forked from OSchip/llvm-project
				
			
		
			
				
	
	
		
			256 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
			
		
		
	
	
			256 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C++
		
	
	
	
| //===-- X86TargetFrameLowering.h - Define frame lowering for X86 -*- C++ -*-==//
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| //
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| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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| // See https://llvm.org/LICENSE.txt for license information.
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| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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| //
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| //===----------------------------------------------------------------------===//
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| //
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| // This class implements X86-specific bits of TargetFrameLowering class.
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| //
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| //===----------------------------------------------------------------------===//
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| 
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| #ifndef LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
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| #define LLVM_LIB_TARGET_X86_X86FRAMELOWERING_H
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| 
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| #include "llvm/CodeGen/TargetFrameLowering.h"
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| 
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| namespace llvm {
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| 
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| class MachineInstrBuilder;
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| class MCCFIInstruction;
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| class X86InstrInfo;
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| class X86Subtarget;
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| class X86RegisterInfo;
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| 
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| class X86FrameLowering : public TargetFrameLowering {
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| public:
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|   X86FrameLowering(const X86Subtarget &STI, MaybeAlign StackAlignOverride);
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| 
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|   // Cached subtarget predicates.
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| 
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|   const X86Subtarget &STI;
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|   const X86InstrInfo &TII;
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|   const X86RegisterInfo *TRI;
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| 
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|   unsigned SlotSize;
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| 
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|   /// Is64Bit implies that x86_64 instructions are available.
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|   bool Is64Bit;
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| 
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|   bool IsLP64;
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| 
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|   /// True if the 64-bit frame or stack pointer should be used. True for most
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|   /// 64-bit targets with the exception of x32. If this is false, 32-bit
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|   /// instruction operands should be used to manipulate StackPtr and FramePtr.
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|   bool Uses64BitFramePtr;
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| 
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|   unsigned StackPtr;
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| 
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|   /// Emit target stack probe code. This is required for all
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|   /// large stack allocations on Windows. The caller is required to materialize
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|   /// the number of bytes to probe in RAX/EAX.
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|   void emitStackProbe(MachineFunction &MF, MachineBasicBlock &MBB,
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|                       MachineBasicBlock::iterator MBBI, const DebugLoc &DL,
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|                       bool InProlog) const;
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| 
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|   /// Replace a StackProbe inline-stub with the actual probe code inline.
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|   void inlineStackProbe(MachineFunction &MF,
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|                         MachineBasicBlock &PrologMBB) const override;
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| 
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|   void emitCalleeSavedFrameMoves(MachineBasicBlock &MBB,
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|                                  MachineBasicBlock::iterator MBBI,
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|                                  const DebugLoc &DL, bool IsPrologue) const;
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| 
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|   /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
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|   /// the function.
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|   void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
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|   void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
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| 
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|   void adjustForSegmentedStacks(MachineFunction &MF,
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|                                 MachineBasicBlock &PrologueMBB) const override;
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| 
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|   void adjustForHiPEPrologue(MachineFunction &MF,
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|                              MachineBasicBlock &PrologueMBB) const override;
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| 
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|   void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
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|                             RegScavenger *RS = nullptr) const override;
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| 
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|   bool
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|   assignCalleeSavedSpillSlots(MachineFunction &MF,
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|                               const TargetRegisterInfo *TRI,
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|                               std::vector<CalleeSavedInfo> &CSI) const override;
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| 
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|   bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
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|                                  MachineBasicBlock::iterator MI,
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|                                  ArrayRef<CalleeSavedInfo> CSI,
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|                                  const TargetRegisterInfo *TRI) const override;
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| 
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|   bool
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|   restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
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|                               MachineBasicBlock::iterator MI,
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|                               MutableArrayRef<CalleeSavedInfo> CSI,
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|                               const TargetRegisterInfo *TRI) const override;
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| 
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|   bool hasFP(const MachineFunction &MF) const override;
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|   bool hasReservedCallFrame(const MachineFunction &MF) const override;
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|   bool canSimplifyCallFramePseudos(const MachineFunction &MF) const override;
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|   bool needsFrameIndexResolution(const MachineFunction &MF) const override;
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| 
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|   int getFrameIndexReference(const MachineFunction &MF, int FI,
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|                              unsigned &FrameReg) const override;
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| 
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|   int getWin64EHFrameIndexRef(const MachineFunction &MF,
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|                               int FI, unsigned &SPReg) const;
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|   int getFrameIndexReferenceSP(const MachineFunction &MF,
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|                                int FI, unsigned &SPReg, int Adjustment) const;
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|   int getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI,
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|                                      unsigned &FrameReg,
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|                                      bool IgnoreSPUpdates) const override;
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| 
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|   MachineBasicBlock::iterator
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|   eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB,
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|                                 MachineBasicBlock::iterator MI) const override;
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| 
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|   unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const override;
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| 
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|   void processFunctionBeforeFrameFinalized(MachineFunction &MF,
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|                                            RegScavenger *RS) const override;
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| 
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|   void
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|   processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF,
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|                                             RegScavenger *RS) const override;
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| 
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|   /// Check the instruction before/after the passed instruction. If
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|   /// it is an ADD/SUB/LEA instruction it is deleted argument and the
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|   /// stack adjustment is returned as a positive value for ADD/LEA and
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|   /// a negative for SUB.
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|   int mergeSPUpdates(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
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|                      bool doMergeWithPrevious) const;
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| 
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|   /// Emit a series of instructions to increment / decrement the stack
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|   /// pointer by a constant value.
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|   void emitSPUpdate(MachineBasicBlock &MBB, MachineBasicBlock::iterator &MBBI,
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|                     const DebugLoc &DL, int64_t NumBytes, bool InEpilogue) const;
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| 
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|   /// Check that LEA can be used on SP in an epilogue sequence for \p MF.
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|   bool canUseLEAForSPInEpilogue(const MachineFunction &MF) const;
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| 
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|   /// Check whether or not the given \p MBB can be used as a prologue
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|   /// for the target.
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|   /// The prologue will be inserted first in this basic block.
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|   /// This method is used by the shrink-wrapping pass to decide if
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|   /// \p MBB will be correctly handled by the target.
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|   /// As soon as the target enable shrink-wrapping without overriding
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|   /// this method, we assume that each basic block is a valid
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|   /// prologue.
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|   bool canUseAsPrologue(const MachineBasicBlock &MBB) const override;
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| 
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|   /// Check whether or not the given \p MBB can be used as a epilogue
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|   /// for the target.
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|   /// The epilogue will be inserted before the first terminator of that block.
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|   /// This method is used by the shrink-wrapping pass to decide if
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|   /// \p MBB will be correctly handled by the target.
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|   bool canUseAsEpilogue(const MachineBasicBlock &MBB) const override;
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| 
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|   /// Returns true if the target will correctly handle shrink wrapping.
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|   bool enableShrinkWrapping(const MachineFunction &MF) const override;
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| 
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|   /// Order the symbols in the local stack.
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|   /// We want to place the local stack objects in some sort of sensible order.
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|   /// The heuristic we use is to try and pack them according to static number
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|   /// of uses and size in order to minimize code size.
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|   void orderFrameObjects(const MachineFunction &MF,
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|                          SmallVectorImpl<int> &ObjectsToAllocate) const override;
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| 
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|   /// Wraps up getting a CFI index and building a MachineInstr for it.
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|   void BuildCFI(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI,
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|                 const DebugLoc &DL, const MCCFIInstruction &CFIInst) const;
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| 
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|   /// Sets up EBP and optionally ESI based on the incoming EBP value.  Only
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|   /// needed for 32-bit. Used in funclet prologues and at catchret destinations.
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|   MachineBasicBlock::iterator
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|   restoreWin32EHStackPointers(MachineBasicBlock &MBB,
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|                               MachineBasicBlock::iterator MBBI,
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|                               const DebugLoc &DL, bool RestoreSP = false) const;
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| 
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|   void restoreWinEHStackPointersInParent(MachineFunction &MF) const;
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| 
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|   int getInitialCFAOffset(const MachineFunction &MF) const override;
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| 
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|   unsigned getInitialCFARegister(const MachineFunction &MF) const override;
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| 
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|   /// Return true if the function has a redzone (accessible bytes past the
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|   /// frame of the top of stack function) as part of it's ABI.  
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|   bool has128ByteRedZone(const MachineFunction& MF) const;
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| 
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| private:
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|   uint64_t calculateMaxStackAlign(const MachineFunction &MF) const;
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| 
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|   /// Emit target stack probe as a call to a helper function
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|   void emitStackProbeCall(MachineFunction &MF, MachineBasicBlock &MBB,
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|                           MachineBasicBlock::iterator MBBI, const DebugLoc &DL,
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|                           bool InProlog) const;
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| 
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|   /// Emit target stack probe as an inline sequence.
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|   void emitStackProbeInline(MachineFunction &MF, MachineBasicBlock &MBB,
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|                             MachineBasicBlock::iterator MBBI,
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|                             const DebugLoc &DL, bool InProlog) const;
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|   void emitStackProbeInlineWindowsCoreCLR64(MachineFunction &MF,
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|                                             MachineBasicBlock &MBB,
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|                                             MachineBasicBlock::iterator MBBI,
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|                                             const DebugLoc &DL,
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|                                             bool InProlog) const;
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|   void emitStackProbeInlineGeneric(MachineFunction &MF, MachineBasicBlock &MBB,
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|                                    MachineBasicBlock::iterator MBBI,
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|                                    const DebugLoc &DL, bool InProlog) const;
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| 
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|   void emitStackProbeInlineGenericBlock(MachineFunction &MF,
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|                                         MachineBasicBlock &MBB,
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|                                         MachineBasicBlock::iterator MBBI,
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|                                         const DebugLoc &DL,
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|                                         uint64_t Offset) const;
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| 
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|   void emitStackProbeInlineGenericLoop(MachineFunction &MF,
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|                                        MachineBasicBlock &MBB,
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|                                        MachineBasicBlock::iterator MBBI,
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|                                        const DebugLoc &DL,
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|                                        uint64_t Offset) const;
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| 
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|   /// Emit a stub to later inline the target stack probe.
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|   MachineInstr *emitStackProbeInlineStub(MachineFunction &MF,
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|                                          MachineBasicBlock &MBB,
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|                                          MachineBasicBlock::iterator MBBI,
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|                                          const DebugLoc &DL,
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|                                          bool InProlog) const;
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| 
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|   /// Aligns the stack pointer by ANDing it with -MaxAlign.
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|   void BuildStackAlignAND(MachineBasicBlock &MBB,
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|                           MachineBasicBlock::iterator MBBI, const DebugLoc &DL,
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|                           unsigned Reg, uint64_t MaxAlign) const;
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| 
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|   /// Make small positive stack adjustments using POPs.
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|   bool adjustStackWithPops(MachineBasicBlock &MBB,
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|                            MachineBasicBlock::iterator MBBI, const DebugLoc &DL,
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|                            int Offset) const;
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| 
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|   /// Adjusts the stack pointer using LEA, SUB, or ADD.
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|   MachineInstrBuilder BuildStackAdjustment(MachineBasicBlock &MBB,
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|                                            MachineBasicBlock::iterator MBBI,
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|                                            const DebugLoc &DL, int64_t Offset,
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|                                            bool InEpilogue) const;
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| 
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|   unsigned getPSPSlotOffsetFromSP(const MachineFunction &MF) const;
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| 
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|   unsigned getWinEHFuncletFrameSize(const MachineFunction &MF) const;
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| 
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|   /// Materialize the catchret target MBB in RAX.
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|   void emitCatchRetReturnValue(MachineBasicBlock &MBB,
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|                                MachineBasicBlock::iterator MBBI,
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|                                MachineInstr *CatchRet) const;
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| };
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| 
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| } // End llvm namespace
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| 
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| #endif
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