[Interpreter] Bytecode graph builder

src/compiler/bytecode-graph-builder.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_BYTECODE_GRAPH_BUILDER_H_
+#define V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_
+
+#include "src/interpreter/bytecodes.h"
+
+#include "src/compiler.h"
+#include "src/compiler/js-graph.h"
+
+namespace v8 {
+namespace internal {
+namespace compiler {
+
+// The BytecodeGraphBuilder produces a high-level IR graph based on
+// interpreter bytecodes.
+class BytecodeGraphBuilder {
+ public:
+  BytecodeGraphBuilder(Zone* local_zone, CompilationInfo* info,
+                       JSGraph* jsgraph);
+  BytecodeGraphBuilder(Zone* local_zone, Handle<BytecodeArray> bytecode_array,
+                       JSGraph* jsgraph);
+
+  // Creates a graph by visiting bytecodes.
+  bool CreateGraph(bool stack_check = true);

[Michael Starzinger, 2015/09/02 12:19:22]

The only reason for the {stack_check} flags is for inlining, where we don't want
sub-graphs to contains a stack. We could just always emit it until we tackle
inlining. Up to you.

+  bool CreateGraphForTest(bool stack_check = true);
+
+  Graph* graph() const { return jsgraph_->graph(); }
+
+ private:
+  class Environment;
+
+  void CreateGraphBody(bool stack_check);
+  void VisitBytecodes();
+
+  Node* LoadAccumulator(Node* value);
+
+  // Convert values in bytecode_array to convenient to handle forms.
+  interpreter::Bytecode bytecode_at(int offset) const;
+  // Get constant from operand at position |offset| in bytecode array.
+  Handle<Object> constant_at(int offset) const;
+  // Get smi8 value from operand at position |offset| in bytecode array.
+  int8_t smi8_at(int offset) const;
+  // Get register from operand at position |offset| in bytecode array.
+  int8_t register_at(int offset) const;
+
+  void set_environment(Environment* env) { environment_ = env; }
+  const Environment* environment() const { return environment_; }
+  Environment* environment() { return environment_; }
+
+  // Node creation helpers
+  Node* NewNode(const Operator* op, bool incomplete = false) {

[Michael Starzinger, 2015/09/02 12:19:22]

The {incomplete} flag is only needed for merge points so that we can
over-reserve space for {Phi}, {Merge} and {Loop} nodes and insert inputs later
without thrashing zone. This will totally depend on how control flow is modeled
in the byte-code. If number of control flow-inputs at every merge point is
known, we won't need it. But I assume we won't know.

+    return MakeNode(op, 0, static_cast<Node**>(NULL), incomplete);
+  }
+
+  Node* NewNode(const Operator* op, Node* n1) {
+    Node* buffer[] = {n1};
+    return MakeNode(op, arraysize(buffer), buffer, false);
+  }
+
+  Node* NewNode(const Operator* op, Node* n1, Node* n2) {
+    Node* buffer[] = {n1, n2};
+    return MakeNode(op, arraysize(buffer), buffer, false);
+  }
+
+  Node* MakeNode(const Operator* op, int value_input_count, Node** value_inputs,
+                 bool incomplete);
+
+  Node* MergeControl(Node* control, Node* other);
+
+  Node** EnsureInputBufferSize(int size);
+
+  void UpdateControlDependencyToLeaveFunction(Node* exit);

[Michael Starzinger, 2015/09/02 12:19:22]

Again depends on how control flow is modeled. Only needed if there are "return"
and "throw" byte-codes that represent non-local control flow.

+
+  void FinishBinaryOperation(Node* node);
+
+  // Growth increment for the temporary buffer used to construct input lists to
+  // new nodes.
+  static const int kInputBufferSizeIncrement = 64;
+
+  // Field accessors
+  CommonOperatorBuilder* common() const { return jsgraph_->common(); }
+  Zone* graph_zone() const { return graph()->zone(); }
+  CompilationInfo* info() const { return info_; }
+  JSGraph* jsgraph() const { return jsgraph_; }
+  JSOperatorBuilder* javascript() const { return jsgraph_->javascript(); }
+  Zone* local_zone() const { return local_zone_; }
+  const Handle<BytecodeArray>& bytecode_array() const {
+    return bytecode_array_;
+  }
+
+  LanguageMode language_mode() const {
+    // TODO(oth): need to propagate language mode through
+    return LanguageMode::SLOPPY;
+  }
+
+#define DECLARE_VISIT_BYTECODE(name, ...) void Visit##name(int operand_offset);
+  BYTECODE_LIST(DECLARE_VISIT_BYTECODE)
+#undef DECLARE_VISIT_BYTECODE
+
+  Zone* local_zone_;
+  CompilationInfo* info_;
+  JSGraph* jsgraph_;
+  Handle<BytecodeArray> bytecode_array_;
+  Environment* environment_;
+
+  // Temporary storage for building node input lists.
+  int input_buffer_size_;
+  Node** input_buffer_;
+
+  // Control nodes that exit the function body.
+  ZoneVector<Node*> exit_controls_;
+
+  DISALLOW_COPY_AND_ASSIGN(BytecodeGraphBuilder);
+};
+
+
+class BytecodeGraphBuilder::Environment : public ZoneObject {
+ public:
+  Environment(BytecodeGraphBuilder* builder, int locals_count,
+              int parameter_count, Node* control_dependency);
+
+  int parameters_count() const { return parameters_count_; }
+  int locals_count() const { return locals_count_; }
+
+  void BindRegister(int register_index, Node* node);
+  Node* LookupRegister(int register_index) const;
+
+  void BindAccumulator(Node* node);
+  Node* LookupAccumulator() const;
+
+  bool IsMarkedAsUnreachable() const;
+  void MarkAsUnreachable();
+
+  // Effect dependency tracked by this environment.
+  Node* GetEffectDependency() { return effect_dependency_; }
+  void UpdateEffectDependency(Node* dependency) {
+    effect_dependency_ = dependency;
+  }
+
+  // Control dependency tracked by this environment.
+  Node* GetControlDependency() const { return control_dependency_; }
+  void UpdateControlDependency(Node* dependency) {
+    control_dependency_ = dependency;
+  }
+
+ private:
+  BytecodeGraphBuilder* builder_;
+  int locals_count_;
+  int parameters_count_;
+  Node* accumulator_;
+  Node* control_dependency_;
+  Node* effect_dependency_;
+  NodeVector values_;
+  int register_base_;
+
+  Zone* zone() const { return builder_->local_zone(); }
+  Graph* graph() const { return builder_->graph(); }
+  CommonOperatorBuilder* common() const { return builder_->common(); }
+  BytecodeGraphBuilder* builder() const { return builder_; }
+  const NodeVector* values() const { return &values_; }
+  NodeVector* values() { return &values_; }
+  Node* accumulator() { return accumulator_; }
+
+  int register_base() const { return register_base_; }
+};
+
+}  // namespace compiler
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_COMPILER_BYTECODE_GRAPH_BUILDER_H_