tools/llvm-mca/Views/RegisterFileStatistics.h

   1 //===--------------------- RegisterFileStatistics.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 view collects and prints register file usage statistics.
  11 ///
  12 /// Example  (-mcpu=btver2):
  13 /// ========================
  14 ///
  15 /// Register File statistics:
  16 /// Total number of mappings created:    6
  17 /// Max number of mappings used:         3
  18 ///
  19 /// *  Register File #1 -- FpuPRF:
  20 ///    Number of physical registers:     72
  21 ///    Total number of mappings created: 0
  22 ///    Max number of mappings used:      0
  23 ///    Number of optimizable moves:      200
  24 ///    Number of moves eliminated:       200 (100.0%)
  25 ///    Number of zero moves:             200 (100.0%)
  26 ///    Max moves eliminated per cycle:   2
  27 ///
  28 /// *  Register File #2 -- IntegerPRF:
  29 ///    Number of physical registers:     64
  30 ///    Total number of mappings created: 6
  31 ///    Max number of mappings used:      3
  32 //
  33 //===----------------------------------------------------------------------===//
  34
  35 #ifndef LLVM_TOOLS_LLVM_MCA_REGISTERFILESTATISTICS_H
  36 #define LLVM_TOOLS_LLVM_MCA_REGISTERFILESTATISTICS_H
  37
  38 #include "Views/View.h"
  39 #include "llvm/ADT/SmallVector.h"
  40 #include "llvm/MC/MCSubtargetInfo.h"
  41
  42 namespace llvm {
  43 namespace mca {
  44
  45 class RegisterFileStatistics : public View {
  46   const llvm::MCSubtargetInfo &STI;
  47
  48   // Used to track the number of physical registers used in a register file.
  49   struct RegisterFileUsage {
  50     unsigned TotalMappings;
  51     unsigned MaxUsedMappings;
  52     unsigned CurrentlyUsedMappings;
  53   };
  54
  55   struct MoveEliminationInfo {
  56     unsigned TotalMoveEliminationCandidates;
  57     unsigned TotalMovesEliminated;
  58     unsigned TotalMovesThatPropagateZero;
  59     unsigned MaxMovesEliminatedPerCycle;
  60     unsigned CurrentMovesEliminated;
  61   };
  62
  63   // There is one entry for each register file implemented by the processor.
  64   llvm::SmallVector<RegisterFileUsage, 4> PRFUsage;
  65   llvm::SmallVector<MoveEliminationInfo, 4> MoveElimInfo;
  66
  67   void updateRegisterFileUsage(ArrayRef<unsigned> UsedPhysRegs);
  68   void updateMoveElimInfo(const Instruction &Inst);
  69
  70 public:
  71   RegisterFileStatistics(const llvm::MCSubtargetInfo &sti);
  72
  73   void onCycleEnd() override;
  74   void onEvent(const HWInstructionEvent &Event) override;
  75   void printView(llvm::raw_ostream &OS) const override;
  76 };
  77 } // namespace mca
  78 } // namespace llvm
  79
  80 #endif