lib/Target/Mips/MipsMachineFunction.h

   1 //===-- MipsMachineFunctionInfo.h - Private data used for Mips ----*- C++ -*-=//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file declares the Mips specific subclass of MachineFunctionInfo.
  11 //
  12 //===----------------------------------------------------------------------===//
  13
  14 #ifndef MIPS_MACHINE_FUNCTION_INFO_H
  15 #define MIPS_MACHINE_FUNCTION_INFO_H
  16
  17 #include "llvm/ADT/SmallVector.h"
  18 #include "llvm/ADT/VectorExtras.h"
  19 #include "llvm/CodeGen/MachineFunction.h"
  20 #include "llvm/CodeGen/MachineFrameInfo.h"
  21
  22 namespace llvm {
  23
  24 /// MipsFunctionInfo - This class is derived from MachineFunction private
  25 /// Mips target-specific information for each MachineFunction.
  26 class MipsFunctionInfo : public MachineFunctionInfo {
  27
  28 private:
  29   /// Holds for each function where on the stack the Frame Pointer must be
  30   /// saved. This is used on Prologue and Epilogue to emit FP save/restore
  31   int FPStackOffset;
  32
  33   /// Holds for each function where on the stack the Return Address must be
  34   /// saved. This is used on Prologue and Epilogue to emit RA save/restore
  35   int RAStackOffset;
  36
  37   /// At each function entry, two special bitmask directives must be emitted
  38   /// to help debugging, for CPU and FPU callee saved registers. Both need
  39   /// the negative offset from the final stack size and its higher registers
  40   /// location on the stack.
  41   int CPUTopSavedRegOff;
  42   int FPUTopSavedRegOff;
  43
  44   /// MipsFIHolder - Holds a FrameIndex and it's Stack Pointer Offset
  45   struct MipsFIHolder {
  46
  47     int FI;
  48     int SPOffset;
  49
  50     MipsFIHolder(int FrameIndex, int StackPointerOffset)
  51       : FI(FrameIndex), SPOffset(StackPointerOffset) {}
  52   };
  53
  54   /// When PIC is used the GP must be saved on the stack on the function
  55   /// prologue and must be reloaded from this stack location after every
  56   /// call. A reference to its stack location and frame index must be kept
  57   /// to be used on emitPrologue and processFunctionBeforeFrameFinalized.
  58   MipsFIHolder GPHolder;
  59
  60   /// On LowerFORMAL_ARGUMENTS the stack size is unknown, so the Stack
  61   /// Pointer Offset calculation of "not in register arguments" must be
  62   /// postponed to emitPrologue.
  63   SmallVector<MipsFIHolder, 16> FnLoadArgs;
  64   bool HasLoadArgs;
  65
  66   // When VarArgs, we must write registers back to caller stack, preserving
  67   // on register arguments. Since the stack size is unknown on
  68   // LowerFORMAL_ARGUMENTS, the Stack Pointer Offset calculation must be
  69   // postponed to emitPrologue.
  70   SmallVector<MipsFIHolder, 4> FnStoreVarArgs;
  71   bool HasStoreVarArgs;
  72
  73   /// SRetReturnReg - Some subtargets require that sret lowering includes
  74   /// returning the value of the returned struct in a register. This field
  75   /// holds the virtual register into which the sret argument is passed.
  76   unsigned SRetReturnReg;
  77
  78 public:
  79   MipsFunctionInfo(MachineFunction& MF)
  80   : FPStackOffset(0), RAStackOffset(0), CPUTopSavedRegOff(0),
  81     FPUTopSavedRegOff(0), GPHolder(-1,-1), HasLoadArgs(false),
  82     HasStoreVarArgs(false), SRetReturnReg(0)
  83   {}
  84
  85   int getFPStackOffset() const { return FPStackOffset; }
  86   void setFPStackOffset(int Off) { FPStackOffset = Off; }
  87
  88   int getRAStackOffset() const { return RAStackOffset; }
  89   void setRAStackOffset(int Off) { RAStackOffset = Off; }
  90
  91   int getCPUTopSavedRegOff() const { return CPUTopSavedRegOff; }
  92   void setCPUTopSavedRegOff(int Off) { CPUTopSavedRegOff = Off; }
  93
  94   int getFPUTopSavedRegOff() const { return FPUTopSavedRegOff; }
  95   void setFPUTopSavedRegOff(int Off) { FPUTopSavedRegOff = Off; }
  96
  97   int getGPStackOffset() const { return GPHolder.SPOffset; }
  98   int getGPFI() const { return GPHolder.FI; }
  99   void setGPStackOffset(int Off) { GPHolder.SPOffset = Off; }
 100   void setGPFI(int FI) { GPHolder.FI = FI; }
 101
 102   bool hasLoadArgs() const { return HasLoadArgs; }
 103   bool hasStoreVarArgs() const { return HasStoreVarArgs; }
 104
 105   void recordLoadArgsFI(int FI, int SPOffset) {
 106     if (!HasLoadArgs) HasLoadArgs=true;
 107     FnLoadArgs.push_back(MipsFIHolder(FI, SPOffset));
 108   }
 109   void recordStoreVarArgsFI(int FI, int SPOffset) {
 110     if (!HasStoreVarArgs) HasStoreVarArgs=true;
 111     FnStoreVarArgs.push_back(MipsFIHolder(FI, SPOffset));
 112   }
 113
 114   void adjustLoadArgsFI(MachineFrameInfo *MFI) const {
 115     if (!hasLoadArgs()) return;
 116     for (unsigned i = 0, e = FnLoadArgs.size(); i != e; ++i)
 117       MFI->setObjectOffset( FnLoadArgs[i].FI, FnLoadArgs[i].SPOffset );
 118   }
 119   void adjustStoreVarArgsFI(MachineFrameInfo *MFI) const {
 120     if (!hasStoreVarArgs()) return;
 121     for (unsigned i = 0, e = FnStoreVarArgs.size(); i != e; ++i)
 122       MFI->setObjectOffset( FnStoreVarArgs[i].FI, FnStoreVarArgs[i].SPOffset );
 123   }
 124
 125   unsigned getSRetReturnReg() const { return SRetReturnReg; }
 126   void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
 127 };
 128
 129 } // end of namespace llvm
 130
 131 #endif // MIPS_MACHINE_FUNCTION_INFO_H