LLVM  10.0.0svn
AArch64MachineFunctionInfo.h
Go to the documentation of this file.
1 //=- AArch64MachineFunctionInfo.h - AArch64 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 AArch64-specific per-machine-function information.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H
14 #define LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H
15 
16 #include "llvm/ADT/ArrayRef.h"
17 #include "llvm/ADT/Optional.h"
18 #include "llvm/ADT/SmallPtrSet.h"
19 #include "llvm/ADT/SmallVector.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.
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  /// SRetReturnReg - sret lowering includes returning the value of the
95  /// returned struct in a register. This field holds the virtual register into
96  /// which the sret argument is passed.
97  unsigned SRetReturnReg = 0;
98 
99  /// Has a value when it is known whether or not the function uses a
100  /// redzone, and no value otherwise.
101  /// Initialized during frame lowering, unless the function has the noredzone
102  /// attribute, in which case it is set to false at construction.
103  Optional<bool> HasRedZone;
104 
105  /// ForwardedMustTailRegParms - A list of virtual and physical registers
106  /// that must be forwarded to every musttail call.
107  SmallVector<ForwardedRegister, 1> ForwardedMustTailRegParms;
108 
109  // Offset from SP-at-entry to the tagged base pointer.
110  // Tagged base pointer is set up to point to the first (lowest address) tagged
111  // stack slot.
112  unsigned TaggedBasePointerOffset;
113 
114 public:
115  AArch64FunctionInfo() = default;
116 
118  (void)MF;
119 
120  // If we already know that the function doesn't have a redzone, set
121  // HasRedZone here.
122  if (MF.getFunction().hasFnAttribute(Attribute::NoRedZone))
123  HasRedZone = false;
124  }
125 
126  unsigned getBytesInStackArgArea() const { return BytesInStackArgArea; }
127  void setBytesInStackArgArea(unsigned bytes) { BytesInStackArgArea = bytes; }
128 
129  unsigned getArgumentStackToRestore() const { return ArgumentStackToRestore; }
130  void setArgumentStackToRestore(unsigned bytes) {
131  ArgumentStackToRestore = bytes;
132  }
133 
134  bool hasStackFrame() const { return HasStackFrame; }
135  void setHasStackFrame(bool s) { HasStackFrame = s; }
136 
137  bool isStackRealigned() const { return StackRealigned; }
138  void setStackRealigned(bool s) { StackRealigned = s; }
139 
141  return CalleeSaveStackHasFreeSpace;
142  }
144  CalleeSaveStackHasFreeSpace = s;
145  }
146 
147  bool isSplitCSR() const { return IsSplitCSR; }
148  void setIsSplitCSR(bool s) { IsSplitCSR = s; }
149 
150  void setLocalStackSize(unsigned Size) { LocalStackSize = Size; }
151  unsigned getLocalStackSize() const { return LocalStackSize; }
152 
153  void setCalleeSavedStackSize(unsigned Size) { CalleeSavedStackSize = Size; }
154  unsigned getCalleeSavedStackSize() const { return CalleeSavedStackSize; }
155 
156  void incNumLocalDynamicTLSAccesses() { ++NumLocalDynamicTLSAccesses; }
157  unsigned getNumLocalDynamicTLSAccesses() const {
158  return NumLocalDynamicTLSAccesses;
159  }
160 
161  Optional<bool> hasRedZone() const { return HasRedZone; }
162  void setHasRedZone(bool s) { HasRedZone = s; }
163 
164  int getVarArgsStackIndex() const { return VarArgsStackIndex; }
165  void setVarArgsStackIndex(int Index) { VarArgsStackIndex = Index; }
166 
167  int getVarArgsGPRIndex() const { return VarArgsGPRIndex; }
168  void setVarArgsGPRIndex(int Index) { VarArgsGPRIndex = Index; }
169 
170  unsigned getVarArgsGPRSize() const { return VarArgsGPRSize; }
171  void setVarArgsGPRSize(unsigned Size) { VarArgsGPRSize = Size; }
172 
173  int getVarArgsFPRIndex() const { return VarArgsFPRIndex; }
174  void setVarArgsFPRIndex(int Index) { VarArgsFPRIndex = Index; }
175 
176  unsigned getVarArgsFPRSize() const { return VarArgsFPRSize; }
177  void setVarArgsFPRSize(unsigned Size) { VarArgsFPRSize = Size; }
178 
179  unsigned getSRetReturnReg() const { return SRetReturnReg; }
180  void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
181 
182  unsigned getJumpTableEntrySize(int Idx) const {
183  auto It = JumpTableEntryInfo.find(Idx);
184  if (It != JumpTableEntryInfo.end())
185  return It->second.first;
186  return 4;
187  }
189  return JumpTableEntryInfo.find(Idx)->second.second;
190  }
191  void setJumpTableEntryInfo(int Idx, unsigned Size, MCSymbol *PCRelSym) {
192  JumpTableEntryInfo[Idx] = std::make_pair(Size, PCRelSym);
193  }
194 
196 
197  const SetOfInstructions &getLOHRelated() const { return LOHRelated; }
198 
199  // Shortcuts for LOH related types.
201  MCLOHType Kind;
202 
203  /// Arguments of this directive. Order matters.
205 
206  public:
208 
210  : Kind(Kind), Args(Args.begin(), Args.end()) {
211  assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!");
212  }
213 
214  MCLOHType getKind() const { return Kind; }
215  LOHArgs getArgs() const { return Args; }
216  };
217 
220 
221  const MILOHContainer &getLOHContainer() const { return LOHContainerSet; }
222 
223  /// Add a LOH directive of this @p Kind and this @p Args.
225  LOHContainerSet.push_back(MILOHDirective(Kind, Args));
226  LOHRelated.insert(Args.begin(), Args.end());
227  }
228 
230  return ForwardedMustTailRegParms;
231  }
232 
233  unsigned getTaggedBasePointerOffset() const {
234  return TaggedBasePointerOffset;
235  }
237  TaggedBasePointerOffset = Offset;
238  }
239 
240 private:
241  // Hold the lists of LOHs.
242  MILOHContainer LOHContainerSet;
243  SetOfInstructions LOHRelated;
244 
246 };
247 
248 } // end namespace llvm
249 
250 #endif // LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H
const_iterator end(StringRef path)
Get end iterator over path.
Definition: Path.cpp:233
AArch64FunctionInfo - This class is derived from MachineFunctionInfo and contains private AArch64-spe...
const_iterator begin(StringRef path, Style style=Style::native)
Get begin iterator over path.
Definition: Path.cpp:224
This class represents lattice values for constants.
Definition: AllocatorList.h:23
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:41
iterator begin() const
Definition: ArrayRef.h:136
unsigned Reg
unsigned getJumpTableEntrySize(int Idx) const
const SetOfInstructions & getLOHRelated() const
bool hasFnAttribute(Attribute::AttrKind Kind) const
Return true if the function has the attribute.
Definition: Function.h:323
MachineFunctionInfo - This class can be derived from and used by targets to hold private target-speci...
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: APFloat.h:41
void setArgumentStackToRestore(unsigned bytes)
AArch64FunctionInfo(MachineFunction &MF)
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory)...
Definition: APInt.h:32
void setJumpTableEntryInfo(int Idx, unsigned Size, MCSymbol *PCRelSym)
MCLOHType
Linker Optimization Hint Type.
SmallVectorImpl< ForwardedRegister > & getForwardedMustTailRegParms()
MCSymbol * getJumpTableEntryPCRelSymbol(int Idx) const
This is a &#39;vector&#39; (really, a variable-sized array), optimized for the case when the array is small...
Definition: SmallVector.h:837
iterator end() const
Definition: ArrayRef.h:137
const Function & getFunction() const
Return the LLVM function that this machine code represents.
Optional< bool > hasRedZone() const
const MILOHContainer & getLOHContainer() const
static bool isValidMCLOHType(unsigned Kind)
uint32_t Size
Definition: Profile.cpp:46
void setBytesInStackArgArea(unsigned bytes)
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
void addLOHDirective(MCLOHType Kind, MILOHArgs Args)
Add a LOH directive of this Kind and this Args.
void setTaggedBasePointerOffset(unsigned Offset)
void setCalleeSavedStackSize(unsigned Size)