llvm-project/llvm/lib/CodeGen/RegAllocScore.h

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3.0 KiB
C++

//==- RegAllocScore.h - evaluate regalloc policy quality ----------*-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
//
//===----------------------------------------------------------------------===//
/// Calculate a measure of the register allocation policy quality. This is used
/// to construct a reward for the training of the ML-driven allocation policy.
/// Currently, the score is the sum of the machine basic block frequency-weighed
/// number of loads, stores, copies, and remat instructions, each factored with
/// a relative weight.
//===----------------------------------------------------------------------===//
#ifndef LLVM_CODEGEN_REGALLOCSCORE_H_
#define LLVM_CODEGEN_REGALLOCSCORE_H_
#include "llvm/ADT/STLFunctionalExtras.h"
namespace llvm {
class AAResults;
class MachineBasicBlock;
class MachineBlockFrequencyInfo;
class MachineFunction;
class MachineInstr;
/// Regalloc score.
class RegAllocScore final {
double CopyCounts = 0.0;
double LoadCounts = 0.0;
double StoreCounts = 0.0;
double CheapRematCounts = 0.0;
double LoadStoreCounts = 0.0;
double ExpensiveRematCounts = 0.0;
public:
RegAllocScore() = default;
RegAllocScore(const RegAllocScore &) = default;
double copyCounts() const { return CopyCounts; }
double loadCounts() const { return LoadCounts; }
double storeCounts() const { return StoreCounts; }
double loadStoreCounts() const { return LoadStoreCounts; }
double expensiveRematCounts() const { return ExpensiveRematCounts; }
double cheapRematCounts() const { return CheapRematCounts; }
void onCopy(double Freq) { CopyCounts += Freq; }
void onLoad(double Freq) { LoadCounts += Freq; }
void onStore(double Freq) { StoreCounts += Freq; }
void onLoadStore(double Freq) { LoadStoreCounts += Freq; }
void onExpensiveRemat(double Freq) { ExpensiveRematCounts += Freq; }
void onCheapRemat(double Freq) { CheapRematCounts += Freq; }
RegAllocScore &operator+=(const RegAllocScore &Other);
bool operator==(const RegAllocScore &Other) const;
bool operator!=(const RegAllocScore &Other) const;
double getScore() const;
};
/// Calculate a score. When comparing 2 scores for the same function but
/// different policies, the better policy would have a smaller score.
/// The implementation is the overload below (which is also easily unittestable)
RegAllocScore calculateRegAllocScore(const MachineFunction &MF,
const MachineBlockFrequencyInfo &MBFI,
AAResults &AAResults);
/// Implementation of the above, which is also more easily unittestable.
RegAllocScore calculateRegAllocScore(
const MachineFunction &MF,
llvm::function_ref<double(const MachineBasicBlock &)> GetBBFreq,
llvm::function_ref<bool(const MachineInstr &)> IsTriviallyRematerializable);
} // end namespace llvm
#endif // LLVM_CODEGEN_REGALLOCSCORE_H_