[turbofan] Deopt support for escape analysis

src/compiler/frame-states.h

 // Copyright 2015 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.
 
 #ifndef V8_COMPILER_FRAME_STATES_H_
 #define V8_COMPILER_FRAME_STATES_H_
 
+#include "src/compiler/machine-type.h"
 #include "src/handles.h"
 #include "src/utils.h"
+#include "src/zone-containers.h"
 
 namespace v8 {
 namespace internal {
 
 // Forward declarations.
 class SharedFunctionInfo;
+class Translation;
 
 namespace compiler {
 
+// Forward declarations.
+class OperandGenerator;
+class CodeGenerator;
+class Node;
+class Instruction;
+class InstructionOperand;
+typedef ZoneVector<InstructionOperand> InstructionOperandVector;
+
 // Flag that describes how to combine the current environment with
 // the output of a node to obtain a framestate for lazy bailout.
 class OutputFrameStateCombine {
  public:
   enum Kind {
     kPushOutput,  // Push the output on the expression stack.
     kPokeAt       // Poke at the given environment location,
                   // counting from the top of the stack.
   };
 
@@ skipping 128 matching lines @@
 std::ostream& operator<<(std::ostream&, FrameStateInfo const&);
 
 static const int kFrameStateParametersInput = 0;
 static const int kFrameStateLocalsInput = 1;
 static const int kFrameStateStackInput = 2;
 static const int kFrameStateContextInput = 3;
 static const int kFrameStateFunctionInput = 4;
 static const int kFrameStateOuterStateInput = 5;
 static const int kFrameStateInputCount = kFrameStateOuterStateInput + 1;
 
+
+enum class FrameStateInputKind { kAny, kStackSlot };
+
+
+class StateObjectCache {
+ public:
+  explicit StateObjectCache(Zone* zone) : objects_(zone) {}
+  static const size_t kNotCached = std::numeric_limits<std::size_t>::max();
+
+  size_t GetObjectId(Node* node) {
+    for (size_t i = 0; i < objects_.size(); ++i) {
+      if (objects_[i] == node) {
+        return i;
+      }
+    }
+    return kNotCached;
+  }
+
+  size_t InsertObject(Node* node) {
+    size_t id = objects_.size();
+    objects_.push_back(node);
+    return id;
+  }
+
+ private:
+  ZoneVector<Node*> objects_;
+};
+
+
+// Forward Declaration.
+class FrameStateDescriptor;
+
+
+class StateValueDescriptor {
+ public:
+  static const size_t kNoId = std::numeric_limits<std::size_t>::max();
+
+  StateValueDescriptor(Zone* zone, MachineType type, size_t id = kNoId)
+      : type_(type), id_(id), fields_(zone) {}
+
+  size_t AddOperand(InstructionOperandVector* inputs, OperandGenerator* g,

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

It is unfortunate that frame state needs to know about low-level details of
codegen and instructions. Why did not you want to keep this in the instruction
selector/codegen?

I understand that this would mean you would have to expose the list of fields
from here, but that does not seem too bad.

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

Done.

+                    StateObjectCache* cache, Node* input, MachineType type,
+                    FrameStateInputKind kind, Zone* zone);
+
+  size_t Translate(CodeGenerator* gen, Translation* translation,
+                   Instruction* instr, size_t frame_state_offset);
+  size_t TranslateOperand(size_t index, CodeGenerator* gen,
+                          Translation* translation, Instruction* instr,
+                          size_t frame_state_offset);
+
+  size_t size() { return fields_.size(); }
+
+  int IsRecursive() { return fields_.size() > 0; }
+  int IsDuplicate() { return fields_.size() == 0 && id_ != kNoId; }

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

I am wondering whether it would not be more readable if you just have an enum
that would say Plain/Recursive/Duplicate here.

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

Great idea, thanks.

+
+  MachineType GetOperandType(size_t index) const {
+    return fields_[index].type_;
+  }
+
+
+ private:
+  MachineType type_;
+  size_t id_;
+  ZoneVector<StateValueDescriptor> fields_;
+};
+
+
+class FrameStateDescriptor : public ZoneObject {
+ public:
+  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 = nullptr);
+
+  FrameStateType type() const { return type_; }
+  BailoutId bailout_id() const { return bailout_id_; }
+  OutputFrameStateCombine state_combine() const { return frame_state_combine_; }
+  size_t parameters_count() const { return parameters_count_; }
+  size_t locals_count() const { return locals_count_; }
+  size_t stack_count() const { return stack_count_; }
+  MaybeHandle<SharedFunctionInfo> shared_info() const { return shared_info_; }
+  FrameStateDescriptor* outer_state() const { return outer_state_; }
+  bool HasContext() const {
+    return type_ == FrameStateType::kJavaScriptFunction;
+  }
+
+  size_t AddInputs(Node* state, OperandGenerator* g, StateObjectCache* cache,
+                   InstructionOperandVector* inputs, FrameStateInputKind kind,
+                   Zone* zone);
+  void TranslateOperands(CodeGenerator* gen, Instruction* instr,
+                         size_t frame_state_offset,
+                         OutputFrameStateCombine combine,
+                         Translation* translation);
+
+  size_t GetSize(OutputFrameStateCombine combine =
+                     OutputFrameStateCombine::Ignore()) const;
+  size_t GetTotalSize() const;
+  size_t GetFrameCount() const;
+  size_t GetJSFrameCount() const;
+
+  MachineType GetType(size_t index) const {
+    return values_.GetOperandType(index);
+  }
+  StateValueDescriptor* GetStateValueDescriptor() { return &values_; }
+
+ private:
+  FrameStateType type_;
+  BailoutId bailout_id_;
+  OutputFrameStateCombine frame_state_combine_;
+  size_t parameters_count_;
+  size_t locals_count_;
+  size_t stack_count_;
+  StateValueDescriptor values_;
+  MaybeHandle<SharedFunctionInfo> const shared_info_;
+  FrameStateDescriptor* outer_state_;
+};
+
+
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_FRAME_STATES_H_