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 "MipsSubtarget.h"
18 #include "llvm/CodeGen/MachineFunction.h"
19 #include "llvm/CodeGen/MachineFrameInfo.h"
20 #include "llvm/Target/TargetFrameLowering.h"
21 #include "llvm/Target/TargetMachine.h"
22 #include <utility>
23 
24 namespace llvm {
25 
26 /// MipsFunctionInfo - This class is derived from MachineFunction private
27 /// Mips target-specific information for each MachineFunction.
28 class MipsFunctionInfo : public MachineFunctionInfo {
29   virtual void anchor();
30 
31   MachineFunction& MF;
32   /// SRetReturnReg - Some subtargets require that sret lowering includes
33   /// returning the value of the returned struct in a register. This field
34   /// holds the virtual register into which the sret argument is passed.
35   unsigned SRetReturnReg;
36 
37   /// GlobalBaseReg - keeps track of the virtual register initialized for
38   /// use as the global base register. This is used for PIC in some PIC
39   /// relocation models.
40   unsigned GlobalBaseReg;
41 
42   /// VarArgsFrameIndex - FrameIndex for start of varargs area.
43   int VarArgsFrameIndex;
44 
45   // Range of frame object indices.
46   // InArgFIRange: Range of indices of all frame objects created during call to
47   //               LowerFormalArguments.
48   // OutArgFIRange: Range of indices of all frame objects created during call to
49   //                LowerCall except for the frame object for restoring $gp.
50   std::pair<int, int> InArgFIRange, OutArgFIRange;
51   int GlobalRegFI;
52   mutable int DynAllocFI; // Frame index of dynamically allocated stack area.
53   unsigned MaxCallFrameSize;
54 
55   bool EmitNOAT;
56 
57 public:
58   MipsFunctionInfo(MachineFunction& MF)
59   : MF(MF), SRetReturnReg(0), GlobalBaseReg(0),
60     VarArgsFrameIndex(0), InArgFIRange(std::make_pair(-1, 0)),
61     OutArgFIRange(std::make_pair(-1, 0)), GlobalRegFI(0), DynAllocFI(0),
62     MaxCallFrameSize(0), EmitNOAT(false)
63   {}
64 
65   bool isInArgFI(int FI) const {
66     return FI <= InArgFIRange.first && FI >= InArgFIRange.second;
67   }
68   void setLastInArgFI(int FI) { InArgFIRange.second = FI; }
69 
70   bool isOutArgFI(int FI) const {
71     return FI <= OutArgFIRange.first && FI >= OutArgFIRange.second;
72   }
73   void extendOutArgFIRange(int FirstFI, int LastFI) {
74     if (!OutArgFIRange.second)
75       // this must be the first time this function was called.
76       OutArgFIRange.first = FirstFI;
77     OutArgFIRange.second = LastFI;
78   }
79 
80   bool isGlobalRegFI(int FI) const {
81     return GlobalRegFI && (FI == GlobalRegFI);
82   }
83 
84   int getGlobalRegFI() const {
85     return GlobalRegFI;
86   }
87 
88   int initGlobalRegFI() {
89     const TargetMachine &TM = MF.getTarget();
90     unsigned RegSize = TM.getSubtarget<MipsSubtarget>().isABI_N64() ? 8 : 4;
91     int64_t StackAlignment = TM.getFrameLowering()->getStackAlignment();
92     uint64_t Offset = RoundUpToAlignment(MaxCallFrameSize, StackAlignment);
93 
94     GlobalRegFI = MF.getFrameInfo()->CreateFixedObject(RegSize, Offset, true);
95     return GlobalRegFI;
96   }
97 
98   // The first call to this function creates a frame object for dynamically
99   // allocated stack area.
100   int getDynAllocFI() const {
101     if (!DynAllocFI)
102       DynAllocFI = MF.getFrameInfo()->CreateFixedObject(4, 0, true);
103 
104     return DynAllocFI;
105   }
106   bool isDynAllocFI(int FI) const { return DynAllocFI && DynAllocFI == FI; }
107 
108   unsigned getSRetReturnReg() const { return SRetReturnReg; }
109   void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
110 
111   bool globalBaseRegSet() const;
112   unsigned getGlobalBaseReg();
113 
114   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
115   void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
116 
117   unsigned getMaxCallFrameSize() const { return MaxCallFrameSize; }
118   void setMaxCallFrameSize(unsigned S) { MaxCallFrameSize = S; }
119 
120   bool getEmitNOAT() const { return EmitNOAT; }
121   void setEmitNOAT() { EmitNOAT = true; }
122 };
123 
124 } // end of namespace llvm
125 
126 #endif // MIPS_MACHINE_FUNCTION_INFO_H
127