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 WIN_ALLOCA instructions.
106   bool HasWinAlloca = 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   Optional<int> SwiftAsyncContextFrameIdx;
117 
118   ValueMap<const Value *, size_t> PreallocatedIds;
119   SmallVector<size_t, 0> PreallocatedStackSizes;
120   SmallVector<SmallVector<size_t, 4>, 0> PreallocatedArgOffsets;
121 
122 private:
123   /// ForwardedMustTailRegParms - A list of virtual and physical registers
124   /// that must be forwarded to every musttail call.
125   SmallVector<ForwardedRegister, 1> ForwardedMustTailRegParms;
126 
127 public:
128   X86MachineFunctionInfo() = default;
129 
130   explicit X86MachineFunctionInfo(MachineFunction &MF) {}
131 
132   bool getForceFramePointer() const { return ForceFramePointer;}
133   void setForceFramePointer(bool forceFP) { ForceFramePointer = forceFP; }
134 
135   bool getHasPushSequences() const { return HasPushSequences; }
136   void setHasPushSequences(bool HasPush) { HasPushSequences = HasPush; }
137 
138   bool getRestoreBasePointer() const { return RestoreBasePointerOffset!=0; }
139   void setRestoreBasePointer(const MachineFunction *MF);
140   int getRestoreBasePointerOffset() const {return RestoreBasePointerOffset; }
141 
142   DenseMap<int, unsigned>& getWinEHXMMSlotInfo() { return WinEHXMMSlotInfo; }
143   const DenseMap<int, unsigned>& getWinEHXMMSlotInfo() const {
144     return WinEHXMMSlotInfo; }
145 
146   unsigned getCalleeSavedFrameSize() const { return CalleeSavedFrameSize; }
147   void setCalleeSavedFrameSize(unsigned bytes) { CalleeSavedFrameSize = bytes; }
148 
149   unsigned getBytesToPopOnReturn() const { return BytesToPopOnReturn; }
150   void setBytesToPopOnReturn (unsigned bytes) { BytesToPopOnReturn = bytes;}
151 
152   int getRAIndex() const { return ReturnAddrIndex; }
153   void setRAIndex(int Index) { ReturnAddrIndex = Index; }
154 
155   int getFAIndex() const { return FrameAddrIndex; }
156   void setFAIndex(int Index) { FrameAddrIndex = Index; }
157 
158   int getTCReturnAddrDelta() const { return TailCallReturnAddrDelta; }
159   void setTCReturnAddrDelta(int delta) {TailCallReturnAddrDelta = delta;}
160 
161   Register getSRetReturnReg() const { return SRetReturnReg; }
162   void setSRetReturnReg(Register Reg) { SRetReturnReg = Reg; }
163 
164   Register getGlobalBaseReg() const { return GlobalBaseReg; }
165   void setGlobalBaseReg(Register Reg) { GlobalBaseReg = Reg; }
166 
167   int getVarArgsFrameIndex() const { return VarArgsFrameIndex; }
168   void setVarArgsFrameIndex(int Idx) { VarArgsFrameIndex = Idx; }
169 
170   int getRegSaveFrameIndex() const { return RegSaveFrameIndex; }
171   void setRegSaveFrameIndex(int Idx) { RegSaveFrameIndex = Idx; }
172 
173   unsigned getVarArgsGPOffset() const { return VarArgsGPOffset; }
174   void setVarArgsGPOffset(unsigned Offset) { VarArgsGPOffset = Offset; }
175 
176   unsigned getVarArgsFPOffset() const { return VarArgsFPOffset; }
177   void setVarArgsFPOffset(unsigned Offset) { VarArgsFPOffset = Offset; }
178 
179   unsigned getArgumentStackSize() const { return ArgumentStackSize; }
180   void setArgumentStackSize(unsigned size) { ArgumentStackSize = size; }
181 
182   unsigned getNumLocalDynamicTLSAccesses() const { return NumLocalDynamics; }
183   void incNumLocalDynamicTLSAccesses() { ++NumLocalDynamics; }
184 
185   bool getHasSEHFramePtrSave() const { return HasSEHFramePtrSave; }
186   void setHasSEHFramePtrSave(bool V) { HasSEHFramePtrSave = V; }
187 
188   int getSEHFramePtrSaveIndex() const { return SEHFramePtrSaveIndex; }
189   void setSEHFramePtrSaveIndex(int Index) { SEHFramePtrSaveIndex = Index; }
190 
191   SmallVectorImpl<ForwardedRegister> &getForwardedMustTailRegParms() {
192     return ForwardedMustTailRegParms;
193   }
194 
195   bool isSplitCSR() const { return IsSplitCSR; }
196   void setIsSplitCSR(bool s) { IsSplitCSR = s; }
197 
198   bool getUsesRedZone() const { return UsesRedZone; }
199   void setUsesRedZone(bool V) { UsesRedZone = V; }
200 
201   bool hasWinAlloca() const { return HasWinAlloca; }
202   void setHasWinAlloca(bool v) { HasWinAlloca = v; }
203 
204   bool hasPreallocatedCall() const { return HasPreallocatedCall; }
205   void setHasPreallocatedCall(bool v) { HasPreallocatedCall = v; }
206 
207   bool hasSwiftAsyncContext() const { return HasSwiftAsyncContext; }
208   void setHasSwiftAsyncContext(bool v) { HasSwiftAsyncContext = v; }
209 
210   Optional<int> getSwiftAsyncContextFrameIdx() const {
211     return SwiftAsyncContextFrameIdx;
212   }
213   void setSwiftAsyncContextFrameIdx(int v) { SwiftAsyncContextFrameIdx = v; }
214 
215   size_t getPreallocatedIdForCallSite(const Value *CS) {
216     auto Insert = PreallocatedIds.insert({CS, PreallocatedIds.size()});
217     if (Insert.second) {
218       PreallocatedStackSizes.push_back(0);
219       PreallocatedArgOffsets.emplace_back();
220     }
221     return Insert.first->second;
222   }
223 
224   void setPreallocatedStackSize(size_t Id, size_t StackSize) {
225     PreallocatedStackSizes[Id] = StackSize;
226   }
227 
228   size_t getPreallocatedStackSize(const size_t Id) {
229     assert(PreallocatedStackSizes[Id] != 0 && "stack size not set");
230     return PreallocatedStackSizes[Id];
231   }
232 
233   void setPreallocatedArgOffsets(size_t Id, ArrayRef<size_t> AO) {
234     PreallocatedArgOffsets[Id].assign(AO.begin(), AO.end());
235   }
236 
237   ArrayRef<size_t> getPreallocatedArgOffsets(const size_t Id) {
238     assert(!PreallocatedArgOffsets[Id].empty() && "arg offsets not set");
239     return PreallocatedArgOffsets[Id];
240   }
241 };
242 
243 } // End llvm namespace
244 
245 #endif
246