1 //=- AArch64MachineFunctionInfo.h - AArch64 machine function info -*- 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 AArch64-specific per-machine-function information. 11 // 12 //===----------------------------------------------------------------------===// 13 14 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H 15 #define LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H 16 17 #include "llvm/ADT/ArrayRef.h" 18 #include "llvm/ADT/Optional.h" 19 #include "llvm/ADT/SmallPtrSet.h" 20 #include "llvm/ADT/SmallVector.h" 21 #include "llvm/CodeGen/MachineFunction.h" 22 #include "llvm/MC/MCLinkerOptimizationHint.h" 23 #include <cassert> 24 25 namespace llvm { 26 27 class MachineInstr; 28 29 /// AArch64FunctionInfo - This class is derived from MachineFunctionInfo and 30 /// contains private AArch64-specific information for each MachineFunction. 31 class AArch64FunctionInfo final : public MachineFunctionInfo { 32 /// Number of bytes of arguments this function has on the stack. If the callee 33 /// is expected to restore the argument stack this should be a multiple of 16, 34 /// all usable during a tail call. 35 /// 36 /// The alternative would forbid tail call optimisation in some cases: if we 37 /// want to transfer control from a function with 8-bytes of stack-argument 38 /// space to a function with 16-bytes then misalignment of this value would 39 /// make a stack adjustment necessary, which could not be undone by the 40 /// callee. 41 unsigned BytesInStackArgArea = 0; 42 43 /// The number of bytes to restore to deallocate space for incoming 44 /// arguments. Canonically 0 in the C calling convention, but non-zero when 45 /// callee is expected to pop the args. 46 unsigned ArgumentStackToRestore = 0; 47 48 /// HasStackFrame - True if this function has a stack frame. Set by 49 /// determineCalleeSaves(). 50 bool HasStackFrame = false; 51 52 /// Amount of stack frame size, not including callee-saved registers. 53 unsigned LocalStackSize; 54 55 /// Amount of stack frame size used for saving callee-saved registers. 56 unsigned CalleeSavedStackSize; 57 58 /// Number of TLS accesses using the special (combinable) 59 /// _TLS_MODULE_BASE_ symbol. 60 unsigned NumLocalDynamicTLSAccesses = 0; 61 62 /// FrameIndex for start of varargs area for arguments passed on the 63 /// stack. 64 int VarArgsStackIndex = 0; 65 66 /// FrameIndex for start of varargs area for arguments passed in 67 /// general purpose registers. 68 int VarArgsGPRIndex = 0; 69 70 /// Size of the varargs area for arguments passed in general purpose 71 /// registers. 72 unsigned VarArgsGPRSize = 0; 73 74 /// FrameIndex for start of varargs area for arguments passed in 75 /// floating-point registers. 76 int VarArgsFPRIndex = 0; 77 78 /// Size of the varargs area for arguments passed in floating-point 79 /// registers. 80 unsigned VarArgsFPRSize = 0; 81 82 /// True if this function has a subset of CSRs that is handled explicitly via 83 /// copies. 84 bool IsSplitCSR = false; 85 86 /// True when the stack gets realigned dynamically because the size of stack 87 /// frame is unknown at compile time. e.g., in case of VLAs. 88 bool StackRealigned = false; 89 90 /// True when the callee-save stack area has unused gaps that may be used for 91 /// other stack allocations. 92 bool CalleeSaveStackHasFreeSpace = false; 93 94 /// Has a value when it is known whether or not the function uses a 95 /// redzone, and no value otherwise. 96 /// Initialized during frame lowering, unless the function has the noredzone 97 /// attribute, in which case it is set to false at construction. 98 Optional<bool> HasRedZone; 99 100 public: 101 AArch64FunctionInfo() = default; 102 103 explicit AArch64FunctionInfo(MachineFunction &MF) { 104 (void)MF; 105 106 // If we already know that the function doesn't have a redzone, set 107 // HasRedZone here. 108 if (MF.getFunction().hasFnAttribute(Attribute::NoRedZone)) 109 HasRedZone = false; 110 } 111 112 unsigned getBytesInStackArgArea() const { return BytesInStackArgArea; } 113 void setBytesInStackArgArea(unsigned bytes) { BytesInStackArgArea = bytes; } 114 115 unsigned getArgumentStackToRestore() const { return ArgumentStackToRestore; } 116 void setArgumentStackToRestore(unsigned bytes) { 117 ArgumentStackToRestore = bytes; 118 } 119 120 bool hasStackFrame() const { return HasStackFrame; } 121 void setHasStackFrame(bool s) { HasStackFrame = s; } 122 123 bool isStackRealigned() const { return StackRealigned; } 124 void setStackRealigned(bool s) { StackRealigned = s; } 125 126 bool hasCalleeSaveStackFreeSpace() const { 127 return CalleeSaveStackHasFreeSpace; 128 } 129 void setCalleeSaveStackHasFreeSpace(bool s) { 130 CalleeSaveStackHasFreeSpace = s; 131 } 132 133 bool isSplitCSR() const { return IsSplitCSR; } 134 void setIsSplitCSR(bool s) { IsSplitCSR = s; } 135 136 void setLocalStackSize(unsigned Size) { LocalStackSize = Size; } 137 unsigned getLocalStackSize() const { return LocalStackSize; } 138 139 void setCalleeSavedStackSize(unsigned Size) { CalleeSavedStackSize = Size; } 140 unsigned getCalleeSavedStackSize() const { return CalleeSavedStackSize; } 141 142 void incNumLocalDynamicTLSAccesses() { ++NumLocalDynamicTLSAccesses; } 143 unsigned getNumLocalDynamicTLSAccesses() const { 144 return NumLocalDynamicTLSAccesses; 145 } 146 147 Optional<bool> hasRedZone() const { return HasRedZone; } 148 void setHasRedZone(bool s) { HasRedZone = s; } 149 150 int getVarArgsStackIndex() const { return VarArgsStackIndex; } 151 void setVarArgsStackIndex(int Index) { VarArgsStackIndex = Index; } 152 153 int getVarArgsGPRIndex() const { return VarArgsGPRIndex; } 154 void setVarArgsGPRIndex(int Index) { VarArgsGPRIndex = Index; } 155 156 unsigned getVarArgsGPRSize() const { return VarArgsGPRSize; } 157 void setVarArgsGPRSize(unsigned Size) { VarArgsGPRSize = Size; } 158 159 int getVarArgsFPRIndex() const { return VarArgsFPRIndex; } 160 void setVarArgsFPRIndex(int Index) { VarArgsFPRIndex = Index; } 161 162 unsigned getVarArgsFPRSize() const { return VarArgsFPRSize; } 163 void setVarArgsFPRSize(unsigned Size) { VarArgsFPRSize = Size; } 164 165 using SetOfInstructions = SmallPtrSet<const MachineInstr *, 16>; 166 167 const SetOfInstructions &getLOHRelated() const { return LOHRelated; } 168 169 // Shortcuts for LOH related types. 170 class MILOHDirective { 171 MCLOHType Kind; 172 173 /// Arguments of this directive. Order matters. 174 SmallVector<const MachineInstr *, 3> Args; 175 176 public: 177 using LOHArgs = ArrayRef<const MachineInstr *>; 178 179 MILOHDirective(MCLOHType Kind, LOHArgs Args) 180 : Kind(Kind), Args(Args.begin(), Args.end()) { 181 assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!"); 182 } 183 184 MCLOHType getKind() const { return Kind; } 185 LOHArgs getArgs() const { return Args; } 186 }; 187 188 using MILOHArgs = MILOHDirective::LOHArgs; 189 using MILOHContainer = SmallVector<MILOHDirective, 32>; 190 191 const MILOHContainer &getLOHContainer() const { return LOHContainerSet; } 192 193 /// Add a LOH directive of this @p Kind and this @p Args. 194 void addLOHDirective(MCLOHType Kind, MILOHArgs Args) { 195 LOHContainerSet.push_back(MILOHDirective(Kind, Args)); 196 LOHRelated.insert(Args.begin(), Args.end()); 197 } 198 199 private: 200 // Hold the lists of LOHs. 201 MILOHContainer LOHContainerSet; 202 SetOfInstructions LOHRelated; 203 }; 204 205 } // end namespace llvm 206 207 #endif // LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H 208
