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 /// getFunction - Return the LLVM function that this machine code represents
160 const Function *getFunction() const { return Fn; }
162 /// getName - Return the name of the corresponding LLVM function.
164 StringRef getName() const;
166 /// getFunctionNumber - Return a unique ID for the current function.
168 unsigned getFunctionNumber() const { return FunctionNumber; }
170 /// getTarget - Return the target machine this machine code is compiled with
172 const TargetMachine &getTarget() const { return Target; }
174 /// getSubtarget - Return the subtarget for which this machine code is being
176 const TargetSubtargetInfo &getSubtarget() const { return *STI; }
177 void setSubtarget(const TargetSubtargetInfo *ST) { STI = ST; }
179 /// getSubtarget - This method returns a pointer to the specified type of
180 /// TargetSubtargetInfo. In debug builds, it verifies that the object being
181 /// returned is of the correct type.
182 template<typename STC> const STC &getSubtarget() const {
183 return *static_cast<const STC *>(STI);
186 /// getRegInfo - Return information about the registers currently in use.
188 MachineRegisterInfo &getRegInfo() { return *RegInfo; }
189 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
191 /// getFrameInfo - Return the frame info object for the current function.
192 /// This object contains information about objects allocated on the stack
193 /// frame of the current function in an abstract way.
195 MachineFrameInfo *getFrameInfo() { return FrameInfo; }
196 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
198 /// getJumpTableInfo - Return the jump table info object for the current
199 /// function. This object contains information about jump tables in the
200 /// current function. If the current function has no jump tables, this will
202 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
203 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
205 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
206 /// does already exist, allocate one.
207 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
210 /// getConstantPool - Return the constant pool object for the current
213 MachineConstantPool *getConstantPool() { return ConstantPool; }
214 const MachineConstantPool *getConstantPool() const { return ConstantPool; }
216 /// getAlignment - Return the alignment (log2, not bytes) of the function.
218 unsigned getAlignment() const { return Alignment; }
220 /// setAlignment - Set the alignment (log2, not bytes) of the function.
222 void setAlignment(unsigned A) { Alignment = A; }
224 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
225 void ensureAlignment(unsigned A) {
226 if (Alignment < A) Alignment = A;
229 /// exposesReturnsTwice - Returns true if the function calls setjmp or
230 /// any other similar functions with attribute "returns twice" without
231 /// having the attribute itself.
232 bool exposesReturnsTwice() const {
233 return ExposesReturnsTwice;
236 /// setCallsSetJmp - Set a flag that indicates if there's a call to
237 /// a "returns twice" function.
238 void setExposesReturnsTwice(bool B) {
239 ExposesReturnsTwice = B;
242 /// Returns true if the function contains any inline assembly.
243 bool hasInlineAsm() const {
247 /// Set a flag that indicates that the function contains inline assembly.
248 void setHasInlineAsm(bool B) {
252 /// getInfo - Keep track of various per-function pieces of information for
253 /// backends that would like to do so.
255 template<typename Ty>
258 MFInfo = Ty::template create<Ty>(Allocator, *this);
259 return static_cast<Ty*>(MFInfo);
262 template<typename Ty>
263 const Ty *getInfo() const {
264 return const_cast<MachineFunction*>(this)->getInfo<Ty>();
267 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
268 /// are inserted into the machine function. The block number for a machine
269 /// basic block can be found by using the MBB::getBlockNumber method, this
270 /// method provides the inverse mapping.
272 MachineBasicBlock *getBlockNumbered(unsigned N) const {
273 assert(N < MBBNumbering.size() && "Illegal block number");
274 assert(MBBNumbering[N] && "Block was removed from the machine function!");
275 return MBBNumbering[N];
278 /// Should we be emitting segmented stack stuff for the function
279 bool shouldSplitStack();
281 /// getNumBlockIDs - Return the number of MBB ID's allocated.
283 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
285 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
286 /// recomputes them. This guarantees that the MBB numbers are sequential,
287 /// dense, and match the ordering of the blocks within the function. If a
288 /// specific MachineBasicBlock is specified, only that block and those after
289 /// it are renumbered.
290 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);
292 /// print - Print out the MachineFunction in a format suitable for debugging
293 /// to the specified stream.
295 void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
297 /// viewCFG - This function is meant for use from the debugger. You can just
298 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
299 /// program, displaying the CFG of the current function with the code for each
300 /// basic block inside. This depends on there being a 'dot' and 'gv' program
303 void viewCFG() const;
305 /// viewCFGOnly - This function is meant for use from the debugger. It works
306 /// just like viewCFG, but it does not include the contents of basic blocks
307 /// into the nodes, just the label. If you are only interested in the CFG
308 /// this can make the graph smaller.
310 void viewCFGOnly() const;
312 /// dump - Print the current MachineFunction to cerr, useful for debugger use.
316 /// verify - Run the current MachineFunction through the machine code
317 /// verifier, useful for debugger use.
318 void verify(Pass *p = nullptr, const char *Banner = nullptr) const;
320 // Provide accessors for the MachineBasicBlock list...
321 typedef BasicBlockListType::iterator iterator;
322 typedef BasicBlockListType::const_iterator const_iterator;
323 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
324 typedef std::reverse_iterator<iterator> reverse_iterator;
326 /// addLiveIn - Add the specified physical register as a live-in value and
327 /// create a corresponding virtual register for it.
328 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
330 //===--------------------------------------------------------------------===//
331 // BasicBlock accessor functions.
333 iterator begin() { return BasicBlocks.begin(); }
334 const_iterator begin() const { return BasicBlocks.begin(); }
335 iterator end () { return BasicBlocks.end(); }
336 const_iterator end () const { return BasicBlocks.end(); }
338 reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
339 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
340 reverse_iterator rend () { return BasicBlocks.rend(); }
341 const_reverse_iterator rend () const { return BasicBlocks.rend(); }
343 unsigned size() const { return (unsigned)BasicBlocks.size();}
344 bool empty() const { return BasicBlocks.empty(); }
345 const MachineBasicBlock &front() const { return BasicBlocks.front(); }
346 MachineBasicBlock &front() { return BasicBlocks.front(); }
347 const MachineBasicBlock & back() const { return BasicBlocks.back(); }
348 MachineBasicBlock & back() { return BasicBlocks.back(); }
350 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
351 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
352 void insert(iterator MBBI, MachineBasicBlock *MBB) {
353 BasicBlocks.insert(MBBI, MBB);
355 void splice(iterator InsertPt, iterator MBBI) {
356 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
358 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
359 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
362 void remove(iterator MBBI) {
363 BasicBlocks.remove(MBBI);
365 void erase(iterator MBBI) {
366 BasicBlocks.erase(MBBI);
369 //===--------------------------------------------------------------------===//
370 // Internal functions used to automatically number MachineBasicBlocks
373 /// \brief Adds the MBB to the internal numbering. Returns the unique number
374 /// assigned to the MBB.
376 unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
377 MBBNumbering.push_back(MBB);
378 return (unsigned)MBBNumbering.size()-1;
381 /// removeFromMBBNumbering - Remove the specific machine basic block from our
382 /// tracker, this is only really to be used by the MachineBasicBlock
384 void removeFromMBBNumbering(unsigned N) {
385 assert(N < MBBNumbering.size() && "Illegal basic block #");
386 MBBNumbering[N] = nullptr;
389 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
390 /// of `new MachineInstr'.
392 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
396 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
397 /// 'Orig' instruction, identical in all ways except the instruction
398 /// has no parent, prev, or next.
400 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
402 MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
404 /// DeleteMachineInstr - Delete the given MachineInstr.
406 void DeleteMachineInstr(MachineInstr *MI);
408 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
409 /// instead of `new MachineBasicBlock'.
411 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr);
413 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
415 void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
417 /// getMachineMemOperand - Allocate a new MachineMemOperand.
418 /// MachineMemOperands are owned by the MachineFunction and need not be
419 /// explicitly deallocated.
420 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
421 unsigned f, uint64_t s,
422 unsigned base_alignment,
423 const AAMDNodes &AAInfo = AAMDNodes(),
424 const MDNode *Ranges = nullptr);
426 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
427 /// an existing one, adjusting by an offset and using the given size.
428 /// MachineMemOperands are owned by the MachineFunction and need not be
429 /// explicitly deallocated.
430 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
431 int64_t Offset, uint64_t Size);
433 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
435 /// Allocate an array of MachineOperands. This is only intended for use by
436 /// internal MachineInstr functions.
437 MachineOperand *allocateOperandArray(OperandCapacity Cap) {
438 return OperandRecycler.allocate(Cap, Allocator);
441 /// Dellocate an array of MachineOperands and recycle the memory. This is
442 /// only intended for use by internal MachineInstr functions.
443 /// Cap must be the same capacity that was used to allocate the array.
444 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
445 OperandRecycler.deallocate(Cap, Array);
448 /// \brief Allocate and initialize a register mask with @p NumRegister bits.
449 uint32_t *allocateRegisterMask(unsigned NumRegister) {
450 unsigned Size = (NumRegister + 31) / 32;
451 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
452 for (unsigned i = 0; i != Size; ++i)
457 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
458 /// pointers. This array is owned by the MachineFunction.
459 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
461 /// extractLoadMemRefs - Allocate an array and populate it with just the
462 /// load information from the given MachineMemOperand sequence.
463 std::pair<MachineInstr::mmo_iterator,
464 MachineInstr::mmo_iterator>
465 extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
466 MachineInstr::mmo_iterator End);
468 /// extractStoreMemRefs - Allocate an array and populate it with just the
469 /// store information from the given MachineMemOperand sequence.
470 std::pair<MachineInstr::mmo_iterator,
471 MachineInstr::mmo_iterator>
472 extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
473 MachineInstr::mmo_iterator End);
475 //===--------------------------------------------------------------------===//
476 // Label Manipulation.
479 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
480 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
481 /// normal 'L' label is returned.
482 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
483 bool isLinkerPrivate = false) const;
485 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
487 MCSymbol *getPICBaseSymbol() const;
490 //===--------------------------------------------------------------------===//
491 // GraphTraits specializations for function basic block graphs (CFGs)
492 //===--------------------------------------------------------------------===//
494 // Provide specializations of GraphTraits to be able to treat a
495 // machine function as a graph of machine basic blocks... these are
496 // the same as the machine basic block iterators, except that the root
497 // node is implicitly the first node of the function.
499 template <> struct GraphTraits<MachineFunction*> :
500 public GraphTraits<MachineBasicBlock*> {
501 static NodeType *getEntryNode(MachineFunction *F) {
505 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
506 typedef MachineFunction::iterator nodes_iterator;
507 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
508 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
509 static unsigned size (MachineFunction *F) { return F->size(); }
511 template <> struct GraphTraits<const MachineFunction*> :
512 public GraphTraits<const MachineBasicBlock*> {
513 static NodeType *getEntryNode(const MachineFunction *F) {
517 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
518 typedef MachineFunction::const_iterator nodes_iterator;
519 static nodes_iterator nodes_begin(const MachineFunction *F) {
522 static nodes_iterator nodes_end (const MachineFunction *F) {
525 static unsigned size (const MachineFunction *F) {
531 // Provide specializations of GraphTraits to be able to treat a function as a
532 // graph of basic blocks... and to walk it in inverse order. Inverse order for
533 // a function is considered to be when traversing the predecessor edges of a BB
534 // instead of the successor edges.
536 template <> struct GraphTraits<Inverse<MachineFunction*> > :
537 public GraphTraits<Inverse<MachineBasicBlock*> > {
538 static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
539 return &G.Graph->front();
542 template <> struct GraphTraits<Inverse<const MachineFunction*> > :
543 public GraphTraits<Inverse<const MachineBasicBlock*> > {
544 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
545 return &G.Graph->front();
549 } // End llvm namespace