fe01014faa
Moved View.h and View.cpp from /tools/llvm-mca/Views/ to /lib/MCA/ and /include/llvm/MCA/. This is so that targets can define their own Views within the /lib/Target/ directory (so that the View can use backend functionality). To enable these Views within mca, targets will need to add them to the vector of Views returned by their target's CustomBehaviour::getViews() methods. Differential Revision: https://reviews.llvm.org/D108520
88 lines
2.7 KiB
C++
88 lines
2.7 KiB
C++
//===--------------------- DispatchStatistics.h -----------------*- C++ -*-===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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/// \file
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///
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/// This file implements a view that prints a few statistics related to the
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/// dispatch logic. It collects and analyzes instruction dispatch events as
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/// well as static/dynamic dispatch stall events.
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///
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/// Example:
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/// ========
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///
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/// Dynamic Dispatch Stall Cycles:
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/// RAT - Register unavailable: 0
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/// RCU - Retire tokens unavailable: 0
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/// SCHEDQ - Scheduler full: 42
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/// LQ - Load queue full: 0
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/// SQ - Store queue full: 0
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/// GROUP - Static restrictions on the dispatch group: 0
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///
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///
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/// Dispatch Logic - number of cycles where we saw N micro opcodes dispatched:
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/// [# dispatched], [# cycles]
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/// 0, 15 (11.5%)
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/// 2, 4 (3.1%)
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///
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//===----------------------------------------------------------------------===//
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#ifndef LLVM_TOOLS_LLVM_MCA_DISPATCHVIEW_H
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#define LLVM_TOOLS_LLVM_MCA_DISPATCHVIEW_H
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#include "llvm/ADT/SmallVector.h"
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#include "llvm/MC/MCSubtargetInfo.h"
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#include "llvm/MCA/View.h"
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#include <map>
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namespace llvm {
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namespace mca {
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class DispatchStatistics : public View {
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unsigned NumDispatched;
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unsigned NumCycles;
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// Counts dispatch stall events caused by unavailability of resources. There
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// is one counter for every generic stall kind (see class HWStallEvent).
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llvm::SmallVector<unsigned, 8> HWStalls;
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using Histogram = std::map<unsigned, unsigned>;
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Histogram DispatchGroupSizePerCycle;
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void updateHistograms() {
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DispatchGroupSizePerCycle[NumDispatched]++;
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NumDispatched = 0;
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}
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void printDispatchHistogram(llvm::raw_ostream &OS) const;
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void printDispatchStalls(llvm::raw_ostream &OS) const;
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public:
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DispatchStatistics()
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: NumDispatched(0), NumCycles(0),
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HWStalls(HWStallEvent::LastGenericEvent) {}
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void onEvent(const HWStallEvent &Event) override;
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void onEvent(const HWInstructionEvent &Event) override;
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void onCycleBegin() override { NumCycles++; }
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void onCycleEnd() override { updateHistograms(); }
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void printView(llvm::raw_ostream &OS) const override {
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printDispatchStalls(OS);
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printDispatchHistogram(OS);
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}
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StringRef getNameAsString() const override { return "DispatchStatistics"; }
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json::Value toJSON() const override;
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};
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} // namespace mca
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} // namespace llvm
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#endif
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