include/llvm/MCA/InstrBuilder.h

   1 //===--------------------- InstrBuilder.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 /// A builder class for instructions that are statically analyzed by llvm-mca.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef LLVM_MCA_INSTRBUILDER_H
  15 #define LLVM_MCA_INSTRBUILDER_H
  16
  17 #include "llvm/MC/MCInstrAnalysis.h"
  18 #include "llvm/MC/MCInstrInfo.h"
  19 #include "llvm/MC/MCRegisterInfo.h"
  20 #include "llvm/MC/MCSubtargetInfo.h"
  21 #include "llvm/MCA/Instruction.h"
  22 #include "llvm/MCA/Support.h"
  23 #include "llvm/Support/Error.h"
  24
  25 namespace llvm {
  26 namespace mca {
  27
  28 /// A builder class that knows how to construct Instruction objects.
  29 ///
  30 /// Every llvm-mca Instruction is described by an object of class InstrDesc.
  31 /// An InstrDesc describes which registers are read/written by the instruction,
  32 /// as well as the instruction latency and hardware resources consumed.
  33 ///
  34 /// This class is used by the tool to construct Instructions and instruction
  35 /// descriptors (i.e. InstrDesc objects).
  36 /// Information from the machine scheduling model is used to identify processor
  37 /// resources that are consumed by an instruction.
  38 class InstrBuilder {
  39   const MCSubtargetInfo &STI;
  40   const MCInstrInfo &MCII;
  41   const MCRegisterInfo &MRI;
  42   const MCInstrAnalysis *MCIA;
  43   SmallVector<uint64_t, 8> ProcResourceMasks;
  44
  45   DenseMap<unsigned short, std::unique_ptr<const InstrDesc>> Descriptors;
  46   DenseMap<const MCInst *, std::unique_ptr<const InstrDesc>> VariantDescriptors;
  47
  48   bool FirstCallInst;
  49   bool FirstReturnInst;
  50
  51   Expected<const InstrDesc &> createInstrDescImpl(const MCInst &MCI);
  52   Expected<const InstrDesc &> getOrCreateInstrDesc(const MCInst &MCI);
  53
  54   InstrBuilder(const InstrBuilder &) = delete;
  55   InstrBuilder &operator=(const InstrBuilder &) = delete;
  56
  57   void populateWrites(InstrDesc &ID, const MCInst &MCI, unsigned SchedClassID);
  58   void populateReads(InstrDesc &ID, const MCInst &MCI, unsigned SchedClassID);
  59   Error verifyInstrDesc(const InstrDesc &ID, const MCInst &MCI) const;
  60
  61 public:
  62   InstrBuilder(const MCSubtargetInfo &STI, const MCInstrInfo &MCII,
  63                const MCRegisterInfo &RI, const MCInstrAnalysis *IA);
  64
  65   void clear() {
  66     VariantDescriptors.shrink_and_clear();
  67     FirstCallInst = true;
  68     FirstReturnInst = true;
  69   }
  70
  71   Expected<std::unique_ptr<Instruction>> createInstruction(const MCInst &MCI);
  72 };
  73 } // namespace mca
  74 } // namespace llvm
  75
  76 #endif // LLVM_MCA_INSTRBUILDER_H