1 //===-- PPCFrameLowering.h - Define frame lowering for PowerPC --*- 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 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_POWERPC_PPCFRAMELOWERING_H
14 #define LLVM_LIB_TARGET_POWERPC_PPCFRAMELOWERING_H
15 
16 #include "PPC.h"
17 #include "llvm/ADT/STLExtras.h"
18 #include "llvm/Target/TargetFrameLowering.h"
19 #include "llvm/Target/TargetMachine.h"
20 
21 namespace llvm {
22 class PPCSubtarget;
23 
24 class PPCFrameLowering: public TargetFrameLowering {
25   const PPCSubtarget &Subtarget;
26   const unsigned ReturnSaveOffset;
27   const unsigned TOCSaveOffset;
28   const unsigned FramePointerSaveOffset;
29   const unsigned LinkageSize;
30   const unsigned BasePointerSaveOffset;
31 
32 public:
33   PPCFrameLowering(const PPCSubtarget &STI);
34 
35   unsigned determineFrameLayout(MachineFunction &MF,
36                                 bool UpdateMF = true,
37                                 bool UseEstimate = false) const;
38 
39   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
40   /// the function.
41   void emitPrologue(MachineFunction &MF) const override;
42   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
43 
44   bool hasFP(const MachineFunction &MF) const override;
45   bool needsFP(const MachineFunction &MF) const;
46   void replaceFPWithRealFP(MachineFunction &MF) const;
47 
48   void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
49                                      RegScavenger *RS = nullptr) const override;
50   void processFunctionBeforeFrameFinalized(MachineFunction &MF,
51                                      RegScavenger *RS = nullptr) const override;
52   void addScavengingSpillSlot(MachineFunction &MF, RegScavenger *RS) const;
53 
54   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
55                                  MachineBasicBlock::iterator MI,
56                                  const std::vector<CalleeSavedInfo> &CSI,
57                                  const TargetRegisterInfo *TRI) const override;
58 
59   void eliminateCallFramePseudoInstr(MachineFunction &MF,
60                                   MachineBasicBlock &MBB,
61                                   MachineBasicBlock::iterator I) const override;
62 
63   bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
64                                   MachineBasicBlock::iterator MI,
65                                   const std::vector<CalleeSavedInfo> &CSI,
66                                   const TargetRegisterInfo *TRI) const override;
67 
68   /// targetHandlesStackFrameRounding - Returns true if the target is
69   /// responsible for rounding up the stack frame (probably at emitPrologue
70   /// time).
targetHandlesStackFrameRounding()71   bool targetHandlesStackFrameRounding() const override { return true; }
72 
73   /// getReturnSaveOffset - Return the previous frame offset to save the
74   /// return address.
getReturnSaveOffset()75   unsigned getReturnSaveOffset() const { return ReturnSaveOffset; }
76 
77   /// getTOCSaveOffset - Return the previous frame offset to save the
78   /// TOC register -- 64-bit SVR4 ABI only.
getTOCSaveOffset()79   unsigned getTOCSaveOffset() const { return TOCSaveOffset; }
80 
81   /// getFramePointerSaveOffset - Return the previous frame offset to save the
82   /// frame pointer.
getFramePointerSaveOffset()83   unsigned getFramePointerSaveOffset() const { return FramePointerSaveOffset; }
84 
85   /// getBasePointerSaveOffset - Return the previous frame offset to save the
86   /// base pointer.
getBasePointerSaveOffset()87   unsigned getBasePointerSaveOffset() const { return BasePointerSaveOffset; }
88 
89   /// getLinkageSize - Return the size of the PowerPC ABI linkage area.
90   ///
getLinkageSize()91   unsigned getLinkageSize() const { return LinkageSize; }
92 
93   const SpillSlot *
94   getCalleeSavedSpillSlots(unsigned &NumEntries) const override;
95 };
96 } // End llvm namespace
97 
98 #endif
99