1 //===-- PPCMachineFunctionInfo.h - Private data used for PowerPC --*- C++ -*-=//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file declares the PowerPC specific subclass of MachineFunctionInfo.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_POWERPC_PPCMACHINEFUNCTIONINFO_H
14 #define LLVM_LIB_TARGET_POWERPC_PPCMACHINEFUNCTIONINFO_H
15 
16 #include "llvm/ADT/SmallVector.h"
17 #include "llvm/CodeGen/MachineFunction.h"
18 #include "llvm/CodeGen/TargetCallingConv.h"
19 
20 namespace llvm {
21 
22 /// PPCFunctionInfo - This class is derived from MachineFunction private
23 /// PowerPC target-specific information for each MachineFunction.
24 class PPCFunctionInfo : public MachineFunctionInfo {
25   virtual void anchor();
26 
27   /// FramePointerSaveIndex - Frame index of where the old frame pointer is
28   /// stored.  Also used as an anchor for instructions that need to be altered
29   /// when using frame pointers (dyna_add, dyna_sub.)
30   int FramePointerSaveIndex = 0;
31 
32   /// ReturnAddrSaveIndex - Frame index of where the return address is stored.
33   ///
34   int ReturnAddrSaveIndex = 0;
35 
36   /// Frame index where the old base pointer is stored.
37   int BasePointerSaveIndex = 0;
38 
39   /// Frame index where the old PIC base pointer is stored.
40   int PICBasePointerSaveIndex = 0;
41 
42   /// MustSaveLR - Indicates whether LR is defined (or clobbered) in the current
43   /// function.  This is only valid after the initial scan of the function by
44   /// PEI.
45   bool MustSaveLR = false;
46 
47   /// MustSaveTOC - Indicates that the TOC save needs to be performed in the
48   /// prologue of the function. This is typically the case when there are
49   /// indirect calls in the function and it is more profitable to save the
50   /// TOC pointer in the prologue than in the block(s) containing the call(s).
51   bool MustSaveTOC = false;
52 
53   /// Do we have to disable shrink-wrapping? This has to be set if we emit any
54   /// instructions that clobber LR in the entry block because discovering this
55   /// in PEI is too late (happens after shrink-wrapping);
56   bool ShrinkWrapDisabled = false;
57 
58   /// Does this function have any stack spills.
59   bool HasSpills = false;
60 
61   /// Does this function spill using instructions with only r+r (not r+i)
62   /// forms.
63   bool HasNonRISpills = false;
64 
65   /// SpillsCR - Indicates whether CR is spilled in the current function.
66   bool SpillsCR = false;
67 
68   /// DisableNonVolatileCR - Indicates whether non-volatile CR fields would be
69   /// disabled.
70   bool DisableNonVolatileCR = false;
71 
72   /// Indicates whether VRSAVE is spilled in the current function.
73   bool SpillsVRSAVE = false;
74 
75   /// LRStoreRequired - The bool indicates whether there is some explicit use of
76   /// the LR/LR8 stack slot that is not obvious from scanning the code.  This
77   /// requires that the code generator produce a store of LR to the stack on
78   /// entry, even though LR may otherwise apparently not be used.
79   bool LRStoreRequired = false;
80 
81   /// This function makes use of the PPC64 ELF TOC base pointer (register r2).
82   bool UsesTOCBasePtr = false;
83 
84   /// MinReservedArea - This is the frame size that is at least reserved in a
85   /// potential caller (parameter+linkage area).
86   unsigned MinReservedArea = 0;
87 
88   /// TailCallSPDelta - Stack pointer delta used when tail calling. Maximum
89   /// amount the stack pointer is adjusted to make the frame bigger for tail
90   /// calls. Used for creating an area before the register spill area.
91   int TailCallSPDelta = 0;
92 
93   /// HasFastCall - Does this function contain a fast call. Used to determine
94   /// how the caller's stack pointer should be calculated (epilog/dynamicalloc).
95   bool HasFastCall = false;
96 
97   /// VarArgsFrameIndex - FrameIndex for start of varargs area.
98   int VarArgsFrameIndex = 0;
99 
100   /// VarArgsStackOffset - StackOffset for start of stack
101   /// arguments.
102 
103   int VarArgsStackOffset = 0;
104 
105   /// VarArgsNumGPR - Index of the first unused integer
106   /// register for parameter passing.
107   unsigned VarArgsNumGPR = 0;
108 
109   /// VarArgsNumFPR - Index of the first unused double
110   /// register for parameter passing.
111   unsigned VarArgsNumFPR = 0;
112 
113   /// CRSpillFrameIndex - FrameIndex for CR spill slot for 32-bit SVR4.
114   int CRSpillFrameIndex = 0;
115 
116   /// If any of CR[2-4] need to be saved in the prologue and restored in the
117   /// epilogue then they are added to this array. This is used for the
118   /// 64-bit SVR4 ABI.
119   SmallVector<unsigned, 3> MustSaveCRs;
120 
121   /// Hold onto our MachineFunction context.
122   MachineFunction &MF;
123 
124   /// Whether this uses the PIC Base register or not.
125   bool UsesPICBase = false;
126 
127   /// True if this function has a subset of CSRs that is handled explicitly via
128   /// copies
129   bool IsSplitCSR = false;
130 
131   /// We keep track attributes for each live-in virtual registers
132   /// to use SExt/ZExt flags in later optimization.
133   std::vector<std::pair<unsigned, ISD::ArgFlagsTy>> LiveInAttrs;
134 
135 public:
136   explicit PPCFunctionInfo(MachineFunction &MF);
137 
138   int getFramePointerSaveIndex() const { return FramePointerSaveIndex; }
139   void setFramePointerSaveIndex(int Idx) { FramePointerSaveIndex = Idx; }
140 
141   int getReturnAddrSaveIndex() const { return ReturnAddrSaveIndex; }
142   void setReturnAddrSaveIndex(int idx) { ReturnAddrSaveIndex = idx; }
143 
144   int getBasePointerSaveIndex() const { return BasePointerSaveIndex; }
145   void setBasePointerSaveIndex(int Idx) { BasePointerSaveIndex = Idx; }
146 
147   int getPICBasePointerSaveIndex() const { return PICBasePointerSaveIndex; }
148   void setPICBasePointerSaveIndex(int Idx) { PICBasePointerSaveIndex = Idx; }
149 
150   unsigned getMinReservedArea() const { return MinReservedArea; }
151   void setMinReservedArea(unsigned size) { MinReservedArea = size; }
152 
153   int getTailCallSPDelta() const { return TailCallSPDelta; }
154   void setTailCallSPDelta(int size) { TailCallSPDelta = size; }
155 
156   /// MustSaveLR - This is set when the prolog/epilog inserter does its initial
157   /// scan of the function. It is true if the LR/LR8 register is ever explicitly
158   /// defined/clobbered in the machine function (e.g. by calls and movpctolr,
159   /// which is used in PIC generation), or if the LR stack slot is explicitly
160   /// referenced by builtin_return_address.
161   void setMustSaveLR(bool U) { MustSaveLR = U; }
162   bool mustSaveLR() const    { return MustSaveLR; }
163 
164   void setMustSaveTOC(bool U) { MustSaveTOC = U; }
165   bool mustSaveTOC() const    { return MustSaveTOC; }
166 
167   /// We certainly don't want to shrink wrap functions if we've emitted a
168   /// MovePCtoLR8 as that has to go into the entry, so the prologue definitely
169   /// has to go into the entry block.
170   void setShrinkWrapDisabled(bool U) { ShrinkWrapDisabled = U; }
171   bool shrinkWrapDisabled() const { return ShrinkWrapDisabled; }
172 
173   void setHasSpills()      { HasSpills = true; }
174   bool hasSpills() const   { return HasSpills; }
175 
176   void setHasNonRISpills()    { HasNonRISpills = true; }
177   bool hasNonRISpills() const { return HasNonRISpills; }
178 
179   void setSpillsCR()       { SpillsCR = true; }
180   bool isCRSpilled() const { return SpillsCR; }
181 
182   void setDisableNonVolatileCR() { DisableNonVolatileCR = true; }
183   bool isNonVolatileCRDisabled() const { return DisableNonVolatileCR; }
184 
185   void setSpillsVRSAVE()       { SpillsVRSAVE = true; }
186   bool isVRSAVESpilled() const { return SpillsVRSAVE; }
187 
188   void setLRStoreRequired() { LRStoreRequired = true; }
189   bool isLRStoreRequired() const { return LRStoreRequired; }
190 
191   void setUsesTOCBasePtr()    { UsesTOCBasePtr = true; }
192   bool usesTOCBasePtr() const { return UsesTOCBasePtr; }
193 
194   void setHasFastCall() { HasFastCall = true; }
195   bool hasFastCall() const { return HasFastCall;}
196 
197   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
198   void setVarArgsFrameIndex(int Index) { VarArgsFrameIndex = Index; }
199 
200   int getVarArgsStackOffset() const { return VarArgsStackOffset; }
201   void setVarArgsStackOffset(int Offset) { VarArgsStackOffset = Offset; }
202 
203   unsigned getVarArgsNumGPR() const { return VarArgsNumGPR; }
204   void setVarArgsNumGPR(unsigned Num) { VarArgsNumGPR = Num; }
205 
206   unsigned getVarArgsNumFPR() const { return VarArgsNumFPR; }
207   void setVarArgsNumFPR(unsigned Num) { VarArgsNumFPR = Num; }
208 
209   /// This function associates attributes for each live-in virtual register.
210   void addLiveInAttr(unsigned VReg, ISD::ArgFlagsTy Flags) {
211     LiveInAttrs.push_back(std::make_pair(VReg, Flags));
212   }
213 
214   /// This function returns true if the specified vreg is
215   /// a live-in register and sign-extended.
216   bool isLiveInSExt(unsigned VReg) const;
217 
218   /// This function returns true if the specified vreg is
219   /// a live-in register and zero-extended.
220   bool isLiveInZExt(unsigned VReg) const;
221 
222   int getCRSpillFrameIndex() const { return CRSpillFrameIndex; }
223   void setCRSpillFrameIndex(int idx) { CRSpillFrameIndex = idx; }
224 
225   const SmallVectorImpl<unsigned> &
226     getMustSaveCRs() const { return MustSaveCRs; }
227   void addMustSaveCR(unsigned Reg) { MustSaveCRs.push_back(Reg); }
228 
229   void setUsesPICBase(bool uses) { UsesPICBase = uses; }
230   bool usesPICBase() const { return UsesPICBase; }
231 
232   bool isSplitCSR() const { return IsSplitCSR; }
233   void setIsSplitCSR(bool s) { IsSplitCSR = s; }
234 
235   MCSymbol *getPICOffsetSymbol() const;
236 
237   MCSymbol *getGlobalEPSymbol() const;
238   MCSymbol *getLocalEPSymbol() const;
239   MCSymbol *getTOCOffsetSymbol() const;
240 };
241 
242 } // end namespace llvm
243 
244 #endif // LLVM_LIB_TARGET_POWERPC_PPCMACHINEFUNCTIONINFO_H
245