1 //===-------------------------- CodeRegion.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 /// This file implements class CodeRegion and CodeRegions.
12 ///
13 /// A CodeRegion describes a region of assembly code guarded by special LLVM-MCA
14 /// comment directives.
15 ///
16 ///   # LLVM-MCA-BEGIN foo
17 ///     ...  ## asm
18 ///   # LLVM-MCA-END
19 ///
20 /// A comment starting with substring LLVM-MCA-BEGIN marks the beginning of a
21 /// new region of code.
22 /// A comment starting with substring LLVM-MCA-END marks the end of the
23 /// last-seen region of code.
24 ///
25 /// Code regions are not allowed to overlap. Each region can have a optional
26 /// description; internally, regions are described by a range of source
27 /// locations (SMLoc objects).
28 ///
29 /// An instruction (a MCInst) is added to a region R only if its location is in
30 /// range [R.RangeStart, R.RangeEnd].
31 //
32 //===----------------------------------------------------------------------===//
33 
34 #ifndef LLVM_TOOLS_LLVM_MCA_CODEREGION_H
35 #define LLVM_TOOLS_LLVM_MCA_CODEREGION_H
36 
37 #include "llvm/ADT/ArrayRef.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   std::vector<llvm::MCInst> 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:
CodeRegion(llvm::StringRef Desc,llvm::SMLoc Start)63   CodeRegion(llvm::StringRef Desc, llvm::SMLoc Start)
64       : Description(Desc), RangeStart(Start), RangeEnd() {}
65 
addInstruction(const llvm::MCInst & Instruction)66   void addInstruction(const llvm::MCInst &Instruction) {
67     Instructions.emplace_back(Instruction);
68   }
69 
startLoc()70   llvm::SMLoc startLoc() const { return RangeStart; }
endLoc()71   llvm::SMLoc endLoc() const { return RangeEnd; }
72 
setEndLocation(llvm::SMLoc End)73   void setEndLocation(llvm::SMLoc End) { RangeEnd = End; }
empty()74   bool empty() const { return Instructions.empty(); }
75   bool isLocInRange(llvm::SMLoc Loc) const;
76 
getInstructions()77   llvm::ArrayRef<llvm::MCInst> getInstructions() const { return Instructions; }
78 
getDescription()79   llvm::StringRef getDescription() const { return Description; }
80 };
81 
82 class CodeRegions {
83   // A source manager. Used by the tool to generate meaningful warnings.
84   llvm::SourceMgr &SM;
85 
86   std::vector<std::unique_ptr<CodeRegion>> Regions;
87 
88   // Construct a new region of code guarded by LLVM-MCA comments.
addRegion(llvm::StringRef Description,llvm::SMLoc Loc)89   void addRegion(llvm::StringRef Description, llvm::SMLoc Loc) {
90     Regions.emplace_back(llvm::make_unique<CodeRegion>(Description, Loc));
91   }
92 
93   CodeRegions(const CodeRegions &) = delete;
94   CodeRegions &operator=(const CodeRegions &) = delete;
95 
96 public:
97   typedef std::vector<std::unique_ptr<CodeRegion>>::iterator iterator;
98   typedef std::vector<std::unique_ptr<CodeRegion>>::const_iterator
99       const_iterator;
100 
begin()101   iterator begin() { return Regions.begin(); }
end()102   iterator end() { return Regions.end(); }
begin()103   const_iterator begin() const { return Regions.cbegin(); }
end()104   const_iterator end() const { return Regions.cend(); }
105 
106   void beginRegion(llvm::StringRef Description, llvm::SMLoc Loc);
107   void endRegion(llvm::SMLoc Loc);
108   void addInstruction(const llvm::MCInst &Instruction);
getSourceMgr()109   llvm::SourceMgr &getSourceMgr() const { return SM; }
110 
CodeRegions(llvm::SourceMgr & S)111   CodeRegions(llvm::SourceMgr &S) : SM(S) {
112     // Create a default region for the input code sequence.
113     addRegion("Default", llvm::SMLoc());
114   }
115 
getInstructionSequence(unsigned Idx)116   llvm::ArrayRef<llvm::MCInst> getInstructionSequence(unsigned Idx) const {
117     return Regions[Idx]->getInstructions();
118   }
119 
empty()120   bool empty() const {
121     return llvm::all_of(Regions, [](const std::unique_ptr<CodeRegion> &Region) {
122       return Region->empty();
123     });
124   }
125 };
126 
127 } // namespace mca
128 } // namespace llvm
129 
130 #endif
131