llvm/llvm/include/llvm/CodeGen/CalcSpillWeights.h

//===- lib/CodeGen/CalcSpillWeights.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
//
//===----------------------------------------------------------------------===//

#ifndef LLVM_CODEGEN_CALCSPILLWEIGHTS_H
#define LLVM_CODEGEN_CALCSPILLWEIGHTS_H

#include "llvm/CodeGen/SlotIndexes.h"

namespace llvm {

class LiveInterval;
class LiveIntervals;
class MachineBlockFrequencyInfo;
class MachineFunction;
class MachineLoopInfo;
class VirtRegMap;

  /// Normalize the spill weight of a live interval
  ///
  /// The spill weight of a live interval is computed as:
  ///
  ///   (sum(use freq) + sum(def freq)) / (K + size)
  ///
  /// @param UseDefFreq Expected number of executed use and def instructions
  ///                   per function call. Derived from block frequencies.
  /// @param Size       Size of live interval as returnexd by getSize()
  /// @param NumInstr   Number of instructions using this live interval
  static inline float normalizeSpillWeight(float UseDefFreq, unsigned Size,
                                           unsigned NumInstr) { … }

  /// Calculate auxiliary information for a virtual register such as its
  /// spill weight and allocation hint.
  class VirtRegAuxInfo { … };
} // end namespace llvm

#endif // LLVM_CODEGEN_CALCSPILLWEIGHTS_H