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diff --git a/include/llvm/Target/TargetFrameLowering.h b/include/llvm/Target/TargetFrameLowering.h
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+++ b/include/llvm/Target/TargetFrameLowering.h
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+//===-- llvm/Target/TargetFrameLowering.h ---------------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// Interface to describe the layout of a stack frame on the target machine.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TARGET_TARGETFRAMELOWERING_H
+#define LLVM_TARGET_TARGETFRAMELOWERING_H
+
+#include "llvm/CodeGen/MachineBasicBlock.h"
+
+#include <utility>
+#include <vector>
+
+namespace llvm {
+  class CalleeSavedInfo;
+  class MachineFunction;
+  class MachineBasicBlock;
+  class MachineMove;
+  class RegScavenger;
+
+/// Information about stack frame layout on the target.  It holds the direction
+/// of stack growth, the known stack alignment on entry to each function, and
+/// the offset to the locals area.
+///
+/// The offset to the local area is the offset from the stack pointer on
+/// function entry to the first location where function data (local variables,
+/// spill locations) can be stored.
+class TargetFrameLowering {
+public:
+  enum StackDirection {
+    StackGrowsUp,        // Adding to the stack increases the stack address
+    StackGrowsDown       // Adding to the stack decreases the stack address
+  };
+
+  // Maps a callee saved register to a stack slot with a fixed offset.
+  struct SpillSlot {
+    unsigned Reg;
+    int Offset; // Offset relative to stack pointer on function entry.
+  };
+private:
+  StackDirection StackDir;
+  unsigned StackAlignment;
+  unsigned TransientStackAlignment;
+  int LocalAreaOffset;
+public:
+  TargetFrameLowering(StackDirection D, unsigned StackAl, int LAO,
+                      unsigned TransAl = 1)
+    : StackDir(D), StackAlignment(StackAl), TransientStackAlignment(TransAl),
+      LocalAreaOffset(LAO) {}
+
+  virtual ~TargetFrameLowering();
+
+  // These methods return information that describes the abstract stack layout
+  // of the target machine.
+
+  /// getStackGrowthDirection - Return the direction the stack grows
+  ///
+  StackDirection getStackGrowthDirection() const { return StackDir; }
+
+  /// getStackAlignment - This method returns the number of bytes to which the
+  /// stack pointer must be aligned on entry to a function.  Typically, this
+  /// is the largest alignment for any data object in the target.
+  ///
+  unsigned getStackAlignment() const { return StackAlignment; }
+
+  /// getTransientStackAlignment - This method returns the number of bytes to
+  /// which the stack pointer must be aligned at all times, even between
+  /// calls.
+  ///
+  unsigned getTransientStackAlignment() const {
+    return TransientStackAlignment;
+  }
+
+  /// getOffsetOfLocalArea - This method returns the offset of the local area
+  /// from the stack pointer on entrance to a function.
+  ///
+  int getOffsetOfLocalArea() const { return LocalAreaOffset; }
+
+  /// getCalleeSavedSpillSlots - This method returns a pointer to an array of
+  /// pairs, that contains an entry for each callee saved register that must be
+  /// spilled to a particular stack location if it is spilled.
+  ///
+  /// Each entry in this array contains a <register,offset> pair, indicating the
+  /// fixed offset from the incoming stack pointer that each register should be
+  /// spilled at. If a register is not listed here, the code generator is
+  /// allowed to spill it anywhere it chooses.
+  ///
+  virtual const SpillSlot *
+  getCalleeSavedSpillSlots(unsigned &NumEntries) const {
+    NumEntries = 0;
+    return 0;
+  }
+
+  /// targetHandlesStackFrameRounding - Returns true if the target is
+  /// responsible for rounding up the stack frame (probably at emitPrologue
+  /// time).
+  virtual bool targetHandlesStackFrameRounding() const {
+    return false;
+  }
+
+  /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
+  /// the function.
+  virtual void emitPrologue(MachineFunction &MF) const = 0;
+  virtual void emitEpilogue(MachineFunction &MF,
+                            MachineBasicBlock &MBB) const = 0;
+
+  /// spillCalleeSavedRegisters - Issues instruction(s) to spill all callee
+  /// saved registers and returns true if it isn't possible / profitable to do
+  /// so by issuing a series of store instructions via
+  /// storeRegToStackSlot(). Returns false otherwise.
+  virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                         MachineBasicBlock::iterator MI,
+                                        const std::vector<CalleeSavedInfo> &CSI,
+                                         const TargetRegisterInfo *TRI) const {
+    return false;
+  }
+
+  /// restoreCalleeSavedRegisters - Issues instruction(s) to restore all callee
+  /// saved registers and returns true if it isn't possible / profitable to do
+  /// so by issuing a series of load instructions via loadRegToStackSlot().
+  /// Returns false otherwise.
+  virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB,
+                                           MachineBasicBlock::iterator MI,
+                                        const std::vector<CalleeSavedInfo> &CSI,
+                                        const TargetRegisterInfo *TRI) const {
+    return false;
+  }
+
+  /// hasFP - Return true if the specified function should have a dedicated
+  /// frame pointer register. For most targets this is true only if the function
+  /// has variable sized allocas or if frame pointer elimination is disabled.
+  virtual bool hasFP(const MachineFunction &MF) const = 0;
+
+  /// hasReservedCallFrame - Under normal circumstances, when a frame pointer is
+  /// not required, we reserve argument space for call sites in the function
+  /// immediately on entry to the current function. This eliminates the need for
+  /// add/sub sp brackets around call sites. Returns true if the call frame is
+  /// included as part of the stack frame.
+  virtual bool hasReservedCallFrame(const MachineFunction &MF) const {
+    return !hasFP(MF);
+  }
+
+  /// canSimplifyCallFramePseudos - When possible, it's best to simplify the
+  /// call frame pseudo ops before doing frame index elimination. This is
+  /// possible only when frame index references between the pseudos won't
+  /// need adjusting for the call frame adjustments. Normally, that's true
+  /// if the function has a reserved call frame or a frame pointer. Some
+  /// targets (Thumb2, for example) may have more complicated criteria,
+  /// however, and can override this behavior.
+  virtual bool canSimplifyCallFramePseudos(const MachineFunction &MF) const {
+    return hasReservedCallFrame(MF) || hasFP(MF);
+  }
+
+  /// getInitialFrameState - Returns a list of machine moves that are assumed
+  /// on entry to all functions.  Note that LabelID is ignored (assumed to be
+  /// the beginning of the function.)
+  virtual void getInitialFrameState(std::vector<MachineMove> &Moves) const;
+
+  /// getFrameIndexOffset - Returns the displacement from the frame register to
+  /// the stack frame of the specified index.
+  virtual int getFrameIndexOffset(const MachineFunction &MF, int FI) const;
+
+  /// getFrameIndexReference - This method should return the base register
+  /// and offset used to reference a frame index location. The offset is
+  /// returned directly, and the base register is returned via FrameReg.
+  virtual int getFrameIndexReference(const MachineFunction &MF, int FI,
+                                     unsigned &FrameReg) const;
+
+  /// processFunctionBeforeCalleeSavedScan - This method is called immediately
+  /// before PrologEpilogInserter scans the physical registers used to determine
+  /// what callee saved registers should be spilled. This method is optional.
+  virtual void processFunctionBeforeCalleeSavedScan(MachineFunction &MF,
+                                                RegScavenger *RS = NULL) const {
+
+  }
+
+  /// processFunctionBeforeFrameFinalized - This method is called immediately
+  /// before the specified function's frame layout (MF.getFrameInfo()) is
+  /// finalized.  Once the frame is finalized, MO_FrameIndex operands are
+  /// replaced with direct constants.  This method is optional.
+  ///
+  virtual void processFunctionBeforeFrameFinalized(MachineFunction &MF) const {
+  }
+};
+
+} // End llvm namespace
+
+#endif