1 //===-- CodeGen/MachineFrameInfo.h - Abstract Stack Frame Rep. --*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // The file defines the MachineFrameInfo class.
12 //===----------------------------------------------------------------------===//
14 #ifndef LLVM_CODEGEN_MACHINEFRAMEINFO_H
15 #define LLVM_CODEGEN_MACHINEFRAMEINFO_H
17 #include "llvm/ADT/SmallVector.h"
18 #include "llvm/Support/DataTypes.h"
25 class TargetRegisterClass;
27 class MachineFunction;
28 class MachineBasicBlock;
29 class TargetFrameLowering;
35 /// The CalleeSavedInfo class tracks the information need to locate where a
36 /// callee saved register is in the current frame.
37 class CalleeSavedInfo {
42 explicit CalleeSavedInfo(unsigned R, int FI = 0)
43 : Reg(R), FrameIdx(FI) {}
46 unsigned getReg() const { return Reg; }
47 int getFrameIdx() const { return FrameIdx; }
48 void setFrameIdx(int FI) { FrameIdx = FI; }
51 /// The MachineFrameInfo class represents an abstract stack frame until
52 /// prolog/epilog code is inserted. This class is key to allowing stack frame
53 /// representation optimizations, such as frame pointer elimination. It also
54 /// allows more mundane (but still important) optimizations, such as reordering
55 /// of abstract objects on the stack frame.
57 /// To support this, the class assigns unique integer identifiers to stack
58 /// objects requested clients. These identifiers are negative integers for
59 /// fixed stack objects (such as arguments passed on the stack) or nonnegative
60 /// for objects that may be reordered. Instructions which refer to stack
61 /// objects use a special MO_FrameIndex operand to represent these frame
64 /// Because this class keeps track of all references to the stack frame, it
65 /// knows when a variable sized object is allocated on the stack. This is the
66 /// sole condition which prevents frame pointer elimination, which is an
67 /// important optimization on register-poor architectures. Because original
68 /// variable sized alloca's in the source program are the only source of
69 /// variable sized stack objects, it is safe to decide whether there will be
70 /// any variable sized objects before all stack objects are known (for
71 /// example, register allocator spill code never needs variable sized
74 /// When prolog/epilog code emission is performed, the final stack frame is
75 /// built and the machine instructions are modified to refer to the actual
76 /// stack offsets of the object, eliminating all MO_FrameIndex operands from
79 /// @brief Abstract Stack Frame Information
80 class MachineFrameInfo {
82 // Represent a single object allocated on the stack.
84 // The offset of this object from the stack pointer on entry to
85 // the function. This field has no meaning for a variable sized element.
88 // The size of this object on the stack. 0 means a variable sized object,
89 // ~0ULL means a dead object.
92 // The required alignment of this stack slot.
95 // If true, the value of the stack object is set before
96 // entering the function and is not modified inside the function. By
97 // default, fixed objects are immutable unless marked otherwise.
100 // If true the stack object is used as spill slot. It
101 // cannot alias any other memory objects.
104 /// If true, this stack slot is used to spill a value (could be deopt
105 /// and/or GC related) over a statepoint. We know that the address of the
106 /// slot can't alias any LLVM IR value. This is very similar to a Spill
107 /// Slot, but is created by statepoint lowering is SelectionDAG, not the
108 /// register allocator.
109 bool isStatepointSpillSlot;
111 /// If this stack object is originated from an Alloca instruction
112 /// this value saves the original IR allocation. Can be NULL.
113 const AllocaInst *Alloca;
115 // If true, the object was mapped into the local frame
116 // block and doesn't need additional handling for allocation beyond that.
119 // If true, an LLVM IR value might point to this object.
120 // Normally, spill slots and fixed-offset objects don't alias IR-accessible
121 // objects, but there are exceptions (on PowerPC, for example, some byval
122 // arguments have ABI-prescribed offsets).
125 /// If true, the object has been zero-extended.
128 /// If true, the object has been zero-extended.
131 StackObject(uint64_t Sz, unsigned Al, int64_t SP, bool IM,
132 bool isSS, const AllocaInst *Val, bool A)
133 : SPOffset(SP), Size(Sz), Alignment(Al), isImmutable(IM),
134 isSpillSlot(isSS), isStatepointSpillSlot(false), Alloca(Val),
135 PreAllocated(false), isAliased(A), isZExt(false), isSExt(false) {}
138 /// The alignment of the stack.
139 unsigned StackAlignment;
141 /// Can the stack be realigned. This can be false if the target does not
142 /// support stack realignment, or if the user asks us not to realign the
143 /// stack. In this situation, overaligned allocas are all treated as dynamic
144 /// allocations and the target must handle them as part of DYNAMIC_STACKALLOC
145 /// lowering. All non-alloca stack objects have their alignment clamped to the
146 /// base ABI stack alignment.
147 /// FIXME: There is room for improvement in this case, in terms of
148 /// grouping overaligned allocas into a "secondary stack frame" and
149 /// then only use a single alloca to allocate this frame and only a
150 /// single virtual register to access it. Currently, without such an
151 /// optimization, each such alloca gets its own dynamic realignment.
152 bool StackRealignable;
154 /// Whether the function has the \c alignstack attribute.
157 /// The list of stack objects allocated.
158 std::vector<StackObject> Objects;
160 /// This contains the number of fixed objects contained on
161 /// the stack. Because fixed objects are stored at a negative index in the
162 /// Objects list, this is also the index to the 0th object in the list.
163 unsigned NumFixedObjects = 0;
165 /// This boolean keeps track of whether any variable
166 /// sized objects have been allocated yet.
167 bool HasVarSizedObjects = false;
169 /// This boolean keeps track of whether there is a call
170 /// to builtin \@llvm.frameaddress.
171 bool FrameAddressTaken = false;
173 /// This boolean keeps track of whether there is a call
174 /// to builtin \@llvm.returnaddress.
175 bool ReturnAddressTaken = false;
177 /// This boolean keeps track of whether there is a call
178 /// to builtin \@llvm.experimental.stackmap.
179 bool HasStackMap = false;
181 /// This boolean keeps track of whether there is a call
182 /// to builtin \@llvm.experimental.patchpoint.
183 bool HasPatchPoint = false;
185 /// The prolog/epilog code inserter calculates the final stack
186 /// offsets for all of the fixed size objects, updating the Objects list
187 /// above. It then updates StackSize to contain the number of bytes that need
188 /// to be allocated on entry to the function.
189 uint64_t StackSize = 0;
191 /// The amount that a frame offset needs to be adjusted to
192 /// have the actual offset from the stack/frame pointer. The exact usage of
193 /// this is target-dependent, but it is typically used to adjust between
194 /// SP-relative and FP-relative offsets. E.G., if objects are accessed via
195 /// SP then OffsetAdjustment is zero; if FP is used, OffsetAdjustment is set
196 /// to the distance between the initial SP and the value in FP. For many
197 /// targets, this value is only used when generating debug info (via
198 /// TargetRegisterInfo::getFrameIndexReference); when generating code, the
199 /// corresponding adjustments are performed directly.
200 int OffsetAdjustment = 0;
202 /// The prolog/epilog code inserter may process objects that require greater
203 /// alignment than the default alignment the target provides.
204 /// To handle this, MaxAlignment is set to the maximum alignment
205 /// needed by the objects on the current frame. If this is greater than the
206 /// native alignment maintained by the compiler, dynamic alignment code will
209 unsigned MaxAlignment = 0;
211 /// Set to true if this function adjusts the stack -- e.g.,
212 /// when calling another function. This is only valid during and after
213 /// prolog/epilog code insertion.
214 bool AdjustsStack = false;
216 /// Set to true if this function has any function calls.
217 bool HasCalls = false;
219 /// The frame index for the stack protector.
220 int StackProtectorIdx = -1;
222 /// The frame index for the function context. Used for SjLj exceptions.
223 int FunctionContextIdx = -1;
225 /// This contains the size of the largest call frame if the target uses frame
226 /// setup/destroy pseudo instructions (as defined in the TargetFrameInfo
227 /// class). This information is important for frame pointer elimination.
228 /// It is only valid during and after prolog/epilog code insertion.
229 unsigned MaxCallFrameSize = 0;
231 /// The prolog/epilog code inserter fills in this vector with each
232 /// callee saved register saved in the frame. Beyond its use by the prolog/
233 /// epilog code inserter, this data used for debug info and exception
235 std::vector<CalleeSavedInfo> CSInfo;
237 /// Has CSInfo been set yet?
238 bool CSIValid = false;
240 /// References to frame indices which are mapped
241 /// into the local frame allocation block. <FrameIdx, LocalOffset>
242 SmallVector<std::pair<int, int64_t>, 32> LocalFrameObjects;
244 /// Size of the pre-allocated local frame block.
245 int64_t LocalFrameSize = 0;
247 /// Required alignment of the local object blob, which is the strictest
248 /// alignment of any object in it.
249 unsigned LocalFrameMaxAlign = 0;
251 /// Whether the local object blob needs to be allocated together. If not,
252 /// PEI should ignore the isPreAllocated flags on the stack objects and
253 /// just allocate them normally.
254 bool UseLocalStackAllocationBlock = false;
256 /// True if the function dynamically adjusts the stack pointer through some
257 /// opaque mechanism like inline assembly or Win32 EH.
258 bool HasOpaqueSPAdjustment = false;
260 /// True if the function contains operations which will lower down to
261 /// instructions which manipulate the stack pointer.
262 bool HasCopyImplyingStackAdjustment = false;
264 /// True if the function contains a call to the llvm.vastart intrinsic.
265 bool HasVAStart = false;
267 /// True if this is a varargs function that contains a musttail call.
268 bool HasMustTailInVarArgFunc = false;
270 /// True if this function contains a tail call. If so immutable objects like
271 /// function arguments are no longer so. A tail call *can* override fixed
272 /// stack objects like arguments so we can't treat them as immutable.
273 bool HasTailCall = false;
275 /// Not null, if shrink-wrapping found a better place for the prologue.
276 MachineBasicBlock *Save = nullptr;
277 /// Not null, if shrink-wrapping found a better place for the epilogue.
278 MachineBasicBlock *Restore = nullptr;
281 explicit MachineFrameInfo(unsigned StackAlignment, bool StackRealignable,
283 : StackAlignment(StackAlignment), StackRealignable(StackRealignable),
284 ForcedRealign(ForcedRealign) {}
286 /// Return true if there are any stack objects in this function.
287 bool hasStackObjects() const { return !Objects.empty(); }
289 /// This method may be called any time after instruction
290 /// selection is complete to determine if the stack frame for this function
291 /// contains any variable sized objects.
292 bool hasVarSizedObjects() const { return HasVarSizedObjects; }
294 /// Return the index for the stack protector object.
295 int getStackProtectorIndex() const { return StackProtectorIdx; }
296 void setStackProtectorIndex(int I) { StackProtectorIdx = I; }
297 bool hasStackProtectorIndex() const { return StackProtectorIdx != -1; }
299 /// Return the index for the function context object.
300 /// This object is used for SjLj exceptions.
301 int getFunctionContextIndex() const { return FunctionContextIdx; }
302 void setFunctionContextIndex(int I) { FunctionContextIdx = I; }
304 /// This method may be called any time after instruction
305 /// selection is complete to determine if there is a call to
306 /// \@llvm.frameaddress in this function.
307 bool isFrameAddressTaken() const { return FrameAddressTaken; }
308 void setFrameAddressIsTaken(bool T) { FrameAddressTaken = T; }
310 /// This method may be called any time after
311 /// instruction selection is complete to determine if there is a call to
312 /// \@llvm.returnaddress in this function.
313 bool isReturnAddressTaken() const { return ReturnAddressTaken; }
314 void setReturnAddressIsTaken(bool s) { ReturnAddressTaken = s; }
316 /// This method may be called any time after instruction
317 /// selection is complete to determine if there is a call to builtin
318 /// \@llvm.experimental.stackmap.
319 bool hasStackMap() const { return HasStackMap; }
320 void setHasStackMap(bool s = true) { HasStackMap = s; }
322 /// This method may be called any time after instruction
323 /// selection is complete to determine if there is a call to builtin
324 /// \@llvm.experimental.patchpoint.
325 bool hasPatchPoint() const { return HasPatchPoint; }
326 void setHasPatchPoint(bool s = true) { HasPatchPoint = s; }
328 /// Return the minimum frame object index.
329 int getObjectIndexBegin() const { return -NumFixedObjects; }
331 /// Return one past the maximum frame object index.
332 int getObjectIndexEnd() const { return (int)Objects.size()-NumFixedObjects; }
334 /// Return the number of fixed objects.
335 unsigned getNumFixedObjects() const { return NumFixedObjects; }
337 /// Return the number of objects.
338 unsigned getNumObjects() const { return Objects.size(); }
340 /// Map a frame index into the local object block
341 void mapLocalFrameObject(int ObjectIndex, int64_t Offset) {
342 LocalFrameObjects.push_back(std::pair<int, int64_t>(ObjectIndex, Offset));
343 Objects[ObjectIndex + NumFixedObjects].PreAllocated = true;
346 /// Get the local offset mapping for a for an object.
347 std::pair<int, int64_t> getLocalFrameObjectMap(int i) const {
348 assert (i >= 0 && (unsigned)i < LocalFrameObjects.size() &&
349 "Invalid local object reference!");
350 return LocalFrameObjects[i];
353 /// Return the number of objects allocated into the local object block.
354 int64_t getLocalFrameObjectCount() const { return LocalFrameObjects.size(); }
356 /// Set the size of the local object blob.
357 void setLocalFrameSize(int64_t sz) { LocalFrameSize = sz; }
359 /// Get the size of the local object blob.
360 int64_t getLocalFrameSize() const { return LocalFrameSize; }
362 /// Required alignment of the local object blob,
363 /// which is the strictest alignment of any object in it.
364 void setLocalFrameMaxAlign(unsigned Align) { LocalFrameMaxAlign = Align; }
366 /// Return the required alignment of the local object blob.
367 unsigned getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; }
369 /// Get whether the local allocation blob should be allocated together or
370 /// let PEI allocate the locals in it directly.
371 bool getUseLocalStackAllocationBlock() const {
372 return UseLocalStackAllocationBlock;
375 /// setUseLocalStackAllocationBlock - Set whether the local allocation blob
376 /// should be allocated together or let PEI allocate the locals in it
378 void setUseLocalStackAllocationBlock(bool v) {
379 UseLocalStackAllocationBlock = v;
382 /// Return true if the object was pre-allocated into the local block.
383 bool isObjectPreAllocated(int ObjectIdx) const {
384 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
385 "Invalid Object Idx!");
386 return Objects[ObjectIdx+NumFixedObjects].PreAllocated;
389 /// Return the size of the specified object.
390 int64_t getObjectSize(int ObjectIdx) const {
391 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
392 "Invalid Object Idx!");
393 return Objects[ObjectIdx+NumFixedObjects].Size;
396 /// Change the size of the specified stack object.
397 void setObjectSize(int ObjectIdx, int64_t Size) {
398 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
399 "Invalid Object Idx!");
400 Objects[ObjectIdx+NumFixedObjects].Size = Size;
403 /// Return the alignment of the specified stack object.
404 unsigned getObjectAlignment(int ObjectIdx) const {
405 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
406 "Invalid Object Idx!");
407 return Objects[ObjectIdx+NumFixedObjects].Alignment;
410 /// setObjectAlignment - Change the alignment of the specified stack object.
411 void setObjectAlignment(int ObjectIdx, unsigned Align) {
412 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
413 "Invalid Object Idx!");
414 Objects[ObjectIdx+NumFixedObjects].Alignment = Align;
415 ensureMaxAlignment(Align);
418 /// Return the underlying Alloca of the specified
419 /// stack object if it exists. Returns 0 if none exists.
420 const AllocaInst* getObjectAllocation(int ObjectIdx) const {
421 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
422 "Invalid Object Idx!");
423 return Objects[ObjectIdx+NumFixedObjects].Alloca;
426 /// Return the assigned stack offset of the specified object
427 /// from the incoming stack pointer.
428 int64_t getObjectOffset(int ObjectIdx) const {
429 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
430 "Invalid Object Idx!");
431 assert(!isDeadObjectIndex(ObjectIdx) &&
432 "Getting frame offset for a dead object?");
433 return Objects[ObjectIdx+NumFixedObjects].SPOffset;
436 bool isObjectZExt(int ObjectIdx) const {
437 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
438 "Invalid Object Idx!");
439 return Objects[ObjectIdx+NumFixedObjects].isZExt;
442 void setObjectZExt(int ObjectIdx, bool IsZExt) {
443 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
444 "Invalid Object Idx!");
445 Objects[ObjectIdx+NumFixedObjects].isZExt = IsZExt;
448 bool isObjectSExt(int ObjectIdx) const {
449 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
450 "Invalid Object Idx!");
451 return Objects[ObjectIdx+NumFixedObjects].isSExt;
454 void setObjectSExt(int ObjectIdx, bool IsSExt) {
455 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
456 "Invalid Object Idx!");
457 Objects[ObjectIdx+NumFixedObjects].isSExt = IsSExt;
460 /// Set the stack frame offset of the specified object. The
461 /// offset is relative to the stack pointer on entry to the function.
462 void setObjectOffset(int ObjectIdx, int64_t SPOffset) {
463 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
464 "Invalid Object Idx!");
465 assert(!isDeadObjectIndex(ObjectIdx) &&
466 "Setting frame offset for a dead object?");
467 Objects[ObjectIdx+NumFixedObjects].SPOffset = SPOffset;
470 /// Return the number of bytes that must be allocated to hold
471 /// all of the fixed size frame objects. This is only valid after
472 /// Prolog/Epilog code insertion has finalized the stack frame layout.
473 uint64_t getStackSize() const { return StackSize; }
475 /// Set the size of the stack.
476 void setStackSize(uint64_t Size) { StackSize = Size; }
478 /// Estimate and return the size of the stack frame.
479 unsigned estimateStackSize(const MachineFunction &MF) const;
481 /// Return the correction for frame offsets.
482 int getOffsetAdjustment() const { return OffsetAdjustment; }
484 /// Set the correction for frame offsets.
485 void setOffsetAdjustment(int Adj) { OffsetAdjustment = Adj; }
487 /// Return the alignment in bytes that this function must be aligned to,
488 /// which is greater than the default stack alignment provided by the target.
489 unsigned getMaxAlignment() const { return MaxAlignment; }
491 /// Make sure the function is at least Align bytes aligned.
492 void ensureMaxAlignment(unsigned Align);
494 /// Return true if this function adjusts the stack -- e.g.,
495 /// when calling another function. This is only valid during and after
496 /// prolog/epilog code insertion.
497 bool adjustsStack() const { return AdjustsStack; }
498 void setAdjustsStack(bool V) { AdjustsStack = V; }
500 /// Return true if the current function has any function calls.
501 bool hasCalls() const { return HasCalls; }
502 void setHasCalls(bool V) { HasCalls = V; }
504 /// Returns true if the function contains opaque dynamic stack adjustments.
505 bool hasOpaqueSPAdjustment() const { return HasOpaqueSPAdjustment; }
506 void setHasOpaqueSPAdjustment(bool B) { HasOpaqueSPAdjustment = B; }
508 /// Returns true if the function contains operations which will lower down to
509 /// instructions which manipulate the stack pointer.
510 bool hasCopyImplyingStackAdjustment() const {
511 return HasCopyImplyingStackAdjustment;
513 void setHasCopyImplyingStackAdjustment(bool B) {
514 HasCopyImplyingStackAdjustment = B;
517 /// Returns true if the function calls the llvm.va_start intrinsic.
518 bool hasVAStart() const { return HasVAStart; }
519 void setHasVAStart(bool B) { HasVAStart = B; }
521 /// Returns true if the function is variadic and contains a musttail call.
522 bool hasMustTailInVarArgFunc() const { return HasMustTailInVarArgFunc; }
523 void setHasMustTailInVarArgFunc(bool B) { HasMustTailInVarArgFunc = B; }
525 /// Returns true if the function contains a tail call.
526 bool hasTailCall() const { return HasTailCall; }
527 void setHasTailCall() { HasTailCall = true; }
529 /// Return the maximum size of a call frame that must be
530 /// allocated for an outgoing function call. This is only available if
531 /// CallFrameSetup/Destroy pseudo instructions are used by the target, and
532 /// then only during or after prolog/epilog code insertion.
534 unsigned getMaxCallFrameSize() const { return MaxCallFrameSize; }
535 void setMaxCallFrameSize(unsigned S) { MaxCallFrameSize = S; }
537 /// Create a new object at a fixed location on the stack.
538 /// All fixed objects should be created before other objects are created for
539 /// efficiency. By default, fixed objects are not pointed to by LLVM IR
540 /// values. This returns an index with a negative value.
541 int CreateFixedObject(uint64_t Size, int64_t SPOffset, bool Immutable,
542 bool isAliased = false);
544 /// Create a spill slot at a fixed location on the stack.
545 /// Returns an index with a negative value.
546 int CreateFixedSpillStackObject(uint64_t Size, int64_t SPOffset,
547 bool Immutable = false);
549 /// Returns true if the specified index corresponds to a fixed stack object.
550 bool isFixedObjectIndex(int ObjectIdx) const {
551 return ObjectIdx < 0 && (ObjectIdx >= -(int)NumFixedObjects);
554 /// Returns true if the specified index corresponds
555 /// to an object that might be pointed to by an LLVM IR value.
556 bool isAliasedObjectIndex(int ObjectIdx) const {
557 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
558 "Invalid Object Idx!");
559 return Objects[ObjectIdx+NumFixedObjects].isAliased;
562 /// isImmutableObjectIndex - Returns true if the specified index corresponds
563 /// to an immutable object.
564 bool isImmutableObjectIndex(int ObjectIdx) const {
565 // Tail calling functions can clobber their function arguments.
568 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
569 "Invalid Object Idx!");
570 return Objects[ObjectIdx+NumFixedObjects].isImmutable;
573 /// Returns true if the specified index corresponds to a spill slot.
574 bool isSpillSlotObjectIndex(int ObjectIdx) const {
575 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
576 "Invalid Object Idx!");
577 return Objects[ObjectIdx+NumFixedObjects].isSpillSlot;
580 bool isStatepointSpillSlotObjectIndex(int ObjectIdx) const {
581 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
582 "Invalid Object Idx!");
583 return Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot;
586 /// Returns true if the specified index corresponds to a dead object.
587 bool isDeadObjectIndex(int ObjectIdx) const {
588 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
589 "Invalid Object Idx!");
590 return Objects[ObjectIdx+NumFixedObjects].Size == ~0ULL;
593 /// Returns true if the specified index corresponds to a variable sized
595 bool isVariableSizedObjectIndex(int ObjectIdx) const {
596 assert(unsigned(ObjectIdx + NumFixedObjects) < Objects.size() &&
597 "Invalid Object Idx!");
598 return Objects[ObjectIdx + NumFixedObjects].Size == 0;
601 void markAsStatepointSpillSlotObjectIndex(int ObjectIdx) {
602 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
603 "Invalid Object Idx!");
604 Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot = true;
605 assert(isStatepointSpillSlotObjectIndex(ObjectIdx) && "inconsistent");
608 /// Create a new statically sized stack object, returning
609 /// a nonnegative identifier to represent it.
610 int CreateStackObject(uint64_t Size, unsigned Alignment, bool isSS,
611 const AllocaInst *Alloca = nullptr);
613 /// Create a new statically sized stack object that represents a spill slot,
614 /// returning a nonnegative identifier to represent it.
615 int CreateSpillStackObject(uint64_t Size, unsigned Alignment);
617 /// Remove or mark dead a statically sized stack object.
618 void RemoveStackObject(int ObjectIdx) {
620 Objects[ObjectIdx+NumFixedObjects].Size = ~0ULL;
623 /// Notify the MachineFrameInfo object that a variable sized object has been
624 /// created. This must be created whenever a variable sized object is
625 /// created, whether or not the index returned is actually used.
626 int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca);
628 /// Returns a reference to call saved info vector for the current function.
629 const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const {
633 /// Used by prolog/epilog inserter to set the function's callee saved
635 void setCalleeSavedInfo(const std::vector<CalleeSavedInfo> &CSI) {
639 /// Has the callee saved info been calculated yet?
640 bool isCalleeSavedInfoValid() const { return CSIValid; }
642 void setCalleeSavedInfoValid(bool v) { CSIValid = v; }
644 MachineBasicBlock *getSavePoint() const { return Save; }
645 void setSavePoint(MachineBasicBlock *NewSave) { Save = NewSave; }
646 MachineBasicBlock *getRestorePoint() const { return Restore; }
647 void setRestorePoint(MachineBasicBlock *NewRestore) { Restore = NewRestore; }
649 /// Return a set of physical registers that are pristine.
651 /// Pristine registers hold a value that is useless to the current function,
652 /// but that must be preserved - they are callee saved registers that are not
655 /// Before the PrologueEpilogueInserter has placed the CSR spill code, this
656 /// method always returns an empty set.
657 BitVector getPristineRegs(const MachineFunction &MF) const;
659 /// Used by the MachineFunction printer to print information about
660 /// stack objects. Implemented in MachineFunction.cpp.
661 void print(const MachineFunction &MF, raw_ostream &OS) const;
663 /// dump - Print the function to stderr.
664 void dump(const MachineFunction &MF) const;
667 } // End llvm namespace