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"
22 #include "llvm/IR/Function.h"
24 #include <cassert>
25 
26 namespace llvm {
27 
28 class MachineInstr;
29 
30 /// AArch64FunctionInfo - This class is derived from MachineFunctionInfo and
31 /// contains private AArch64-specific information for each MachineFunction.
33  /// Number of bytes of arguments this function has on the stack. If the callee
34  /// is expected to restore the argument stack this should be a multiple of 16,
35  /// all usable during a tail call.
36  ///
37  /// The alternative would forbid tail call optimisation in some cases: if we
38  /// want to transfer control from a function with 8-bytes of stack-argument
39  /// space to a function with 16-bytes then misalignment of this value would
40  /// make a stack adjustment necessary, which could not be undone by the
41  /// callee.
42  unsigned BytesInStackArgArea = 0;
43 
44  /// The number of bytes to restore to deallocate space for incoming
45  /// arguments. Canonically 0 in the C calling convention, but non-zero when
46  /// callee is expected to pop the args.
47  unsigned ArgumentStackToRestore = 0;
48 
49  /// HasStackFrame - True if this function has a stack frame. Set by
50  /// determineCalleeSaves().
51  bool HasStackFrame = false;
52 
53  /// Amount of stack frame size, not including callee-saved registers.
54  unsigned LocalStackSize;
55 
56  /// Amount of stack frame size used for saving callee-saved registers.
57  unsigned CalleeSavedStackSize;
58 
59  /// Number of TLS accesses using the special (combinable)
60  /// _TLS_MODULE_BASE_ symbol.
61  unsigned NumLocalDynamicTLSAccesses = 0;
62 
63  /// FrameIndex for start of varargs area for arguments passed on the
64  /// stack.
65  int VarArgsStackIndex = 0;
66 
67  /// FrameIndex for start of varargs area for arguments passed in
68  /// general purpose registers.
69  int VarArgsGPRIndex = 0;
70 
71  /// Size of the varargs area for arguments passed in general purpose
72  /// registers.
73  unsigned VarArgsGPRSize = 0;
74 
75  /// FrameIndex for start of varargs area for arguments passed in
76  /// floating-point registers.
77  int VarArgsFPRIndex = 0;
78 
79  /// Size of the varargs area for arguments passed in floating-point
80  /// registers.
81  unsigned VarArgsFPRSize = 0;
82 
83  /// True if this function has a subset of CSRs that is handled explicitly via
84  /// copies.
85  bool IsSplitCSR = false;
86 
87  /// True when the stack gets realigned dynamically because the size of stack
88  /// frame is unknown at compile time. e.g., in case of VLAs.
89  bool StackRealigned = false;
90 
91  /// True when the callee-save stack area has unused gaps that may be used for
92  /// other stack allocations.
93  bool CalleeSaveStackHasFreeSpace = false;
94 
95  /// SRetReturnReg - sret lowering includes returning the value of the
96  /// returned struct in a register. This field holds the virtual register into
97  /// which the sret argument is passed.
98  unsigned SRetReturnReg = 0;
99  /// SVE stack size (for predicates and data vectors) are maintained here
100  /// rather than in FrameInfo, as the placement and Stack IDs are target
101  /// specific.
102  uint64_t StackSizeSVE = 0;
103 
104  /// HasCalculatedStackSizeSVE indicates whether StackSizeSVE is valid.
105  bool HasCalculatedStackSizeSVE = false;
106 
107  /// Has a value when it is known whether or not the function uses a
108  /// redzone, and no value otherwise.
109  /// Initialized during frame lowering, unless the function has the noredzone
110  /// attribute, in which case it is set to false at construction.
111  Optional<bool> HasRedZone;
112 
113  /// ForwardedMustTailRegParms - A list of virtual and physical registers
114  /// that must be forwarded to every musttail call.
115  SmallVector<ForwardedRegister, 1> ForwardedMustTailRegParms;
116 
117  // Offset from SP-at-entry to the tagged base pointer.
118  // Tagged base pointer is set up to point to the first (lowest address) tagged
119  // stack slot.
120  unsigned TaggedBasePointerOffset;
121 
122 public:
123  AArch64FunctionInfo() = default;
124 
126  (void)MF;
127 
128  // If we already know that the function doesn't have a redzone, set
129  // HasRedZone here.
130  if (MF.getFunction().hasFnAttribute(Attribute::NoRedZone))
131  HasRedZone = false;
132  }
133 
134  unsigned getBytesInStackArgArea() const { return BytesInStackArgArea; }
135  void setBytesInStackArgArea(unsigned bytes) { BytesInStackArgArea = bytes; }
136 
137  unsigned getArgumentStackToRestore() const { return ArgumentStackToRestore; }
138  void setArgumentStackToRestore(unsigned bytes) {
139  ArgumentStackToRestore = bytes;
140  }
141 
142  bool hasCalculatedStackSizeSVE() const { return HasCalculatedStackSizeSVE; }
143 
144  void setStackSizeSVE(uint64_t S) {
145  HasCalculatedStackSizeSVE = true;
146  StackSizeSVE = S;
147  }
148 
149  uint64_t getStackSizeSVE() const { return StackSizeSVE; }
150 
151  bool hasStackFrame() const { return HasStackFrame; }
152  void setHasStackFrame(bool s) { HasStackFrame = s; }
153 
154  bool isStackRealigned() const { return StackRealigned; }
155  void setStackRealigned(bool s) { StackRealigned = s; }
156 
158  return CalleeSaveStackHasFreeSpace;
159  }
161  CalleeSaveStackHasFreeSpace = s;
162  }
163 
164  bool isSplitCSR() const { return IsSplitCSR; }
165  void setIsSplitCSR(bool s) { IsSplitCSR = s; }
166 
167  void setLocalStackSize(unsigned Size) { LocalStackSize = Size; }
168  unsigned getLocalStackSize() const { return LocalStackSize; }
169 
170  void setCalleeSavedStackSize(unsigned Size) { CalleeSavedStackSize = Size; }
171  unsigned getCalleeSavedStackSize() const { return CalleeSavedStackSize; }
172 
173  void incNumLocalDynamicTLSAccesses() { ++NumLocalDynamicTLSAccesses; }
174  unsigned getNumLocalDynamicTLSAccesses() const {
175  return NumLocalDynamicTLSAccesses;
176  }
177 
178  Optional<bool> hasRedZone() const { return HasRedZone; }
179  void setHasRedZone(bool s) { HasRedZone = s; }
180 
181  int getVarArgsStackIndex() const { return VarArgsStackIndex; }
182  void setVarArgsStackIndex(int Index) { VarArgsStackIndex = Index; }
183 
184  int getVarArgsGPRIndex() const { return VarArgsGPRIndex; }
185  void setVarArgsGPRIndex(int Index) { VarArgsGPRIndex = Index; }
186 
187  unsigned getVarArgsGPRSize() const { return VarArgsGPRSize; }
188  void setVarArgsGPRSize(unsigned Size) { VarArgsGPRSize = Size; }
189 
190  int getVarArgsFPRIndex() const { return VarArgsFPRIndex; }
191  void setVarArgsFPRIndex(int Index) { VarArgsFPRIndex = Index; }
192 
193  unsigned getVarArgsFPRSize() const { return VarArgsFPRSize; }
194  void setVarArgsFPRSize(unsigned Size) { VarArgsFPRSize = Size; }
195 
196  unsigned getSRetReturnReg() const { return SRetReturnReg; }
197  void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
198 
199  unsigned getJumpTableEntrySize(int Idx) const {
200  auto It = JumpTableEntryInfo.find(Idx);
201  if (It != JumpTableEntryInfo.end())
202  return It->second.first;
203  return 4;
204  }
206  return JumpTableEntryInfo.find(Idx)->second.second;
207  }
208  void setJumpTableEntryInfo(int Idx, unsigned Size, MCSymbol *PCRelSym) {
209  JumpTableEntryInfo[Idx] = std::make_pair(Size, PCRelSym);
210  }
211 
213 
214  const SetOfInstructions &getLOHRelated() const { return LOHRelated; }
215 
216  // Shortcuts for LOH related types.
218  MCLOHType Kind;
219 
220  /// Arguments of this directive. Order matters.
222 
223  public:
225 
227  : Kind(Kind), Args(Args.begin(), Args.end()) {
228  assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!");
229  }
230 
231  MCLOHType getKind() const { return Kind; }
232  LOHArgs getArgs() const { return Args; }
233  };
234 
237 
238  const MILOHContainer &getLOHContainer() const { return LOHContainerSet; }
239 
240  /// Add a LOH directive of this @p Kind and this @p Args.
242  LOHContainerSet.push_back(MILOHDirective(Kind, Args));
243  LOHRelated.insert(Args.begin(), Args.end());
244  }
245 
247  return ForwardedMustTailRegParms;
248  }
249 
250  unsigned getTaggedBasePointerOffset() const {
251  return TaggedBasePointerOffset;
252  }
254  TaggedBasePointerOffset = Offset;
255  }
256 
257 private:
258  // Hold the lists of LOHs.
259  MILOHContainer LOHContainerSet;
260  SetOfInstructions LOHRelated;
261 
263 };
264 
265 } // end namespace llvm
266 
267 #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)