[turbofan] Get rid of the StructuredMacroAssembler.

test/cctest/compiler/structured-machine-assembler.h

-// Copyright 2014 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_CCTEST_COMPILER_STRUCTURED_MACHINE_ASSEMBLER_H_
-#define V8_CCTEST_COMPILER_STRUCTURED_MACHINE_ASSEMBLER_H_
-
-#include "src/v8.h"
-
-#include "src/compiler/common-operator.h"
-#include "src/compiler/graph-builder.h"
-#include "src/compiler/machine-operator.h"
-#include "src/compiler/node.h"
-#include "src/compiler/operator.h"
-#include "src/compiler/raw-machine-assembler.h"
-
-
-namespace v8 {
-namespace internal {
-namespace compiler {
-
-class BasicBlock;
-class Schedule;
-class StructuredMachineAssembler;
-
-
-class Variable : public ZoneObject {
- public:
-  Node* Get() const;
-  void Set(Node* value) const;
-
- private:
-  Variable(StructuredMachineAssembler* smasm, int offset)
-      : smasm_(smasm), offset_(offset) {}
-
-  friend class StructuredMachineAssembler;
-  friend class StructuredMachineAssemblerFriend;
-  StructuredMachineAssembler* const smasm_;
-  const int offset_;
-};
-
-
-class StructuredMachineAssembler : public RawMachineAssembler {
- public:
-  class Environment : public ZoneObject {
-   public:
-    Environment(Zone* zone, BasicBlock* block, bool is_dead_);
-
-   private:
-    BasicBlock* block_;
-    NodeVector variables_;
-    bool is_dead_;
-    friend class StructuredMachineAssembler;
-    DISALLOW_COPY_AND_ASSIGN(Environment);
-  };
-
-  class IfBuilder;
-  friend class IfBuilder;
-  class LoopBuilder;
-  friend class LoopBuilder;
-
-  StructuredMachineAssembler(Graph* graph, MachineSignature* machine_sig,
-                             MachineType word = kMachPtr);
-  virtual ~StructuredMachineAssembler() {}
-
-  // Variables.
-  Variable NewVariable(Node* initial_value);
-  // Control flow.
-  void Return(Node* value);
-
- protected:
-  virtual Node* MakeNode(Operator* op, int input_count, Node** inputs);
-
- private:
-  typedef ZoneVector<Environment*> EnvironmentVector;
-
-  NodeVector* CurrentVars() { return &current_environment_->variables_; }
-  Node*& VariableAt(Environment* environment, int offset);
-  Node* GetVariable(int offset);
-  void SetVariable(int offset, Node* value);
-
-  void AddBranch(Environment* environment, Node* condition,
-                 Environment* true_val, Environment* false_val);
-  void AddGoto(Environment* from, Environment* to);
-  BasicBlock* TrampolineFor(BasicBlock* block);
-
-  void CopyCurrentAsDead();
-  Environment* Copy(Environment* environment) {
-    return Copy(environment, static_cast<int>(environment->variables_.size()));
-  }
-  Environment* Copy(Environment* environment, int truncate_at);
-  void Merge(EnvironmentVector* environments, int truncate_at);
-  Environment* CopyForLoopHeader(Environment* environment);
-  void MergeBackEdgesToLoopHeader(Environment* header,
-                                  EnvironmentVector* environments);
-
-  Environment* current_environment_;
-  int number_of_variables_;
-
-  friend class Variable;
-  // For testing only.
-  friend class StructuredMachineAssemblerFriend;
-  DISALLOW_COPY_AND_ASSIGN(StructuredMachineAssembler);
-};
-
-// IfBuilder constructs of nested if-else expressions which more or less follow
-// C semantics.  Foe example:
-//
-//  if (x) {do_x} else if (y) {do_y} else {do_z}
-//
-// would look like this:
-//
-//  IfBuilder b;
-//  b.If(x).Then();
-//  do_x
-//  b.Else();
-//  b.If().Then();
-//  do_y
-//  b.Else();
-//  do_z
-//  b.End();
-//
-// Then() and Else() can be skipped, representing an empty block in C.
-// Combinations like If(x).Then().If(x).Then() are legitimate, but
-// Else().Else() is not. That is, once you've nested an If(), you can't get to a
-// higher level If() branch.
-// TODO(dcarney): describe expressions once the api is finalized.
-class StructuredMachineAssembler::IfBuilder {
- public:
-  explicit IfBuilder(StructuredMachineAssembler* smasm);
-  ~IfBuilder() {
-    if (!IsDone()) End();
-  }
-
-  IfBuilder& If();  // TODO(dcarney): this should take an expression.
-  IfBuilder& If(Node* condition);
-  void Then();
-  void Else();
-  void End();
-
-  // The next 4 functions are exposed for expression support.
-  // They will be private once I have a nice expression api.
-  void And();
-  void Or();
-  IfBuilder& OpenParen() {
-    DCHECK(smasm_->current_environment_ != NULL);
-    CurrentClause()->PushNewExpressionState();
-    return *this;
-  }
-  IfBuilder& CloseParen() {
-    DCHECK(smasm_->current_environment_ == NULL);
-    CurrentClause()->PopExpressionState();
-    return *this;
-  }
-
- private:
-  // UnresolvedBranch represents the chain of environments created while
-  // generating an expression.  At this point, a branch Node
-  // cannot be created, as the target environments of the branch are not yet
-  // available, so everything required to create the branch Node is
-  // stored in this structure until the target environments are resolved.
-  struct UnresolvedBranch : public ZoneObject {
-    UnresolvedBranch(Environment* environment, Node* condition,
-                     UnresolvedBranch* next)
-        : environment_(environment), condition_(condition), next_(next) {}
-    // environment_ will eventually be terminated by a branch on condition_.
-    Environment* environment_;
-    Node* condition_;
-    // next_ is the next link in the UnresolvedBranch chain, and will be
-    // either the true or false branch jumped to from environment_.
-    UnresolvedBranch* next_;
-  };
-
-  struct ExpressionState {
-    int pending_then_size_;
-    int pending_else_size_;
-  };
-
-  typedef ZoneVector<ExpressionState> ExpressionStates;
-  typedef ZoneVector<UnresolvedBranch*> PendingMergeStack;
-  struct IfClause;
-  typedef ZoneVector<IfClause*> IfClauses;
-
-  struct PendingMergeStackRange {
-    PendingMergeStack* merge_stack_;
-    int start_;
-    int size_;
-  };
-
-  enum CombineType { kCombineThen, kCombineElse };
-  enum ResolutionType { kExpressionTerm, kExpressionDone };
-
-  // IfClause represents one level of if-then-else nesting plus the associated
-  // expression.
-  // A call to If() triggers creation of a new nesting level after expression
-  // creation is complete - ie Then() or Else() has been called.
-  struct IfClause : public ZoneObject {
-    IfClause(Zone* zone, int initial_environment_size);
-    void CopyEnvironments(const PendingMergeStackRange& data,
-                          EnvironmentVector* environments);
-    void ResolvePendingMerges(StructuredMachineAssembler* smasm,
-                              CombineType combine_type,
-                              ResolutionType resolution_type);
-    PendingMergeStackRange ComputeRelevantMerges(CombineType combine_type);
-    void FinalizeBranches(StructuredMachineAssembler* smasm,
-                          const PendingMergeStackRange& offset_data,
-                          CombineType combine_type,
-                          Environment* then_environment,
-                          Environment* else_environment);
-    void PushNewExpressionState();
-    void PopExpressionState();
-
-    // Each invocation of And or Or creates a new UnresolvedBranch.
-    // These form a singly-linked list, of which we only need to keep track of
-    // the tail.  On creation of an UnresolvedBranch, pending_then_merges_ and
-    // pending_else_merges_ each push a copy, which are removed on merges to the
-    // respective environment.
-    UnresolvedBranch* unresolved_list_tail_;
-    int initial_environment_size_;
-    // expression_states_ keeps track of the state of pending_*_merges_,
-    // pushing and popping the lengths of these on
-    // OpenParend() and CloseParend() respectively.
-    ExpressionStates expression_states_;
-    PendingMergeStack pending_then_merges_;
-    PendingMergeStack pending_else_merges_;
-    // then_environment_ is created iff there is a call to Then(), otherwise
-    // branches which would merge to it merge to the exit environment instead.
-    // Likewise for else_environment_.
-    Environment* then_environment_;
-    Environment* else_environment_;
-  };
-
-  IfClause* CurrentClause() { return if_clauses_.back(); }
-  void AddCurrentToPending();
-  void PushNewIfClause();
-  bool IsDone() { return if_clauses_.empty(); }
-
-  StructuredMachineAssembler* smasm_;
-  IfClauses if_clauses_;
-  EnvironmentVector pending_exit_merges_;
-  DISALLOW_COPY_AND_ASSIGN(IfBuilder);
-};
-
-
-class StructuredMachineAssembler::LoopBuilder {
- public:
-  explicit LoopBuilder(StructuredMachineAssembler* smasm);
-  ~LoopBuilder() {
-    if (!IsDone()) End();
-  }
-
-  void Break();
-  void Continue();
-  void End();
-
- private:
-  friend class StructuredMachineAssembler;
-  bool IsDone() { return header_environment_ == NULL; }
-
-  StructuredMachineAssembler* smasm_;
-  Environment* header_environment_;
-  EnvironmentVector pending_header_merges_;
-  EnvironmentVector pending_exit_merges_;
-  DISALLOW_COPY_AND_ASSIGN(LoopBuilder);
-};
-
-}  // namespace compiler
-}  // namespace internal
-}  // namespace v8
-
-#endif  // V8_CCTEST_COMPILER_STRUCTURED_MACHINE_ASSEMBLER_H_