LLVM  16.0.0git
TargetFrameLowering.h
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1 //===-- llvm/CodeGen/TargetFrameLowering.h ----------------------*- 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 // Interface to describe the layout of a stack frame on the target machine.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #ifndef LLVM_CODEGEN_TARGETFRAMELOWERING_H
14 #define LLVM_CODEGEN_TARGETFRAMELOWERING_H
15 
17 #include "llvm/Support/TypeSize.h"
18 #include <vector>
19 
20 namespace llvm {
21  class BitVector;
22  class CalleeSavedInfo;
23  class MachineFunction;
24  class RegScavenger;
25 
26 namespace TargetStackID {
27 enum Value {
28  Default = 0,
29  SGPRSpill = 1,
31  WasmLocal = 3,
32  NoAlloc = 255
33 };
34 }
35 
36 /// Information about stack frame layout on the target. It holds the direction
37 /// of stack growth, the known stack alignment on entry to each function, and
38 /// the offset to the locals area.
39 ///
40 /// The offset to the local area is the offset from the stack pointer on
41 /// function entry to the first location where function data (local variables,
42 /// spill locations) can be stored.
44 public:
46  StackGrowsUp, // Adding to the stack increases the stack address
47  StackGrowsDown // Adding to the stack decreases the stack address
48  };
49 
50  // Maps a callee saved register to a stack slot with a fixed offset.
51  struct SpillSlot {
52  unsigned Reg;
53  int Offset; // Offset relative to stack pointer on function entry.
54  };
55 
56  struct DwarfFrameBase {
57  // The frame base may be either a register (the default), the CFA,
58  // or a WebAssembly-specific location description.
60  struct WasmFrameBase {
61  unsigned Kind; // Wasm local, global, or value stack
62  unsigned Index;
63  };
64  union {
65  unsigned Reg;
67  } Location;
68  };
69 
70 private:
71  StackDirection StackDir;
72  Align StackAlignment;
73  Align TransientStackAlignment;
74  int LocalAreaOffset;
75  bool StackRealignable;
76 public:
78  Align TransAl = Align(1), bool StackReal = true)
79  : StackDir(D), StackAlignment(StackAl), TransientStackAlignment(TransAl),
80  LocalAreaOffset(LAO), StackRealignable(StackReal) {}
81 
82  virtual ~TargetFrameLowering();
83 
84  // These methods return information that describes the abstract stack layout
85  // of the target machine.
86 
87  /// getStackGrowthDirection - Return the direction the stack grows
88  ///
89  StackDirection getStackGrowthDirection() const { return StackDir; }
90 
91  /// getStackAlignment - This method returns the number of bytes to which the
92  /// stack pointer must be aligned on entry to a function. Typically, this
93  /// is the largest alignment for any data object in the target.
94  ///
95  unsigned getStackAlignment() const { return StackAlignment.value(); }
96  /// getStackAlignment - This method returns the number of bytes to which the
97  /// stack pointer must be aligned on entry to a function. Typically, this
98  /// is the largest alignment for any data object in the target.
99  ///
100  Align getStackAlign() const { return StackAlignment; }
101 
102  /// alignSPAdjust - This method aligns the stack adjustment to the correct
103  /// alignment.
104  ///
105  int alignSPAdjust(int SPAdj) const {
106  if (SPAdj < 0) {
107  SPAdj = -alignTo(-SPAdj, StackAlignment);
108  } else {
109  SPAdj = alignTo(SPAdj, StackAlignment);
110  }
111  return SPAdj;
112  }
113 
114  /// getTransientStackAlignment - This method returns the number of bytes to
115  /// which the stack pointer must be aligned at all times, even between
116  /// calls.
117  ///
118  Align getTransientStackAlign() const { return TransientStackAlignment; }
119 
120  /// isStackRealignable - This method returns whether the stack can be
121  /// realigned.
122  bool isStackRealignable() const {
123  return StackRealignable;
124  }
125 
126  /// Return the skew that has to be applied to stack alignment under
127  /// certain conditions (e.g. stack was adjusted before function \p MF
128  /// was called).
129  virtual unsigned getStackAlignmentSkew(const MachineFunction &MF) const;
130 
131  /// This method returns whether or not it is safe for an object with the
132  /// given stack id to be bundled into the local area.
133  virtual bool isStackIdSafeForLocalArea(unsigned StackId) const {
134  return true;
135  }
136 
137  /// getOffsetOfLocalArea - This method returns the offset of the local area
138  /// from the stack pointer on entrance to a function.
139  ///
140  int getOffsetOfLocalArea() const { return LocalAreaOffset; }
141 
142  /// Control the placement of special register scavenging spill slots when
143  /// allocating a stack frame.
144  ///
145  /// If this returns true, the frame indexes used by the RegScavenger will be
146  /// allocated closest to the incoming stack pointer.
148  const MachineFunction &MF) const;
149 
150  /// assignCalleeSavedSpillSlots - Allows target to override spill slot
151  /// assignment logic. If implemented, assignCalleeSavedSpillSlots() should
152  /// assign frame slots to all CSI entries and return true. If this method
153  /// returns false, spill slots will be assigned using generic implementation.
154  /// assignCalleeSavedSpillSlots() may add, delete or rearrange elements of
155  /// CSI.
157  const TargetRegisterInfo *TRI,
158  std::vector<CalleeSavedInfo> &CSI,
159  unsigned &MinCSFrameIndex,
160  unsigned &MaxCSFrameIndex) const {
161  return assignCalleeSavedSpillSlots(MF, TRI, CSI);
162  }
163 
164  virtual bool
166  const TargetRegisterInfo *TRI,
167  std::vector<CalleeSavedInfo> &CSI) const {
168  return false;
169  }
170 
171  /// getCalleeSavedSpillSlots - This method returns a pointer to an array of
172  /// pairs, that contains an entry for each callee saved register that must be
173  /// spilled to a particular stack location if it is spilled.
174  ///
175  /// Each entry in this array contains a <register,offset> pair, indicating the
176  /// fixed offset from the incoming stack pointer that each register should be
177  /// spilled at. If a register is not listed here, the code generator is
178  /// allowed to spill it anywhere it chooses.
179  ///
180  virtual const SpillSlot *
181  getCalleeSavedSpillSlots(unsigned &NumEntries) const {
182  NumEntries = 0;
183  return nullptr;
184  }
185 
186  /// targetHandlesStackFrameRounding - Returns true if the target is
187  /// responsible for rounding up the stack frame (probably at emitPrologue
188  /// time).
189  virtual bool targetHandlesStackFrameRounding() const {
190  return false;
191  }
192 
193  /// Returns true if the target will correctly handle shrink wrapping.
194  virtual bool enableShrinkWrapping(const MachineFunction &MF) const {
195  return false;
196  }
197 
198  /// Returns true if the stack slot holes in the fixed and callee-save stack
199  /// area should be used when allocating other stack locations to reduce stack
200  /// size.
201  virtual bool enableStackSlotScavenging(const MachineFunction &MF) const {
202  return false;
203  }
204 
205  /// Returns true if the target can safely skip saving callee-saved registers
206  /// for noreturn nounwind functions.
207  virtual bool enableCalleeSaveSkip(const MachineFunction &MF) const;
208 
209  /// emitProlog/emitEpilog - These methods insert prolog and epilog code into
210  /// the function.
211  virtual void emitPrologue(MachineFunction &MF,
212  MachineBasicBlock &MBB) const = 0;
213  virtual void emitEpilogue(MachineFunction &MF,
214  MachineBasicBlock &MBB) const = 0;
215 
216  /// emitZeroCallUsedRegs - Zeros out call used registers.
217  virtual void emitZeroCallUsedRegs(BitVector RegsToZero,
218  MachineBasicBlock &MBB) const {}
219 
220  /// With basic block sections, emit callee saved frame moves for basic blocks
221  /// that are in a different section.
222  virtual void
225 
226  /// Returns true if we may need to fix the unwind information for the
227  /// function.
228  virtual bool enableCFIFixup(MachineFunction &MF) const;
229 
230  /// Emit CFI instructions that recreate the state of the unwind information
231  /// upon fucntion entry.
233 
234  /// Replace a StackProbe stub (if any) with the actual probe code inline
236  MachineBasicBlock &PrologueMBB) const {}
237 
238  /// Does the stack probe function call return with a modified stack pointer?
239  virtual bool stackProbeFunctionModifiesSP() const { return false; }
240 
241  /// Adjust the prologue to have the function use segmented stacks. This works
242  /// by adding a check even before the "normal" function prologue.
244  MachineBasicBlock &PrologueMBB) const {}
245 
246  /// Adjust the prologue to add Erlang Run-Time System (ERTS) specific code in
247  /// the assembly prologue to explicitly handle the stack.
249  MachineBasicBlock &PrologueMBB) const {}
250 
251  /// spillCalleeSavedRegisters - Issues instruction(s) to spill all callee
252  /// saved registers and returns true if it isn't possible / profitable to do
253  /// so by issuing a series of store instructions via
254  /// storeRegToStackSlot(). Returns false otherwise.
258  const TargetRegisterInfo *TRI) const {
259  return false;
260  }
261 
262  /// restoreCalleeSavedRegisters - Issues instruction(s) to restore all callee
263  /// saved registers and returns true if it isn't possible / profitable to do
264  /// so by issuing a series of load instructions via loadRegToStackSlot().
265  /// If it returns true, and any of the registers in CSI is not restored,
266  /// it sets the corresponding Restored flag in CSI to false.
267  /// Returns false otherwise.
268  virtual bool
272  const TargetRegisterInfo *TRI) const {
273  return false;
274  }
275 
276  /// Return true if the target wants to keep the frame pointer regardless of
277  /// the function attribute "frame-pointer".
278  virtual bool keepFramePointer(const MachineFunction &MF) const {
279  return false;
280  }
281 
282  /// hasFP - Return true if the specified function should have a dedicated
283  /// frame pointer register. For most targets this is true only if the function
284  /// has variable sized allocas or if frame pointer elimination is disabled.
285  virtual bool hasFP(const MachineFunction &MF) const = 0;
286 
287  /// hasReservedCallFrame - Under normal circumstances, when a frame pointer is
288  /// not required, we reserve argument space for call sites in the function
289  /// immediately on entry to the current function. This eliminates the need for
290  /// add/sub sp brackets around call sites. Returns true if the call frame is
291  /// included as part of the stack frame.
292  virtual bool hasReservedCallFrame(const MachineFunction &MF) const {
293  return !hasFP(MF);
294  }
295 
296  /// canSimplifyCallFramePseudos - When possible, it's best to simplify the
297  /// call frame pseudo ops before doing frame index elimination. This is
298  /// possible only when frame index references between the pseudos won't
299  /// need adjusting for the call frame adjustments. Normally, that's true
300  /// if the function has a reserved call frame or a frame pointer. Some
301  /// targets (Thumb2, for example) may have more complicated criteria,
302  /// however, and can override this behavior.
303  virtual bool canSimplifyCallFramePseudos(const MachineFunction &MF) const {
304  return hasReservedCallFrame(MF) || hasFP(MF);
305  }
306 
307  // needsFrameIndexResolution - Do we need to perform FI resolution for
308  // this function. Normally, this is required only when the function
309  // has any stack objects. However, targets may want to override this.
310  virtual bool needsFrameIndexResolution(const MachineFunction &MF) const;
311 
312  /// getFrameIndexReference - This method should return the base register
313  /// and offset used to reference a frame index location. The offset is
314  /// returned directly, and the base register is returned via FrameReg.
315  virtual StackOffset getFrameIndexReference(const MachineFunction &MF, int FI,
316  Register &FrameReg) const;
317 
318  /// Same as \c getFrameIndexReference, except that the stack pointer (as
319  /// opposed to the frame pointer) will be the preferred value for \p
320  /// FrameReg. This is generally used for emitting statepoint or EH tables that
321  /// use offsets from RSP. If \p IgnoreSPUpdates is true, the returned
322  /// offset is only guaranteed to be valid with respect to the value of SP at
323  /// the end of the prologue.
324  virtual StackOffset
326  Register &FrameReg,
327  bool IgnoreSPUpdates) const {
328  // Always safe to dispatch to getFrameIndexReference.
329  return getFrameIndexReference(MF, FI, FrameReg);
330  }
331 
332  /// getNonLocalFrameIndexReference - This method returns the offset used to
333  /// reference a frame index location. The offset can be from either FP/BP/SP
334  /// based on which base register is returned by llvm.localaddress.
336  int FI) const {
337  // By default, dispatch to getFrameIndexReference. Interested targets can
338  // override this.
339  Register FrameReg;
340  return getFrameIndexReference(MF, FI, FrameReg);
341  }
342 
343  /// Returns the callee-saved registers as computed by determineCalleeSaves
344  /// in the BitVector \p SavedRegs.
345  virtual void getCalleeSaves(const MachineFunction &MF,
346  BitVector &SavedRegs) const;
347 
348  /// This method determines which of the registers reported by
349  /// TargetRegisterInfo::getCalleeSavedRegs() should actually get saved.
350  /// The default implementation checks populates the \p SavedRegs bitset with
351  /// all registers which are modified in the function, targets may override
352  /// this function to save additional registers.
353  /// This method also sets up the register scavenger ensuring there is a free
354  /// register or a frameindex available.
355  /// This method should not be called by any passes outside of PEI, because
356  /// it may change state passed in by \p MF and \p RS. The preferred
357  /// interface outside PEI is getCalleeSaves.
358  virtual void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs,
359  RegScavenger *RS = nullptr) const;
360 
361  /// processFunctionBeforeFrameFinalized - This method is called immediately
362  /// before the specified function's frame layout (MF.getFrameInfo()) is
363  /// finalized. Once the frame is finalized, MO_FrameIndex operands are
364  /// replaced with direct constants. This method is optional.
365  ///
367  RegScavenger *RS = nullptr) const {
368  }
369 
370  /// processFunctionBeforeFrameIndicesReplaced - This method is called
371  /// immediately before MO_FrameIndex operands are eliminated, but after the
372  /// frame is finalized. This method is optional.
373  virtual void
375  RegScavenger *RS = nullptr) const {}
376 
377  virtual unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const {
378  report_fatal_error("WinEH not implemented for this target");
379  }
380 
381  /// This method is called during prolog/epilog code insertion to eliminate
382  /// call frame setup and destroy pseudo instructions (but only if the Target
383  /// is using them). It is responsible for eliminating these instructions,
384  /// replacing them with concrete instructions. This method need only be
385  /// implemented if using call frame setup/destroy pseudo instructions.
386  /// Returns an iterator pointing to the instruction after the replaced one.
391  llvm_unreachable("Call Frame Pseudo Instructions do not exist on this "
392  "target!");
393  }
394 
395 
396  /// Order the symbols in the local stack frame.
397  /// The list of objects that we want to order is in \p objectsToAllocate as
398  /// indices into the MachineFrameInfo. The array can be reordered in any way
399  /// upon return. The contents of the array, however, may not be modified (i.e.
400  /// only their order may be changed).
401  /// By default, just maintain the original order.
402  virtual void
404  SmallVectorImpl<int> &objectsToAllocate) const {
405  }
406 
407  /// Check whether or not the given \p MBB can be used as a prologue
408  /// for the target.
409  /// The prologue will be inserted first in this basic block.
410  /// This method is used by the shrink-wrapping pass to decide if
411  /// \p MBB will be correctly handled by the target.
412  /// As soon as the target enable shrink-wrapping without overriding
413  /// this method, we assume that each basic block is a valid
414  /// prologue.
415  virtual bool canUseAsPrologue(const MachineBasicBlock &MBB) const {
416  return true;
417  }
418 
419  /// Check whether or not the given \p MBB can be used as a epilogue
420  /// for the target.
421  /// The epilogue will be inserted before the first terminator of that block.
422  /// This method is used by the shrink-wrapping pass to decide if
423  /// \p MBB will be correctly handled by the target.
424  /// As soon as the target enable shrink-wrapping without overriding
425  /// this method, we assume that each basic block is a valid
426  /// epilogue.
427  virtual bool canUseAsEpilogue(const MachineBasicBlock &MBB) const {
428  return true;
429  }
430 
431  /// Returns the StackID that scalable vectors should be associated with.
433  return TargetStackID::Default;
434  }
435 
437  switch (ID) {
438  default:
439  return false;
442  return true;
443  }
444  }
445 
446  /// Check if given function is safe for not having callee saved registers.
447  /// This is used when interprocedural register allocation is enabled.
448  static bool isSafeForNoCSROpt(const Function &F);
449 
450  /// Check if the no-CSR optimisation is profitable for the given function.
451  virtual bool isProfitableForNoCSROpt(const Function &F) const {
452  return true;
453  }
454 
455  /// Return initial CFA offset value i.e. the one valid at the beginning of the
456  /// function (before any stack operations).
457  virtual int getInitialCFAOffset(const MachineFunction &MF) const;
458 
459  /// Return initial CFA register value i.e. the one valid at the beginning of
460  /// the function (before any stack operations).
461  virtual Register getInitialCFARegister(const MachineFunction &MF) const;
462 
463  /// Return the frame base information to be encoded in the DWARF subprogram
464  /// debug info.
465  virtual DwarfFrameBase getDwarfFrameBase(const MachineFunction &MF) const;
466 };
467 
468 } // End llvm namespace
469 
470 #endif
llvm::TargetFrameLowering::orderFrameObjects
virtual void orderFrameObjects(const MachineFunction &MF, SmallVectorImpl< int > &objectsToAllocate) const
Order the symbols in the local stack frame.
Definition: TargetFrameLowering.h:403
llvm::TargetFrameLowering::getCalleeSaves
virtual void getCalleeSaves(const MachineFunction &MF, BitVector &SavedRegs) const
Returns the callee-saved registers as computed by determineCalleeSaves in the BitVector SavedRegs.
Definition: TargetFrameLoweringImpl.cpp:70
llvm::alignTo
uint64_t alignTo(uint64_t Size, Align A)
Returns a multiple of A needed to store Size bytes.
Definition: Alignment.h:156
llvm::TargetFrameLowering::DwarfFrameBase::WasmFrameBase::Index
unsigned Index
Definition: TargetFrameLowering.h:62
llvm::TargetFrameLowering::DwarfFrameBase::Location
union llvm::TargetFrameLowering::DwarfFrameBase::@233 Location
llvm::TargetFrameLowering::DwarfFrameBase::Reg
unsigned Reg
Definition: TargetFrameLowering.h:65
MI
IRTranslator LLVM IR MI
Definition: IRTranslator.cpp:108
llvm
This is an optimization pass for GlobalISel generic memory operations.
Definition: AddressRanges.h:18
llvm::TargetStackID::WasmLocal
@ WasmLocal
Definition: TargetFrameLowering.h:31
llvm::TargetFrameLowering::needsFrameIndexResolution
virtual bool needsFrameIndexResolution(const MachineFunction &MF) const
Definition: TargetFrameLoweringImpl.cpp:65
llvm::TargetFrameLowering
Information about stack frame layout on the target.
Definition: TargetFrameLowering.h:43
llvm::Function
Definition: Function.h:60
TypeSize.h
llvm::TargetFrameLowering::getInitialCFARegister
virtual Register getInitialCFARegister(const MachineFunction &MF) const
Return initial CFA register value i.e.
Definition: TargetFrameLoweringImpl.cpp:171
llvm::TargetFrameLowering::isStackIdSafeForLocalArea
virtual bool isStackIdSafeForLocalArea(unsigned StackId) const
This method returns whether or not it is safe for an object with the given stack id to be bundled int...
Definition: TargetFrameLowering.h:133
MachineBasicBlock.h
llvm::TargetRegisterInfo
TargetRegisterInfo base class - We assume that the target defines a static array of TargetRegisterDes...
Definition: TargetRegisterInfo.h:237
llvm::TargetFrameLowering::resetCFIToInitialState
virtual void resetCFIToInitialState(MachineBasicBlock &MBB) const
Emit CFI instructions that recreate the state of the unwind information upon fucntion entry.
Definition: TargetFrameLowering.h:232
llvm::TargetFrameLowering::DwarfFrameBase
Definition: TargetFrameLowering.h:56
llvm::TargetFrameLowering::getDwarfFrameBase
virtual DwarfFrameBase getDwarfFrameBase(const MachineFunction &MF) const
Return the frame base information to be encoded in the DWARF subprogram debug info.
Definition: TargetFrameLoweringImpl.cpp:176
llvm::TargetFrameLowering::processFunctionBeforeFrameIndicesReplaced
virtual void processFunctionBeforeFrameIndicesReplaced(MachineFunction &MF, RegScavenger *RS=nullptr) const
processFunctionBeforeFrameIndicesReplaced - This method is called immediately before MO_FrameIndex op...
Definition: TargetFrameLowering.h:374
llvm::TargetFrameLowering::~TargetFrameLowering
virtual ~TargetFrameLowering()
llvm::TargetFrameLowering::enableCalleeSaveSkip
virtual bool enableCalleeSaveSkip(const MachineFunction &MF) const
Returns true if the target can safely skip saving callee-saved registers for noreturn nounwind functi...
Definition: TargetFrameLoweringImpl.cpp:33
llvm::TargetFrameLowering::getStackIDForScalableVectors
virtual TargetStackID::Value getStackIDForScalableVectors() const
Returns the StackID that scalable vectors should be associated with.
Definition: TargetFrameLowering.h:432
TRI
unsigned const TargetRegisterInfo * TRI
Definition: MachineSink.cpp:1628
F
#define F(x, y, z)
Definition: MD5.cpp:55
llvm::TargetFrameLowering::StackDirection
StackDirection
Definition: TargetFrameLowering.h:45
llvm::TargetFrameLowering::getTransientStackAlign
Align getTransientStackAlign() const
getTransientStackAlignment - This method returns the number of bytes to which the stack pointer must ...
Definition: TargetFrameLowering.h:118
llvm::TargetFrameLowering::DwarfFrameBase::WasmLoc
struct WasmFrameBase WasmLoc
Definition: TargetFrameLowering.h:66
llvm::TargetFrameLowering::eliminateCallFramePseudoInstr
virtual MachineBasicBlock::iterator eliminateCallFramePseudoInstr(MachineFunction &MF, MachineBasicBlock &MBB, MachineBasicBlock::iterator MI) const
This method is called during prolog/epilog code insertion to eliminate call frame setup and destroy p...
Definition: TargetFrameLowering.h:388
llvm::TargetFrameLowering::processFunctionBeforeFrameFinalized
virtual void processFunctionBeforeFrameFinalized(MachineFunction &MF, RegScavenger *RS=nullptr) const
processFunctionBeforeFrameFinalized - This method is called immediately before the specified function...
Definition: TargetFrameLowering.h:366
llvm::TargetFrameLowering::getStackAlignment
unsigned getStackAlignment() const
getStackAlignment - This method returns the number of bytes to which the stack pointer must be aligne...
Definition: TargetFrameLowering.h:95
llvm::TargetFrameLowering::isProfitableForNoCSROpt
virtual bool isProfitableForNoCSROpt(const Function &F) const
Check if the no-CSR optimisation is profitable for the given function.
Definition: TargetFrameLowering.h:451
llvm::TargetFrameLowering::getOffsetOfLocalArea
int getOffsetOfLocalArea() const
getOffsetOfLocalArea - This method returns the offset of the local area from the stack pointer on ent...
Definition: TargetFrameLowering.h:140
llvm::TargetFrameLowering::enableCFIFixup
virtual bool enableCFIFixup(MachineFunction &MF) const
Returns true if we may need to fix the unwind information for the function.
Definition: TargetFrameLoweringImpl.cpp:40
llvm::TargetFrameLowering::DwarfFrameBase::Register
@ Register
Definition: TargetFrameLowering.h:59
llvm::MutableArrayRef
MutableArrayRef - Represent a mutable reference to an array (0 or more elements consecutively in memo...
Definition: ArrayRef.h:28
llvm::TargetFrameLowering::enableShrinkWrapping
virtual bool enableShrinkWrapping(const MachineFunction &MF) const
Returns true if the target will correctly handle shrink wrapping.
Definition: TargetFrameLowering.h:194
llvm::TargetFrameLowering::getNonLocalFrameIndexReference
virtual StackOffset getNonLocalFrameIndexReference(const MachineFunction &MF, int FI) const
getNonLocalFrameIndexReference - This method returns the offset used to reference a frame index locat...
Definition: TargetFrameLowering.h:335
llvm::TargetFrameLowering::canUseAsEpilogue
virtual bool canUseAsEpilogue(const MachineBasicBlock &MBB) const
Check whether or not the given MBB can be used as a epilogue for the target.
Definition: TargetFrameLowering.h:427
llvm::TargetFrameLowering::getStackAlign
Align getStackAlign() const
getStackAlignment - This method returns the number of bytes to which the stack pointer must be aligne...
Definition: TargetFrameLowering.h:100
llvm::TargetFrameLowering::DwarfFrameBase::CFA
@ CFA
Definition: TargetFrameLowering.h:59
llvm::TargetFrameLowering::hasReservedCallFrame
virtual bool hasReservedCallFrame(const MachineFunction &MF) const
hasReservedCallFrame - Under normal circumstances, when a frame pointer is not required,...
Definition: TargetFrameLowering.h:292
llvm::TargetFrameLowering::inlineStackProbe
virtual void inlineStackProbe(MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
Replace a StackProbe stub (if any) with the actual probe code inline.
Definition: TargetFrameLowering.h:235
llvm::TargetFrameLowering::keepFramePointer
virtual bool keepFramePointer(const MachineFunction &MF) const
Return true if the target wants to keep the frame pointer regardless of the function attribute "frame...
Definition: TargetFrameLowering.h:278
llvm::TargetFrameLowering::isStackRealignable
bool isStackRealignable() const
isStackRealignable - This method returns whether the stack can be realigned.
Definition: TargetFrameLowering.h:122
llvm::TargetFrameLowering::hasFP
virtual bool hasFP(const MachineFunction &MF) const =0
hasFP - Return true if the specified function should have a dedicated frame pointer register.
llvm::TargetFrameLowering::assignCalleeSavedSpillSlots
virtual bool assignCalleeSavedSpillSlots(MachineFunction &MF, const TargetRegisterInfo *TRI, std::vector< CalleeSavedInfo > &CSI) const
Definition: TargetFrameLowering.h:165
llvm::TargetFrameLowering::spillCalleeSavedRegisters
virtual bool spillCalleeSavedRegisters(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, ArrayRef< CalleeSavedInfo > CSI, const TargetRegisterInfo *TRI) const
spillCalleeSavedRegisters - Issues instruction(s) to spill all callee saved registers and returns tru...
Definition: TargetFrameLowering.h:255
llvm::report_fatal_error
void report_fatal_error(Error Err, bool gen_crash_diag=true)
Report a serious error, calling any installed error handler.
Definition: Error.cpp:145
llvm::BitVector
Definition: BitVector.h:75
llvm::TargetFrameLowering::DwarfFrameBase::Kind
enum llvm::TargetFrameLowering::DwarfFrameBase::FrameBaseKind Kind
Align
uint64_t Align
Definition: ELFObjHandler.cpp:81
llvm::Align
This struct is a compact representation of a valid (non-zero power of two) alignment.
Definition: Alignment.h:39
llvm::CallingConv::ID
unsigned ID
LLVM IR allows to use arbitrary numbers as calling convention identifiers.
Definition: CallingConv.h:24
llvm::TargetFrameLowering::DwarfFrameBase::WasmFrameBase::Kind
unsigned Kind
Definition: TargetFrameLowering.h:61
llvm::MachineBasicBlock
Definition: MachineBasicBlock.h:94
llvm::TargetFrameLowering::emitCalleeSavedFrameMovesFullCFA
virtual void emitCalleeSavedFrameMovesFullCFA(MachineBasicBlock &MBB, MachineBasicBlock::iterator MBBI) const
With basic block sections, emit callee saved frame moves for basic blocks that are in a different sec...
Definition: TargetFrameLowering.h:223
llvm::TargetFrameLowering::alignSPAdjust
int alignSPAdjust(int SPAdj) const
alignSPAdjust - This method aligns the stack adjustment to the correct alignment.
Definition: TargetFrameLowering.h:105
llvm::TargetFrameLowering::isSupportedStackID
virtual bool isSupportedStackID(TargetStackID::Value ID) const
Definition: TargetFrameLowering.h:436
llvm::TargetFrameLowering::getCalleeSavedSpillSlots
virtual const SpillSlot * getCalleeSavedSpillSlots(unsigned &NumEntries) const
getCalleeSavedSpillSlots - This method returns a pointer to an array of pairs, that contains an entry...
Definition: TargetFrameLowering.h:181
D
static GCRegistry::Add< StatepointGC > D("statepoint-example", "an example strategy for statepoint")
llvm::TargetFrameLowering::DwarfFrameBase::FrameBaseKind
FrameBaseKind
Definition: TargetFrameLowering.h:59
llvm::TargetFrameLowering::adjustForSegmentedStacks
virtual void adjustForSegmentedStacks(MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
Adjust the prologue to have the function use segmented stacks.
Definition: TargetFrameLowering.h:243
llvm::RegScavenger
Definition: RegisterScavenging.h:34
llvm::TargetFrameLowering::restoreCalleeSavedRegisters
virtual bool restoreCalleeSavedRegisters(MachineBasicBlock &MBB, MachineBasicBlock::iterator MI, MutableArrayRef< CalleeSavedInfo > CSI, const TargetRegisterInfo *TRI) const
restoreCalleeSavedRegisters - Issues instruction(s) to restore all callee saved registers and returns...
Definition: TargetFrameLowering.h:269
llvm::TargetStackID::ScalableVector
@ ScalableVector
Definition: TargetFrameLowering.h:30
llvm::TargetFrameLowering::isSafeForNoCSROpt
static bool isSafeForNoCSROpt(const Function &F)
Check if given function is safe for not having callee saved registers.
Definition: TargetFrameLoweringImpl.cpp:154
llvm::TargetFrameLowering::adjustForHiPEPrologue
virtual void adjustForHiPEPrologue(MachineFunction &MF, MachineBasicBlock &PrologueMBB) const
Adjust the prologue to add Erlang Run-Time System (ERTS) specific code in the assembly prologue to ex...
Definition: TargetFrameLowering.h:248
llvm::TargetFrameLowering::getStackGrowthDirection
StackDirection getStackGrowthDirection() const
getStackGrowthDirection - Return the direction the stack grows
Definition: TargetFrameLowering.h:89
llvm::TargetFrameLowering::assignCalleeSavedSpillSlots
virtual bool assignCalleeSavedSpillSlots(MachineFunction &MF, const TargetRegisterInfo *TRI, std::vector< CalleeSavedInfo > &CSI, unsigned &MinCSFrameIndex, unsigned &MaxCSFrameIndex) const
assignCalleeSavedSpillSlots - Allows target to override spill slot assignment logic.
Definition: TargetFrameLowering.h:156
llvm::MachineFunction
Definition: MachineFunction.h:257
llvm::ArrayRef
ArrayRef - Represent a constant reference to an array (0 or more elements consecutively in memory),...
Definition: APInt.h:32
llvm::TargetFrameLowering::enableStackSlotScavenging
virtual bool enableStackSlotScavenging(const MachineFunction &MF) const
Returns true if the stack slot holes in the fixed and callee-save stack area should be used when allo...
Definition: TargetFrameLowering.h:201
MBBI
MachineBasicBlock MachineBasicBlock::iterator MBBI
Definition: AArch64SLSHardening.cpp:75
llvm::TargetStackID::NoAlloc
@ NoAlloc
Definition: TargetFrameLowering.h:32
llvm_unreachable
#define llvm_unreachable(msg)
Marks that the current location is not supposed to be reachable.
Definition: ErrorHandling.h:143
llvm::TargetFrameLowering::emitZeroCallUsedRegs
virtual void emitZeroCallUsedRegs(BitVector RegsToZero, MachineBasicBlock &MBB) const
emitZeroCallUsedRegs - Zeros out call used registers.
Definition: TargetFrameLowering.h:217
llvm::StackOffset
StackOffset is a class to represent an offset with 2 dimensions, named fixed and scalable,...
Definition: TypeSize.h:134
llvm::TargetFrameLowering::DwarfFrameBase::WasmFrameBase
Definition: TargetFrameLowering.h:60
llvm::Register
Wrapper class representing virtual and physical registers.
Definition: Register.h:19
llvm::TargetFrameLowering::canUseAsPrologue
virtual bool canUseAsPrologue(const MachineBasicBlock &MBB) const
Check whether or not the given MBB can be used as a prologue for the target.
Definition: TargetFrameLowering.h:415
MBB
MachineBasicBlock & MBB
Definition: AArch64SLSHardening.cpp:74
llvm::TargetFrameLowering::stackProbeFunctionModifiesSP
virtual bool stackProbeFunctionModifiesSP() const
Does the stack probe function call return with a modified stack pointer?
Definition: TargetFrameLowering.h:239
llvm::TargetFrameLowering::allocateScavengingFrameIndexesNearIncomingSP
virtual bool allocateScavengingFrameIndexesNearIncomingSP(const MachineFunction &MF) const
Control the placement of special register scavenging spill slots when allocating a stack frame.
Definition: TargetFrameLoweringImpl.cpp:144
llvm::Align::value
uint64_t value() const
This is a hole in the type system and should not be abused.
Definition: Alignment.h:85
llvm::TargetFrameLowering::getFrameIndexReference
virtual StackOffset getFrameIndexReference(const MachineFunction &MF, int FI, Register &FrameReg) const
getFrameIndexReference - This method should return the base register and offset used to reference a f...
Definition: TargetFrameLoweringImpl.cpp:50
llvm::TargetFrameLowering::SpillSlot::Offset
int Offset
Definition: TargetFrameLowering.h:53
llvm::TargetStackID::Value
Value
Definition: TargetFrameLowering.h:27
llvm::TargetStackID::Default
@ Default
Definition: TargetFrameLowering.h:28
llvm::TargetFrameLowering::canSimplifyCallFramePseudos
virtual bool canSimplifyCallFramePseudos(const MachineFunction &MF) const
canSimplifyCallFramePseudos - When possible, it's best to simplify the call frame pseudo ops before d...
Definition: TargetFrameLowering.h:303
llvm::TargetFrameLowering::SpillSlot::Reg
unsigned Reg
Definition: TargetFrameLowering.h:52
llvm::TargetStackID::SGPRSpill
@ SGPRSpill
Definition: TargetFrameLowering.h:29
llvm::TargetFrameLowering::targetHandlesStackFrameRounding
virtual bool targetHandlesStackFrameRounding() const
targetHandlesStackFrameRounding - Returns true if the target is responsible for rounding up the stack...
Definition: TargetFrameLowering.h:189
llvm::TargetFrameLowering::getWinEHParentFrameOffset
virtual unsigned getWinEHParentFrameOffset(const MachineFunction &MF) const
Definition: TargetFrameLowering.h:377
llvm::TargetFrameLowering::TargetFrameLowering
TargetFrameLowering(StackDirection D, Align StackAl, int LAO, Align TransAl=Align(1), bool StackReal=true)
Definition: TargetFrameLowering.h:77
llvm::SmallVectorImpl< int >
llvm::TargetFrameLowering::StackGrowsDown
@ StackGrowsDown
Definition: TargetFrameLowering.h:47
llvm::TargetFrameLowering::getInitialCFAOffset
virtual int getInitialCFAOffset(const MachineFunction &MF) const
Return initial CFA offset value i.e.
Definition: TargetFrameLoweringImpl.cpp:166
llvm::TargetFrameLowering::emitPrologue
virtual void emitPrologue(MachineFunction &MF, MachineBasicBlock &MBB) const =0
emitProlog/emitEpilog - These methods insert prolog and epilog code into the function.
llvm::TargetFrameLowering::determineCalleeSaves
virtual void determineCalleeSaves(MachineFunction &MF, BitVector &SavedRegs, RegScavenger *RS=nullptr) const
This method determines which of the registers reported by TargetRegisterInfo::getCalleeSavedRegs() sh...
Definition: TargetFrameLoweringImpl.cpp:83
llvm::TargetFrameLowering::getFrameIndexReferencePreferSP
virtual StackOffset getFrameIndexReferencePreferSP(const MachineFunction &MF, int FI, Register &FrameReg, bool IgnoreSPUpdates) const
Same as getFrameIndexReference, except that the stack pointer (as opposed to the frame pointer) will ...
Definition: TargetFrameLowering.h:325
llvm::TargetFrameLowering::emitEpilogue
virtual void emitEpilogue(MachineFunction &MF, MachineBasicBlock &MBB) const =0
llvm::MachineInstrBundleIterator< MachineInstr >
llvm::TargetFrameLowering::SpillSlot
Definition: TargetFrameLowering.h:51
llvm::TargetFrameLowering::StackGrowsUp
@ StackGrowsUp
Definition: TargetFrameLowering.h:46
llvm::TargetFrameLowering::getStackAlignmentSkew
virtual unsigned getStackAlignmentSkew(const MachineFunction &MF) const
Return the skew that has to be applied to stack alignment under certain conditions (e....
Definition: TargetFrameLoweringImpl.cpp:134