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 
clear()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
77