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      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