DbgValueHistoryCalculator.h revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f 
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 CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H_
11#define CODEGEN_ASMPRINTER_DBGVALUEHISTORYCALCULATOR_H_
12
13#include "llvm/ADT/MapVector.h"
14#include "llvm/ADT/SmallVector.h"
15
16namespace llvm {
17
18class MachineFunction;
19class MachineInstr;
20class MDNode;
21class TargetRegisterInfo;
22
23// For each user variable, keep a list of instruction ranges where this variable
24// is accessible. The variables are listed in order of appearance.
25class DbgValueHistoryMap {
26  // Each instruction range starts with a DBG_VALUE instruction, specifying the
27  // location of a variable, which is assumed to be valid until the end of the
28  // range. If end is not specified, location is valid until the start
29  // instruction of the next instruction range, or until the end of the
30  // function.
31  typedef std::pair<const MachineInstr *, const MachineInstr *> InstrRange;
32  typedef SmallVector<InstrRange, 4> InstrRanges;
33  typedef MapVector<const MDNode *, InstrRanges> InstrRangesMap;
34  InstrRangesMap VarInstrRanges;
35
36public:
37  void startInstrRange(const MDNode *Var, const MachineInstr &MI);
38  void endInstrRange(const MDNode *Var, const MachineInstr &MI);
39  // Returns register currently describing @Var. If @Var is currently
40  // unaccessible or is not described by a register, returns 0.
41  unsigned getRegisterForVar(const MDNode *Var) const;
42
43  bool empty() const { return VarInstrRanges.empty(); }
44  void clear() { VarInstrRanges.clear(); }
45  InstrRangesMap::const_iterator begin() const { return VarInstrRanges.begin(); }
46  InstrRangesMap::const_iterator end() const { return VarInstrRanges.end(); }
47};
48
49void calculateDbgValueHistory(const MachineFunction *MF,
50                              const TargetRegisterInfo *TRI,
51                              DbgValueHistoryMap &Result);
52}
53
54#endif
55