1 //===-- X86TargetFrameLowering.h - Define frame lowering for X86 -*- 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 class implements X86-specific bits of TargetFrameLowering class.
11 //
12 //===----------------------------------------------------------------------===//
13 
14 #ifndef LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
15 #define LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
16 
17 #include "llvm/Target/TargetFrameLowering.h"
18 
19 namespace llvm {
20 
21 class MCSymbol;
22 class X86TargetMachine;
23 class X86Subtarget;
24 
25 class X86FrameLowering : public TargetFrameLowering {
26 public:
27   explicit X86FrameLowering(StackDirection D, unsigned StackAl, int LAO)
28     : TargetFrameLowering(StackGrowsDown, StackAl, LAO) {}
29 
30   static void getStackProbeFunction(const X86Subtarget &STI,
31                                     unsigned &CallOp,
32                                     const char *&Symbol);
33 
34   void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
35                                  MachineBasicBlock::iterator MBBI,
36                                  DebugLoc DL) const;
37 
38   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
39   /// the function.
40   void emitPrologue(MachineFunction &MF) const override;
41   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
42 
43   void adjustForSegmentedStacks(MachineFunction &MF) const override;
44 
45   void adjustForHiPEPrologue(MachineFunction &MF) const override;
46 
47   void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
48                                      RegScavenger *RS = nullptr) const override;
49 
50   bool
51   assignCalleeSavedSpillSlots(MachineFunction &MF,
52                               const TargetRegisterInfo *TRI,
53                               std::vector<CalleeSavedInfo> &CSI) const override;
54 
55   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
56                                  MachineBasicBlock::iterator MI,
57                                  const std::vector<CalleeSavedInfo> &CSI,
58                                  const TargetRegisterInfo *TRI) const override;
59 
60   bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
61                                   MachineBasicBlock::iterator MI,
62                                   const std::vector<CalleeSavedInfo> &CSI,
63                                   const TargetRegisterInfo *TRI) const override;
64 
65   bool hasFP(const MachineFunction &MF) const override;
66   bool hasReservedCallFrame(const MachineFunction &MF) const override;
67 
68   int getFrameIndexOffset(const MachineFunction &MF, int FI) const override;
69   int getFrameIndexReference(const MachineFunction &MF, int FI,
70                              unsigned &FrameReg) const override;
71 
72   int getFrameIndexOffsetFromSP(const MachineFunction &MF, int FI) const;
73   int getFrameIndexReferenceFromSP(const MachineFunction &MF, int FI,
74                                    unsigned &FrameReg) const override;
75 
76   void eliminateCallFramePseudoInstr(MachineFunction &MF,
77                                  MachineBasicBlock &MBB,
78                                  MachineBasicBlock::iterator MI) const override;
79 
80 private:
81   /// convertArgMovsToPushes - This method tries to convert a call sequence
82   /// that uses sub and mov instructions to put the argument onto the stack
83   /// into a series of pushes.
84   /// Returns true if the transformation succeeded, false if not.
85   bool convertArgMovsToPushes(MachineFunction &MF,
86                               MachineBasicBlock &MBB,
87                               MachineBasicBlock::iterator I,
88                               uint64_t Amount) const;
89 };
90 
91 } // End llvm namespace
92 
93 #endif
94