llvm/tools/llvm-mca/Views/DispatchStatistics.cpp

   1 //===--------------------- DispatchStatistics.cpp ---------------------*- C++
   2 //-*-===//
   3 //
   4 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   5 // See https://llvm.org/LICENSE.txt for license information.
   6 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   7 //
   8 //===----------------------------------------------------------------------===//
   9 /// \file
  10 ///
  11 /// This file implements the DispatchStatistics interface.
  12 ///
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "Views/DispatchStatistics.h"
  16 #include "llvm/Support/Format.h"
  17
  18 namespace llvm {
  19 namespace mca {
  20
  21 void DispatchStatistics::onEvent(const HWStallEvent &Event) {
  22   if (Event.Type < HWStallEvent::LastGenericEvent)
  23     HWStalls[Event.Type]++;
  24 }
  25
  26 void DispatchStatistics::onEvent(const HWInstructionEvent &Event) {
  27   if (Event.Type != HWInstructionEvent::Dispatched)
  28     return;
  29
  30   const auto &DE = static_cast<const HWInstructionDispatchedEvent &>(Event);
  31   NumDispatched += DE.MicroOpcodes;
  32 }
  33
  34 void DispatchStatistics::printDispatchHistogram(raw_ostream &OS) const {
  35   std::string Buffer;
  36   raw_string_ostream TempStream(Buffer);
  37   TempStream << "\n\nDispatch Logic - "
  38              << "number of cycles where we saw N micro opcodes dispatched:\n";
  39   TempStream << "[# dispatched], [# cycles]\n";
  40   for (const std::pair<const unsigned, unsigned> &Entry :
  41        DispatchGroupSizePerCycle) {
  42     double Percentage = ((double)Entry.second / NumCycles) * 100.0;
  43     TempStream << " " << Entry.first << ",              " << Entry.second
  44                << "  (" << format("%.1f", floor((Percentage * 10) + 0.5) / 10)
  45                << "%)\n";
  46   }
  47
  48   TempStream.flush();
  49   OS << Buffer;
  50 }
  51
  52 static void printStalls(raw_ostream &OS, unsigned NumStalls,
  53                         unsigned NumCycles) {
  54   if (!NumStalls) {
  55     OS << NumStalls;
  56     return;
  57   }
  58
  59   double Percentage = ((double)NumStalls / NumCycles) * 100.0;
  60   OS << NumStalls << "  ("
  61      << format("%.1f", floor((Percentage * 10) + 0.5) / 10) << "%)";
  62 }
  63
  64 void DispatchStatistics::printDispatchStalls(raw_ostream &OS) const {
  65   std::string Buffer;
  66   raw_string_ostream SS(Buffer);
  67   SS << "\n\nDynamic Dispatch Stall Cycles:\n";
  68   SS << "RAT     - Register unavailable:                      ";
  69   printStalls(SS, HWStalls[HWStallEvent::RegisterFileStall], NumCycles);
  70   SS << "\nRCU     - Retire tokens unavailable:                 ";
  71   printStalls(SS, HWStalls[HWStallEvent::RetireControlUnitStall], NumCycles);
  72   SS << "\nSCHEDQ  - Scheduler full:                            ";
  73   printStalls(SS, HWStalls[HWStallEvent::SchedulerQueueFull], NumCycles);
  74   SS << "\nLQ      - Load queue full:                           ";
  75   printStalls(SS, HWStalls[HWStallEvent::LoadQueueFull], NumCycles);
  76   SS << "\nSQ      - Store queue full:                          ";
  77   printStalls(SS, HWStalls[HWStallEvent::StoreQueueFull], NumCycles);
  78   SS << "\nGROUP   - Static restrictions on the dispatch group: ";
  79   printStalls(SS, HWStalls[HWStallEvent::DispatchGroupStall], NumCycles);
  80   SS << '\n';
  81   SS.flush();
  82   OS << Buffer;
  83 }
  84
  85 } // namespace mca
  86 } // namespace llvm