MachineFrameInfo.h revision 288943
1//===-- CodeGen/MachineFrameInfo.h - Abstract Stack Frame Rep. --*- C++ -*-===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// The file defines the MachineFrameInfo class. 11// 12//===----------------------------------------------------------------------===// 13 14#ifndef LLVM_CODEGEN_MACHINEFRAMEINFO_H 15#define LLVM_CODEGEN_MACHINEFRAMEINFO_H 16 17#include "llvm/ADT/SmallVector.h" 18#include "llvm/Support/DataTypes.h" 19#include <cassert> 20#include <vector> 21 22namespace llvm { 23class raw_ostream; 24class DataLayout; 25class TargetRegisterClass; 26class Type; 27class MachineFunction; 28class MachineBasicBlock; 29class TargetFrameLowering; 30class TargetMachine; 31class BitVector; 32class Value; 33class AllocaInst; 34 35/// The CalleeSavedInfo class tracks the information need to locate where a 36/// callee saved register is in the current frame. 37class CalleeSavedInfo { 38 unsigned Reg; 39 int FrameIdx; 40 41public: 42 explicit CalleeSavedInfo(unsigned R, int FI = 0) 43 : Reg(R), FrameIdx(FI) {} 44 45 // Accessors. 46 unsigned getReg() const { return Reg; } 47 int getFrameIdx() const { return FrameIdx; } 48 void setFrameIdx(int FI) { FrameIdx = FI; } 49}; 50 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. 56/// 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 62/// indexes. 63/// 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 72/// objects). 73/// 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 77/// the program. 78/// 79/// @brief Abstract Stack Frame Information 80class MachineFrameInfo { 81 82 // Represent a single object allocated on the stack. 83 struct StackObject { 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. 86 int64_t SPOffset; 87 88 // The size of this object on the stack. 0 means a variable sized object, 89 // ~0ULL means a dead object. 90 uint64_t Size; 91 92 // The required alignment of this stack slot. 93 unsigned Alignment; 94 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. 98 bool isImmutable; 99 100 // If true the stack object is used as spill slot. It 101 // cannot alias any other memory objects. 102 bool isSpillSlot; 103 104 /// If this stack object is originated from an Alloca instruction 105 /// this value saves the original IR allocation. Can be NULL. 106 const AllocaInst *Alloca; 107 108 // If true, the object was mapped into the local frame 109 // block and doesn't need additional handling for allocation beyond that. 110 bool PreAllocated; 111 112 // If true, an LLVM IR value might point to this object. 113 // Normally, spill slots and fixed-offset objects don't alias IR-accessible 114 // objects, but there are exceptions (on PowerPC, for example, some byval 115 // arguments have ABI-prescribed offsets). 116 bool isAliased; 117 118 StackObject(uint64_t Sz, unsigned Al, int64_t SP, bool IM, 119 bool isSS, const AllocaInst *Val, bool A) 120 : SPOffset(SP), Size(Sz), Alignment(Al), isImmutable(IM), 121 isSpillSlot(isSS), Alloca(Val), PreAllocated(false), isAliased(A) {} 122 }; 123 124 /// The alignment of the stack. 125 unsigned StackAlignment; 126 127 /// Can the stack be realigned. 128 bool StackRealignable; 129 130 /// The list of stack objects allocated. 131 std::vector<StackObject> Objects; 132 133 /// This contains the number of fixed objects contained on 134 /// the stack. Because fixed objects are stored at a negative index in the 135 /// Objects list, this is also the index to the 0th object in the list. 136 unsigned NumFixedObjects; 137 138 /// This boolean keeps track of whether any variable 139 /// sized objects have been allocated yet. 140 bool HasVarSizedObjects; 141 142 /// This boolean keeps track of whether there is a call 143 /// to builtin \@llvm.frameaddress. 144 bool FrameAddressTaken; 145 146 /// This boolean keeps track of whether there is a call 147 /// to builtin \@llvm.returnaddress. 148 bool ReturnAddressTaken; 149 150 /// This boolean keeps track of whether there is a call 151 /// to builtin \@llvm.experimental.stackmap. 152 bool HasStackMap; 153 154 /// This boolean keeps track of whether there is a call 155 /// to builtin \@llvm.experimental.patchpoint. 156 bool HasPatchPoint; 157 158 /// The prolog/epilog code inserter calculates the final stack 159 /// offsets for all of the fixed size objects, updating the Objects list 160 /// above. It then updates StackSize to contain the number of bytes that need 161 /// to be allocated on entry to the function. 162 uint64_t StackSize; 163 164 /// The amount that a frame offset needs to be adjusted to 165 /// have the actual offset from the stack/frame pointer. The exact usage of 166 /// this is target-dependent, but it is typically used to adjust between 167 /// SP-relative and FP-relative offsets. E.G., if objects are accessed via 168 /// SP then OffsetAdjustment is zero; if FP is used, OffsetAdjustment is set 169 /// to the distance between the initial SP and the value in FP. For many 170 /// targets, this value is only used when generating debug info (via 171 /// TargetRegisterInfo::getFrameIndexOffset); when generating code, the 172 /// corresponding adjustments are performed directly. 173 int OffsetAdjustment; 174 175 /// The prolog/epilog code inserter may process objects that require greater 176 /// alignment than the default alignment the target provides. 177 /// To handle this, MaxAlignment is set to the maximum alignment 178 /// needed by the objects on the current frame. If this is greater than the 179 /// native alignment maintained by the compiler, dynamic alignment code will 180 /// be needed. 181 /// 182 unsigned MaxAlignment; 183 184 /// Set to true if this function adjusts the stack -- e.g., 185 /// when calling another function. This is only valid during and after 186 /// prolog/epilog code insertion. 187 bool AdjustsStack; 188 189 /// Set to true if this function has any function calls. 190 bool HasCalls; 191 192 /// The frame index for the stack protector. 193 int StackProtectorIdx; 194 195 /// The frame index for the function context. Used for SjLj exceptions. 196 int FunctionContextIdx; 197 198 /// This contains the size of the largest call frame if the target uses frame 199 /// setup/destroy pseudo instructions (as defined in the TargetFrameInfo 200 /// class). This information is important for frame pointer elimination. 201 /// If is only valid during and after prolog/epilog code insertion. 202 unsigned MaxCallFrameSize; 203 204 /// The prolog/epilog code inserter fills in this vector with each 205 /// callee saved register saved in the frame. Beyond its use by the prolog/ 206 /// epilog code inserter, this data used for debug info and exception 207 /// handling. 208 std::vector<CalleeSavedInfo> CSInfo; 209 210 /// Has CSInfo been set yet? 211 bool CSIValid; 212 213 /// References to frame indices which are mapped 214 /// into the local frame allocation block. <FrameIdx, LocalOffset> 215 SmallVector<std::pair<int, int64_t>, 32> LocalFrameObjects; 216 217 /// Size of the pre-allocated local frame block. 218 int64_t LocalFrameSize; 219 220 /// Required alignment of the local object blob, which is the strictest 221 /// alignment of any object in it. 222 unsigned LocalFrameMaxAlign; 223 224 /// Whether the local object blob needs to be allocated together. If not, 225 /// PEI should ignore the isPreAllocated flags on the stack objects and 226 /// just allocate them normally. 227 bool UseLocalStackAllocationBlock; 228 229 /// Whether the "realign-stack" option is on. 230 bool RealignOption; 231 232 /// True if the function dynamically adjusts the stack pointer through some 233 /// opaque mechanism like inline assembly or Win32 EH. 234 bool HasOpaqueSPAdjustment; 235 236 /// True if the function contains a call to the llvm.vastart intrinsic. 237 bool HasVAStart; 238 239 /// True if this is a varargs function that contains a musttail call. 240 bool HasMustTailInVarArgFunc; 241 242 /// True if this function contains a tail call. If so immutable objects like 243 /// function arguments are no longer so. A tail call *can* override fixed 244 /// stack objects like arguments so we can't treat them as immutable. 245 bool HasTailCall; 246 247 /// Not null, if shrink-wrapping found a better place for the prologue. 248 MachineBasicBlock *Save; 249 /// Not null, if shrink-wrapping found a better place for the epilogue. 250 MachineBasicBlock *Restore; 251 252public: 253 explicit MachineFrameInfo(unsigned StackAlign, bool isStackRealign, 254 bool RealignOpt) 255 : StackAlignment(StackAlign), StackRealignable(isStackRealign), 256 RealignOption(RealignOpt) { 257 StackSize = NumFixedObjects = OffsetAdjustment = MaxAlignment = 0; 258 HasVarSizedObjects = false; 259 FrameAddressTaken = false; 260 ReturnAddressTaken = false; 261 HasStackMap = false; 262 HasPatchPoint = false; 263 AdjustsStack = false; 264 HasCalls = false; 265 StackProtectorIdx = -1; 266 FunctionContextIdx = -1; 267 MaxCallFrameSize = 0; 268 CSIValid = false; 269 LocalFrameSize = 0; 270 LocalFrameMaxAlign = 0; 271 UseLocalStackAllocationBlock = false; 272 HasOpaqueSPAdjustment = false; 273 HasVAStart = false; 274 HasMustTailInVarArgFunc = false; 275 Save = nullptr; 276 Restore = nullptr; 277 HasTailCall = false; 278 } 279 280 /// Return true if there are any stack objects in this function. 281 bool hasStackObjects() const { return !Objects.empty(); } 282 283 /// 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; } 287 288 /// Return the index for the stack protector object. 289 int getStackProtectorIndex() const { return StackProtectorIdx; } 290 void setStackProtectorIndex(int I) { StackProtectorIdx = I; } 291 292 /// Return the index for the function context object. 293 /// This object is used for SjLj exceptions. 294 int getFunctionContextIndex() const { return FunctionContextIdx; } 295 void setFunctionContextIndex(int I) { FunctionContextIdx = I; } 296 297 /// This method may be called any time after instruction 298 /// selection is complete to determine if there is a call to 299 /// \@llvm.frameaddress in this function. 300 bool isFrameAddressTaken() const { return FrameAddressTaken; } 301 void setFrameAddressIsTaken(bool T) { FrameAddressTaken = T; } 302 303 /// This method may be called any time after 304 /// instruction selection is complete to determine if there is a call to 305 /// \@llvm.returnaddress in this function. 306 bool isReturnAddressTaken() const { return ReturnAddressTaken; } 307 void setReturnAddressIsTaken(bool s) { ReturnAddressTaken = s; } 308 309 /// This method may be called any time after instruction 310 /// selection is complete to determine if there is a call to builtin 311 /// \@llvm.experimental.stackmap. 312 bool hasStackMap() const { return HasStackMap; } 313 void setHasStackMap(bool s = true) { HasStackMap = s; } 314 315 /// This method may be called any time after instruction 316 /// selection is complete to determine if there is a call to builtin 317 /// \@llvm.experimental.patchpoint. 318 bool hasPatchPoint() const { return HasPatchPoint; } 319 void setHasPatchPoint(bool s = true) { HasPatchPoint = s; } 320 321 /// Return the minimum frame object index. 322 int getObjectIndexBegin() const { return -NumFixedObjects; } 323 324 /// Return one past the maximum frame object index. 325 int getObjectIndexEnd() const { return (int)Objects.size()-NumFixedObjects; } 326 327 /// Return the number of fixed objects. 328 unsigned getNumFixedObjects() const { return NumFixedObjects; } 329 330 /// Return the number of objects. 331 unsigned getNumObjects() const { return Objects.size(); } 332 333 /// Map a frame index into the local object block 334 void mapLocalFrameObject(int ObjectIndex, int64_t Offset) { 335 LocalFrameObjects.push_back(std::pair<int, int64_t>(ObjectIndex, Offset)); 336 Objects[ObjectIndex + NumFixedObjects].PreAllocated = true; 337 } 338 339 /// Get the local offset mapping for a for an object. 340 std::pair<int, int64_t> getLocalFrameObjectMap(int i) { 341 assert (i >= 0 && (unsigned)i < LocalFrameObjects.size() && 342 "Invalid local object reference!"); 343 return LocalFrameObjects[i]; 344 } 345 346 /// Return the number of objects allocated into the local object block. 347 int64_t getLocalFrameObjectCount() { return LocalFrameObjects.size(); } 348 349 /// Set the size of the local object blob. 350 void setLocalFrameSize(int64_t sz) { LocalFrameSize = sz; } 351 352 /// Get the size of the local object blob. 353 int64_t getLocalFrameSize() const { return LocalFrameSize; } 354 355 /// Required alignment of the local object blob, 356 /// which is the strictest alignment of any object in it. 357 void setLocalFrameMaxAlign(unsigned Align) { LocalFrameMaxAlign = Align; } 358 359 /// Return the required alignment of the local object blob. 360 unsigned getLocalFrameMaxAlign() const { return LocalFrameMaxAlign; } 361 362 /// Get whether the local allocation blob should be allocated together or 363 /// let PEI allocate the locals in it directly. 364 bool getUseLocalStackAllocationBlock() {return UseLocalStackAllocationBlock;} 365 366 /// setUseLocalStackAllocationBlock - Set whether the local allocation blob 367 /// should be allocated together or let PEI allocate the locals in it 368 /// directly. 369 void setUseLocalStackAllocationBlock(bool v) { 370 UseLocalStackAllocationBlock = v; 371 } 372 373 /// Return true if the object was pre-allocated into the local block. 374 bool isObjectPreAllocated(int ObjectIdx) const { 375 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 376 "Invalid Object Idx!"); 377 return Objects[ObjectIdx+NumFixedObjects].PreAllocated; 378 } 379 380 /// Return the size of the specified object. 381 int64_t getObjectSize(int ObjectIdx) const { 382 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 383 "Invalid Object Idx!"); 384 return Objects[ObjectIdx+NumFixedObjects].Size; 385 } 386 387 /// Change the size of the specified stack object. 388 void setObjectSize(int ObjectIdx, int64_t Size) { 389 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 390 "Invalid Object Idx!"); 391 Objects[ObjectIdx+NumFixedObjects].Size = Size; 392 } 393 394 /// Return the alignment of the specified stack object. 395 unsigned getObjectAlignment(int ObjectIdx) const { 396 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 397 "Invalid Object Idx!"); 398 return Objects[ObjectIdx+NumFixedObjects].Alignment; 399 } 400 401 /// setObjectAlignment - Change the alignment of the specified stack object. 402 void setObjectAlignment(int ObjectIdx, unsigned Align) { 403 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 404 "Invalid Object Idx!"); 405 Objects[ObjectIdx+NumFixedObjects].Alignment = Align; 406 ensureMaxAlignment(Align); 407 } 408 409 /// Return the underlying Alloca of the specified 410 /// stack object if it exists. Returns 0 if none exists. 411 const AllocaInst* getObjectAllocation(int ObjectIdx) const { 412 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 413 "Invalid Object Idx!"); 414 return Objects[ObjectIdx+NumFixedObjects].Alloca; 415 } 416 417 /// Return the assigned stack offset of the specified object 418 /// from the incoming stack pointer. 419 int64_t getObjectOffset(int ObjectIdx) const { 420 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 421 "Invalid Object Idx!"); 422 assert(!isDeadObjectIndex(ObjectIdx) && 423 "Getting frame offset for a dead object?"); 424 return Objects[ObjectIdx+NumFixedObjects].SPOffset; 425 } 426 427 /// Set the stack frame offset of the specified object. The 428 /// offset is relative to the stack pointer on entry to the function. 429 void setObjectOffset(int ObjectIdx, int64_t SPOffset) { 430 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 431 "Invalid Object Idx!"); 432 assert(!isDeadObjectIndex(ObjectIdx) && 433 "Setting frame offset for a dead object?"); 434 Objects[ObjectIdx+NumFixedObjects].SPOffset = SPOffset; 435 } 436 437 /// Return the number of bytes that must be allocated to hold 438 /// all of the fixed size frame objects. This is only valid after 439 /// Prolog/Epilog code insertion has finalized the stack frame layout. 440 uint64_t getStackSize() const { return StackSize; } 441 442 /// Set the size of the stack. 443 void setStackSize(uint64_t Size) { StackSize = Size; } 444 445 /// Estimate and return the size of the stack frame. 446 unsigned estimateStackSize(const MachineFunction &MF) const; 447 448 /// Return the correction for frame offsets. 449 int getOffsetAdjustment() const { return OffsetAdjustment; } 450 451 /// Set the correction for frame offsets. 452 void setOffsetAdjustment(int Adj) { OffsetAdjustment = Adj; } 453 454 /// Return the alignment in bytes that this function must be aligned to, 455 /// which is greater than the default stack alignment provided by the target. 456 unsigned getMaxAlignment() const { return MaxAlignment; } 457 458 /// Make sure the function is at least Align bytes aligned. 459 void ensureMaxAlignment(unsigned Align); 460 461 /// Return true if this function adjusts the stack -- e.g., 462 /// when calling another function. This is only valid during and after 463 /// prolog/epilog code insertion. 464 bool adjustsStack() const { return AdjustsStack; } 465 void setAdjustsStack(bool V) { AdjustsStack = V; } 466 467 /// Return true if the current function has any function calls. 468 bool hasCalls() const { return HasCalls; } 469 void setHasCalls(bool V) { HasCalls = V; } 470 471 /// Returns true if the function contains opaque dynamic stack adjustments. 472 bool hasOpaqueSPAdjustment() const { return HasOpaqueSPAdjustment; } 473 void setHasOpaqueSPAdjustment(bool B) { HasOpaqueSPAdjustment = B; } 474 475 /// Returns true if the function calls the llvm.va_start intrinsic. 476 bool hasVAStart() const { return HasVAStart; } 477 void setHasVAStart(bool B) { HasVAStart = B; } 478 479 /// Returns true if the function is variadic and contains a musttail call. 480 bool hasMustTailInVarArgFunc() const { return HasMustTailInVarArgFunc; } 481 void setHasMustTailInVarArgFunc(bool B) { HasMustTailInVarArgFunc = B; } 482 483 /// Returns true if the function contains a tail call. 484 bool hasTailCall() const { return HasTailCall; } 485 void setHasTailCall() { HasTailCall = true; } 486 487 /// Return the maximum size of a call frame that must be 488 /// allocated for an outgoing function call. This is only available if 489 /// CallFrameSetup/Destroy pseudo instructions are used by the target, and 490 /// then only during or after prolog/epilog code insertion. 491 /// 492 unsigned getMaxCallFrameSize() const { return MaxCallFrameSize; } 493 void setMaxCallFrameSize(unsigned S) { MaxCallFrameSize = S; } 494 495 /// Create a new object at a fixed location on the stack. 496 /// All fixed objects should be created before other objects are created for 497 /// efficiency. By default, fixed objects are not pointed to by LLVM IR 498 /// values. This returns an index with a negative value. 499 int CreateFixedObject(uint64_t Size, int64_t SPOffset, bool Immutable, 500 bool isAliased = false); 501 502 /// Create a spill slot at a fixed location on the stack. 503 /// Returns an index with a negative value. 504 int CreateFixedSpillStackObject(uint64_t Size, int64_t SPOffset); 505 506 /// Returns true if the specified index corresponds to a fixed stack object. 507 bool isFixedObjectIndex(int ObjectIdx) const { 508 return ObjectIdx < 0 && (ObjectIdx >= -(int)NumFixedObjects); 509 } 510 511 /// Returns true if the specified index corresponds 512 /// to an object that might be pointed to by an LLVM IR value. 513 bool isAliasedObjectIndex(int ObjectIdx) const { 514 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 515 "Invalid Object Idx!"); 516 return Objects[ObjectIdx+NumFixedObjects].isAliased; 517 } 518 519 /// isImmutableObjectIndex - Returns true if the specified index corresponds 520 /// to an immutable object. 521 bool isImmutableObjectIndex(int ObjectIdx) const { 522 // Tail calling functions can clobber their function arguments. 523 if (HasTailCall) 524 return false; 525 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 526 "Invalid Object Idx!"); 527 return Objects[ObjectIdx+NumFixedObjects].isImmutable; 528 } 529 530 /// Returns true if the specified index corresponds to a spill slot. 531 bool isSpillSlotObjectIndex(int ObjectIdx) const { 532 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 533 "Invalid Object Idx!"); 534 return Objects[ObjectIdx+NumFixedObjects].isSpillSlot; 535 } 536 537 /// Returns true if the specified index corresponds to a dead object. 538 bool isDeadObjectIndex(int ObjectIdx) const { 539 assert(unsigned(ObjectIdx+NumFixedObjects) < Objects.size() && 540 "Invalid Object Idx!"); 541 return Objects[ObjectIdx+NumFixedObjects].Size == ~0ULL; 542 } 543 544 /// Returns true if the specified index corresponds to a variable sized 545 /// object. 546 bool isVariableSizedObjectIndex(int ObjectIdx) const { 547 assert(unsigned(ObjectIdx + NumFixedObjects) < Objects.size() && 548 "Invalid Object Idx!"); 549 return Objects[ObjectIdx + NumFixedObjects].Size == 0; 550 } 551 552 /// Create a new statically sized stack object, returning 553 /// a nonnegative identifier to represent it. 554 int CreateStackObject(uint64_t Size, unsigned Alignment, bool isSS, 555 const AllocaInst *Alloca = nullptr); 556 557 /// Create a new statically sized stack object that represents a spill slot, 558 /// returning a nonnegative identifier to represent it. 559 int CreateSpillStackObject(uint64_t Size, unsigned Alignment); 560 561 /// Remove or mark dead a statically sized stack object. 562 void RemoveStackObject(int ObjectIdx) { 563 // Mark it dead. 564 Objects[ObjectIdx+NumFixedObjects].Size = ~0ULL; 565 } 566 567 /// Notify the MachineFrameInfo object that a variable sized object has been 568 /// created. This must be created whenever a variable sized object is 569 /// created, whether or not the index returned is actually used. 570 int CreateVariableSizedObject(unsigned Alignment, const AllocaInst *Alloca); 571 572 /// Returns a reference to call saved info vector for the current function. 573 const std::vector<CalleeSavedInfo> &getCalleeSavedInfo() const { 574 return CSInfo; 575 } 576 577 /// Used by prolog/epilog inserter to set the function's callee saved 578 /// information. 579 void setCalleeSavedInfo(const std::vector<CalleeSavedInfo> &CSI) { 580 CSInfo = CSI; 581 } 582 583 /// Has the callee saved info been calculated yet? 584 bool isCalleeSavedInfoValid() const { return CSIValid; } 585 586 void setCalleeSavedInfoValid(bool v) { CSIValid = v; } 587 588 MachineBasicBlock *getSavePoint() const { return Save; } 589 void setSavePoint(MachineBasicBlock *NewSave) { Save = NewSave; } 590 MachineBasicBlock *getRestorePoint() const { return Restore; } 591 void setRestorePoint(MachineBasicBlock *NewRestore) { Restore = NewRestore; } 592 593 /// Return a set of physical registers that are pristine. 594 /// 595 /// Pristine registers hold a value that is useless to the current function, 596 /// but that must be preserved - they are callee saved registers that are not 597 /// saved. 598 /// 599 /// Before the PrologueEpilogueInserter has placed the CSR spill code, this 600 /// method always returns an empty set. 601 BitVector getPristineRegs(const MachineFunction &MF) const; 602 603 /// Used by the MachineFunction printer to print information about 604 /// stack objects. Implemented in MachineFunction.cpp. 605 void print(const MachineFunction &MF, raw_ostream &OS) const; 606 607 /// dump - Print the function to stderr. 608 void dump(const MachineFunction &MF) const; 609}; 610 611} // End llvm namespace 612 613#endif 614