1 //===-- llvm/CodeGen/AsmPrinter/DbgValueHistoryCalculator.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 
10 #ifndef LLVM_LIB_CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H
11 #define LLVM_LIB_CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H
12 
13 #include "llvm/ADT/MapVector.h"
14 #include "llvm/ADT/SmallVector.h"
15 
16 namespace llvm {
17 
18 class MachineFunction;
19 class MachineInstr;
20 class MDLocalVariable;
21 class MDLocation;
22 class TargetRegisterInfo;
23 
24 // For each user variable, keep a list of instruction ranges where this variable
25 // is accessible. The variables are listed in order of appearance.
26 class DbgValueHistoryMap {
27   // Each instruction range starts with a DBG_VALUE instruction, specifying the
28   // location of a variable, which is assumed to be valid until the end of the
29   // range. If end is not specified, location is valid until the start
30   // instruction of the next instruction range, or until the end of the
31   // function.
32 public:
33   typedef std::pair<const MachineInstr *, const MachineInstr *> InstrRange;
34   typedef SmallVector<InstrRange, 4> InstrRanges;
35   typedef std::pair<const MDLocalVariable *, const MDLocation *>
36       InlinedVariable;
37   typedef MapVector<InlinedVariable, InstrRanges> InstrRangesMap;
38 
39 private:
40   InstrRangesMap VarInstrRanges;
41 
42 public:
43   void startInstrRange(InlinedVariable Var, const MachineInstr &MI);
44   void endInstrRange(InlinedVariable Var, const MachineInstr &MI);
45   // Returns register currently describing @Var. If @Var is currently
46   // unaccessible or is not described by a register, returns 0.
47   unsigned getRegisterForVar(InlinedVariable Var) const;
48 
empty()49   bool empty() const { return VarInstrRanges.empty(); }
clear()50   void clear() { VarInstrRanges.clear(); }
begin()51   InstrRangesMap::const_iterator begin() const { return VarInstrRanges.begin(); }
end()52   InstrRangesMap::const_iterator end() const { return VarInstrRanges.end(); }
53 };
54 
55 void calculateDbgValueHistory(const MachineFunction *MF,
56                               const TargetRegisterInfo *TRI,
57                               DbgValueHistoryMap &Result);
58 }
59 
60 #endif
61