PBQPRAConstraint.h

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//===- llvm/CodeGen/PBQPRAConstraint.h --------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file defines the PBQPBuilder interface, for classes which build PBQP
// instances to represent register allocation problems, and the RegAllocPBQP
// interface.
//
//===----------------------------------------------------------------------===//
 
#ifndef LLVM_CODEGEN_PBQPRACONSTRAINT_H
#define LLVM_CODEGEN_PBQPRACONSTRAINT_H
 
#include <algorithm>
#include <memory>
#include <vector>
 
namespace llvm {
 
namespace PBQP {
namespace RegAlloc {
 
// Forward declare PBQP graph class.
class PBQPRAGraph;
 
} // end namespace RegAlloc
} // end namespace PBQP
 
using PBQPRAGraph = PBQP::RegAlloc::PBQPRAGraph;
 
/// Abstract base for classes implementing PBQP register allocation
///        constraints (e.g. Spill-costs, interference, coalescing).
class PBQPRAConstraint {
public:
  virtual ~PBQPRAConstraint() = 0;
  virtual void apply(PBQPRAGraph &G) = 0;
 
private:
  virtual void anchor();
};
 
/// PBQP register allocation constraint composer.
///
///   Constraints added to this list will be applied, in the order that they are
/// added, to the PBQP graph.
class PBQPRAConstraintList : public PBQPRAConstraint {
public:
  void apply(PBQPRAGraph &G) override {
    for (auto &C : Constraints)
      C->apply(G);
  }
 
  void addConstraint(std::unique_ptr<PBQPRAConstraint> C) {
    if (C)
      Constraints.push_back(std::move(C));
  }
 
private:
  std::vector<std::unique_ptr<PBQPRAConstraint>> Constraints;
 
  void anchor() override;
};
 
} // end namespace llvm
 
#endif // LLVM_CODEGEN_PBQPRACONSTRAINT_H