1//===--- StackMapLivenessAnalysis - StackMap Liveness Analysis --*- 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// This pass calculates the liveness for each basic block in a function and
11// attaches the register live-out information to a patchpoint intrinsic (if
12// present).
13//
14//===----------------------------------------------------------------------===//
15
16#ifndef LLVM_CODEGEN_STACKMAP_LIVENESS_ANALYSIS_H
17#define LLVM_CODEGEN_STACKMAP_LIVENESS_ANALYSIS_H
18
19#include "llvm/CodeGen/LivePhysRegs.h"
20#include "llvm/CodeGen/MachineFunctionPass.h"
21
22
23namespace llvm {
24
25/// \brief This pass calculates the liveness information for each basic block in
26/// a function and attaches the register live-out information to a patchpoint
27/// intrinsic if present.
28///
29/// This pass can be disabled via the -enable-patchpoint-liveness=false flag.
30/// The pass skips functions that don't have any patchpoint intrinsics. The
31/// information provided by this pass is optional and not required by the
32/// aformentioned intrinsic to function.
33class StackMapLiveness : public MachineFunctionPass {
34  MachineFunction *MF;
35  const TargetRegisterInfo *TRI;
36  LivePhysRegs LiveRegs;
37public:
38  static char ID;
39
40  /// \brief Default construct and initialize the pass.
41  StackMapLiveness();
42
43  /// \brief Tell the pass manager which passes we depend on and what
44  /// information we preserve.
45  void getAnalysisUsage(AnalysisUsage &AU) const override;
46
47  /// \brief Calculate the liveness information for the given machine function.
48  bool runOnMachineFunction(MachineFunction &MF) override;
49
50private:
51  /// \brief Performs the actual liveness calculation for the function.
52  bool calculateLiveness();
53
54  /// \brief Add the current register live set to the instruction.
55  void addLiveOutSetToMI(MachineInstr &MI);
56
57  /// \brief Create a register mask and initialize it with the registers from
58  /// the register live set.
59  uint32_t *createRegisterMask() const;
60};
61
62} // llvm namespace
63
64#endif // LLVM_CODEGEN_STACKMAP_LIVENESS_ANALYSIS_H
65