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"
24 class MachineFunction;
25 class MachineBasicBlock;
29 /// The CalleeSavedInfo class tracks the information need to locate where a
30 /// callee saved register is in the current frame.
31 class CalleeSavedInfo {
36 explicit CalleeSavedInfo(unsigned R, int FI = 0)
37 : Reg(R), FrameIdx(FI) {}
40 unsigned getReg() const { return Reg; }
41 int getFrameIdx() const { return FrameIdx; }
42 void setFrameIdx(int FI) { FrameIdx = FI; }
45 /// The MachineFrameInfo class represents an abstract stack frame until
46 /// prolog/epilog code is inserted. This class is key to allowing stack frame
47 /// representation optimizations, such as frame pointer elimination. It also
48 /// allows more mundane (but still important) optimizations, such as reordering
49 /// of abstract objects on the stack frame.
51 /// To support this, the class assigns unique integer identifiers to stack
52 /// objects requested clients. These identifiers are negative integers for
53 /// fixed stack objects (such as arguments passed on the stack) or nonnegative
54 /// for objects that may be reordered. Instructions which refer to stack
55 /// objects use a special MO_FrameIndex operand to represent these frame
58 /// Because this class keeps track of all references to the stack frame, it
59 /// knows when a variable sized object is allocated on the stack. This is the
60 /// sole condition which prevents frame pointer elimination, which is an
61 /// important optimization on register-poor architectures. Because original
62 /// variable sized alloca's in the source program are the only source of
63 /// variable sized stack objects, it is safe to decide whether there will be
64 /// any variable sized objects before all stack objects are known (for
65 /// example, register allocator spill code never needs variable sized
68 /// When prolog/epilog code emission is performed, the final stack frame is
69 /// built and the machine instructions are modified to refer to the actual
70 /// stack offsets of the object, eliminating all MO_FrameIndex operands from
73 /// @brief Abstract Stack Frame Information
74 class MachineFrameInfo {
76 // Represent a single object allocated on the stack.
78 // The offset of this object from the stack pointer on entry to
79 // the function. This field has no meaning for a variable sized element.
82 // The size of this object on the stack. 0 means a variable sized object,
83 // ~0ULL means a dead object.
86 // The required alignment of this stack slot.
89 // If true, the value of the stack object is set before
90 // entering the function and is not modified inside the function. By
91 // default, fixed objects are immutable unless marked otherwise.
94 // If true the stack object is used as spill slot. It
95 // cannot alias any other memory objects.
98 /// If true, this stack slot is used to spill a value (could be deopt
99 /// and/or GC related) over a statepoint. We know that the address of the
100 /// slot can't alias any LLVM IR value. This is very similar to a Spill
101 /// Slot, but is created by statepoint lowering is SelectionDAG, not the
102 /// register allocator.
103 bool isStatepointSpillSlot;
105 /// If this stack object is originated from an Alloca instruction
106 /// this value saves the original IR allocation. Can be NULL.
107 const AllocaInst *Alloca;
109 // If true, the object was mapped into the local frame
110 // block and doesn't need additional handling for allocation beyond that.
113 // If true, an LLVM IR value might point to this object.
114 // Normally, spill slots and fixed-offset objects don't alias IR-accessible
115 // objects, but there are exceptions (on PowerPC, for example, some byval
116 // arguments have ABI-prescribed offsets).
119 /// If true, the object has been zero-extended.
122 /// If true, the object has been zero-extended.
125 StackObject(uint64_t Sz, unsigned Al, int64_t SP, bool IM,
126 bool isSS, const AllocaInst *Val, bool A)
127 : SPOffset(SP), Size(Sz), Alignment(Al), isImmutable(IM),
128 isSpillSlot(isSS), isStatepointSpillSlot(false), Alloca(Val),
129 PreAllocated(false), isAliased(A), isZExt(false), isSExt(false) {}
132 /// The alignment of the stack.
133 unsigned StackAlignment;
135 /// Can the stack be realigned. This can be false if the target does not
136 /// support stack realignment, or if the user asks us not to realign the
137 /// stack. In this situation, overaligned allocas are all treated as dynamic
138 /// allocations and the target must handle them as part of DYNAMIC_STACKALLOC
139 /// lowering. All non-alloca stack objects have their alignment clamped to the
140 /// base ABI stack alignment.
141 /// FIXME: There is room for improvement in this case, in terms of
142 /// grouping overaligned allocas into a "secondary stack frame" and
143 /// then only use a single alloca to allocate this frame and only a
144 /// single virtual register to access it. Currently, without such an
145 /// optimization, each such alloca gets its own dynamic realignment.
146 bool StackRealignable;
148 /// Whether the function has the \c alignstack attribute.
151 /// The list of stack objects allocated.
152 std::vector<StackObject> Objects;
154 /// This contains the number of fixed objects contained on
155 /// the stack. Because fixed objects are stored at a negative index in the
156 /// Objects list, this is also the index to the 0th object in the list.
157 unsigned NumFixedObjects = 0;
159 /// This boolean keeps track of whether any variable
160 /// sized objects have been allocated yet.
161 bool HasVarSizedObjects = false;
163 /// This boolean keeps track of whether there is a call
164 /// to builtin \@llvm.frameaddress.
165 bool FrameAddressTaken = false;
167 /// This boolean keeps track of whether there is a call
168 /// to builtin \@llvm.returnaddress.
169 bool ReturnAddressTaken = false;
171 /// This boolean keeps track of whether there is a call
172 /// to builtin \@llvm.experimental.stackmap.
173 bool HasStackMap = false;
175 /// This boolean keeps track of whether there is a call
176 /// to builtin \@llvm.experimental.patchpoint.
177 bool HasPatchPoint = false;
179 /// The prolog/epilog code inserter calculates the final stack
180 /// offsets for all of the fixed size objects, updating the Objects list
181 /// above. It then updates StackSize to contain the number of bytes that need
182 /// to be allocated on entry to the function.
183 uint64_t StackSize = 0;
185 /// The amount that a frame offset needs to be adjusted to
186 /// have the actual offset from the stack/frame pointer. The exact usage of
187 /// this is target-dependent, but it is typically used to adjust between
188 /// SP-relative and FP-relative offsets. E.G., if objects are accessed via
189 /// SP then OffsetAdjustment is zero; if FP is used, OffsetAdjustment is set
190 /// to the distance between the initial SP and the value in FP. For many
191 /// targets, this value is only used when generating debug info (via
192 /// TargetRegisterInfo::getFrameIndexReference); when generating code, the
193 /// corresponding adjustments are performed directly.
194 int OffsetAdjustment = 0;
196 /// The prolog/epilog code inserter may process objects that require greater
197 /// alignment than the default alignment the target provides.
198 /// To handle this, MaxAlignment is set to the maximum alignment
199 /// needed by the objects on the current frame. If this is greater than the
200 /// native alignment maintained by the compiler, dynamic alignment code will
203 unsigned MaxAlignment = 0;
205 /// Set to true if this function adjusts the stack -- e.g.,
206 /// when calling another function. This is only valid during and after
207 /// prolog/epilog code insertion.
208 bool AdjustsStack = false;
210 /// Set to true if this function has any function calls.
211 bool HasCalls = false;
213 /// The frame index for the stack protector.
214 int StackProtectorIdx = -1;
216 /// The frame index for the function context. Used for SjLj exceptions.
217 int FunctionContextIdx = -1;
219 /// This contains the size of the largest call frame if the target uses frame
220 /// setup/destroy pseudo instructions (as defined in the TargetFrameInfo
221 /// class). This information is important for frame pointer elimination.
222 /// It is only valid during and after prolog/epilog code insertion.
223 unsigned MaxCallFrameSize = ~0u;
225 /// The prolog/epilog code inserter fills in this vector with each
226 /// callee saved register saved in the frame. Beyond its use by the prolog/
227 /// epilog code inserter, this data used for debug info and exception
229 std::vector<CalleeSavedInfo> CSInfo;
231 /// Has CSInfo been set yet?
232 bool CSIValid = false;
234 /// References to frame indices which are mapped
235 /// into the local frame allocation block. <FrameIdx, LocalOffset>
236 SmallVector<std::pair<int, int64_t>, 32> LocalFrameObjects;
238 /// Size of the pre-allocated local frame block.
239 int64_t LocalFrameSize = 0;
241 /// Required alignment of the local object blob, which is the strictest
242 /// alignment of any object in it.
243 unsigned LocalFrameMaxAlign = 0;
245 /// Whether the local object blob needs to be allocated together. If not,
246 /// PEI should ignore the isPreAllocated flags on the stack objects and
247 /// just allocate them normally.
248 bool UseLocalStackAllocationBlock = false;
250 /// True if the function dynamically adjusts the stack pointer through some
251 /// opaque mechanism like inline assembly or Win32 EH.
252 bool HasOpaqueSPAdjustment = false;
254 /// True if the function contains operations which will lower down to
255 /// instructions which manipulate the stack pointer.
256 bool HasCopyImplyingStackAdjustment = false;
258 /// True if the function contains a call to the llvm.vastart intrinsic.
259 bool HasVAStart = false;
261 /// True if this is a varargs function that contains a musttail call.
262 bool HasMustTailInVarArgFunc = false;
264 /// True if this function contains a tail call. If so immutable objects like
265 /// function arguments are no longer so. A tail call *can* override fixed
266 /// stack objects like arguments so we can't treat them as immutable.
267 bool HasTailCall = false;
269 /// Not null, if shrink-wrapping found a better place for the prologue.
270 MachineBasicBlock *Save = nullptr;
271 /// Not null, if shrink-wrapping found a better place for the epilogue.
272 MachineBasicBlock *Restore = nullptr;
275 explicit MachineFrameInfo(unsigned StackAlignment, bool StackRealignable,
277 : StackAlignment(StackAlignment), StackRealignable(StackRealignable),
278 ForcedRealign(ForcedRealign) {}
280 /// Return true if there are any stack objects in this function.
281 bool hasStackObjects() const { return !Objects.empty(); }
283 /// This method may be called any time after instruction
284 /// selection is complete to determine if the stack frame for this function
285 /// contains any variable sized objects.
286 bool hasVarSizedObjects() const { return HasVarSizedObjects; }
288 /// Return the index for the stack protector object.
289 int getStackProtectorIndex() const { return StackProtectorIdx; }
290 void setStackProtectorIndex(int I) { StackProtectorIdx = I; }
291 bool hasStackProtectorIndex() const { return StackProtectorIdx != -1; }
293 /// Return the index for the function context object.
294 /// This object is used for SjLj exceptions.
295 int getFunctionContextIndex() const { return FunctionContextIdx; }
296 void setFunctionContextIndex(int I) { FunctionContextIdx = I; }
298 /// This method may be called any time after instruction
299 /// selection is complete to determine if there is a call to
300 /// \@llvm.frameaddress in this function.
301 bool isFrameAddressTaken() const { return FrameAddressTaken; }
302 void setFrameAddressIsTaken(bool T) { FrameAddressTaken = T; }
304 /// This method may be called any time after
305 /// instruction selection is complete to determine if there is a call to
306 /// \@llvm.returnaddress in this function.
307 bool isReturnAddressTaken() const { return ReturnAddressTaken; }
308 void setReturnAddressIsTaken(bool s) { ReturnAddressTaken = s; }
310 /// This method may be called any time after instruction
311 /// selection is complete to determine if there is a call to builtin
312 /// \@llvm.experimental.stackmap.
313 bool hasStackMap() const { return HasStackMap; }
314 void setHasStackMap(bool s = true) { HasStackMap = 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.patchpoint.
319 bool hasPatchPoint() const { return HasPatchPoint; }
320 void setHasPatchPoint(bool s = true) { HasPatchPoint = s; }
322 /// Return the minimum frame object index.
323 int getObjectIndexBegin() const { return -NumFixedObjects; }
325 /// Return one past the maximum frame object index.
326 int getObjectIndexEnd() const { return (int)Objects.size()-NumFixedObjects; }
328 /// Return the number of fixed objects.
329 unsigned getNumFixedObjects() const { return NumFixedObjects; }
331 /// Return the number of objects.
332 unsigned getNumObjects() const { return Objects.size(); }
334 /// Map a frame index into the local object block
335 void mapLocalFrameObject(int ObjectIndex, int64_t Offset) {
336 LocalFrameObjects.push_back(std::pair<int, int64_t>(ObjectIndex, Offset));
337 Objects[ObjectIndex + NumFixedObjects].PreAllocated = true;
340 /// Get the local offset mapping for a for an object.
341 std::pair<int, int64_t> getLocalFrameObjectMap(int i) const {
342 assert (i >= 0 && (unsigned)i < LocalFrameObjects.size() &&
343 "Invalid local object reference!");
344 return LocalFrameObjects[i];
347 /// Return the number of objects allocated into the local object block.
348 int64_t getLocalFrameObjectCount() const { return LocalFrameObjects.size(); }
350 /// Set the size of the local object blob.
351 void setLocalFrameSize(int64_t sz) { LocalFrameSize = sz; }
353 /// Get the size of the local object blob.
354 int64_t getLocalFrameSize() const { return LocalFrameSize; }
356 /// Required alignment of the local object blob,
357 /// which is the strictest alignment of any object in it.
358 void setLocalFrameMaxAlign(unsigned Align) { LocalFrameMaxAlign = Align; }
360 /// Return the required alignment of the local object blob.
361 unsigned getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; }
363 /// Get whether the local allocation blob should be allocated together or
364 /// let PEI allocate the locals in it directly.
365 bool getUseLocalStackAllocationBlock() const {
366 return UseLocalStackAllocationBlock;
369 /// setUseLocalStackAllocationBlock - Set whether the local allocation blob
370 /// should be allocated together or let PEI allocate the locals in it
372 void setUseLocalStackAllocationBlock(bool v) {
373 UseLocalStackAllocationBlock = v;
376 /// Return true if the object was pre-allocated into the local block.
377 bool isObjectPreAllocated(int ObjectIdx) const {
378 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
379 "Invalid Object Idx!");
380 return Objects[ObjectIdx+NumFixedObjects].PreAllocated;
383 /// Return the size of the specified object.
384 int64_t getObjectSize(int ObjectIdx) const {
385 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
386 "Invalid Object Idx!");
387 return Objects[ObjectIdx+NumFixedObjects].Size;
390 /// Change the size of the specified stack object.
391 void setObjectSize(int ObjectIdx, int64_t Size) {
392 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
393 "Invalid Object Idx!");
394 Objects[ObjectIdx+NumFixedObjects].Size = Size;
397 /// Return the alignment of the specified stack object.
398 unsigned getObjectAlignment(int ObjectIdx) const {
399 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
400 "Invalid Object Idx!");
401 return Objects[ObjectIdx+NumFixedObjects].Alignment;
404 /// setObjectAlignment - Change the alignment of the specified stack object.
405 void setObjectAlignment(int ObjectIdx, unsigned Align) {
406 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
407 "Invalid Object Idx!");
408 Objects[ObjectIdx+NumFixedObjects].Alignment = Align;
409 ensureMaxAlignment(Align);
412 /// Return the underlying Alloca of the specified
413 /// stack object if it exists. Returns 0 if none exists.
414 const AllocaInst* getObjectAllocation(int ObjectIdx) const {
415 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
416 "Invalid Object Idx!");
417 return Objects[ObjectIdx+NumFixedObjects].Alloca;
420 /// Return the assigned stack offset of the specified object
421 /// from the incoming stack pointer.
422 int64_t getObjectOffset(int ObjectIdx) const {
423 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
424 "Invalid Object Idx!");
425 assert(!isDeadObjectIndex(ObjectIdx) &&
426 "Getting frame offset for a dead object?");
427 return Objects[ObjectIdx+NumFixedObjects].SPOffset;
430 bool isObjectZExt(int ObjectIdx) const {
431 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
432 "Invalid Object Idx!");
433 return Objects[ObjectIdx+NumFixedObjects].isZExt;
436 void setObjectZExt(int ObjectIdx, bool IsZExt) {
437 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
438 "Invalid Object Idx!");
439 Objects[ObjectIdx+NumFixedObjects].isZExt = IsZExt;
442 bool isObjectSExt(int ObjectIdx) const {
443 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
444 "Invalid Object Idx!");
445 return Objects[ObjectIdx+NumFixedObjects].isSExt;
448 void setObjectSExt(int ObjectIdx, bool IsSExt) {
449 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
450 "Invalid Object Idx!");
451 Objects[ObjectIdx+NumFixedObjects].isSExt = IsSExt;
454 /// Set the stack frame offset of the specified object. The
455 /// offset is relative to the stack pointer on entry to the function.
456 void setObjectOffset(int ObjectIdx, int64_t SPOffset) {
457 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
458 "Invalid Object Idx!");
459 assert(!isDeadObjectIndex(ObjectIdx) &&
460 "Setting frame offset for a dead object?");
461 Objects[ObjectIdx+NumFixedObjects].SPOffset = SPOffset;
464 /// Return the number of bytes that must be allocated to hold
465 /// all of the fixed size frame objects. This is only valid after
466 /// Prolog/Epilog code insertion has finalized the stack frame layout.
467 uint64_t getStackSize() const { return StackSize; }
469 /// Set the size of the stack.
470 void setStackSize(uint64_t Size) { StackSize = Size; }
472 /// Estimate and return the size of the stack frame.
473 unsigned estimateStackSize(const MachineFunction &MF) const;
475 /// Return the correction for frame offsets.
476 int getOffsetAdjustment() const { return OffsetAdjustment; }
478 /// Set the correction for frame offsets.
479 void setOffsetAdjustment(int Adj) { OffsetAdjustment = Adj; }
481 /// Return the alignment in bytes that this function must be aligned to,
482 /// which is greater than the default stack alignment provided by the target.
483 unsigned getMaxAlignment() const { return MaxAlignment; }
485 /// Make sure the function is at least Align bytes aligned.
486 void ensureMaxAlignment(unsigned Align);
488 /// Return true if this function adjusts the stack -- e.g.,
489 /// when calling another function. This is only valid during and after
490 /// prolog/epilog code insertion.
491 bool adjustsStack() const { return AdjustsStack; }
492 void setAdjustsStack(bool V) { AdjustsStack = V; }
494 /// Return true if the current function has any function calls.
495 bool hasCalls() const { return HasCalls; }
496 void setHasCalls(bool V) { HasCalls = V; }
498 /// Returns true if the function contains opaque dynamic stack adjustments.
499 bool hasOpaqueSPAdjustment() const { return HasOpaqueSPAdjustment; }
500 void setHasOpaqueSPAdjustment(bool B) { HasOpaqueSPAdjustment = B; }
502 /// Returns true if the function contains operations which will lower down to
503 /// instructions which manipulate the stack pointer.
504 bool hasCopyImplyingStackAdjustment() const {
505 return HasCopyImplyingStackAdjustment;
507 void setHasCopyImplyingStackAdjustment(bool B) {
508 HasCopyImplyingStackAdjustment = B;
511 /// Returns true if the function calls the llvm.va_start intrinsic.
512 bool hasVAStart() const { return HasVAStart; }
513 void setHasVAStart(bool B) { HasVAStart = B; }
515 /// Returns true if the function is variadic and contains a musttail call.
516 bool hasMustTailInVarArgFunc() const { return HasMustTailInVarArgFunc; }
517 void setHasMustTailInVarArgFunc(bool B) { HasMustTailInVarArgFunc = B; }
519 /// Returns true if the function contains a tail call.
520 bool hasTailCall() const { return HasTailCall; }
521 void setHasTailCall() { HasTailCall = true; }
523 /// Computes the maximum size of a callframe and the AdjustsStack property.
524 /// This only works for targets defining
525 /// TargetInstrInfo::getCallFrameSetupOpcode(), getCallFrameDestroyOpcode(),
526 /// and getFrameSize().
527 /// This is usually computed by the prologue epilogue inserter but some
528 /// targets may call this to compute it earlier.
529 void computeMaxCallFrameSize(const MachineFunction &MF);
531 /// Return the maximum size of a call frame that must be
532 /// allocated for an outgoing function call. This is only available if
533 /// CallFrameSetup/Destroy pseudo instructions are used by the target, and
534 /// then only during or after prolog/epilog code insertion.
536 unsigned getMaxCallFrameSize() const {
537 // TODO: Enable this assert when targets are fixed.
538 //assert(isMaxCallFrameSizeComputed() && "MaxCallFrameSize not computed yet");
539 if (!isMaxCallFrameSizeComputed())
541 return MaxCallFrameSize;
543 bool isMaxCallFrameSizeComputed() const {
544 return MaxCallFrameSize != ~0u;
546 void setMaxCallFrameSize(unsigned S) { MaxCallFrameSize = S; }
548 /// Create a new object at a fixed location on the stack.
549 /// All fixed objects should be created before other objects are created for
550 /// efficiency. By default, fixed objects are not pointed to by LLVM IR
551 /// values. This returns an index with a negative value.
552 int CreateFixedObject(uint64_t Size, int64_t SPOffset, bool Immutable,
553 bool isAliased = false);
555 /// Create a spill slot at a fixed location on the stack.
556 /// Returns an index with a negative value.
557 int CreateFixedSpillStackObject(uint64_t Size, int64_t SPOffset,
558 bool Immutable = false);
560 /// Returns true if the specified index corresponds to a fixed stack object.
561 bool isFixedObjectIndex(int ObjectIdx) const {
562 return ObjectIdx < 0 && (ObjectIdx >= -(int)NumFixedObjects);
565 /// Returns true if the specified index corresponds
566 /// to an object that might be pointed to by an LLVM IR value.
567 bool isAliasedObjectIndex(int ObjectIdx) const {
568 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
569 "Invalid Object Idx!");
570 return Objects[ObjectIdx+NumFixedObjects].isAliased;
573 /// Returns true if the specified index corresponds to an immutable object.
574 bool isImmutableObjectIndex(int ObjectIdx) const {
575 // Tail calling functions can clobber their function arguments.
578 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
579 "Invalid Object Idx!");
580 return Objects[ObjectIdx+NumFixedObjects].isImmutable;
583 /// Marks the immutability of an object.
584 void setIsImmutableObjectIndex(int ObjectIdx, bool Immutable) {
585 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
586 "Invalid Object Idx!");
587 Objects[ObjectIdx+NumFixedObjects].isImmutable = Immutable;
590 /// Returns true if the specified index corresponds to a spill slot.
591 bool isSpillSlotObjectIndex(int ObjectIdx) const {
592 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
593 "Invalid Object Idx!");
594 return Objects[ObjectIdx+NumFixedObjects].isSpillSlot;
597 bool isStatepointSpillSlotObjectIndex(int ObjectIdx) const {
598 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
599 "Invalid Object Idx!");
600 return Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot;
603 /// Returns true if the specified index corresponds to a dead object.
604 bool isDeadObjectIndex(int ObjectIdx) const {
605 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
606 "Invalid Object Idx!");
607 return Objects[ObjectIdx+NumFixedObjects].Size == ~0ULL;
610 /// Returns true if the specified index corresponds to a variable sized
612 bool isVariableSizedObjectIndex(int ObjectIdx) const {
613 assert(unsigned(ObjectIdx + NumFixedObjects) < Objects.size() &&
614 "Invalid Object Idx!");
615 return Objects[ObjectIdx + NumFixedObjects].Size == 0;
618 void markAsStatepointSpillSlotObjectIndex(int ObjectIdx) {
619 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
620 "Invalid Object Idx!");
621 Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot = true;
622 assert(isStatepointSpillSlotObjectIndex(ObjectIdx) && "inconsistent");
625 /// Create a new statically sized stack object, returning
626 /// a nonnegative identifier to represent it.
627 int CreateStackObject(uint64_t Size, unsigned Alignment, bool isSS,
628 const AllocaInst *Alloca = nullptr);
630 /// Create a new statically sized stack object that represents a spill slot,
631 /// returning a nonnegative identifier to represent it.
632 int CreateSpillStackObject(uint64_t Size, unsigned Alignment);
634 /// Remove or mark dead a statically sized stack object.
635 void RemoveStackObject(int ObjectIdx) {
637 Objects[ObjectIdx+NumFixedObjects].Size = ~0ULL;
640 /// Notify the MachineFrameInfo object that a variable sized object has been
641 /// created. This must be created whenever a variable sized object is
642 /// created, whether or not the index returned is actually used.
643 int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca);
645 /// Returns a reference to call saved info vector for the current function.
646 const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const {
650 /// Used by prolog/epilog inserter to set the function's callee saved
652 void setCalleeSavedInfo(const std::vector<CalleeSavedInfo> &CSI) {
656 /// Has the callee saved info been calculated yet?
657 bool isCalleeSavedInfoValid() const { return CSIValid; }
659 void setCalleeSavedInfoValid(bool v) { CSIValid = v; }
661 MachineBasicBlock *getSavePoint() const { return Save; }
662 void setSavePoint(MachineBasicBlock *NewSave) { Save = NewSave; }
663 MachineBasicBlock *getRestorePoint() const { return Restore; }
664 void setRestorePoint(MachineBasicBlock *NewRestore) { Restore = NewRestore; }
666 /// Return a set of physical registers that are pristine.
668 /// Pristine registers hold a value that is useless to the current function,
669 /// but that must be preserved - they are callee saved registers that are not
672 /// Before the PrologueEpilogueInserter has placed the CSR spill code, this
673 /// method always returns an empty set.
674 BitVector getPristineRegs(const MachineFunction &MF) const;
676 /// Used by the MachineFunction printer to print information about
677 /// stack objects. Implemented in MachineFunction.cpp.
678 void print(const MachineFunction &MF, raw_ostream &OS) const;
680 /// dump - Print the function to stderr.
681 void dump(const MachineFunction &MF) const;
684 } // End llvm namespace