1 files changed, 93 insertions, 0 deletions
diff --git a/lib/Target/SystemZ/SystemZFrameLowering.h b/lib/Target/SystemZ/SystemZFrameLowering.h
new file mode 100644
index 0000000000..5ca049c486
--- /dev/null
+++ b/lib/Target/SystemZ/SystemZFrameLowering.h
@@ -0,0 +1,93 @@
+//===-- SystemZFrameLowering.h - Frame lowering for SystemZ -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef SYSTEMZFRAMELOWERING_H
+#define SYSTEMZFRAMELOWERING_H
+
+#include "SystemZSubtarget.h"
+#include "llvm/ADT/IndexedMap.h"
+#include "llvm/Target/TargetFrameLowering.h"
+
+namespace llvm {
+class SystemZTargetMachine;
+class SystemZSubtarget;
+
+class SystemZFrameLowering : public TargetFrameLowering {
+  IndexedMap<unsigned> RegSpillOffsets;
+
+protected:
+  const SystemZTargetMachine &TM;
+  const SystemZSubtarget &STI;
+
+public:
+  SystemZFrameLowering(const SystemZTargetMachine &tm,
+                       const SystemZSubtarget &sti);
+
+  // Override FrameLowering.
+  virtual void
+    processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+                                         RegScavenger *RS) const LLVM_OVERRIDE;
+  virtual bool
+    spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                              MachineBasicBlock::iterator MBBI,
+                              const std::vector<CalleeSavedInfo> &CSI,
+                              const TargetRegisterInfo *TRI) const
+    LLVM_OVERRIDE;
+  virtual bool
+    restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                MachineBasicBlock::iterator MBBII,
+                                const std::vector<CalleeSavedInfo> &CSI,
+                                const TargetRegisterInfo *TRI) const
+    LLVM_OVERRIDE;
+  virtual void emitPrologue(MachineFunction &MF) const LLVM_OVERRIDE;
+  virtual void emitEpilogue(MachineFunction &MF,
+                            MachineBasicBlock &MBB) const LLVM_OVERRIDE;
+  virtual bool hasFP(const MachineFunction &MF) const LLVM_OVERRIDE;
+  virtual int getFrameIndexOffset(const MachineFunction &MF,
+                                  int FI) const LLVM_OVERRIDE;
+  virtual bool hasReservedCallFrame(const MachineFunction &MF) const
+    LLVM_OVERRIDE;
+  virtual void
+  eliminateCallFramePseudoInstr(MachineFunction &MF,
+                                MachineBasicBlock &MBB,
+                                MachineBasicBlock::iterator MI) const
+    LLVM_OVERRIDE;
+
+  // The target-independent code automatically allocates save slots for
+  // call-saved GPRs.  However, we don't need those slots for SystemZ,
+  // because the ABI sets aside GPR save slots in the caller-allocated part
+  // of the frame.  Since the target-independent code puts this unneeded
+  // area at the top of the callee-allocated part of frame, we choose not
+  // to allocate it and adjust the offsets accordingly.  Return the
+  // size of this unallocated area.
+  // FIXME: seems a bit hackish.
+  uint64_t getUnallocatedTopBytes(const MachineFunction &MF) const;
+
+  // Return the number of bytes in the callee-allocated part of the frame.
+  uint64_t getAllocatedStackSize(const MachineFunction &MF) const;
+
+  // Return the number of frame bytes that should be reserved for
+  // an emergency spill slot, for use by the register scaveneger.
+  // Return 0 if register scaveging won't be needed.
+  unsigned getEmergencySpillSlotSize(const MachineFunction &MF) const;
+
+  // Return the offset from the frame pointer of the emergency spill slot,
+  // which always fits within a 12-bit unsigned displacement field.
+  // Only valid if getEmergencySpillSlotSize(MF) returns nonzero.
+  unsigned getEmergencySpillSlotOffset(const MachineFunction &MF) const;
+
+  // 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.
+  unsigned getRegSpillOffset(unsigned Reg) const {
+    return RegSpillOffsets[Reg];
+  }
+};
+} // end namespace llvm
+
+#endif