| //===--------------------- SummaryView.cpp -------------------*- 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 |
| // |
| //===----------------------------------------------------------------------===// |
| /// \file |
| /// |
| /// This file implements the functionalities used by the SummaryView to print |
| /// the report information. |
| /// |
| //===----------------------------------------------------------------------===// |
| |
| #include "Views/SummaryView.h" |
| #include "llvm/ADT/SmallVector.h" |
| #include "llvm/MCA/Support.h" |
| #include "llvm/Support/Format.h" |
| |
| namespace llvm { |
| namespace mca { |
| |
| #define DEBUG_TYPE "llvm-mca" |
| |
| SummaryView::SummaryView(const MCSchedModel &Model, ArrayRef<MCInst> S, |
| unsigned Width, bool EmitBottleneckAnalysis) |
| : SM(Model), Source(S), DispatchWidth(Width?Width: Model.IssueWidth), |
| LastInstructionIdx(0), |
| TotalCycles(0), NumMicroOps(0), BPI({0, 0, 0, 0, 0}), |
| ResourcePressureDistribution(Model.getNumProcResourceKinds(), 0), |
| ProcResourceUsage(Model.getNumProcResourceKinds(), 0), |
| ProcResourceMasks(Model.getNumProcResourceKinds()), |
| ResIdx2ProcResID(Model.getNumProcResourceKinds(), 0), |
| PressureIncreasedBecauseOfResources(false), |
| PressureIncreasedBecauseOfDataDependencies(false), |
| SeenStallCycles(false), |
| ShouldEmitBottleneckAnalysis(EmitBottleneckAnalysis) { |
| computeProcResourceMasks(SM, ProcResourceMasks); |
| for (unsigned I = 1, E = SM.getNumProcResourceKinds(); I < E; ++I) { |
| unsigned Index = getResourceStateIndex(ProcResourceMasks[I]); |
| ResIdx2ProcResID[Index] = I; |
| } |
| } |
| |
| void SummaryView::onEvent(const HWInstructionEvent &Event) { |
| if (Event.Type == HWInstructionEvent::Dispatched) |
| LastInstructionIdx = Event.IR.getSourceIndex(); |
| |
| // We are only interested in the "instruction retired" events generated by |
| // the retire stage for instructions that are part of iteration #0. |
| if (Event.Type != HWInstructionEvent::Retired || |
| Event.IR.getSourceIndex() >= Source.size()) |
| return; |
| |
| // Update the cumulative number of resource cycles based on the processor |
| // resource usage information available from the instruction descriptor. We |
| // need to compute the cumulative number of resource cycles for every |
| // processor resource which is consumed by an instruction of the block. |
| const Instruction &Inst = *Event.IR.getInstruction(); |
| const InstrDesc &Desc = Inst.getDesc(); |
| NumMicroOps += Desc.NumMicroOps; |
| for (const std::pair<uint64_t, const ResourceUsage> &RU : Desc.Resources) { |
| if (RU.second.size()) { |
| unsigned ProcResID = ResIdx2ProcResID[getResourceStateIndex(RU.first)]; |
| ProcResourceUsage[ProcResID] += RU.second.size(); |
| } |
| } |
| } |
| |
| void SummaryView::onEvent(const HWPressureEvent &Event) { |
| assert(Event.Reason != HWPressureEvent::INVALID && |
| "Unexpected invalid event!"); |
| |
| switch (Event.Reason) { |
| default: |
| break; |
| |
| case HWPressureEvent::RESOURCES: { |
| PressureIncreasedBecauseOfResources = true; |
| ++BPI.ResourcePressureCycles; |
| uint64_t ResourceMask = Event.ResourceMask; |
| while (ResourceMask) { |
| uint64_t Current = ResourceMask & (-ResourceMask); |
| unsigned Index = getResourceStateIndex(Current); |
| unsigned ProcResID = ResIdx2ProcResID[Index]; |
| const MCProcResourceDesc &PRDesc = *SM.getProcResource(ProcResID); |
| if (!PRDesc.SubUnitsIdxBegin) { |
| ResourcePressureDistribution[Index]++; |
| ResourceMask ^= Current; |
| continue; |
| } |
| |
| for (unsigned I = 0, E = PRDesc.NumUnits; I < E; ++I) { |
| unsigned OtherProcResID = PRDesc.SubUnitsIdxBegin[I]; |
| unsigned OtherMask = ProcResourceMasks[OtherProcResID]; |
| ResourcePressureDistribution[getResourceStateIndex(OtherMask)]++; |
| } |
| |
| ResourceMask ^= Current; |
| } |
| } |
| |
| break; |
| case HWPressureEvent::REGISTER_DEPS: |
| PressureIncreasedBecauseOfDataDependencies = true; |
| ++BPI.RegisterDependencyCycles; |
| break; |
| case HWPressureEvent::MEMORY_DEPS: |
| PressureIncreasedBecauseOfDataDependencies = true; |
| ++BPI.MemoryDependencyCycles; |
| break; |
| } |
| } |
| |
| void SummaryView::printBottleneckHints(raw_ostream &OS) const { |
| if (!SeenStallCycles || !BPI.PressureIncreaseCycles) { |
| OS << "\nNo resource or data dependency bottlenecks discovered.\n"; |
| return; |
| } |
| |
| double PressurePerCycle = |
| (double)BPI.PressureIncreaseCycles * 100 / TotalCycles; |
| double ResourcePressurePerCycle = |
| (double)BPI.ResourcePressureCycles * 100 / TotalCycles; |
| double DDPerCycle = (double)BPI.DataDependencyCycles * 100 / TotalCycles; |
| double RegDepPressurePerCycle = |
| (double)BPI.RegisterDependencyCycles * 100 / TotalCycles; |
| double MemDepPressurePerCycle = |
| (double)BPI.MemoryDependencyCycles * 100 / TotalCycles; |
| |
| OS << "\nCycles with backend pressure increase [ " |
| << format("%.2f", floor((PressurePerCycle * 100) + 0.5) / 100) << "% ]"; |
| |
| OS << "\nThroughput Bottlenecks: " |
| << "\n Resource Pressure [ " |
| << format("%.2f", floor((ResourcePressurePerCycle * 100) + 0.5) / 100) |
| << "% ]"; |
| |
| if (BPI.PressureIncreaseCycles) { |
| for (unsigned I = 0, E = ResourcePressureDistribution.size(); I < E; ++I) { |
| if (ResourcePressureDistribution[I]) { |
| double Frequency = |
| (double)ResourcePressureDistribution[I] * 100 / TotalCycles; |
| unsigned Index = ResIdx2ProcResID[getResourceStateIndex(1ULL << I)]; |
| const MCProcResourceDesc &PRDesc = *SM.getProcResource(Index); |
| OS << "\n - " << PRDesc.Name << " [ " |
| << format("%.2f", floor((Frequency * 100) + 0.5) / 100) << "% ]"; |
| } |
| } |
| } |
| |
| OS << "\n Data Dependencies: [ " |
| << format("%.2f", floor((DDPerCycle * 100) + 0.5) / 100) << "% ]"; |
| |
| OS << "\n - Register Dependencies [ " |
| << format("%.2f", floor((RegDepPressurePerCycle * 100) + 0.5) / 100) |
| << "% ]"; |
| |
| OS << "\n - Memory Dependencies [ " |
| << format("%.2f", floor((MemDepPressurePerCycle * 100) + 0.5) / 100) |
| << "% ]\n\n"; |
| } |
| |
| void SummaryView::printView(raw_ostream &OS) const { |
| unsigned Instructions = Source.size(); |
| unsigned Iterations = (LastInstructionIdx / Instructions) + 1; |
| unsigned TotalInstructions = Instructions * Iterations; |
| unsigned TotalUOps = NumMicroOps * Iterations; |
| double IPC = (double)TotalInstructions / TotalCycles; |
| double UOpsPerCycle = (double)TotalUOps / TotalCycles; |
| double BlockRThroughput = computeBlockRThroughput( |
| SM, DispatchWidth, NumMicroOps, ProcResourceUsage); |
| |
| std::string Buffer; |
| raw_string_ostream TempStream(Buffer); |
| TempStream << "Iterations: " << Iterations; |
| TempStream << "\nInstructions: " << TotalInstructions; |
| TempStream << "\nTotal Cycles: " << TotalCycles; |
| TempStream << "\nTotal uOps: " << TotalUOps << '\n'; |
| TempStream << "\nDispatch Width: " << DispatchWidth; |
| TempStream << "\nuOps Per Cycle: " |
| << format("%.2f", floor((UOpsPerCycle * 100) + 0.5) / 100); |
| TempStream << "\nIPC: " |
| << format("%.2f", floor((IPC * 100) + 0.5) / 100); |
| TempStream << "\nBlock RThroughput: " |
| << format("%.1f", floor((BlockRThroughput * 10) + 0.5) / 10) |
| << '\n'; |
| if (ShouldEmitBottleneckAnalysis) |
| printBottleneckHints(TempStream); |
| TempStream.flush(); |
| OS << Buffer; |
| } |
| } // namespace mca. |
| } // namespace llvm |