PPCMachineFunctionInfo.h

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//===-- PPCMachineFunctionInfo.h - Private data used for PowerPC --*- C++ -*-=//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file declares the PowerPC specific subclass of MachineFunctionInfo.
//
//===----------------------------------------------------------------------===//

#ifndef PPC_MACHINE_FUNCTION_INFO_H
#define PPC_MACHINE_FUNCTION_INFO_H

#include "llvm/CodeGen/MachineFunction.h"

namespace llvm {

/// PPCFunctionInfo - This class is derived from MachineFunction private
/// PowerPC target-specific information for each MachineFunction.
class PPCFunctionInfo : public MachineFunctionInfo {
private:
  /// FramePointerSaveIndex - Frame index of where the old frame pointer is
  /// stored.  Also used as an anchor for instructions that need to be altered
  /// when using frame pointers (dyna_add, dyna_sub.)
  int FramePointerSaveIndex;
  
  /// ReturnAddrSaveIndex - Frame index of where the return address is stored.
  ///
  int ReturnAddrSaveIndex;

  /// MustSaveLR - Indicates whether LR is defined (or clobbered) in the current
  /// function.  This is only valid after the initial scan of the function by
  /// PEI.
  bool MustSaveLR;

  /// SpillsCR - Indicates whether CR is spilled in the current function.
  bool SpillsCR;

  /// LRStoreRequired - The bool indicates whether there is some explicit use of
  /// the LR/LR8 stack slot that is not obvious from scanning the code.  This
  /// requires that the code generator produce a store of LR to the stack on
  /// entry, even though LR may otherwise apparently not be used.
  bool LRStoreRequired;

  /// MinReservedArea - This is the frame size that is at least reserved in a
  /// potential caller (parameter+linkage area).
  unsigned MinReservedArea;

  /// TailCallSPDelta - Stack pointer delta used when tail calling. Maximum
  /// amount the stack pointer is adjusted to make the frame bigger for tail
  /// calls. Used for creating an area before the register spill area.
  int TailCallSPDelta;

  /// HasFastCall - Does this function contain a fast call. Used to determine
  /// how the caller's stack pointer should be calculated (epilog/dynamicalloc).
  bool HasFastCall;

public:
  PPCFunctionInfo(MachineFunction &MF) 
    : FramePointerSaveIndex(0),
      ReturnAddrSaveIndex(0),
      SpillsCR(false),
      LRStoreRequired(false),
      MinReservedArea(0),
      TailCallSPDelta(0),
      HasFastCall(false) {}

  int getFramePointerSaveIndex() const { return FramePointerSaveIndex; }
  void setFramePointerSaveIndex(int Idx) { FramePointerSaveIndex = Idx; }
  
  int getReturnAddrSaveIndex() const { return ReturnAddrSaveIndex; }
  void setReturnAddrSaveIndex(int idx) { ReturnAddrSaveIndex = idx; }

  unsigned getMinReservedArea() const { return MinReservedArea; }
  void setMinReservedArea(unsigned size) { MinReservedArea = size; }

  int getTailCallSPDelta() const { return TailCallSPDelta; }
  void setTailCallSPDelta(int size) { TailCallSPDelta = size; }

  /// MustSaveLR - This is set when the prolog/epilog inserter does its initial
  /// scan of the function. It is true if the LR/LR8 register is ever explicitly
  /// defined/clobbered in the machine function (e.g. by calls and movpctolr,
  /// which is used in PIC generation), or if the LR stack slot is explicitly
  /// referenced by builtin_return_address.
  void setMustSaveLR(bool U) { MustSaveLR = U; }
  bool mustSaveLR() const    { return MustSaveLR; }

  void setSpillsCR()       { SpillsCR = true; }
  bool isCRSpilled() const { return SpillsCR; }

  void setLRStoreRequired() { LRStoreRequired = true; }
  bool isLRStoreRequired() const { return LRStoreRequired; }

  void setHasFastCall() { HasFastCall = true; }
  bool hasFastCall() const { return HasFastCall;}
};

} // end of namespace llvm


#endif