1//===--------------------- DispatchStatistics.h -----------------*- C++ -*-===// 2// 3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4// See https://llvm.org/LICENSE.txt for license information. 5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6// 7//===----------------------------------------------------------------------===// 8/// \file 9/// 10/// This file implements a view that prints a few statistics related to the 11/// dispatch logic. It collects and analyzes instruction dispatch events as 12/// well as static/dynamic dispatch stall events. 13/// 14/// Example: 15/// ======== 16/// 17/// Dynamic Dispatch Stall Cycles: 18/// RAT - Register unavailable: 0 19/// RCU - Retire tokens unavailable: 0 20/// SCHEDQ - Scheduler full: 42 21/// LQ - Load queue full: 0 22/// SQ - Store queue full: 0 23/// GROUP - Static restrictions on the dispatch group: 0 24/// 25/// 26/// Dispatch Logic - number of cycles where we saw N micro opcodes dispatched: 27/// [# dispatched], [# cycles] 28/// 0, 15 (11.5%) 29/// 2, 4 (3.1%) 30/// 31//===----------------------------------------------------------------------===// 32 33#ifndef LLVM_TOOLS_LLVM_MCA_DISPATCHVIEW_H 34#define LLVM_TOOLS_LLVM_MCA_DISPATCHVIEW_H 35 36#include "Views/View.h" 37#include "llvm/ADT/SmallVector.h" 38#include "llvm/MC/MCSubtargetInfo.h" 39#include <map> 40 41namespace llvm { 42namespace mca { 43 44class DispatchStatistics : public View { 45 unsigned NumDispatched; 46 unsigned NumCycles; 47 48 // Counts dispatch stall events caused by unavailability of resources. There 49 // is one counter for every generic stall kind (see class HWStallEvent). 50 llvm::SmallVector<unsigned, 8> HWStalls; 51 52 using Histogram = std::map<unsigned, unsigned>; 53 Histogram DispatchGroupSizePerCycle; 54 55 void updateHistograms() { 56 DispatchGroupSizePerCycle[NumDispatched]++; 57 NumDispatched = 0; 58 } 59 60 void printDispatchHistogram(llvm::raw_ostream &OS) const; 61 62 void printDispatchStalls(llvm::raw_ostream &OS) const; 63 64public: 65 DispatchStatistics() 66 : NumDispatched(0), NumCycles(0), 67 HWStalls(HWStallEvent::LastGenericEvent) {} 68 69 void onEvent(const HWStallEvent &Event) override; 70 71 void onEvent(const HWInstructionEvent &Event) override; 72 73 void onCycleBegin() override { NumCycles++; } 74 75 void onCycleEnd() override { updateHistograms(); } 76 77 void printView(llvm::raw_ostream &OS) const override { 78 printDispatchStalls(OS); 79 printDispatchHistogram(OS); 80 } 81 StringRef getNameAsString() const override { return "DispatchStatistics"; } 82}; 83} // namespace mca 84} // namespace llvm 85 86#endif 87