        MachineType type,
+                                        FrameStateInputKind kind, Zone* zone) {
+  switch (input->opcode()) {
+    case IrOpcode::kObjectState: {
+      size_t id = cache->GetObjectId(input);
+      if (id == StateObjectCache::kNotCached) {
+        size_t entries = 0;
+        id = cache->InsertObject(input);
+        fields_.push_back(StateValueDescriptor(zone, kMachAnyTagged, id));
+        StateValueDescriptor& desc = fields_.back();
+        for (Edge edge : input->input_edges()) {
+          entries += desc.AddOperand(inputs, g, cache, edge.to(),
+                                     kMachAnyTagged, kind, zone);
+        }
+        return entries;
+      } else {
+        fields_.push_back(StateValueDescriptor(zone, kMachAnyTagged, id));

[Jarin, 2015/12/02 12:24:34]

I think it would be nice to somehow signal in the code that this is a duplicate
object (e.g.., have a StateValueDescriptor::Duplicate static method or the
enum).

[sigurds, 2015/12/02 16:35:13]

Great idea, thanks.

+        return 0;
+      }
+    } break;

[Jarin, 2015/12/02 12:24:34]

The "break;" should go before the brace.

[sigurds, 2015/12/02 16:35:12]

Done.

+    default:
+      inputs->push_back(g->UseForDeopt(input, kind));
+      fields_.push_back(StateValueDescriptor(zone, type));
+      return 1;
+  }
+}
+
+
+size_t FrameStateDescriptor::AddInputs(Node* state, OperandGenerator* g,
+                                       StateObjectCache* cache,
+                                       InstructionOperandVector* inputs,
+                                       FrameStateInputKind kind, Zone* zone) {
+  DCHECK_EQ(IrOpcode::kFrameState, state->op()->opcode());
+
+  size_t entries = 0;
+  size_t initial_size = inputs->size();
+
+  if (outer_state()) {
+    entries +=
+        outer_state()->AddInputs(state->InputAt(kFrameStateOuterStateInput), g,
+                                 cache, inputs, kind, zone);
+  }
+
+  Node* parameters = state->InputAt(kFrameStateParametersInput);
+  Node* locals = state->InputAt(kFrameStateLocalsInput);
+  Node* stack = state->InputAt(kFrameStateStackInput);
+  Node* context = state->InputAt(kFrameStateContextInput);
+  Node* function = state->InputAt(kFrameStateFunctionInput);
+
+  DCHECK_EQ(parameters_count(), StateValuesAccess(parameters).size());
+  DCHECK_EQ(locals_count(), StateValuesAccess(locals).size());
+  DCHECK_EQ(stack_count(), StateValuesAccess(stack).size());
+
+  StateValueDescriptor* desc = GetStateValueDescriptor();
+  entries +=
+      desc->AddOperand(inputs, g, cache, function, kMachAnyTagged, kind, zone);
+  for (StateValuesAccess::TypedNode input_node :
+       StateValuesAccess(parameters)) {
+    entries += desc->AddOperand(inputs, g, cache, input_node.node,
+                                input_node.type, kind, zone);
+  }
+  if (HasContext()) {
+    entries +=
+        desc->AddOperand(inputs, g, cache, context, kMachAnyTagged, kind, zone);
+  }
+  for (StateValuesAccess::TypedNode input_node : StateValuesAccess(locals)) {
+    entries += desc->AddOperand(inputs, g, cache, input_node.node,
+                                input_node.type, kind, zone);
+  }
+  for (StateValuesAccess::TypedNode input_node : StateValuesAccess(stack)) {
+    entries += desc->AddOperand(inputs, g, cache, input_node.node,
+                                input_node.type, kind, zone);
+  }
+  DCHECK_EQ(initial_size + entries, inputs->size());
+  return entries;
+}
+
+
+size_t StateValueDescriptor::Translate(CodeGenerator* gen,

[Jarin, 2015/12/02 12:24:34]

Description of return value, please. (Number of consumed operands.)

[sigurds, 2015/12/02 16:35:13]

Done.

+                                       Translation* translation,
+                                       Instruction* instr,
+                                       size_t frame_state_offset) {
+  if (IsRecursive()) {
+    size_t entries = 0;
+    translation->BeginCapturedObject(static_cast<int>(size()));
+    for (size_t index = 0; index < fields_.size(); index++) {
+      entries += fields_[index].Translate(gen, translation, instr,
+                                          frame_state_offset + index);
+    }
+    return entries;
+  } else if (IsDuplicate()) {
+    translation->DuplicateObject(static_cast<int>(id_));
+    return 0;
+  } else {
+    gen->AddTranslationForOperand(translation, instr,
+                                  instr->InputAt(frame_state_offset), type_);
+    return 1;
+  }
+}
+
+
+size_t StateValueDescriptor::TranslateOperand(size_t index, CodeGenerator* gen,
+                                              Translation* translation,
+                                              Instruction* instr,
+                                              size_t frame_state_offset) {
+  return fields_[index].Translate(gen, translation, instr,
+                                  frame_state_offset + index);
+}
+
+
+void FrameStateDescriptor::TranslateOperands(CodeGenerator* gen,
+                                             Instruction* instr,
+                                             size_t frame_state_offset,
+                                             OutputFrameStateCombine combine,
+                                             Translation* translation) {
+  for (size_t index = 0; index < GetSize(combine); index++) {
+    switch (combine.kind()) {
+      case OutputFrameStateCombine::kPushOutput: {
+        DCHECK(combine.GetPushCount() <= instr->OutputCount());
+        size_t size_without_output = GetSize(OutputFrameStateCombine::Ignore());
+        // If the index is past the existing stack items in values_.
+        if (index >= size_without_output) {
+          // Materialize the result of the call instruction in this slot.
+          gen->AddTranslationForOperand(
+              translation, instr, instr->OutputAt(index - size_without_output),
+              kMachAnyTagged);
+          continue;
+        }
+        break;
+      }
+      case OutputFrameStateCombine::kPokeAt:
+        // The result of the call should be placed at position
+        // [index_from_top] in the stack (overwriting whatever was
+        // previously there).
+        size_t index_from_top =
+            GetSize(combine) - 1 - combine.GetOffsetToPokeAt();
+        if (index >= index_from_top &&
+            index < index_from_top + instr->OutputCount()) {
+          gen->AddTranslationForOperand(translation, instr,
+                                        instr->OutputAt(index - index_from_top),
+                                        kMachAnyTagged);
+          continue;
+        }
+        break;
+    }
+    // Add the additional fields we read during materialization.
+    frame_state_offset += values_.TranslateOperand(index, gen, translation,
+                                                   instr, frame_state_offset) -
+                          1;
+  }
+}
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8