llvm.org GIT mirror llvm / release_28 include / llvm / CodeGen / CalcSpillWeights.h

Tree @release_28 (Download .tar.gz)

CalcSpillWeights.h @release_28raw · history · blame

//===---------------- lib/CodeGen/CalcSpillWeights.h ------------*- C++ -*-===//
//                     The LLVM Compiler Infrastructure
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.


#include "llvm/CodeGen/MachineFunctionPass.h"
#include "llvm/ADT/DenseMap.h"

namespace llvm {

  class LiveInterval;
  class LiveIntervals;
  class MachineLoopInfo;

  /// VirtRegAuxInfo - Calculate auxiliary information for a virtual
  /// register such as its spill weight and allocation hint.
  class VirtRegAuxInfo {
    MachineFunction &mf_;
    LiveIntervals &lis_;
    const MachineLoopInfo &loops_;
    DenseMap<unsigned, float> hint_;
    VirtRegAuxInfo(MachineFunction &mf, LiveIntervals &lis,
                   const MachineLoopInfo &loops) :
      mf_(mf), lis_(lis), loops_(loops) {}

    /// CalculateRegClass - recompute the register class for reg from its uses.
    /// Since the register class can affect the allocation hint, this function
    /// should be called before CalculateWeightAndHint if both are called.
    void CalculateRegClass(unsigned reg);

    /// CalculateWeightAndHint - (re)compute li's spill weight and allocation
    /// hint.
    void CalculateWeightAndHint(LiveInterval &li);

  /// CalculateSpillWeights - Compute spill weights for all virtual register
  /// live intervals.
  class CalculateSpillWeights : public MachineFunctionPass {
    static char ID;

    CalculateSpillWeights() : MachineFunctionPass(ID) {}

    virtual void getAnalysisUsage(AnalysisUsage &au) const;

    virtual bool runOnMachineFunction(MachineFunction &fn);

    /// Returns true if the given live interval is zero length.
    bool isZeroLengthInterval(LiveInterval *li) const;