xref: /external/v8/src/arm/lithium-gap-resolver-arm.h

// Copyright 2011 the V8 project authors. All rights reserved.
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#ifndef V8_ARM_LITHIUM_GAP_RESOLVER_ARM_H_
#define V8_ARM_LITHIUM_GAP_RESOLVER_ARM_H_

#include "v8.h"

#include "lithium.h"

namespace v8 {
namespace internal {

class LCodeGen;
class LGapResolver;

class LGapResolver BASE_EMBEDDED {
 public:
  explicit LGapResolver(LCodeGen* owner);

  // Resolve a set of parallel moves, emitting assembler instructions.
  void Resolve(LParallelMove* parallel_move);

 private:
  // Build the initial list of moves.
  void BuildInitialMoveList(LParallelMove* parallel_move);

  // Perform the move at the moves_ index in question (possibly requiring
  // other moves to satisfy dependencies).
  void PerformMove(int index);

  // If a cycle is found in the series of moves, save the blocking value to
  // a scratch register.  The cycle must be found by hitting the root of the
  // depth-first search.
  void BreakCycle(int index);

  // After a cycle has been resolved, restore the value from the scratch
  // register to its proper destination.
  void RestoreValue();

  // Emit a move and remove it from the move graph.
  void EmitMove(int index);

  // Verify the move list before performing moves.
  void Verify();

  LCodeGen* cgen_;

  // List of moves not yet resolved.
  ZoneList<LMoveOperands> moves_;

  int root_index_;
  bool in_cycle_;
  LOperand* saved_destination_;
};

} }  // namespace v8::internal

#endif  // V8_ARM_LITHIUM_GAP_RESOLVER_ARM_H_