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 {
34 /// Flag indicating whether the register is actually restored in the epilog.
35 /// In most cases, if a register is saved, it is also restored. There are
36 /// some situations, though, when this is not the case. For example, the
37 /// LR register on ARM is usually saved, but on exit from the function its
38 /// saved value may be loaded directly into PC. Since liveness tracking of
39 /// physical registers treats callee-saved registers are live outside of
40 /// the function, LR would be treated as live-on-exit, even though in these
41 /// scenarios it is not. This flag is added to indicate that the saved
42 /// register described by this object is not restored in the epilog.
43 /// The long-term solution is to model the liveness of callee-saved registers
44 /// by implicit uses on the return instructions, however, the required
45 /// changes in the ARM backend would be quite extensive.
49 explicit CalleeSavedInfo(unsigned R, int FI = 0)
50 : Reg(R), FrameIdx(FI), Restored(true) {}
53 unsigned getReg() const { return Reg; }
54 int getFrameIdx() const { return FrameIdx; }
55 void setFrameIdx(int FI) { FrameIdx = FI; }
56 bool isRestored() const { return Restored; }
57 void setRestored(bool R) { Restored = R; }
60 /// The MachineFrameInfo class represents an abstract stack frame until
61 /// prolog/epilog code is inserted. This class is key to allowing stack frame
62 /// representation optimizations, such as frame pointer elimination. It also
63 /// allows more mundane (but still important) optimizations, such as reordering
64 /// of abstract objects on the stack frame.
66 /// To support this, the class assigns unique integer identifiers to stack
67 /// objects requested clients. These identifiers are negative integers for
68 /// fixed stack objects (such as arguments passed on the stack) or nonnegative
69 /// for objects that may be reordered. Instructions which refer to stack
70 /// objects use a special MO_FrameIndex operand to represent these frame
73 /// Because this class keeps track of all references to the stack frame, it
74 /// knows when a variable sized object is allocated on the stack. This is the
75 /// sole condition which prevents frame pointer elimination, which is an
76 /// important optimization on register-poor architectures. Because original
77 /// variable sized alloca's in the source program are the only source of
78 /// variable sized stack objects, it is safe to decide whether there will be
79 /// any variable sized objects before all stack objects are known (for
80 /// example, register allocator spill code never needs variable sized
83 /// When prolog/epilog code emission is performed, the final stack frame is
84 /// built and the machine instructions are modified to refer to the actual
85 /// stack offsets of the object, eliminating all MO_FrameIndex operands from
88 /// @brief Abstract Stack Frame Information
89 class MachineFrameInfo {
91 // Represent a single object allocated on the stack.
93 // The offset of this object from the stack pointer on entry to
94 // the function. This field has no meaning for a variable sized element.
97 // The size of this object on the stack. 0 means a variable sized object,
98 // ~0ULL means a dead object.
101 // The required alignment of this stack slot.
104 // If true, the value of the stack object is set before
105 // entering the function and is not modified inside the function. By
106 // default, fixed objects are immutable unless marked otherwise.
109 // If true the stack object is used as spill slot. It
110 // cannot alias any other memory objects.
113 /// If true, this stack slot is used to spill a value (could be deopt
114 /// and/or GC related) over a statepoint. We know that the address of the
115 /// slot can't alias any LLVM IR value. This is very similar to a Spill
116 /// Slot, but is created by statepoint lowering is SelectionDAG, not the
117 /// register allocator.
118 bool isStatepointSpillSlot = false;
120 /// Identifier for stack memory type analagous to address space. If this is
121 /// non-0, the meaning is target defined. Offsets cannot be directly
122 /// compared between objects with different stack IDs. The object may not
123 /// necessarily reside in the same contiguous memory block as other stack
124 /// objects. Objects with differing stack IDs should not be merged or
125 /// replaced substituted for each other.
128 /// If this stack object is originated from an Alloca instruction
129 /// this value saves the original IR allocation. Can be NULL.
130 const AllocaInst *Alloca;
132 // If true, the object was mapped into the local frame
133 // block and doesn't need additional handling for allocation beyond that.
134 bool PreAllocated = false;
136 // If true, an LLVM IR value might point to this object.
137 // Normally, spill slots and fixed-offset objects don't alias IR-accessible
138 // objects, but there are exceptions (on PowerPC, for example, some byval
139 // arguments have ABI-prescribed offsets).
142 /// If true, the object has been zero-extended.
145 /// If true, the object has been zero-extended.
148 StackObject(uint64_t Size, unsigned Alignment, int64_t SPOffset,
149 bool IsImmutable, bool IsSpillSlot, const AllocaInst *Alloca,
150 bool IsAliased, uint8_t StackID = 0)
151 : SPOffset(SPOffset), Size(Size), Alignment(Alignment),
152 isImmutable(IsImmutable), isSpillSlot(IsSpillSlot),
153 StackID(StackID), Alloca(Alloca), isAliased(IsAliased) {}
156 /// The alignment of the stack.
157 unsigned StackAlignment;
159 /// Can the stack be realigned. This can be false if the target does not
160 /// support stack realignment, or if the user asks us not to realign the
161 /// stack. In this situation, overaligned allocas are all treated as dynamic
162 /// allocations and the target must handle them as part of DYNAMIC_STACKALLOC
163 /// lowering. All non-alloca stack objects have their alignment clamped to the
164 /// base ABI stack alignment.
165 /// FIXME: There is room for improvement in this case, in terms of
166 /// grouping overaligned allocas into a "secondary stack frame" and
167 /// then only use a single alloca to allocate this frame and only a
168 /// single virtual register to access it. Currently, without such an
169 /// optimization, each such alloca gets its own dynamic realignment.
170 bool StackRealignable;
172 /// Whether the function has the \c alignstack attribute.
175 /// The list of stack objects allocated.
176 std::vector<StackObject> Objects;
178 /// This contains the number of fixed objects contained on
179 /// the stack. Because fixed objects are stored at a negative index in the
180 /// Objects list, this is also the index to the 0th object in the list.
181 unsigned NumFixedObjects = 0;
183 /// This boolean keeps track of whether any variable
184 /// sized objects have been allocated yet.
185 bool HasVarSizedObjects = false;
187 /// This boolean keeps track of whether there is a call
188 /// to builtin \@llvm.frameaddress.
189 bool FrameAddressTaken = false;
191 /// This boolean keeps track of whether there is a call
192 /// to builtin \@llvm.returnaddress.
193 bool ReturnAddressTaken = false;
195 /// This boolean keeps track of whether there is a call
196 /// to builtin \@llvm.experimental.stackmap.
197 bool HasStackMap = false;
199 /// This boolean keeps track of whether there is a call
200 /// to builtin \@llvm.experimental.patchpoint.
201 bool HasPatchPoint = false;
203 /// The prolog/epilog code inserter calculates the final stack
204 /// offsets for all of the fixed size objects, updating the Objects list
205 /// above. It then updates StackSize to contain the number of bytes that need
206 /// to be allocated on entry to the function.
207 uint64_t StackSize = 0;
209 /// The amount that a frame offset needs to be adjusted to
210 /// have the actual offset from the stack/frame pointer. The exact usage of
211 /// this is target-dependent, but it is typically used to adjust between
212 /// SP-relative and FP-relative offsets. E.G., if objects are accessed via
213 /// SP then OffsetAdjustment is zero; if FP is used, OffsetAdjustment is set
214 /// to the distance between the initial SP and the value in FP. For many
215 /// targets, this value is only used when generating debug info (via
216 /// TargetRegisterInfo::getFrameIndexReference); when generating code, the
217 /// corresponding adjustments are performed directly.
218 int OffsetAdjustment = 0;
220 /// The prolog/epilog code inserter may process objects that require greater
221 /// alignment than the default alignment the target provides.
222 /// To handle this, MaxAlignment is set to the maximum alignment
223 /// needed by the objects on the current frame. If this is greater than the
224 /// native alignment maintained by the compiler, dynamic alignment code will
227 unsigned MaxAlignment = 0;
229 /// Set to true if this function adjusts the stack -- e.g.,
230 /// when calling another function. This is only valid during and after
231 /// prolog/epilog code insertion.
232 bool AdjustsStack = false;
234 /// Set to true if this function has any function calls.
235 bool HasCalls = false;
237 /// The frame index for the stack protector.
238 int StackProtectorIdx = -1;
240 /// The frame index for the function context. Used for SjLj exceptions.
241 int FunctionContextIdx = -1;
243 /// This contains the size of the largest call frame if the target uses frame
244 /// setup/destroy pseudo instructions (as defined in the TargetFrameInfo
245 /// class). This information is important for frame pointer elimination.
246 /// It is only valid during and after prolog/epilog code insertion.
247 unsigned MaxCallFrameSize = ~0u;
249 /// The prolog/epilog code inserter fills in this vector with each
250 /// callee saved register saved in the frame. Beyond its use by the prolog/
251 /// epilog code inserter, this data used for debug info and exception
253 std::vector<CalleeSavedInfo> CSInfo;
255 /// Has CSInfo been set yet?
256 bool CSIValid = false;
258 /// References to frame indices which are mapped
259 /// into the local frame allocation block. <FrameIdx, LocalOffset>
260 SmallVector<std::pair<int, int64_t>, 32> LocalFrameObjects;
262 /// Size of the pre-allocated local frame block.
263 int64_t LocalFrameSize = 0;
265 /// Required alignment of the local object blob, which is the strictest
266 /// alignment of any object in it.
267 unsigned LocalFrameMaxAlign = 0;
269 /// Whether the local object blob needs to be allocated together. If not,
270 /// PEI should ignore the isPreAllocated flags on the stack objects and
271 /// just allocate them normally.
272 bool UseLocalStackAllocationBlock = false;
274 /// True if the function dynamically adjusts the stack pointer through some
275 /// opaque mechanism like inline assembly or Win32 EH.
276 bool HasOpaqueSPAdjustment = false;
278 /// True if the function contains operations which will lower down to
279 /// instructions which manipulate the stack pointer.
280 bool HasCopyImplyingStackAdjustment = false;
282 /// True if the function contains a call to the llvm.vastart intrinsic.
283 bool HasVAStart = false;
285 /// True if this is a varargs function that contains a musttail call.
286 bool HasMustTailInVarArgFunc = false;
288 /// True if this function contains a tail call. If so immutable objects like
289 /// function arguments are no longer so. A tail call *can* override fixed
290 /// stack objects like arguments so we can't treat them as immutable.
291 bool HasTailCall = false;
293 /// Not null, if shrink-wrapping found a better place for the prologue.
294 MachineBasicBlock *Save = nullptr;
295 /// Not null, if shrink-wrapping found a better place for the epilogue.
296 MachineBasicBlock *Restore = nullptr;
299 explicit MachineFrameInfo(unsigned StackAlignment, bool StackRealignable,
301 : StackAlignment(StackAlignment), StackRealignable(StackRealignable),
302 ForcedRealign(ForcedRealign) {}
304 /// Return true if there are any stack objects in this function.
305 bool hasStackObjects() const { return !Objects.empty(); }
307 /// This method may be called any time after instruction
308 /// selection is complete to determine if the stack frame for this function
309 /// contains any variable sized objects.
310 bool hasVarSizedObjects() const { return HasVarSizedObjects; }
312 /// Return the index for the stack protector object.
313 int getStackProtectorIndex() const { return StackProtectorIdx; }
314 void setStackProtectorIndex(int I) { StackProtectorIdx = I; }
315 bool hasStackProtectorIndex() const { return StackProtectorIdx != -1; }
317 /// Return the index for the function context object.
318 /// This object is used for SjLj exceptions.
319 int getFunctionContextIndex() const { return FunctionContextIdx; }
320 void setFunctionContextIndex(int I) { FunctionContextIdx = I; }
322 /// This method may be called any time after instruction
323 /// selection is complete to determine if there is a call to
324 /// \@llvm.frameaddress in this function.
325 bool isFrameAddressTaken() const { return FrameAddressTaken; }
326 void setFrameAddressIsTaken(bool T) { FrameAddressTaken = T; }
328 /// This method may be called any time after
329 /// instruction selection is complete to determine if there is a call to
330 /// \@llvm.returnaddress in this function.
331 bool isReturnAddressTaken() const { return ReturnAddressTaken; }
332 void setReturnAddressIsTaken(bool s) { ReturnAddressTaken = s; }
334 /// This method may be called any time after instruction
335 /// selection is complete to determine if there is a call to builtin
336 /// \@llvm.experimental.stackmap.
337 bool hasStackMap() const { return HasStackMap; }
338 void setHasStackMap(bool s = true) { HasStackMap = s; }
340 /// This method may be called any time after instruction
341 /// selection is complete to determine if there is a call to builtin
342 /// \@llvm.experimental.patchpoint.
343 bool hasPatchPoint() const { return HasPatchPoint; }
344 void setHasPatchPoint(bool s = true) { HasPatchPoint = s; }
346 /// Return the minimum frame object index.
347 int getObjectIndexBegin() const { return -NumFixedObjects; }
349 /// Return one past the maximum frame object index.
350 int getObjectIndexEnd() const { return (int)Objects.size()-NumFixedObjects; }
352 /// Return the number of fixed objects.
353 unsigned getNumFixedObjects() const { return NumFixedObjects; }
355 /// Return the number of objects.
356 unsigned getNumObjects() const { return Objects.size(); }
358 /// Map a frame index into the local object block
359 void mapLocalFrameObject(int ObjectIndex, int64_t Offset) {
360 LocalFrameObjects.push_back(std::pair<int, int64_t>(ObjectIndex, Offset));
361 Objects[ObjectIndex + NumFixedObjects].PreAllocated = true;
364 /// Get the local offset mapping for a for an object.
365 std::pair<int, int64_t> getLocalFrameObjectMap(int i) const {
366 assert (i >= 0 && (unsigned)i < LocalFrameObjects.size() &&
367 "Invalid local object reference!");
368 return LocalFrameObjects[i];
371 /// Return the number of objects allocated into the local object block.
372 int64_t getLocalFrameObjectCount() const { return LocalFrameObjects.size(); }
374 /// Set the size of the local object blob.
375 void setLocalFrameSize(int64_t sz) { LocalFrameSize = sz; }
377 /// Get the size of the local object blob.
378 int64_t getLocalFrameSize() const { return LocalFrameSize; }
380 /// Required alignment of the local object blob,
381 /// which is the strictest alignment of any object in it.
382 void setLocalFrameMaxAlign(unsigned Align) { LocalFrameMaxAlign = Align; }
384 /// Return the required alignment of the local object blob.
385 unsigned getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; }
387 /// Get whether the local allocation blob should be allocated together or
388 /// let PEI allocate the locals in it directly.
389 bool getUseLocalStackAllocationBlock() const {
390 return UseLocalStackAllocationBlock;
393 /// setUseLocalStackAllocationBlock - Set whether the local allocation blob
394 /// should be allocated together or let PEI allocate the locals in it
396 void setUseLocalStackAllocationBlock(bool v) {
397 UseLocalStackAllocationBlock = v;
400 /// Return true if the object was pre-allocated into the local block.
401 bool isObjectPreAllocated(int ObjectIdx) const {
402 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
403 "Invalid Object Idx!");
404 return Objects[ObjectIdx+NumFixedObjects].PreAllocated;
407 /// Return the size of the specified object.
408 int64_t getObjectSize(int ObjectIdx) const {
409 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
410 "Invalid Object Idx!");
411 return Objects[ObjectIdx+NumFixedObjects].Size;
414 /// Change the size of the specified stack object.
415 void setObjectSize(int ObjectIdx, int64_t Size) {
416 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
417 "Invalid Object Idx!");
418 Objects[ObjectIdx+NumFixedObjects].Size = Size;
421 /// Return the alignment of the specified stack object.
422 unsigned getObjectAlignment(int ObjectIdx) const {
423 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
424 "Invalid Object Idx!");
425 return Objects[ObjectIdx+NumFixedObjects].Alignment;
428 /// setObjectAlignment - Change the alignment of the specified stack object.
429 void setObjectAlignment(int ObjectIdx, unsigned Align) {
430 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
431 "Invalid Object Idx!");
432 Objects[ObjectIdx+NumFixedObjects].Alignment = Align;
433 ensureMaxAlignment(Align);
436 /// Return the underlying Alloca of the specified
437 /// stack object if it exists. Returns 0 if none exists.
438 const AllocaInst* getObjectAllocation(int ObjectIdx) const {
439 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
440 "Invalid Object Idx!");
441 return Objects[ObjectIdx+NumFixedObjects].Alloca;
444 /// Return the assigned stack offset of the specified object
445 /// from the incoming stack pointer.
446 int64_t getObjectOffset(int ObjectIdx) const {
447 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
448 "Invalid Object Idx!");
449 assert(!isDeadObjectIndex(ObjectIdx) &&
450 "Getting frame offset for a dead object?");
451 return Objects[ObjectIdx+NumFixedObjects].SPOffset;
454 bool isObjectZExt(int ObjectIdx) const {
455 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
456 "Invalid Object Idx!");
457 return Objects[ObjectIdx+NumFixedObjects].isZExt;
460 void setObjectZExt(int ObjectIdx, bool IsZExt) {
461 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
462 "Invalid Object Idx!");
463 Objects[ObjectIdx+NumFixedObjects].isZExt = IsZExt;
466 bool isObjectSExt(int ObjectIdx) const {
467 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
468 "Invalid Object Idx!");
469 return Objects[ObjectIdx+NumFixedObjects].isSExt;
472 void setObjectSExt(int ObjectIdx, bool IsSExt) {
473 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
474 "Invalid Object Idx!");
475 Objects[ObjectIdx+NumFixedObjects].isSExt = IsSExt;
478 /// Set the stack frame offset of the specified object. The
479 /// offset is relative to the stack pointer on entry to the function.
480 void setObjectOffset(int ObjectIdx, int64_t SPOffset) {
481 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
482 "Invalid Object Idx!");
483 assert(!isDeadObjectIndex(ObjectIdx) &&
484 "Setting frame offset for a dead object?");
485 Objects[ObjectIdx+NumFixedObjects].SPOffset = SPOffset;
488 /// Return the number of bytes that must be allocated to hold
489 /// all of the fixed size frame objects. This is only valid after
490 /// Prolog/Epilog code insertion has finalized the stack frame layout.
491 uint64_t getStackSize() const { return StackSize; }
493 /// Set the size of the stack.
494 void setStackSize(uint64_t Size) { StackSize = Size; }
496 /// Estimate and return the size of the stack frame.
497 unsigned estimateStackSize(const MachineFunction &MF) const;
499 /// Return the correction for frame offsets.
500 int getOffsetAdjustment() const { return OffsetAdjustment; }
502 /// Set the correction for frame offsets.
503 void setOffsetAdjustment(int Adj) { OffsetAdjustment = Adj; }
505 /// Return the alignment in bytes that this function must be aligned to,
506 /// which is greater than the default stack alignment provided by the target.
507 unsigned getMaxAlignment() const { return MaxAlignment; }
509 /// Make sure the function is at least Align bytes aligned.
510 void ensureMaxAlignment(unsigned Align);
512 /// Return true if this function adjusts the stack -- e.g.,
513 /// when calling another function. This is only valid during and after
514 /// prolog/epilog code insertion.
515 bool adjustsStack() const { return AdjustsStack; }
516 void setAdjustsStack(bool V) { AdjustsStack = V; }
518 /// Return true if the current function has any function calls.
519 bool hasCalls() const { return HasCalls; }
520 void setHasCalls(bool V) { HasCalls = V; }
522 /// Returns true if the function contains opaque dynamic stack adjustments.
523 bool hasOpaqueSPAdjustment() const { return HasOpaqueSPAdjustment; }
524 void setHasOpaqueSPAdjustment(bool B) { HasOpaqueSPAdjustment = B; }
526 /// Returns true if the function contains operations which will lower down to
527 /// instructions which manipulate the stack pointer.
528 bool hasCopyImplyingStackAdjustment() const {
529 return HasCopyImplyingStackAdjustment;
531 void setHasCopyImplyingStackAdjustment(bool B) {
532 HasCopyImplyingStackAdjustment = B;
535 /// Returns true if the function calls the llvm.va_start intrinsic.
536 bool hasVAStart() const { return HasVAStart; }
537 void setHasVAStart(bool B) { HasVAStart = B; }
539 /// Returns true if the function is variadic and contains a musttail call.
540 bool hasMustTailInVarArgFunc() const { return HasMustTailInVarArgFunc; }
541 void setHasMustTailInVarArgFunc(bool B) { HasMustTailInVarArgFunc = B; }
543 /// Returns true if the function contains a tail call.
544 bool hasTailCall() const { return HasTailCall; }
545 void setHasTailCall() { HasTailCall = true; }
547 /// Computes the maximum size of a callframe and the AdjustsStack property.
548 /// This only works for targets defining
549 /// TargetInstrInfo::getCallFrameSetupOpcode(), getCallFrameDestroyOpcode(),
550 /// and getFrameSize().
551 /// This is usually computed by the prologue epilogue inserter but some
552 /// targets may call this to compute it earlier.
553 void computeMaxCallFrameSize(const MachineFunction &MF);
555 /// Return the maximum size of a call frame that must be
556 /// allocated for an outgoing function call. This is only available if
557 /// CallFrameSetup/Destroy pseudo instructions are used by the target, and
558 /// then only during or after prolog/epilog code insertion.
560 unsigned getMaxCallFrameSize() const {
561 // TODO: Enable this assert when targets are fixed.
562 //assert(isMaxCallFrameSizeComputed() && "MaxCallFrameSize not computed yet");
563 if (!isMaxCallFrameSizeComputed())
565 return MaxCallFrameSize;
567 bool isMaxCallFrameSizeComputed() const {
568 return MaxCallFrameSize != ~0u;
570 void setMaxCallFrameSize(unsigned S) { MaxCallFrameSize = S; }
572 /// Create a new object at a fixed location on the stack.
573 /// All fixed objects should be created before other objects are created for
574 /// efficiency. By default, fixed objects are not pointed to by LLVM IR
575 /// values. This returns an index with a negative value.
576 int CreateFixedObject(uint64_t Size, int64_t SPOffset, bool IsImmutable,
577 bool isAliased = false);
579 /// Create a spill slot at a fixed location on the stack.
580 /// Returns an index with a negative value.
581 int CreateFixedSpillStackObject(uint64_t Size, int64_t SPOffset,
582 bool IsImmutable = false);
584 /// Returns true if the specified index corresponds to a fixed stack object.
585 bool isFixedObjectIndex(int ObjectIdx) const {
586 return ObjectIdx < 0 && (ObjectIdx >= -(int)NumFixedObjects);
589 /// Returns true if the specified index corresponds
590 /// to an object that might be pointed to by an LLVM IR value.
591 bool isAliasedObjectIndex(int ObjectIdx) const {
592 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
593 "Invalid Object Idx!");
594 return Objects[ObjectIdx+NumFixedObjects].isAliased;
597 /// Returns true if the specified index corresponds to an immutable object.
598 bool isImmutableObjectIndex(int ObjectIdx) const {
599 // Tail calling functions can clobber their function arguments.
602 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
603 "Invalid Object Idx!");
604 return Objects[ObjectIdx+NumFixedObjects].isImmutable;
607 /// Marks the immutability of an object.
608 void setIsImmutableObjectIndex(int ObjectIdx, bool IsImmutable) {
609 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
610 "Invalid Object Idx!");
611 Objects[ObjectIdx+NumFixedObjects].isImmutable = IsImmutable;
614 /// Returns true if the specified index corresponds to a spill slot.
615 bool isSpillSlotObjectIndex(int ObjectIdx) const {
616 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
617 "Invalid Object Idx!");
618 return Objects[ObjectIdx+NumFixedObjects].isSpillSlot;
621 bool isStatepointSpillSlotObjectIndex(int ObjectIdx) const {
622 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
623 "Invalid Object Idx!");
624 return Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot;
628 uint8_t getStackID(int ObjectIdx) const {
629 return Objects[ObjectIdx+NumFixedObjects].StackID;
633 void setStackID(int ObjectIdx, uint8_t ID) {
634 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
635 "Invalid Object Idx!");
636 Objects[ObjectIdx+NumFixedObjects].StackID = ID;
639 /// Returns true if the specified index corresponds to a dead object.
640 bool isDeadObjectIndex(int ObjectIdx) const {
641 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
642 "Invalid Object Idx!");
643 return Objects[ObjectIdx+NumFixedObjects].Size == ~0ULL;
646 /// Returns true if the specified index corresponds to a variable sized
648 bool isVariableSizedObjectIndex(int ObjectIdx) const {
649 assert(unsigned(ObjectIdx + NumFixedObjects) < Objects.size() &&
650 "Invalid Object Idx!");
651 return Objects[ObjectIdx + NumFixedObjects].Size == 0;
654 void markAsStatepointSpillSlotObjectIndex(int ObjectIdx) {
655 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() &&
656 "Invalid Object Idx!");
657 Objects[ObjectIdx+NumFixedObjects].isStatepointSpillSlot = true;
658 assert(isStatepointSpillSlotObjectIndex(ObjectIdx) && "inconsistent");
661 /// Create a new statically sized stack object, returning
662 /// a nonnegative identifier to represent it.
663 int CreateStackObject(uint64_t Size, unsigned Alignment, bool isSpillSlot,
664 const AllocaInst *Alloca = nullptr, uint8_t ID = 0);
666 /// Create a new statically sized stack object that represents a spill slot,
667 /// returning a nonnegative identifier to represent it.
668 int CreateSpillStackObject(uint64_t Size, unsigned Alignment);
670 /// Remove or mark dead a statically sized stack object.
671 void RemoveStackObject(int ObjectIdx) {
673 Objects[ObjectIdx+NumFixedObjects].Size = ~0ULL;
676 /// Notify the MachineFrameInfo object that a variable sized object has been
677 /// created. This must be created whenever a variable sized object is
678 /// created, whether or not the index returned is actually used.
679 int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca);
681 /// Returns a reference to call saved info vector for the current function.
682 const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const {
685 /// \copydoc getCalleeSavedInfo()
686 std::vector<CalleeSavedInfo> &getCalleeSavedInfo() { return CSInfo; }
688 /// Used by prolog/epilog inserter to set the function's callee saved
690 void setCalleeSavedInfo(const std::vector<CalleeSavedInfo> &CSI) {
694 /// Has the callee saved info been calculated yet?
695 bool isCalleeSavedInfoValid() const { return CSIValid; }
697 void setCalleeSavedInfoValid(bool v) { CSIValid = v; }
699 MachineBasicBlock *getSavePoint() const { return Save; }
700 void setSavePoint(MachineBasicBlock *NewSave) { Save = NewSave; }
701 MachineBasicBlock *getRestorePoint() const { return Restore; }
702 void setRestorePoint(MachineBasicBlock *NewRestore) { Restore = NewRestore; }
704 /// Return a set of physical registers that are pristine.
706 /// Pristine registers hold a value that is useless to the current function,
707 /// but that must be preserved - they are callee saved registers that are not
710 /// Before the PrologueEpilogueInserter has placed the CSR spill code, this
711 /// method always returns an empty set.
712 BitVector getPristineRegs(const MachineFunction &MF) const;
714 /// Used by the MachineFunction printer to print information about
715 /// stack objects. Implemented in MachineFunction.cpp.
716 void print(const MachineFunction &MF, raw_ostream &OS) const;
718 /// dump - Print the function to stderr.
719 void dump(const MachineFunction &MF) const;
722 } // End llvm namespace