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diff --git a/contrib/llvm-project/llvm/lib/Target/SystemZ/SystemZFrameLowering.h b/contrib/llvm-project/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
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+++ b/contrib/llvm-project/llvm/lib/Target/SystemZ/SystemZFrameLowering.h
@@ -0,0 +1,173 @@
+//===-- SystemZFrameLowering.h - Frame lowering for SystemZ -----*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
+#define LLVM_LIB_TARGET_SYSTEMZ_SYSTEMZFRAMELOWERING_H
+
+#include "MCTargetDesc/SystemZMCTargetDesc.h"
+#include "SystemZInstrBuilder.h"
+#include "SystemZMachineFunctionInfo.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/CodeGen/TargetFrameLowering.h"
+#include "llvm/Support/TypeSize.h"
+
+namespace llvm {
+class SystemZSubtarget;
+
+class SystemZFrameLowering : public TargetFrameLowering {
+public:
+  SystemZFrameLowering(StackDirection D, Align StackAl, int LAO, Align TransAl,
+                       bool StackReal, unsigned PointerSize);
+
+  static std::unique_ptr<SystemZFrameLowering>
+  create(const SystemZSubtarget &STI);
+
+  // Override TargetFrameLowering.
+  bool allocateScavengingFrameIndexesNearIncomingSP(
+    const MachineFunction &MF) const override {
+    // SystemZ wants normal register scavenging slots, as close to the stack or
+    // frame pointer as possible.
+    // The default implementation assumes an x86-like layout, where the frame
+    // pointer is at the opposite end of the frame from the stack pointer.
+    // This meant that when frame pointer elimination was disabled,
+    // the slots ended up being as close as possible to the incoming
+    // stack pointer, which is the opposite of what we want on SystemZ.
+    return false;
+  }
+
+  bool hasReservedCallFrame(const MachineFunction &MF) const override;
+
+  // Return the offset of the backchain.
+  virtual unsigned getBackchainOffset(MachineFunction &MF) const = 0;
+
+  // Return the offset of the return address.
+  virtual int getReturnAddressOffset(MachineFunction &MF) const = 0;
+
+  // Get or create the frame index of where the old frame pointer is stored.
+  virtual int getOrCreateFramePointerSaveIndex(MachineFunction &MF) const = 0;
+
+  // Return the size of a pointer (in bytes).
+  unsigned getPointerSize() const { return PointerSize; }
+
+private:
+  unsigned PointerSize;
+};
+
+class SystemZELFFrameLowering : public SystemZFrameLowering {
+  IndexedMap<unsigned> RegSpillOffsets;
+
+public:
+  SystemZELFFrameLowering(unsigned PointerSize);
+
+  // Override TargetFrameLowering.
+  bool
+  assignCalleeSavedSpillSlots(MachineFunction &MF,
+                              const TargetRegisterInfo *TRI,
+                              std::vector<CalleeSavedInfo> &CSI) const override;
+  void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
+                            RegScavenger *RS) const override;
+  bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                 MachineBasicBlock::iterator MBBI,
+                                 ArrayRef<CalleeSavedInfo> CSI,
+                                 const TargetRegisterInfo *TRI) const override;
+  bool
+  restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator MBBII,
+                              MutableArrayRef<CalleeSavedInfo> CSI,
+                              const TargetRegisterInfo *TRI) const override;
+  void processFunctionBeforeFrameFinalized(MachineFunction &MF,
+                                           RegScavenger *RS) const override;
+  void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+  void inlineStackProbe(MachineFunction &MF,
+                        MachineBasicBlock &PrologMBB) const override;
+  bool hasFP(const MachineFunction &MF) const override;
+  StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
+                                     Register &FrameReg) const override;
+  void
+  orderFrameObjects(const MachineFunction &MF,
+                    SmallVectorImpl<int> &ObjectsToAllocate) const override;
+
+  // Return the byte offset from the incoming stack pointer of Reg's
+  // ABI-defined save slot.  Return 0 if no slot is defined for Reg.  Adjust
+  // the offset in case MF has packed-stack.
+  unsigned getRegSpillOffset(MachineFunction &MF, Register Reg) const;
+
+  bool usePackedStack(MachineFunction &MF) const;
+
+  // Return the offset of the backchain.
+  unsigned getBackchainOffset(MachineFunction &MF) const override {
+    // The back chain is stored topmost with packed-stack.
+    return usePackedStack(MF) ? SystemZMC::ELFCallFrameSize - 8 : 0;
+  }
+
+  // Return the offset of the return address.
+  int getReturnAddressOffset(MachineFunction &MF) const override {
+    return (usePackedStack(MF) ? -2 : 14) * getPointerSize();
+  }
+
+  // Get or create the frame index of where the old frame pointer is stored.
+  int getOrCreateFramePointerSaveIndex(MachineFunction &MF) const override;
+};
+
+class SystemZXPLINKFrameLowering : public SystemZFrameLowering {
+  IndexedMap<unsigned> RegSpillOffsets;
+
+public:
+  SystemZXPLINKFrameLowering(unsigned PointerSize);
+
+  bool
+  assignCalleeSavedSpillSlots(MachineFunction &MF,
+                              const TargetRegisterInfo *TRI,
+                              std::vector<CalleeSavedInfo> &CSI) const override;
+
+  void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
+                            RegScavenger *RS) const override;
+
+  bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                 MachineBasicBlock::iterator MBBI,
+                                 ArrayRef<CalleeSavedInfo> CSI,
+                                 const TargetRegisterInfo *TRI) const override;
+
+  bool
+  restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator MBBII,
+                              MutableArrayRef<CalleeSavedInfo> CSI,
+                              const TargetRegisterInfo *TRI) const override;
+
+  void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+
+  void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const override;
+
+  void inlineStackProbe(MachineFunction &MF,
+                        MachineBasicBlock &PrologMBB) const override;
+
+  bool hasFP(const MachineFunction &MF) const override;
+
+  void processFunctionBeforeFrameFinalized(MachineFunction &MF,
+                                           RegScavenger *RS) const override;
+
+  void determineFrameLayout(MachineFunction &MF) const;
+
+  // Return the offset of the backchain.
+  unsigned getBackchainOffset(MachineFunction &MF) const override {
+    // The back chain is always the first element of the frame.
+    return 0;
+  }
+
+  // Return the offset of the return address.
+  int getReturnAddressOffset(MachineFunction &MF) const override {
+    return 3 * getPointerSize();
+  }
+
+  // Get or create the frame index of where the old frame pointer is stored.
+  int getOrCreateFramePointerSaveIndex(MachineFunction &MF) const override;
+};
+} // end namespace llvm
+
+#endif