1 //===-- X86TargetFrameLowering.h - Define frame lowering for X86 -*- C++ -*-==//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This class implements X86-specific bits of TargetFrameLowering class.
12 //===----------------------------------------------------------------------===//
14 #ifndef X86_FRAMELOWERING_H
15 #define X86_FRAMELOWERING_H
17 #include "X86Subtarget.h"
18 #include "llvm/MC/MCDwarf.h"
19 #include "llvm/Target/TargetFrameLowering.h"
25 /// Compact unwind encoding values.
26 enum CompactUnwindEncodings {
27 /// [RE]BP based frame where [RE]BP is pused on the stack immediately after
28 /// the return address, then [RE]SP is moved to [RE]BP.
29 UNWIND_MODE_BP_FRAME = 0x01000000,
31 /// A frameless function with a small constant stack size.
32 UNWIND_MODE_STACK_IMMD = 0x02000000,
34 /// A frameless function with a large constant stack size.
35 UNWIND_MODE_STACK_IND = 0x03000000,
37 /// No compact unwind encoding is available.
38 UNWIND_MODE_DWARF = 0x04000000,
40 /// Mask for encoding the frame registers.
41 UNWIND_BP_FRAME_REGISTERS = 0x00007FFF,
43 /// Mask for encoding the frameless registers.
44 UNWIND_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF
50 class X86TargetMachine;
52 class X86FrameLowering : public TargetFrameLowering {
53 const X86TargetMachine &TM;
54 const X86Subtarget &STI;
56 explicit X86FrameLowering(const X86TargetMachine &tm, const X86Subtarget &sti)
57 : TargetFrameLowering(StackGrowsDown,
58 sti.getStackAlignment(),
59 (sti.is64Bit() ? -8 : -4)),
63 void emitCalleeSavedFrameMoves(MachineFunction &MF, MCSymbol *Label,
64 unsigned FramePtr) const;
66 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
68 void emitPrologue(MachineFunction &MF) const;
69 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const;
71 void adjustForSegmentedStacks(MachineFunction &MF) const;
73 void adjustForHiPEPrologue(MachineFunction &MF) const;
75 void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
76 RegScavenger *RS = NULL) const;
78 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
79 MachineBasicBlock::iterator MI,
80 const std::vector<CalleeSavedInfo> &CSI,
81 const TargetRegisterInfo *TRI) const;
83 bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
84 MachineBasicBlock::iterator MI,
85 const std::vector<CalleeSavedInfo> &CSI,
86 const TargetRegisterInfo *TRI) const;
88 bool hasFP(const MachineFunction &MF) const;
89 bool hasReservedCallFrame(const MachineFunction &MF) const;
91 int getFrameIndexOffset(const MachineFunction &MF, int FI) const;
92 int getFrameIndexReference(const MachineFunction &MF, int FI,
93 unsigned &FrameReg) const;
94 uint32_t getCompactUnwindEncoding(MachineFunction &MF) const;
96 void eliminateCallFramePseudoInstr(MachineFunction &MF,
97 MachineBasicBlock &MBB,
98 MachineBasicBlock::iterator MI) const;
101 } // End llvm namespace