1 //===-------------------------- CodeRegion.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 file implements class CodeRegion and CodeRegions.
11 ///
12 /// A CodeRegion describes a region of assembly code guarded by special LLVM-MCA
13 /// comment directives.
14 ///
15 ///   # LLVM-MCA-BEGIN foo
16 ///     ...  ## asm
17 ///   # LLVM-MCA-END
18 ///
19 /// A comment starting with substring LLVM-MCA-BEGIN marks the beginning of a
20 /// new region of code.
21 /// A comment starting with substring LLVM-MCA-END marks the end of the
22 /// last-seen region of code.
23 ///
24 /// Code regions are not allowed to overlap. Each region can have a optional
25 /// description; internally, regions are described by a range of source
26 /// locations (SMLoc objects).
27 ///
28 /// An instruction (a MCInst) is added to a region R only if its location is in
29 /// range [R.RangeStart, R.RangeEnd].
30 //
31 //===----------------------------------------------------------------------===//
32 
33 #ifndef LLVM_TOOLS_LLVM_MCA_CODEREGION_H
34 #define LLVM_TOOLS_LLVM_MCA_CODEREGION_H
35 
36 #include "llvm/ADT/ArrayRef.h"
37 #include "llvm/ADT/SmallVector.h"
38 #include "llvm/ADT/StringRef.h"
39 #include "llvm/MC/MCInst.h"
40 #include "llvm/Support/SMLoc.h"
41 #include "llvm/Support/SourceMgr.h"
42 #include <vector>
43 
44 namespace llvm {
45 namespace mca {
46 
47 /// A region of assembly code.
48 ///
49 /// It identifies a sequence of machine instructions.
50 class CodeRegion {
51   // An optional descriptor for this region.
52   llvm::StringRef Description;
53   // Instructions that form this region.
54   llvm::SmallVector<llvm::MCInst, 8> Instructions;
55   // Source location range.
56   llvm::SMLoc RangeStart;
57   llvm::SMLoc RangeEnd;
58 
59   CodeRegion(const CodeRegion &) = delete;
60   CodeRegion &operator=(const CodeRegion &) = delete;
61 
62 public:
63   CodeRegion(llvm::StringRef Desc, llvm::SMLoc Start)
64       : Description(Desc), RangeStart(Start), RangeEnd() {}
65 
66   void addInstruction(const llvm::MCInst &Instruction) {
67     Instructions.emplace_back(Instruction);
68   }
69 
70   llvm::SMLoc startLoc() const { return RangeStart; }
71   llvm::SMLoc endLoc() const { return RangeEnd; }
72 
73   void setEndLocation(llvm::SMLoc End) { RangeEnd = End; }
74   bool empty() const { return Instructions.empty(); }
75   bool isLocInRange(llvm::SMLoc Loc) const;
76 
77   llvm::ArrayRef<llvm::MCInst> getInstructions() const { return Instructions; }
78 
79   llvm::StringRef getDescription() const { return Description; }
80 };
81 
82 class CodeRegionParseError final : public Error {};
83 
84 class CodeRegions {
85   // A source manager. Used by the tool to generate meaningful warnings.
86   llvm::SourceMgr &SM;
87 
88   using UniqueCodeRegion = std::unique_ptr<CodeRegion>;
89   std::vector<UniqueCodeRegion> Regions;
90   llvm::StringMap<unsigned> ActiveRegions;
91   bool FoundErrors;
92 
93   CodeRegions(const CodeRegions &) = delete;
94   CodeRegions &operator=(const CodeRegions &) = delete;
95 
96 public:
97   CodeRegions(llvm::SourceMgr &S);
98 
99   typedef std::vector<UniqueCodeRegion>::iterator iterator;
100   typedef std::vector<UniqueCodeRegion>::const_iterator const_iterator;
101 
102   iterator begin() { return Regions.begin(); }
103   iterator end() { return Regions.end(); }
104   const_iterator begin() const { return Regions.cbegin(); }
105   const_iterator end() const { return Regions.cend(); }
106 
107   void beginRegion(llvm::StringRef Description, llvm::SMLoc Loc);
108   void endRegion(llvm::StringRef Description, llvm::SMLoc Loc);
109   void addInstruction(const llvm::MCInst &Instruction);
110   llvm::SourceMgr &getSourceMgr() const { return SM; }
111 
112   llvm::ArrayRef<llvm::MCInst> getInstructionSequence(unsigned Idx) const {
113     return Regions[Idx]->getInstructions();
114   }
115 
116   bool empty() const {
117     return llvm::all_of(Regions, [](const UniqueCodeRegion &Region) {
118       return Region->empty();
119     });
120   }
121 
122   bool isValid() const { return !FoundErrors; }
123 };
124 
125 } // namespace mca
126 } // namespace llvm
127 
128 #endif
129