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 X86_FRAMELOWERING_H 15 #define X86_FRAMELOWERING_H 16 17 #include "X86Subtarget.h" 18 #include "llvm/MC/MCDwarf.h" 19 #include "llvm/Target/TargetFrameLowering.h" 20 21 namespace llvm { 22 23 namespace CU { 24 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, 30 31 /// A frameless function with a small constant stack size. 32 UNWIND_MODE_STACK_IMMD = 0x02000000, 33 34 /// A frameless function with a large constant stack size. 35 UNWIND_MODE_STACK_IND = 0x03000000, 36 37 /// No compact unwind encoding is available. 38 UNWIND_MODE_DWARF = 0x04000000, 39 40 /// Mask for encoding the frame registers. 41 UNWIND_BP_FRAME_REGISTERS = 0x00007FFF, 42 43 /// Mask for encoding the frameless registers. 44 UNWIND_FRAMELESS_STACK_REG_PERMUTATION = 0x000003FF 45 }; 46 47 } // end CU namespace 48 49 class MCSymbol; 50 class X86TargetMachine; 51 52 class X86FrameLowering : public TargetFrameLowering { 53 const X86TargetMachine &TM; 54 const X86Subtarget &STI; 55 public: 56 explicit X86FrameLowering(const X86TargetMachine &tm, const X86Subtarget &sti) 57 : TargetFrameLowering(StackGrowsDown, 58 sti.getStackAlignment(), 59 (sti.is64Bit() ? -8 : -4)), 60 TM(tm), STI(sti) { 61 } 62 63 void emitCalleeSavedFrameMoves(MachineFunction &MF, MCSymbol *Label, 64 unsigned FramePtr) const; 65 66 /// emitProlog/emitEpilog - These methods insert prolog and epilog code into 67 /// the function. 68 void emitPrologue(MachineFunction &MF) const; 69 void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const; 70 71 void adjustForSegmentedStacks(MachineFunction &MF) const; 72 73 void adjustForHiPEPrologue(MachineFunction &MF) const; 74 75 void processFunctionBeforeCalleeSavedScan(MachineFunction &MF, 76 RegScavenger *RS = NULL) const; 77 78 bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, 79 MachineBasicBlock::iterator MI, 80 const std::vector<CalleeSavedInfo> &CSI, 81 const TargetRegisterInfo *TRI) const; 82 83 bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB, 84 MachineBasicBlock::iterator MI, 85 const std::vector<CalleeSavedInfo> &CSI, 86 const TargetRegisterInfo *TRI) const; 87 88 bool hasFP(const MachineFunction &MF) const; 89 bool hasReservedCallFrame(const MachineFunction &MF) const; 90 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; 95 96 void eliminateCallFramePseudoInstr(MachineFunction &MF, 97 MachineBasicBlock &MBB, 98 MachineBasicBlock::iterator MI) const; 99 }; 100 101 } // End llvm namespace 102 103 #endif 104
