1 //===-- X86MachineFunctionInfo.h - X86 machine function info ----*- 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 X86-specific per-machine-function information.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_X86_X86MACHINEFUNCTIONINFO_H
14 #define LLVM_LIB_TARGET_X86_X86MACHINEFUNCTIONINFO_H
15 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/CodeGen/CallingConvLower.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 
21 namespace llvm {
22 
23 /// X86MachineFunctionInfo - This class is derived from MachineFunction and
24 /// contains private X86 target-specific information for each MachineFunction.
25 class X86MachineFunctionInfo : public MachineFunctionInfo {
26   virtual void anchor();
27 
28   /// ForceFramePointer - True if the function is required to use of frame
29   /// pointer for reasons other than it containing dynamic allocation or
30   /// that FP eliminatation is turned off. For example, Cygwin main function
31   /// contains stack pointer re-alignment code which requires FP.
32   bool ForceFramePointer = false;
33 
34   /// RestoreBasePointerOffset - Non-zero if the function has base pointer
35   /// and makes call to llvm.eh.sjlj.setjmp. When non-zero, the value is a
36   /// displacement from the frame pointer to a slot where the base pointer
37   /// is stashed.
38   signed char RestoreBasePointerOffset = 0;
39 
40   /// WinEHXMMSlotInfo - Slot information of XMM registers in the stack frame
41   /// in bytes.
42   DenseMap<int, unsigned> WinEHXMMSlotInfo;
43 
44   /// CalleeSavedFrameSize - Size of the callee-saved register portion of the
45   /// stack frame in bytes.
46   unsigned CalleeSavedFrameSize = 0;
47 
48   /// BytesToPopOnReturn - Number of bytes function pops on return (in addition
49   /// to the space used by the return address).
50   /// Used on windows platform for stdcall & fastcall name decoration
51   unsigned BytesToPopOnReturn = 0;
52 
53   /// ReturnAddrIndex - FrameIndex for return slot.
54   int ReturnAddrIndex = 0;
55 
56   /// FrameIndex for return slot.
57   int FrameAddrIndex = 0;
58 
59   /// TailCallReturnAddrDelta - The number of bytes by which return address
60   /// stack slot is moved as the result of tail call optimization.
61   int TailCallReturnAddrDelta = 0;
62 
63   /// SRetReturnReg - Some subtargets require that sret lowering includes
64   /// returning the value of the returned struct in a register. This field
65   /// holds the virtual register into which the sret argument is passed.
66   Register SRetReturnReg;
67 
68   /// GlobalBaseReg - keeps track of the virtual register initialized for
69   /// use as the global base register. This is used for PIC in some PIC
70   /// relocation models.
71   Register GlobalBaseReg;
72 
73   /// VarArgsFrameIndex - FrameIndex for start of varargs area.
74   int VarArgsFrameIndex = 0;
75   /// RegSaveFrameIndex - X86-64 vararg func register save area.
76   int RegSaveFrameIndex = 0;
77   /// VarArgsGPOffset - X86-64 vararg func int reg offset.
78   unsigned VarArgsGPOffset = 0;
79   /// VarArgsFPOffset - X86-64 vararg func fp reg offset.
80   unsigned VarArgsFPOffset = 0;
81   /// ArgumentStackSize - The number of bytes on stack consumed by the arguments
82   /// being passed on the stack.
83   unsigned ArgumentStackSize = 0;
84   /// NumLocalDynamics - Number of local-dynamic TLS accesses.
85   unsigned NumLocalDynamics = 0;
86   /// HasPushSequences - Keeps track of whether this function uses sequences
87   /// of pushes to pass function parameters.
88   bool HasPushSequences = false;
89 
90   /// True if the function recovers from an SEH exception, and therefore needs
91   /// to spill and restore the frame pointer.
92   bool HasSEHFramePtrSave = false;
93 
94   /// The frame index of a stack object containing the original frame pointer
95   /// used to address arguments in a function using a base pointer.
96   int SEHFramePtrSaveIndex = 0;
97 
98   /// True if this function has a subset of CSRs that is handled explicitly via
99   /// copies.
100   bool IsSplitCSR = false;
101 
102   /// True if this function uses the red zone.
103   bool UsesRedZone = false;
104 
105   /// True if this function has DYN_ALLOCA instructions.
106   bool HasDynAlloca = false;
107 
108   /// True if this function has any preallocated calls.
109   bool HasPreallocatedCall = false;
110 
111   /// Whether this function has an extended frame record [Ctx, RBP, Return
112   /// addr]. If so, bit 60 of the in-memory frame pointer will be 1 to enable
113   /// other tools to detect the extended record.
114   bool HasSwiftAsyncContext = false;
115 
116   /// True if this function has tile virtual register. This is used to
117   /// determine if we should insert tilerelease in frame lowering.
118   bool HasVirtualTileReg = false;
119 
120   /// True if this function has CFI directives that adjust the CFA.
121   /// This is used to determine if we should direct the debugger to use
122   /// the CFA instead of the stack pointer.
123   bool HasCFIAdjustCfa = false;
124 
125   MachineInstr *StackPtrSaveMI = nullptr;
126 
127   std::optional<int> SwiftAsyncContextFrameIdx;
128 
129   // Preallocated fields are only used during isel.
130   // FIXME: Can we find somewhere else to store these?
131   DenseMap<const Value *, size_t> PreallocatedIds;
132   SmallVector<size_t, 0> PreallocatedStackSizes;
133   SmallVector<SmallVector<size_t, 4>, 0> PreallocatedArgOffsets;
134 
135 private:
136   /// ForwardedMustTailRegParms - A list of virtual and physical registers
137   /// that must be forwarded to every musttail call.
138   SmallVector<ForwardedRegister, 1> ForwardedMustTailRegParms;
139 
140 public:
141   X86MachineFunctionInfo() = default;
142   X86MachineFunctionInfo(const Function &F, const TargetSubtargetInfo *STI) {}
143 
144   X86MachineFunctionInfo(const X86MachineFunctionInfo &) = default;
145 
146   MachineFunctionInfo *
147   clone(BumpPtrAllocator &Allocator, MachineFunction &DestMF,
148         const DenseMap<MachineBasicBlock *, MachineBasicBlock *> &Src2DstMBB)
149       const override;
150 
151   bool getForceFramePointer() const { return ForceFramePointer;}
152   void setForceFramePointer(bool forceFP) { ForceFramePointer = forceFP; }
153 
154   bool getHasPushSequences() const { return HasPushSequences; }
155   void setHasPushSequences(bool HasPush) { HasPushSequences = HasPush; }
156 
157   bool getRestoreBasePointer() const { return RestoreBasePointerOffset!=0; }
158   void setRestoreBasePointer(const MachineFunction *MF);
159   void setRestoreBasePointer(unsigned CalleeSavedFrameSize) {
160     RestoreBasePointerOffset = -CalleeSavedFrameSize;
161   }
162   int getRestoreBasePointerOffset() const {return RestoreBasePointerOffset; }
163 
164   DenseMap<int, unsigned>& getWinEHXMMSlotInfo() { return WinEHXMMSlotInfo; }
165   const DenseMap<int, unsigned>& getWinEHXMMSlotInfo() const {
166     return WinEHXMMSlotInfo; }
167 
168   unsigned getCalleeSavedFrameSize() const { return CalleeSavedFrameSize; }
169   void setCalleeSavedFrameSize(unsigned bytes) { CalleeSavedFrameSize = bytes; }
170 
171   unsigned getBytesToPopOnReturn() const { return BytesToPopOnReturn; }
172   void setBytesToPopOnReturn (unsigned bytes) { BytesToPopOnReturn = bytes;}
173 
174   int getRAIndex() const { return ReturnAddrIndex; }
175   void setRAIndex(int Index) { ReturnAddrIndex = Index; }
176 
177   int getFAIndex() const { return FrameAddrIndex; }
178   void setFAIndex(int Index) { FrameAddrIndex = Index; }
179 
180   int getTCReturnAddrDelta() const { return TailCallReturnAddrDelta; }
181   void setTCReturnAddrDelta(int delta) {TailCallReturnAddrDelta = delta;}
182 
183   Register getSRetReturnReg() const { return SRetReturnReg; }
184   void setSRetReturnReg(Register Reg) { SRetReturnReg = Reg; }
185 
186   Register getGlobalBaseReg() const { return GlobalBaseReg; }
187   void setGlobalBaseReg(Register Reg) { GlobalBaseReg = Reg; }
188 
189   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
190   void setVarArgsFrameIndex(int Idx) { VarArgsFrameIndex = Idx; }
191 
192   int getRegSaveFrameIndex() const { return RegSaveFrameIndex; }
193   void setRegSaveFrameIndex(int Idx) { RegSaveFrameIndex = Idx; }
194 
195   unsigned getVarArgsGPOffset() const { return VarArgsGPOffset; }
196   void setVarArgsGPOffset(unsigned Offset) { VarArgsGPOffset = Offset; }
197 
198   unsigned getVarArgsFPOffset() const { return VarArgsFPOffset; }
199   void setVarArgsFPOffset(unsigned Offset) { VarArgsFPOffset = Offset; }
200 
201   unsigned getArgumentStackSize() const { return ArgumentStackSize; }
202   void setArgumentStackSize(unsigned size) { ArgumentStackSize = size; }
203 
204   unsigned getNumLocalDynamicTLSAccesses() const { return NumLocalDynamics; }
205   void incNumLocalDynamicTLSAccesses() { ++NumLocalDynamics; }
206 
207   bool getHasSEHFramePtrSave() const { return HasSEHFramePtrSave; }
208   void setHasSEHFramePtrSave(bool V) { HasSEHFramePtrSave = V; }
209 
210   int getSEHFramePtrSaveIndex() const { return SEHFramePtrSaveIndex; }
211   void setSEHFramePtrSaveIndex(int Index) { SEHFramePtrSaveIndex = Index; }
212 
213   SmallVectorImpl<ForwardedRegister> &getForwardedMustTailRegParms() {
214     return ForwardedMustTailRegParms;
215   }
216 
217   bool isSplitCSR() const { return IsSplitCSR; }
218   void setIsSplitCSR(bool s) { IsSplitCSR = s; }
219 
220   bool getUsesRedZone() const { return UsesRedZone; }
221   void setUsesRedZone(bool V) { UsesRedZone = V; }
222 
223   bool hasDynAlloca() const { return HasDynAlloca; }
224   void setHasDynAlloca(bool v) { HasDynAlloca = v; }
225 
226   bool hasPreallocatedCall() const { return HasPreallocatedCall; }
227   void setHasPreallocatedCall(bool v) { HasPreallocatedCall = v; }
228 
229   bool hasSwiftAsyncContext() const { return HasSwiftAsyncContext; }
230   void setHasSwiftAsyncContext(bool v) { HasSwiftAsyncContext = v; }
231 
232   bool hasVirtualTileReg() const { return HasVirtualTileReg; }
233   void setHasVirtualTileReg(bool v) { HasVirtualTileReg = v; }
234 
235   bool hasCFIAdjustCfa() const { return HasCFIAdjustCfa; }
236   void setHasCFIAdjustCfa(bool v) { HasCFIAdjustCfa = v; }
237 
238   void setStackPtrSaveMI(MachineInstr *MI) { StackPtrSaveMI = MI; }
239   MachineInstr *getStackPtrSaveMI() const { return StackPtrSaveMI; }
240 
241   std::optional<int> getSwiftAsyncContextFrameIdx() const {
242     return SwiftAsyncContextFrameIdx;
243   }
244   void setSwiftAsyncContextFrameIdx(int v) { SwiftAsyncContextFrameIdx = v; }
245 
246   size_t getPreallocatedIdForCallSite(const Value *CS) {
247     auto Insert = PreallocatedIds.insert({CS, PreallocatedIds.size()});
248     if (Insert.second) {
249       PreallocatedStackSizes.push_back(0);
250       PreallocatedArgOffsets.emplace_back();
251     }
252     return Insert.first->second;
253   }
254 
255   void setPreallocatedStackSize(size_t Id, size_t StackSize) {
256     PreallocatedStackSizes[Id] = StackSize;
257   }
258 
259   size_t getPreallocatedStackSize(const size_t Id) {
260     assert(PreallocatedStackSizes[Id] != 0 && "stack size not set");
261     return PreallocatedStackSizes[Id];
262   }
263 
264   void setPreallocatedArgOffsets(size_t Id, ArrayRef<size_t> AO) {
265     PreallocatedArgOffsets[Id].assign(AO.begin(), AO.end());
266   }
267 
268   ArrayRef<size_t> getPreallocatedArgOffsets(const size_t Id) {
269     assert(!PreallocatedArgOffsets[Id].empty() && "arg offsets not set");
270     return PreallocatedArgOffsets[Id];
271   }
272 };
273 
274 } // End llvm namespace
275 
276 #endif
277