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 &) LLVM_DELETED_FUNCTION;
149 void operator=(const MachineFunction&) LLVM_DELETED_FUNCTION;
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 /// getRegInfo - Return information about the registers currently in use.
181 MachineRegisterInfo &getRegInfo() { return *RegInfo; }
182 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
184 /// getFrameInfo - Return the frame info object for the current function.
185 /// This object contains information about objects allocated on the stack
186 /// frame of the current function in an abstract way.
188 MachineFrameInfo *getFrameInfo() { return FrameInfo; }
189 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
191 /// getJumpTableInfo - Return the jump table info object for the current
192 /// function. This object contains information about jump tables in the
193 /// current function. If the current function has no jump tables, this will
195 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
196 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
198 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
199 /// does already exist, allocate one.
200 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
203 /// getConstantPool - Return the constant pool object for the current
206 MachineConstantPool *getConstantPool() { return ConstantPool; }
207 const MachineConstantPool *getConstantPool() const { return ConstantPool; }
209 /// getAlignment - Return the alignment (log2, not bytes) of the function.
211 unsigned getAlignment() const { return Alignment; }
213 /// setAlignment - Set the alignment (log2, not bytes) of the function.
215 void setAlignment(unsigned A) { Alignment = A; }
217 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
218 void ensureAlignment(unsigned A) {
219 if (Alignment < A) Alignment = A;
222 /// exposesReturnsTwice - Returns true if the function calls setjmp or
223 /// any other similar functions with attribute "returns twice" without
224 /// having the attribute itself.
225 bool exposesReturnsTwice() const {
226 return ExposesReturnsTwice;
229 /// setCallsSetJmp - Set a flag that indicates if there's a call to
230 /// a "returns twice" function.
231 void setExposesReturnsTwice(bool B) {
232 ExposesReturnsTwice = B;
235 /// Returns true if the function contains any inline assembly.
236 bool hasInlineAsm() const {
240 /// Set a flag that indicates that the function contains inline assembly.
241 void setHasInlineAsm(bool B) {
245 /// getInfo - Keep track of various per-function pieces of information for
246 /// backends that would like to do so.
248 template<typename Ty>
251 MFInfo = Ty::template create<Ty>(Allocator, *this);
252 return static_cast<Ty*>(MFInfo);
255 template<typename Ty>
256 const Ty *getInfo() const {
257 return const_cast<MachineFunction*>(this)->getInfo<Ty>();
260 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
261 /// are inserted into the machine function. The block number for a machine
262 /// basic block can be found by using the MBB::getBlockNumber method, this
263 /// method provides the inverse mapping.
265 MachineBasicBlock *getBlockNumbered(unsigned N) const {
266 assert(N < MBBNumbering.size() && "Illegal block number");
267 assert(MBBNumbering[N] && "Block was removed from the machine function!");
268 return MBBNumbering[N];
271 /// Should we be emitting segmented stack stuff for the function
272 bool shouldSplitStack();
274 /// getNumBlockIDs - Return the number of MBB ID's allocated.
276 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
278 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
279 /// recomputes them. This guarantees that the MBB numbers are sequential,
280 /// dense, and match the ordering of the blocks within the function. If a
281 /// specific MachineBasicBlock is specified, only that block and those after
282 /// it are renumbered.
283 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);
285 /// print - Print out the MachineFunction in a format suitable for debugging
286 /// to the specified stream.
288 void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
290 /// viewCFG - This function is meant for use from the debugger. You can just
291 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
292 /// program, displaying the CFG of the current function with the code for each
293 /// basic block inside. This depends on there being a 'dot' and 'gv' program
296 void viewCFG() const;
298 /// viewCFGOnly - This function is meant for use from the debugger. It works
299 /// just like viewCFG, but it does not include the contents of basic blocks
300 /// into the nodes, just the label. If you are only interested in the CFG
301 /// this can make the graph smaller.
303 void viewCFGOnly() const;
305 /// dump - Print the current MachineFunction to cerr, useful for debugger use.
309 /// verify - Run the current MachineFunction through the machine code
310 /// verifier, useful for debugger use.
311 void verify(Pass *p = nullptr, const char *Banner = nullptr) const;
313 // Provide accessors for the MachineBasicBlock list...
314 typedef BasicBlockListType::iterator iterator;
315 typedef BasicBlockListType::const_iterator const_iterator;
316 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
317 typedef std::reverse_iterator<iterator> reverse_iterator;
319 /// addLiveIn - Add the specified physical register as a live-in value and
320 /// create a corresponding virtual register for it.
321 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
323 //===--------------------------------------------------------------------===//
324 // BasicBlock accessor functions.
326 iterator begin() { return BasicBlocks.begin(); }
327 const_iterator begin() const { return BasicBlocks.begin(); }
328 iterator end () { return BasicBlocks.end(); }
329 const_iterator end () const { return BasicBlocks.end(); }
331 reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
332 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
333 reverse_iterator rend () { return BasicBlocks.rend(); }
334 const_reverse_iterator rend () const { return BasicBlocks.rend(); }
336 unsigned size() const { return (unsigned)BasicBlocks.size();}
337 bool empty() const { return BasicBlocks.empty(); }
338 const MachineBasicBlock &front() const { return BasicBlocks.front(); }
339 MachineBasicBlock &front() { return BasicBlocks.front(); }
340 const MachineBasicBlock & back() const { return BasicBlocks.back(); }
341 MachineBasicBlock & back() { return BasicBlocks.back(); }
343 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
344 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
345 void insert(iterator MBBI, MachineBasicBlock *MBB) {
346 BasicBlocks.insert(MBBI, MBB);
348 void splice(iterator InsertPt, iterator MBBI) {
349 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
351 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
352 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
355 void remove(iterator MBBI) {
356 BasicBlocks.remove(MBBI);
358 void erase(iterator MBBI) {
359 BasicBlocks.erase(MBBI);
362 //===--------------------------------------------------------------------===//
363 // Internal functions used to automatically number MachineBasicBlocks
366 /// \brief Adds the MBB to the internal numbering. Returns the unique number
367 /// assigned to the MBB.
369 unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
370 MBBNumbering.push_back(MBB);
371 return (unsigned)MBBNumbering.size()-1;
374 /// removeFromMBBNumbering - Remove the specific machine basic block from our
375 /// tracker, this is only really to be used by the MachineBasicBlock
377 void removeFromMBBNumbering(unsigned N) {
378 assert(N < MBBNumbering.size() && "Illegal basic block #");
379 MBBNumbering[N] = nullptr;
382 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
383 /// of `new MachineInstr'.
385 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
389 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
390 /// 'Orig' instruction, identical in all ways except the instruction
391 /// has no parent, prev, or next.
393 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
395 MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
397 /// DeleteMachineInstr - Delete the given MachineInstr.
399 void DeleteMachineInstr(MachineInstr *MI);
401 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
402 /// instead of `new MachineBasicBlock'.
404 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr);
406 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
408 void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
410 /// getMachineMemOperand - Allocate a new MachineMemOperand.
411 /// MachineMemOperands are owned by the MachineFunction and need not be
412 /// explicitly deallocated.
413 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
414 unsigned f, uint64_t s,
415 unsigned base_alignment,
416 const AAMDNodes &AAInfo = AAMDNodes(),
417 const MDNode *Ranges = nullptr);
419 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
420 /// an existing one, adjusting by an offset and using the given size.
421 /// MachineMemOperands are owned by the MachineFunction and need not be
422 /// explicitly deallocated.
423 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
424 int64_t Offset, uint64_t Size);
426 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
428 /// Allocate an array of MachineOperands. This is only intended for use by
429 /// internal MachineInstr functions.
430 MachineOperand *allocateOperandArray(OperandCapacity Cap) {
431 return OperandRecycler.allocate(Cap, Allocator);
434 /// Dellocate an array of MachineOperands and recycle the memory. This is
435 /// only intended for use by internal MachineInstr functions.
436 /// Cap must be the same capacity that was used to allocate the array.
437 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
438 OperandRecycler.deallocate(Cap, Array);
441 /// \brief Allocate and initialize a register mask with @p NumRegister bits.
442 uint32_t *allocateRegisterMask(unsigned NumRegister) {
443 unsigned Size = (NumRegister + 31) / 32;
444 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
445 for (unsigned i = 0; i != Size; ++i)
450 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
451 /// pointers. This array is owned by the MachineFunction.
452 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
454 /// extractLoadMemRefs - Allocate an array and populate it with just the
455 /// load information from the given MachineMemOperand sequence.
456 std::pair<MachineInstr::mmo_iterator,
457 MachineInstr::mmo_iterator>
458 extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
459 MachineInstr::mmo_iterator End);
461 /// extractStoreMemRefs - Allocate an array and populate it with just the
462 /// store information from the given MachineMemOperand sequence.
463 std::pair<MachineInstr::mmo_iterator,
464 MachineInstr::mmo_iterator>
465 extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
466 MachineInstr::mmo_iterator End);
468 //===--------------------------------------------------------------------===//
469 // Label Manipulation.
472 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
473 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
474 /// normal 'L' label is returned.
475 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
476 bool isLinkerPrivate = false) const;
478 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
480 MCSymbol *getPICBaseSymbol() const;
483 //===--------------------------------------------------------------------===//
484 // GraphTraits specializations for function basic block graphs (CFGs)
485 //===--------------------------------------------------------------------===//
487 // Provide specializations of GraphTraits to be able to treat a
488 // machine function as a graph of machine basic blocks... these are
489 // the same as the machine basic block iterators, except that the root
490 // node is implicitly the first node of the function.
492 template <> struct GraphTraits<MachineFunction*> :
493 public GraphTraits<MachineBasicBlock*> {
494 static NodeType *getEntryNode(MachineFunction *F) {
498 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
499 typedef MachineFunction::iterator nodes_iterator;
500 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
501 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
502 static unsigned size (MachineFunction *F) { return F->size(); }
504 template <> struct GraphTraits<const MachineFunction*> :
505 public GraphTraits<const MachineBasicBlock*> {
506 static NodeType *getEntryNode(const MachineFunction *F) {
510 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
511 typedef MachineFunction::const_iterator nodes_iterator;
512 static nodes_iterator nodes_begin(const MachineFunction *F) {
515 static nodes_iterator nodes_end (const MachineFunction *F) {
518 static unsigned size (const MachineFunction *F) {
524 // Provide specializations of GraphTraits to be able to treat a function as a
525 // graph of basic blocks... and to walk it in inverse order. Inverse order for
526 // a function is considered to be when traversing the predecessor edges of a BB
527 // instead of the successor edges.
529 template <> struct GraphTraits<Inverse<MachineFunction*> > :
530 public GraphTraits<Inverse<MachineBasicBlock*> > {
531 static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
532 return &G.Graph->front();
535 template <> struct GraphTraits<Inverse<const MachineFunction*> > :
536 public GraphTraits<Inverse<const MachineBasicBlock*> > {
537 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
538 return &G.Graph->front();
542 } // End llvm namespace