MBlazeMachineFunction.h revision 218893 
1//===-- MBlazeMachineFunctionInfo.h - Private data ----------------*- 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 MBlaze specific subclass of MachineFunctionInfo.
11//
12//===----------------------------------------------------------------------===//
13
14#ifndef MBLAZE_MACHINE_FUNCTION_INFO_H
15#define MBLAZE_MACHINE_FUNCTION_INFO_H
16
17#include "llvm/ADT/DenseMap.h"
18#include "llvm/ADT/SmallVector.h"
19#include "llvm/ADT/VectorExtras.h"
20#include "llvm/CodeGen/MachineFunction.h"
21#include "llvm/CodeGen/MachineFrameInfo.h"
22
23namespace llvm {
24
25/// MBlazeFunctionInfo - This class is derived from MachineFunction private
26/// MBlaze target-specific information for each MachineFunction.
27class MBlazeFunctionInfo : public MachineFunctionInfo {
28
29private:
30  /// Holds for each function where on the stack the Frame Pointer must be
31  /// saved. This is used on Prologue and Epilogue to emit FP save/restore
32  int FPStackOffset;
33
34  /// Holds for each function where on the stack the Return Address must be
35  /// saved. This is used on Prologue and Epilogue to emit RA save/restore
36  int RAStackOffset;
37
38  /// MBlazeFIHolder - Holds a FrameIndex and it's Stack Pointer Offset
39  struct MBlazeFIHolder {
40
41    int FI;
42    int SPOffset;
43
44    MBlazeFIHolder(int FrameIndex, int StackPointerOffset)
45      : FI(FrameIndex), SPOffset(StackPointerOffset) {}
46  };
47
48  /// When PIC is used the GP must be saved on the stack on the function
49  /// prologue and must be reloaded from this stack location after every
50  /// call. A reference to its stack location and frame index must be kept
51  /// to be used on emitPrologue and processFunctionBeforeFrameFinalized.
52  MBlazeFIHolder GPHolder;
53
54  /// On LowerFormalArguments the stack size is unknown, so the Stack
55  /// Pointer Offset calculation of "not in register arguments" must be
56  /// postponed to emitPrologue.
57  SmallVector<MBlazeFIHolder, 16> FnLoadArgs;
58  bool HasLoadArgs;
59
60  // When VarArgs, we must write registers back to caller stack, preserving
61  // on register arguments. Since the stack size is unknown on
62  // LowerFormalArguments, the Stack Pointer Offset calculation must be
63  // postponed to emitPrologue.
64  SmallVector<MBlazeFIHolder, 4> FnStoreVarArgs;
65  bool HasStoreVarArgs;
66
67  // When determining the final stack layout some of the frame indexes may
68  // be replaced by new frame indexes that reside in the caller's stack
69  // frame. The replacements are recorded in this structure.
70  DenseMap<int,int> FIReplacements;
71
72  /// SRetReturnReg - Some subtargets require that sret lowering includes
73  /// returning the value of the returned struct in a register. This field
74  /// holds the virtual register into which the sret argument is passed.
75  unsigned SRetReturnReg;
76
77  /// GlobalBaseReg - keeps track of the virtual register initialized for
78  /// use as the global base register. This is used for PIC in some PIC
79  /// relocation models.
80  unsigned GlobalBaseReg;
81
82  // VarArgsFrameIndex - FrameIndex for start of varargs area.
83  int VarArgsFrameIndex;
84
85  /// LiveInFI - keeps track of the frame indexes in a callers stack
86  /// frame that are live into a function.
87  SmallVector<int, 16> LiveInFI;
88
89public:
90  MBlazeFunctionInfo(MachineFunction& MF)
91  : FPStackOffset(0), RAStackOffset(0), GPHolder(-1,-1), HasLoadArgs(false),
92    HasStoreVarArgs(false), SRetReturnReg(0), GlobalBaseReg(0),
93    VarArgsFrameIndex(0), LiveInFI()
94  {}
95
96  int getFPStackOffset() const { return FPStackOffset; }
97  void setFPStackOffset(int Off) { FPStackOffset = Off; }
98
99  int getRAStackOffset() const { return RAStackOffset; }
100  void setRAStackOffset(int Off) { RAStackOffset = Off; }
101
102  int getGPStackOffset() const { return GPHolder.SPOffset; }
103  int getGPFI() const { return GPHolder.FI; }
104  void setGPStackOffset(int Off) { GPHolder.SPOffset = Off; }
105  void setGPFI(int FI) { GPHolder.FI = FI; }
106  bool needGPSaveRestore() const { return GPHolder.SPOffset != -1; }
107
108  bool hasLoadArgs() const { return HasLoadArgs; }
109  bool hasStoreVarArgs() const { return HasStoreVarArgs; }
110
111  void recordLiveIn(int FI) {
112    LiveInFI.push_back(FI);
113  }
114
115  bool isLiveIn(int FI) {
116    for (unsigned i = 0, e = LiveInFI.size(); i < e; ++i)
117      if (FI == LiveInFI[i]) return true;
118
119    return false;
120  }
121
122  const SmallVector<int, 16>& getLiveIn() const { return LiveInFI; }
123
124  void recordReplacement(int OFI, int NFI) {
125    FIReplacements.insert(std::make_pair(OFI,NFI));
126  }
127
128  bool hasReplacement(int OFI) const {
129    return FIReplacements.find(OFI) != FIReplacements.end();
130  }
131
132  int getReplacement(int OFI) const {
133    return FIReplacements.lookup(OFI);
134  }
135
136  void recordLoadArgsFI(int FI, int SPOffset) {
137    if (!HasLoadArgs) HasLoadArgs=true;
138    FnLoadArgs.push_back(MBlazeFIHolder(FI, SPOffset));
139  }
140
141  void recordStoreVarArgsFI(int FI, int SPOffset) {
142    if (!HasStoreVarArgs) HasStoreVarArgs=true;
143    FnStoreVarArgs.push_back(MBlazeFIHolder(FI, SPOffset));
144  }
145
146  void adjustLoadArgsFI(MachineFrameInfo *MFI) const {
147    if (!hasLoadArgs()) return;
148    for (unsigned i = 0, e = FnLoadArgs.size(); i != e; ++i)
149      MFI->setObjectOffset(FnLoadArgs[i].FI, FnLoadArgs[i].SPOffset);
150  }
151
152  void adjustStoreVarArgsFI(MachineFrameInfo *MFI) const {
153    if (!hasStoreVarArgs()) return;
154    for (unsigned i = 0, e = FnStoreVarArgs.size(); i != e; ++i)
155      MFI->setObjectOffset(FnStoreVarArgs[i].FI, FnStoreVarArgs[i].SPOffset);
156  }
157
158  unsigned getSRetReturnReg() const { return SRetReturnReg; }
159  void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
160
161  unsigned getGlobalBaseReg() const { return GlobalBaseReg; }
162  void setGlobalBaseReg(unsigned Reg) { GlobalBaseReg = Reg; }
163
164  int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
165  void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
166};
167
168} // end of namespace llvm
169
170#endif // MBLAZE_MACHINE_FUNCTION_INFO_H
171