LLVM 19.0.0git
AArch64MachineFunctionInfo.h
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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"
23#include "llvm/IR/Function.h"
25#include "llvm/MC/MCSymbol.h"
26#include <cassert>
27#include <optional>
28
29namespace llvm {
30
31namespace yaml {
32struct AArch64FunctionInfo;
33} // end namespace yaml
34
35class AArch64Subtarget;
36class MachineInstr;
37
38/// AArch64FunctionInfo - This class is derived from MachineFunctionInfo and
39/// contains private AArch64-specific information for each MachineFunction.
41 /// Number of bytes of arguments this function has on the stack. If the callee
42 /// is expected to restore the argument stack this should be a multiple of 16,
43 /// all usable during a tail call.
44 ///
45 /// The alternative would forbid tail call optimisation in some cases: if we
46 /// want to transfer control from a function with 8-bytes of stack-argument
47 /// space to a function with 16-bytes then misalignment of this value would
48 /// make a stack adjustment necessary, which could not be undone by the
49 /// callee.
50 unsigned BytesInStackArgArea = 0;
51
52 /// The number of bytes to restore to deallocate space for incoming
53 /// arguments. Canonically 0 in the C calling convention, but non-zero when
54 /// callee is expected to pop the args.
55 unsigned ArgumentStackToRestore = 0;
56
57 /// Space just below incoming stack pointer reserved for arguments being
58 /// passed on the stack during a tail call. This will be the difference
59 /// between the largest tail call argument space needed in this function and
60 /// what's already available by reusing space of incoming arguments.
61 unsigned TailCallReservedStack = 0;
62
63 /// HasStackFrame - True if this function has a stack frame. Set by
64 /// determineCalleeSaves().
65 bool HasStackFrame = false;
66
67 /// Amount of stack frame size, not including callee-saved registers.
68 uint64_t LocalStackSize = 0;
69
70 /// The start and end frame indices for the SVE callee saves.
71 int MinSVECSFrameIndex = 0;
72 int MaxSVECSFrameIndex = 0;
73
74 /// Amount of stack frame size used for saving callee-saved registers.
75 unsigned CalleeSavedStackSize = 0;
76 unsigned SVECalleeSavedStackSize = 0;
77 bool HasCalleeSavedStackSize = false;
78
79 /// Number of TLS accesses using the special (combinable)
80 /// _TLS_MODULE_BASE_ symbol.
81 unsigned NumLocalDynamicTLSAccesses = 0;
82
83 /// FrameIndex for start of varargs area for arguments passed on the
84 /// stack.
85 int VarArgsStackIndex = 0;
86
87 /// Offset of start of varargs area for arguments passed on the stack.
88 unsigned VarArgsStackOffset = 0;
89
90 /// FrameIndex for start of varargs area for arguments passed in
91 /// general purpose registers.
92 int VarArgsGPRIndex = 0;
93
94 /// Size of the varargs area for arguments passed in general purpose
95 /// registers.
96 unsigned VarArgsGPRSize = 0;
97
98 /// FrameIndex for start of varargs area for arguments passed in
99 /// floating-point registers.
100 int VarArgsFPRIndex = 0;
101
102 /// Size of the varargs area for arguments passed in floating-point
103 /// registers.
104 unsigned VarArgsFPRSize = 0;
105
106 /// True if this function has a subset of CSRs that is handled explicitly via
107 /// copies.
108 bool IsSplitCSR = false;
109
110 /// True when the stack gets realigned dynamically because the size of stack
111 /// frame is unknown at compile time. e.g., in case of VLAs.
112 bool StackRealigned = false;
113
114 /// True when the callee-save stack area has unused gaps that may be used for
115 /// other stack allocations.
116 bool CalleeSaveStackHasFreeSpace = false;
117
118 /// SRetReturnReg - sret lowering includes returning the value of the
119 /// returned struct in a register. This field holds the virtual register into
120 /// which the sret argument is passed.
121 Register SRetReturnReg;
122
123 /// SVE stack size (for predicates and data vectors) are maintained here
124 /// rather than in FrameInfo, as the placement and Stack IDs are target
125 /// specific.
126 uint64_t StackSizeSVE = 0;
127
128 /// HasCalculatedStackSizeSVE indicates whether StackSizeSVE is valid.
129 bool HasCalculatedStackSizeSVE = false;
130
131 /// Has a value when it is known whether or not the function uses a
132 /// redzone, and no value otherwise.
133 /// Initialized during frame lowering, unless the function has the noredzone
134 /// attribute, in which case it is set to false at construction.
135 std::optional<bool> HasRedZone;
136
137 /// ForwardedMustTailRegParms - A list of virtual and physical registers
138 /// that must be forwarded to every musttail call.
139 SmallVector<ForwardedRegister, 1> ForwardedMustTailRegParms;
140
141 /// FrameIndex for the tagged base pointer.
142 std::optional<int> TaggedBasePointerIndex;
143
144 /// Offset from SP-at-entry to the tagged base pointer.
145 /// Tagged base pointer is set up to point to the first (lowest address)
146 /// tagged stack slot.
147 unsigned TaggedBasePointerOffset;
148
149 /// OutliningStyle denotes, if a function was outined, how it was outlined,
150 /// e.g. Tail Call, Thunk, or Function if none apply.
151 std::optional<std::string> OutliningStyle;
152
153 // Offset from SP-after-callee-saved-spills (i.e. SP-at-entry minus
154 // CalleeSavedStackSize) to the address of the frame record.
155 int CalleeSaveBaseToFrameRecordOffset = 0;
156
157 /// SignReturnAddress is true if PAC-RET is enabled for the function with
158 /// defaults being sign non-leaf functions only, with the B key.
159 bool SignReturnAddress = false;
160
161 /// SignReturnAddressAll modifies the default PAC-RET mode to signing leaf
162 /// functions as well.
163 bool SignReturnAddressAll = false;
164
165 /// SignWithBKey modifies the default PAC-RET mode to signing with the B key.
166 bool SignWithBKey = false;
167
168 /// SigningInstrOffset captures the offset of the PAC-RET signing instruction
169 /// within the prologue, so it can be re-used for authentication in the
170 /// epilogue when using PC as a second salt (FEAT_PAuth_LR)
171 MCSymbol *SignInstrLabel = nullptr;
172
173 /// BranchTargetEnforcement enables placing BTI instructions at potential
174 /// indirect branch destinations.
175 bool BranchTargetEnforcement = false;
176
177 /// Indicates that SP signing should be diversified with PC as-per PAuthLR.
178 /// This is set by -mbranch-protection and will emit NOP instructions unless
179 /// the subtarget feature +pauthlr is also used (in which case non-NOP
180 /// instructions are emitted).
181 bool BranchProtectionPAuthLR = false;
182
183 /// Whether this function has an extended frame record [Ctx, FP, LR]. If so,
184 /// bit 60 of the in-memory FP will be 1 to enable other tools to detect the
185 /// extended record.
186 bool HasSwiftAsyncContext = false;
187
188 /// The stack slot where the Swift asynchronous context is stored.
189 int SwiftAsyncContextFrameIdx = std::numeric_limits<int>::max();
190
191 bool IsMTETagged = false;
192
193 /// The function has Scalable Vector or Scalable Predicate register argument
194 /// or return type
195 bool IsSVECC = false;
196
197 /// The frame-index for the TPIDR2 object used for lazy saves.
198 Register LazySaveTPIDR2Obj = 0;
199
200 /// Whether this function changes streaming mode within the function.
201 bool HasStreamingModeChanges = false;
202
203 /// True if the function need unwind information.
204 mutable std::optional<bool> NeedsDwarfUnwindInfo;
205
206 /// True if the function need asynchronous unwind information.
207 mutable std::optional<bool> NeedsAsyncDwarfUnwindInfo;
208
209 int64_t StackProbeSize = 0;
210
211 // Holds a register containing pstate.sm. This is set
212 // on function entry to record the initial pstate of a function.
213 Register PStateSMReg = MCRegister::NoRegister;
214
215public:
217
221 const override;
222
223 Register getPStateSMReg() const { return PStateSMReg; };
224 void setPStateSMReg(Register Reg) { PStateSMReg = Reg; };
225
226 bool isSVECC() const { return IsSVECC; };
227 void setIsSVECC(bool s) { IsSVECC = s; };
228
229 unsigned getLazySaveTPIDR2Obj() const { return LazySaveTPIDR2Obj; }
230 void setLazySaveTPIDR2Obj(unsigned Reg) { LazySaveTPIDR2Obj = Reg; }
231
233
234 unsigned getBytesInStackArgArea() const { return BytesInStackArgArea; }
235 void setBytesInStackArgArea(unsigned bytes) { BytesInStackArgArea = bytes; }
236
237 unsigned getArgumentStackToRestore() const { return ArgumentStackToRestore; }
238 void setArgumentStackToRestore(unsigned bytes) {
239 ArgumentStackToRestore = bytes;
240 }
241
242 unsigned getTailCallReservedStack() const { return TailCallReservedStack; }
243 void setTailCallReservedStack(unsigned bytes) {
244 TailCallReservedStack = bytes;
245 }
246
247 bool hasCalculatedStackSizeSVE() const { return HasCalculatedStackSizeSVE; }
248
250 HasCalculatedStackSizeSVE = true;
251 StackSizeSVE = S;
252 }
253
254 uint64_t getStackSizeSVE() const { return StackSizeSVE; }
255
256 bool hasStackFrame() const { return HasStackFrame; }
257 void setHasStackFrame(bool s) { HasStackFrame = s; }
258
259 bool isStackRealigned() const { return StackRealigned; }
260 void setStackRealigned(bool s) { StackRealigned = s; }
261
263 return CalleeSaveStackHasFreeSpace;
264 }
266 CalleeSaveStackHasFreeSpace = s;
267 }
268 bool isSplitCSR() const { return IsSplitCSR; }
269 void setIsSplitCSR(bool s) { IsSplitCSR = s; }
270
271 void setLocalStackSize(uint64_t Size) { LocalStackSize = Size; }
272 uint64_t getLocalStackSize() const { return LocalStackSize; }
273
274 void setOutliningStyle(std::string Style) { OutliningStyle = Style; }
275 std::optional<std::string> getOutliningStyle() const {
276 return OutliningStyle;
277 }
278
280 CalleeSavedStackSize = Size;
281 HasCalleeSavedStackSize = true;
282 }
283
284 // When CalleeSavedStackSize has not been set (for example when
285 // some MachineIR pass is run in isolation), then recalculate
286 // the CalleeSavedStackSize directly from the CalleeSavedInfo.
287 // Note: This information can only be recalculated after PEI
288 // has assigned offsets to the callee save objects.
289 unsigned getCalleeSavedStackSize(const MachineFrameInfo &MFI) const {
290 bool ValidateCalleeSavedStackSize = false;
291
292#ifndef NDEBUG
293 // Make sure the calculated size derived from the CalleeSavedInfo
294 // equals the cached size that was calculated elsewhere (e.g. in
295 // determineCalleeSaves).
296 ValidateCalleeSavedStackSize = HasCalleeSavedStackSize;
297#endif
298
299 if (!HasCalleeSavedStackSize || ValidateCalleeSavedStackSize) {
300 assert(MFI.isCalleeSavedInfoValid() && "CalleeSavedInfo not calculated");
301 if (MFI.getCalleeSavedInfo().empty())
302 return 0;
303
304 int64_t MinOffset = std::numeric_limits<int64_t>::max();
305 int64_t MaxOffset = std::numeric_limits<int64_t>::min();
306 for (const auto &Info : MFI.getCalleeSavedInfo()) {
307 int FrameIdx = Info.getFrameIdx();
308 if (MFI.getStackID(FrameIdx) != TargetStackID::Default)
309 continue;
310 int64_t Offset = MFI.getObjectOffset(FrameIdx);
311 int64_t ObjSize = MFI.getObjectSize(FrameIdx);
312 MinOffset = std::min<int64_t>(Offset, MinOffset);
313 MaxOffset = std::max<int64_t>(Offset + ObjSize, MaxOffset);
314 }
315
316 if (SwiftAsyncContextFrameIdx != std::numeric_limits<int>::max()) {
318 int64_t ObjSize = MFI.getObjectSize(getSwiftAsyncContextFrameIdx());
319 MinOffset = std::min<int64_t>(Offset, MinOffset);
320 MaxOffset = std::max<int64_t>(Offset + ObjSize, MaxOffset);
321 }
322
323 unsigned Size = alignTo(MaxOffset - MinOffset, 16);
324 assert((!HasCalleeSavedStackSize || getCalleeSavedStackSize() == Size) &&
325 "Invalid size calculated for callee saves");
326 return Size;
327 }
328
330 }
331
332 unsigned getCalleeSavedStackSize() const {
333 assert(HasCalleeSavedStackSize &&
334 "CalleeSavedStackSize has not been calculated");
335 return CalleeSavedStackSize;
336 }
337
338 // Saves the CalleeSavedStackSize for SVE vectors in 'scalable bytes'
340 SVECalleeSavedStackSize = Size;
341 }
342 unsigned getSVECalleeSavedStackSize() const {
343 return SVECalleeSavedStackSize;
344 }
345
346 void setMinMaxSVECSFrameIndex(int Min, int Max) {
347 MinSVECSFrameIndex = Min;
348 MaxSVECSFrameIndex = Max;
349 }
350
351 int getMinSVECSFrameIndex() const { return MinSVECSFrameIndex; }
352 int getMaxSVECSFrameIndex() const { return MaxSVECSFrameIndex; }
353
354 void incNumLocalDynamicTLSAccesses() { ++NumLocalDynamicTLSAccesses; }
356 return NumLocalDynamicTLSAccesses;
357 }
358
359 std::optional<bool> hasRedZone() const { return HasRedZone; }
360 void setHasRedZone(bool s) { HasRedZone = s; }
361
362 int getVarArgsStackIndex() const { return VarArgsStackIndex; }
363 void setVarArgsStackIndex(int Index) { VarArgsStackIndex = Index; }
364
365 unsigned getVarArgsStackOffset() const { return VarArgsStackOffset; }
366 void setVarArgsStackOffset(unsigned Offset) { VarArgsStackOffset = Offset; }
367
368 int getVarArgsGPRIndex() const { return VarArgsGPRIndex; }
369 void setVarArgsGPRIndex(int Index) { VarArgsGPRIndex = Index; }
370
371 unsigned getVarArgsGPRSize() const { return VarArgsGPRSize; }
372 void setVarArgsGPRSize(unsigned Size) { VarArgsGPRSize = Size; }
373
374 int getVarArgsFPRIndex() const { return VarArgsFPRIndex; }
375 void setVarArgsFPRIndex(int Index) { VarArgsFPRIndex = Index; }
376
377 unsigned getVarArgsFPRSize() const { return VarArgsFPRSize; }
378 void setVarArgsFPRSize(unsigned Size) { VarArgsFPRSize = Size; }
379
380 unsigned getSRetReturnReg() const { return SRetReturnReg; }
381 void setSRetReturnReg(unsigned Reg) { SRetReturnReg = Reg; }
382
383 unsigned getJumpTableEntrySize(int Idx) const {
384 return JumpTableEntryInfo[Idx].first;
385 }
387 return JumpTableEntryInfo[Idx].second;
388 }
389 void setJumpTableEntryInfo(int Idx, unsigned Size, MCSymbol *PCRelSym) {
390 if ((unsigned)Idx >= JumpTableEntryInfo.size())
391 JumpTableEntryInfo.resize(Idx+1);
392 JumpTableEntryInfo[Idx] = std::make_pair(Size, PCRelSym);
393 }
394
396
397 const SetOfInstructions &getLOHRelated() const { return LOHRelated; }
398
399 // Shortcuts for LOH related types.
401 MCLOHType Kind;
402
403 /// Arguments of this directive. Order matters.
405
406 public:
408
410 : Kind(Kind), Args(Args.begin(), Args.end()) {
411 assert(isValidMCLOHType(Kind) && "Invalid LOH directive type!");
412 }
413
414 MCLOHType getKind() const { return Kind; }
415 LOHArgs getArgs() const { return Args; }
416 };
417
420
421 const MILOHContainer &getLOHContainer() const { return LOHContainerSet; }
422
423 /// Add a LOH directive of this @p Kind and this @p Args.
425 LOHContainerSet.push_back(MILOHDirective(Kind, Args));
426 LOHRelated.insert(Args.begin(), Args.end());
427 }
428
430 return ForwardedMustTailRegParms;
431 }
432
433 std::optional<int> getTaggedBasePointerIndex() const {
434 return TaggedBasePointerIndex;
435 }
436 void setTaggedBasePointerIndex(int Index) { TaggedBasePointerIndex = Index; }
437
438 unsigned getTaggedBasePointerOffset() const {
439 return TaggedBasePointerOffset;
440 }
442 TaggedBasePointerOffset = Offset;
443 }
444
446 return CalleeSaveBaseToFrameRecordOffset;
447 }
449 CalleeSaveBaseToFrameRecordOffset = Offset;
450 }
451
452 bool shouldSignReturnAddress(const MachineFunction &MF) const;
453 bool shouldSignReturnAddress(bool SpillsLR) const;
454
456
457 bool shouldSignWithBKey() const { return SignWithBKey; }
458
459 MCSymbol *getSigningInstrLabel() const { return SignInstrLabel; }
460 void setSigningInstrLabel(MCSymbol *Label) { SignInstrLabel = Label; }
461
462 bool isMTETagged() const { return IsMTETagged; }
463
464 bool branchTargetEnforcement() const { return BranchTargetEnforcement; }
465
466 bool branchProtectionPAuthLR() const { return BranchProtectionPAuthLR; }
467
468 void setHasSwiftAsyncContext(bool HasContext) {
469 HasSwiftAsyncContext = HasContext;
470 }
471 bool hasSwiftAsyncContext() const { return HasSwiftAsyncContext; }
472
474 SwiftAsyncContextFrameIdx = FI;
475 }
476 int getSwiftAsyncContextFrameIdx() const { return SwiftAsyncContextFrameIdx; }
477
478 bool needsDwarfUnwindInfo(const MachineFunction &MF) const;
479 bool needsAsyncDwarfUnwindInfo(const MachineFunction &MF) const;
480
481 bool hasStreamingModeChanges() const { return HasStreamingModeChanges; }
482 void setHasStreamingModeChanges(bool HasChanges) {
483 HasStreamingModeChanges = HasChanges;
484 }
485
486 bool hasStackProbing() const { return StackProbeSize != 0; }
487
488 int64_t getStackProbeSize() const { return StackProbeSize; }
489
490private:
491 // Hold the lists of LOHs.
492 MILOHContainer LOHContainerSet;
493 SetOfInstructions LOHRelated;
494
495 SmallVector<std::pair<unsigned, MCSymbol *>, 2> JumpTableEntryInfo;
496};
497
498namespace yaml {
500 std::optional<bool> HasRedZone;
501
504
505 void mappingImpl(yaml::IO &YamlIO) override;
507};
508
510 static void mapping(IO &YamlIO, AArch64FunctionInfo &MFI) {
511 YamlIO.mapOptional("hasRedZone", MFI.HasRedZone);
512 }
513};
514
515} // end namespace yaml
516
517} // end namespace llvm
518
519#endif // LLVM_LIB_TARGET_AARCH64_AARCH64MACHINEFUNCTIONINFO_H
Analysis containing CSE Info
Definition: CSEInfo.cpp:27
Returns the sub type a function will return at a given Idx Should correspond to the result type of an ExtractValue instruction executed with just that one unsigned Idx
uint64_t Size
IO & YamlIO
Definition: ELFYAML.cpp:1290
#define F(x, y, z)
Definition: MD5.cpp:55
unsigned Reg
Basic Register Allocator
assert(ImpDefSCC.getReg()==AMDGPU::SCC &&ImpDefSCC.isDef())
This file defines the SmallPtrSet class.
This file defines the SmallVector class.
AArch64FunctionInfo - This class is derived from MachineFunctionInfo and contains private AArch64-spe...
void addLOHDirective(MCLOHType Kind, MILOHArgs Args)
Add a LOH directive of this Kind and this Args.
bool needsShadowCallStackPrologueEpilogue(MachineFunction &MF) const
unsigned getCalleeSavedStackSize(const MachineFrameInfo &MFI) const
void setCalleeSaveBaseToFrameRecordOffset(int Offset)
void setVarArgsStackOffset(unsigned Offset)
void setTailCallReservedStack(unsigned bytes)
SmallVector< MILOHDirective, 32 > MILOHContainer
SmallVectorImpl< ForwardedRegister > & getForwardedMustTailRegParms()
bool shouldSignReturnAddress(const MachineFunction &MF) const
const SetOfInstructions & getLOHRelated() const
void setBytesInStackArgArea(unsigned bytes)
void setCalleeSavedStackSize(unsigned Size)
void setSigningInstrLabel(MCSymbol *Label)
void setHasSwiftAsyncContext(bool HasContext)
std::optional< int > getTaggedBasePointerIndex() const
unsigned getJumpTableEntrySize(int Idx) const
bool needsDwarfUnwindInfo(const MachineFunction &MF) const
void setOutliningStyle(std::string Style)
MCSymbol * getJumpTableEntryPCRelSymbol(int Idx) const
SmallPtrSet< const MachineInstr *, 16 > SetOfInstructions
void setTaggedBasePointerOffset(unsigned Offset)
std::optional< bool > hasRedZone() const
void setSVECalleeSavedStackSize(unsigned Size)
std::optional< std::string > getOutliningStyle() const
void initializeBaseYamlFields(const yaml::AArch64FunctionInfo &YamlMFI)
const MILOHContainer & getLOHContainer() const
void setJumpTableEntryInfo(int Idx, unsigned Size, MCSymbol *PCRelSym)
bool needsAsyncDwarfUnwindInfo(const MachineFunction &MF) const
MachineFunctionInfo * clone(BumpPtrAllocator &Allocator, MachineFunction &DestMF, const DenseMap< MachineBasicBlock *, MachineBasicBlock * > &Src2DstMBB) const override
Make a functionally equivalent copy of this MachineFunctionInfo in MF.
void setArgumentStackToRestore(unsigned bytes)
void setMinMaxSVECSFrameIndex(int Min, int Max)
void setHasStreamingModeChanges(bool HasChanges)
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: ArrayRef.h:41
Allocate memory in an ever growing pool, as if by bump-pointer.
Definition: Allocator.h:66
static constexpr unsigned NoRegister
Definition: MCRegister.h:52
MCSymbol - Instances of this class represent a symbol name in the MC file, and MCSymbols are created ...
Definition: MCSymbol.h:40
The MachineFrameInfo class represents an abstract stack frame until prolog/epilog code is inserted.
bool isCalleeSavedInfoValid() const
Has the callee saved info been calculated yet?
int64_t getObjectSize(int ObjectIdx) const
Return the size of the specified object.
const std::vector< CalleeSavedInfo > & getCalleeSavedInfo() const
Returns a reference to call saved info vector for the current function.
uint8_t getStackID(int ObjectIdx) const
int64_t getObjectOffset(int ObjectIdx) const
Return the assigned stack offset of the specified object from the incoming stack pointer.
Wrapper class representing virtual and physical registers.
Definition: Register.h:19
std::pair< iterator, bool > insert(PtrType Ptr)
Inserts Ptr if and only if there is no element in the container equal to Ptr.
Definition: SmallPtrSet.h:342
This class consists of common code factored out of the SmallVector class to reduce code duplication b...
Definition: SmallVector.h:586
void push_back(const T &Elt)
Definition: SmallVector.h:426
This is a 'vector' (really, a variable-sized array), optimized for the case when the array is small.
Definition: SmallVector.h:1209
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
@ Offset
Definition: DWP.cpp:456
static bool isValidMCLOHType(unsigned Kind)
MCLOHType
Linker Optimization Hint Type.
uint64_t alignTo(uint64_t Size, Align A)
Returns a multiple of A needed to store Size bytes.
Definition: Alignment.h:155
MachineFunctionInfo - This class can be derived from and used by targets to hold private target-speci...
void mappingImpl(yaml::IO &YamlIO) override
Targets should override this in a way that mirrors the implementation of llvm::MachineFunctionInfo.
static void mapping(IO &YamlIO, AArch64FunctionInfo &MFI)