1 //===-- llvm/CodeGen/MachineFunction.h --------------------------*- 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 // Collect native machine code for a function. This class contains a list of
11 // MachineBasicBlock instances that make up the current compiled function.
13 // This class also contains pointers to various classes which hold
14 // target-specific information about the generated code.
16 //===----------------------------------------------------------------------===//
18 #ifndef LLVM_CODEGEN_MACHINEFUNCTION_H
19 #define LLVM_CODEGEN_MACHINEFUNCTION_H
21 #include "llvm/ADT/ilist.h"
22 #include "llvm/CodeGen/MachineBasicBlock.h"
23 #include "llvm/IR/DebugLoc.h"
24 #include "llvm/IR/Metadata.h"
25 #include "llvm/Support/Allocator.h"
26 #include "llvm/Support/ArrayRecycler.h"
27 #include "llvm/Support/Recycler.h"
34 class MachineRegisterInfo;
35 class MachineFrameInfo;
36 class MachineConstantPool;
37 class MachineJumpTableInfo;
38 class MachineModuleInfo;
42 class TargetSubtargetInfo;
43 class TargetRegisterClass;
44 struct MachinePointerInfo;
47 struct ilist_traits<MachineBasicBlock>
48 : public ilist_default_traits<MachineBasicBlock> {
49 mutable ilist_half_node<MachineBasicBlock> Sentinel;
51 MachineBasicBlock *createSentinel() const {
52 return static_cast<MachineBasicBlock*>(&Sentinel);
54 void destroySentinel(MachineBasicBlock *) const {}
56 MachineBasicBlock *provideInitialHead() const { return createSentinel(); }
57 MachineBasicBlock *ensureHead(MachineBasicBlock*) const {
58 return createSentinel();
60 static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {}
62 void addNodeToList(MachineBasicBlock* MBB);
63 void removeNodeFromList(MachineBasicBlock* MBB);
64 void deleteNode(MachineBasicBlock *MBB);
66 void createNode(const MachineBasicBlock &);
69 /// MachineFunctionInfo - This class can be derived from and used by targets to
70 /// hold private target-specific information for each MachineFunction. Objects
71 /// of type are accessed/created with MF::getInfo and destroyed when the
72 /// MachineFunction is destroyed.
73 struct MachineFunctionInfo {
74 virtual ~MachineFunctionInfo();
76 /// \brief Factory function: default behavior is to call new using the
77 /// supplied allocator.
79 /// This function can be overridden in a derive class.
81 static Ty *create(BumpPtrAllocator &Allocator, MachineFunction &MF) {
82 return new (Allocator.Allocate<Ty>()) Ty(MF);
86 class MachineFunction {
88 const TargetMachine &Target;
89 const TargetSubtargetInfo *STI;
91 MachineModuleInfo &MMI;
93 // RegInfo - Information about each register in use in the function.
94 MachineRegisterInfo *RegInfo;
96 // Used to keep track of target-specific per-machine function information for
97 // the target implementation.
98 MachineFunctionInfo *MFInfo;
100 // Keep track of objects allocated on the stack.
101 MachineFrameInfo *FrameInfo;
103 // Keep track of constants which are spilled to memory
104 MachineConstantPool *ConstantPool;
106 // Keep track of jump tables for switch instructions
107 MachineJumpTableInfo *JumpTableInfo;
109 // Function-level unique numbering for MachineBasicBlocks. When a
110 // MachineBasicBlock is inserted into a MachineFunction is it automatically
111 // numbered and this vector keeps track of the mapping from ID's to MBB's.
112 std::vector<MachineBasicBlock*> MBBNumbering;
114 // Pool-allocate MachineFunction-lifetime and IR objects.
115 BumpPtrAllocator Allocator;
117 // Allocation management for instructions in function.
118 Recycler<MachineInstr> InstructionRecycler;
120 // Allocation management for operand arrays on instructions.
121 ArrayRecycler<MachineOperand> OperandRecycler;
123 // Allocation management for basic blocks in function.
124 Recycler<MachineBasicBlock> BasicBlockRecycler;
126 // List of machine basic blocks in function
127 typedef ilist<MachineBasicBlock> BasicBlockListType;
128 BasicBlockListType BasicBlocks;
130 /// FunctionNumber - This provides a unique ID for each function emitted in
131 /// this translation unit.
133 unsigned FunctionNumber;
135 /// Alignment - The alignment of the function.
138 /// ExposesReturnsTwice - True if the function calls setjmp or related
139 /// functions with attribute "returns twice", but doesn't have
140 /// the attribute itself.
141 /// This is used to limit optimizations which cannot reason
142 /// about the control flow of such functions.
143 bool ExposesReturnsTwice;
145 /// True if the function includes any inline assembly.
148 MachineFunction(const MachineFunction &) = delete;
149 void operator=(const MachineFunction&) = delete;
151 MachineFunction(const Function *Fn, const TargetMachine &TM,
152 unsigned FunctionNum, MachineModuleInfo &MMI);
155 MachineModuleInfo &getMMI() const { return MMI; }
156 MCContext &getContext() const { return Ctx; }
158 /// Return the DataLayout attached to the Module associated to this MF.
159 const DataLayout &getDataLayout() const;
161 /// getFunction - Return the LLVM function that this machine code represents
163 const Function *getFunction() const { return Fn; }
165 /// getName - Return the name of the corresponding LLVM function.
167 StringRef getName() const;
169 /// getFunctionNumber - Return a unique ID for the current function.
171 unsigned getFunctionNumber() const { return FunctionNumber; }
173 /// getTarget - Return the target machine this machine code is compiled with
175 const TargetMachine &getTarget() const { return Target; }
177 /// getSubtarget - Return the subtarget for which this machine code is being
179 const TargetSubtargetInfo &getSubtarget() const { return *STI; }
180 void setSubtarget(const TargetSubtargetInfo *ST) { STI = ST; }
182 /// getSubtarget - This method returns a pointer to the specified type of
183 /// TargetSubtargetInfo. In debug builds, it verifies that the object being
184 /// returned is of the correct type.
185 template<typename STC> const STC &getSubtarget() const {
186 return *static_cast<const STC *>(STI);
189 /// getRegInfo - Return information about the registers currently in use.
191 MachineRegisterInfo &getRegInfo() { return *RegInfo; }
192 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
194 /// getFrameInfo - Return the frame info object for the current function.
195 /// This object contains information about objects allocated on the stack
196 /// frame of the current function in an abstract way.
198 MachineFrameInfo *getFrameInfo() { return FrameInfo; }
199 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
201 /// getJumpTableInfo - Return the jump table info object for the current
202 /// function. This object contains information about jump tables in the
203 /// current function. If the current function has no jump tables, this will
205 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
206 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
208 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
209 /// does already exist, allocate one.
210 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
213 /// getConstantPool - Return the constant pool object for the current
216 MachineConstantPool *getConstantPool() { return ConstantPool; }
217 const MachineConstantPool *getConstantPool() const { return ConstantPool; }
219 /// getAlignment - Return the alignment (log2, not bytes) of the function.
221 unsigned getAlignment() const { return Alignment; }
223 /// setAlignment - Set the alignment (log2, not bytes) of the function.
225 void setAlignment(unsigned A) { Alignment = A; }
227 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
228 void ensureAlignment(unsigned A) {
229 if (Alignment < A) Alignment = A;
232 /// exposesReturnsTwice - Returns true if the function calls setjmp or
233 /// any other similar functions with attribute "returns twice" without
234 /// having the attribute itself.
235 bool exposesReturnsTwice() const {
236 return ExposesReturnsTwice;
239 /// setCallsSetJmp - Set a flag that indicates if there's a call to
240 /// a "returns twice" function.
241 void setExposesReturnsTwice(bool B) {
242 ExposesReturnsTwice = B;
245 /// Returns true if the function contains any inline assembly.
246 bool hasInlineAsm() const {
250 /// Set a flag that indicates that the function contains inline assembly.
251 void setHasInlineAsm(bool B) {
255 /// getInfo - Keep track of various per-function pieces of information for
256 /// backends that would like to do so.
258 template<typename Ty>
261 MFInfo = Ty::template create<Ty>(Allocator, *this);
262 return static_cast<Ty*>(MFInfo);
265 template<typename Ty>
266 const Ty *getInfo() const {
267 return const_cast<MachineFunction*>(this)->getInfo<Ty>();
270 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
271 /// are inserted into the machine function. The block number for a machine
272 /// basic block can be found by using the MBB::getBlockNumber method, this
273 /// method provides the inverse mapping.
275 MachineBasicBlock *getBlockNumbered(unsigned N) const {
276 assert(N < MBBNumbering.size() && "Illegal block number");
277 assert(MBBNumbering[N] && "Block was removed from the machine function!");
278 return MBBNumbering[N];
281 /// Should we be emitting segmented stack stuff for the function
282 bool shouldSplitStack();
284 /// getNumBlockIDs - Return the number of MBB ID's allocated.
286 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
288 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
289 /// recomputes them. This guarantees that the MBB numbers are sequential,
290 /// dense, and match the ordering of the blocks within the function. If a
291 /// specific MachineBasicBlock is specified, only that block and those after
292 /// it are renumbered.
293 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);
295 /// print - Print out the MachineFunction in a format suitable for debugging
296 /// to the specified stream.
298 void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
300 /// viewCFG - This function is meant for use from the debugger. You can just
301 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
302 /// program, displaying the CFG of the current function with the code for each
303 /// basic block inside. This depends on there being a 'dot' and 'gv' program
306 void viewCFG() const;
308 /// viewCFGOnly - This function is meant for use from the debugger. It works
309 /// just like viewCFG, but it does not include the contents of basic blocks
310 /// into the nodes, just the label. If you are only interested in the CFG
311 /// this can make the graph smaller.
313 void viewCFGOnly() const;
315 /// dump - Print the current MachineFunction to cerr, useful for debugger use.
319 /// verify - Run the current MachineFunction through the machine code
320 /// verifier, useful for debugger use.
321 void verify(Pass *p = nullptr, const char *Banner = nullptr) const;
323 // Provide accessors for the MachineBasicBlock list...
324 typedef BasicBlockListType::iterator iterator;
325 typedef BasicBlockListType::const_iterator const_iterator;
326 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
327 typedef std::reverse_iterator<iterator> reverse_iterator;
329 /// addLiveIn - Add the specified physical register as a live-in value and
330 /// create a corresponding virtual register for it.
331 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
333 //===--------------------------------------------------------------------===//
334 // BasicBlock accessor functions.
336 iterator begin() { return BasicBlocks.begin(); }
337 const_iterator begin() const { return BasicBlocks.begin(); }
338 iterator end () { return BasicBlocks.end(); }
339 const_iterator end () const { return BasicBlocks.end(); }
341 reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
342 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
343 reverse_iterator rend () { return BasicBlocks.rend(); }
344 const_reverse_iterator rend () const { return BasicBlocks.rend(); }
346 unsigned size() const { return (unsigned)BasicBlocks.size();}
347 bool empty() const { return BasicBlocks.empty(); }
348 const MachineBasicBlock &front() const { return BasicBlocks.front(); }
349 MachineBasicBlock &front() { return BasicBlocks.front(); }
350 const MachineBasicBlock & back() const { return BasicBlocks.back(); }
351 MachineBasicBlock & back() { return BasicBlocks.back(); }
353 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
354 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
355 void insert(iterator MBBI, MachineBasicBlock *MBB) {
356 BasicBlocks.insert(MBBI, MBB);
358 void splice(iterator InsertPt, iterator MBBI) {
359 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
361 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
362 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
365 void remove(iterator MBBI) {
366 BasicBlocks.remove(MBBI);
368 void erase(iterator MBBI) {
369 BasicBlocks.erase(MBBI);
372 //===--------------------------------------------------------------------===//
373 // Internal functions used to automatically number MachineBasicBlocks
376 /// \brief Adds the MBB to the internal numbering. Returns the unique number
377 /// assigned to the MBB.
379 unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
380 MBBNumbering.push_back(MBB);
381 return (unsigned)MBBNumbering.size()-1;
384 /// removeFromMBBNumbering - Remove the specific machine basic block from our
385 /// tracker, this is only really to be used by the MachineBasicBlock
387 void removeFromMBBNumbering(unsigned N) {
388 assert(N < MBBNumbering.size() && "Illegal basic block #");
389 MBBNumbering[N] = nullptr;
392 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
393 /// of `new MachineInstr'.
395 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
399 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
400 /// 'Orig' instruction, identical in all ways except the instruction
401 /// has no parent, prev, or next.
403 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
405 MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
407 /// DeleteMachineInstr - Delete the given MachineInstr.
409 void DeleteMachineInstr(MachineInstr *MI);
411 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
412 /// instead of `new MachineBasicBlock'.
414 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr);
416 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
418 void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
420 /// getMachineMemOperand - Allocate a new MachineMemOperand.
421 /// MachineMemOperands are owned by the MachineFunction and need not be
422 /// explicitly deallocated.
423 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
424 unsigned f, uint64_t s,
425 unsigned base_alignment,
426 const AAMDNodes &AAInfo = AAMDNodes(),
427 const MDNode *Ranges = nullptr);
429 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
430 /// an existing one, adjusting by an offset and using the given size.
431 /// MachineMemOperands are owned by the MachineFunction and need not be
432 /// explicitly deallocated.
433 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
434 int64_t Offset, uint64_t Size);
436 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
438 /// Allocate an array of MachineOperands. This is only intended for use by
439 /// internal MachineInstr functions.
440 MachineOperand *allocateOperandArray(OperandCapacity Cap) {
441 return OperandRecycler.allocate(Cap, Allocator);
444 /// Dellocate an array of MachineOperands and recycle the memory. This is
445 /// only intended for use by internal MachineInstr functions.
446 /// Cap must be the same capacity that was used to allocate the array.
447 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
448 OperandRecycler.deallocate(Cap, Array);
451 /// \brief Allocate and initialize a register mask with @p NumRegister bits.
452 uint32_t *allocateRegisterMask(unsigned NumRegister) {
453 unsigned Size = (NumRegister + 31) / 32;
454 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
455 for (unsigned i = 0; i != Size; ++i)
460 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
461 /// pointers. This array is owned by the MachineFunction.
462 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
464 /// extractLoadMemRefs - Allocate an array and populate it with just the
465 /// load information from the given MachineMemOperand sequence.
466 std::pair<MachineInstr::mmo_iterator,
467 MachineInstr::mmo_iterator>
468 extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
469 MachineInstr::mmo_iterator End);
471 /// extractStoreMemRefs - Allocate an array and populate it with just the
472 /// store information from the given MachineMemOperand sequence.
473 std::pair<MachineInstr::mmo_iterator,
474 MachineInstr::mmo_iterator>
475 extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
476 MachineInstr::mmo_iterator End);
478 //===--------------------------------------------------------------------===//
479 // Label Manipulation.
482 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
483 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
484 /// normal 'L' label is returned.
485 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
486 bool isLinkerPrivate = false) const;
488 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
490 MCSymbol *getPICBaseSymbol() const;
493 //===--------------------------------------------------------------------===//
494 // GraphTraits specializations for function basic block graphs (CFGs)
495 //===--------------------------------------------------------------------===//
497 // Provide specializations of GraphTraits to be able to treat a
498 // machine function as a graph of machine basic blocks... these are
499 // the same as the machine basic block iterators, except that the root
500 // node is implicitly the first node of the function.
502 template <> struct GraphTraits<MachineFunction*> :
503 public GraphTraits<MachineBasicBlock*> {
504 static NodeType *getEntryNode(MachineFunction *F) {
508 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
509 typedef MachineFunction::iterator nodes_iterator;
510 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
511 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
512 static unsigned size (MachineFunction *F) { return F->size(); }
514 template <> struct GraphTraits<const MachineFunction*> :
515 public GraphTraits<const MachineBasicBlock*> {
516 static NodeType *getEntryNode(const MachineFunction *F) {
520 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
521 typedef MachineFunction::const_iterator nodes_iterator;
522 static nodes_iterator nodes_begin(const MachineFunction *F) {
525 static nodes_iterator nodes_end (const MachineFunction *F) {
528 static unsigned size (const MachineFunction *F) {
534 // Provide specializations of GraphTraits to be able to treat a function as a
535 // graph of basic blocks... and to walk it in inverse order. Inverse order for
536 // a function is considered to be when traversing the predecessor edges of a BB
537 // instead of the successor edges.
539 template <> struct GraphTraits<Inverse<MachineFunction*> > :
540 public GraphTraits<Inverse<MachineBasicBlock*> > {
541 static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
542 return &G.Graph->front();
545 template <> struct GraphTraits<Inverse<const MachineFunction*> > :
546 public GraphTraits<Inverse<const MachineBasicBlock*> > {
547 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
548 return &G.Graph->front();
552 } // End llvm namespace