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//===--------------------- BackendStatistics.h ------------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
/// \file
///
/// This file implements a printer class for printing generic Backend
/// statistics related to the scheduler and retire unit.
///
/// Example:
/// ========
///
/// Schedulers - number of cycles where we saw N instructions issued:
/// [# issued], [# cycles]
/// 0, 7 (5.4%)
/// 1, 4 (3.1%)
/// 2, 8 (6.2%)
///
/// Retire Control Unit - number of cycles where we saw N instructions retired:
/// [# retired], [# cycles]
/// 0, 9 (6.9%)
/// 1, 6 (4.6%)
/// 2, 1 (0.8%)
/// 4, 3 (2.3%)
///
/// Scheduler's queue usage:
/// JALU01, 0/20
/// JFPU01, 18/18
/// JLSAGU, 0/12
///
//===----------------------------------------------------------------------===//
#ifndef LLVM_TOOLS_LLVM_MCA_BACKENDSTATISTICS_H
#define LLVM_TOOLS_LLVM_MCA_BACKENDSTATISTICS_H
#include "View.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/MC/MCSubtargetInfo.h"
namespace mca {
class BackendStatistics : public View {
const llvm::MCSubtargetInfo &STI;
using Histogram = llvm::DenseMap<unsigned, unsigned>;
Histogram RetiredPerCycle;
Histogram IssuedPerCycle;
unsigned NumIssued;
unsigned NumRetired;
unsigned NumCycles;
// Tracks the usage of a scheduler's queue.
struct BufferUsage {
unsigned SlotsInUse;
unsigned MaxUsedSlots;
};
// There is a map entry for each buffered resource in the scheduling model.
// Every time a buffer is consumed/freed, this view updates the corresponding
// entry.
llvm::DenseMap<unsigned, BufferUsage> BufferedResources;
void updateHistograms() {
IssuedPerCycle[NumIssued]++;
RetiredPerCycle[NumRetired]++;
NumIssued = 0;
NumRetired = 0;
}
void printRetireUnitStatistics(llvm::raw_ostream &OS) const;
void printSchedulerStatistics(llvm::raw_ostream &OS) const;
void printRCUStatistics(llvm::raw_ostream &OS, const Histogram &Histogram,
unsigned Cycles) const;
void printIssuePerCycle(const Histogram &IssuePerCycle,
unsigned TotalCycles) const;
void printSchedulerUsage(llvm::raw_ostream &OS,
const llvm::MCSchedModel &SM) const;
public:
BackendStatistics(const llvm::MCSubtargetInfo &sti)
: STI(sti), NumIssued(0), NumRetired(0), NumCycles(0) { }
void onInstructionEvent(const HWInstructionEvent &Event) override;
void onCycleBegin(unsigned Cycle) override { NumCycles++; }
void onCycleEnd(unsigned Cycle) override { updateHistograms(); }
// Increases the number of used scheduler queue slots of every buffered
// resource in the Buffers set.
void onReservedBuffers(llvm::ArrayRef<unsigned> Buffers) override;
// Decreases by one the number of used scheduler queue slots of every
// buffered resource in the Buffers set.
void onReleasedBuffers(llvm::ArrayRef<unsigned> Buffers) override;
void printView(llvm::raw_ostream &OS) const override {
printSchedulerStatistics(OS);
printRetireUnitStatistics(OS);
printSchedulerUsage(OS, STI.getSchedModel());
}
};
} // namespace mca
#endif
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