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1 //===--------------------- InstrBuilder.h -----------------------*- C++ -*-===//
2 //
3 //                     The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //
8 //===----------------------------------------------------------------------===//
9 /// \file
10 ///
11 /// A builder class for instructions that are statically analyzed by llvm-mca.
12 //
13 //===----------------------------------------------------------------------===//
14 
15 #ifndef LLVM_TOOLS_LLVM_MCA_INSTRBUILDER_H
16 #define LLVM_TOOLS_LLVM_MCA_INSTRBUILDER_H
17 
18 #include "Instruction.h"
19 #include "Support.h"
20 #include "llvm/MC/MCInstPrinter.h"
21 #include "llvm/MC/MCInstrAnalysis.h"
22 #include "llvm/MC/MCInstrInfo.h"
23 #include "llvm/MC/MCRegisterInfo.h"
24 #include "llvm/MC/MCSubtargetInfo.h"
25 
26 namespace mca {
27 
28 class DispatchUnit;
29 
30 /// A builder class that knows how to construct Instruction objects.
31 ///
32 /// Every llvm-mca Instruction is described by an object of class InstrDesc.
33 /// An InstrDesc describes which registers are read/written by the instruction,
34 /// as well as the instruction latency and hardware resources consumed.
35 ///
36 /// This class is used by the tool to construct Instructions and instruction
37 /// descriptors (i.e. InstrDesc objects).
38 /// Information from the machine scheduling model is used to identify processor
39 /// resources that are consumed by an instruction.
40 class InstrBuilder {
41   const llvm::MCSubtargetInfo &STI;
42   const llvm::MCInstrInfo &MCII;
43   const llvm::MCRegisterInfo &MRI;
44   const llvm::MCInstrAnalysis &MCIA;
45   llvm::MCInstPrinter &MCIP;
46   llvm::SmallVector<uint64_t, 8> ProcResourceMasks;
47 
48   llvm::DenseMap<unsigned short, std::unique_ptr<const InstrDesc>> Descriptors;
49   llvm::DenseMap<const llvm::MCInst *, std::unique_ptr<const InstrDesc>>
50       VariantDescriptors;
51 
52   const InstrDesc &createInstrDescImpl(const llvm::MCInst &MCI);
53   InstrBuilder(const InstrBuilder &) = delete;
54   InstrBuilder &operator=(const InstrBuilder &) = delete;
55 
56   void populateWrites(InstrDesc &ID, const llvm::MCInst &MCI,
57                       unsigned SchedClassID);
58   void populateReads(InstrDesc &ID, const llvm::MCInst &MCI,
59                      unsigned SchedClassID);
60 
61 public:
InstrBuilder(const llvm::MCSubtargetInfo & sti,const llvm::MCInstrInfo & mcii,const llvm::MCRegisterInfo & mri,const llvm::MCInstrAnalysis & mcia,llvm::MCInstPrinter & mcip)62   InstrBuilder(const llvm::MCSubtargetInfo &sti, const llvm::MCInstrInfo &mcii,
63                const llvm::MCRegisterInfo &mri,
64                const llvm::MCInstrAnalysis &mcia, llvm::MCInstPrinter &mcip)
65       : STI(sti), MCII(mcii), MRI(mri), MCIA(mcia), MCIP(mcip),
66         ProcResourceMasks(STI.getSchedModel().getNumProcResourceKinds()) {
67     computeProcResourceMasks(STI.getSchedModel(), ProcResourceMasks);
68   }
69 
70   const InstrDesc &getOrCreateInstrDesc(const llvm::MCInst &MCI);
71   // Returns an array of processor resource masks.
72   // Masks are computed by function mca::computeProcResourceMasks. see
73   // Support.h for a description of how masks are computed and how masks can be
74   // used to solve set membership problems.
getProcResourceMasks()75   llvm::ArrayRef<uint64_t> getProcResourceMasks() const {
76     return ProcResourceMasks;
77   }
78 
clear()79   void clear() { VariantDescriptors.shrink_and_clear(); }
80 
81   std::unique_ptr<Instruction> createInstruction(const llvm::MCInst &MCI);
82 };
83 } // namespace mca
84 
85 #endif
86