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();
77 class MachineFunction {
79 const TargetMachine &Target;
80 const TargetSubtargetInfo *STI;
82 MachineModuleInfo &MMI;
84 // RegInfo - Information about each register in use in the function.
85 MachineRegisterInfo *RegInfo;
87 // Used to keep track of target-specific per-machine function information for
88 // the target implementation.
89 MachineFunctionInfo *MFInfo;
91 // Keep track of objects allocated on the stack.
92 MachineFrameInfo *FrameInfo;
94 // Keep track of constants which are spilled to memory
95 MachineConstantPool *ConstantPool;
97 // Keep track of jump tables for switch instructions
98 MachineJumpTableInfo *JumpTableInfo;
100 // Function-level unique numbering for MachineBasicBlocks. When a
101 // MachineBasicBlock is inserted into a MachineFunction is it automatically
102 // numbered and this vector keeps track of the mapping from ID's to MBB's.
103 std::vector<MachineBasicBlock*> MBBNumbering;
105 // Pool-allocate MachineFunction-lifetime and IR objects.
106 BumpPtrAllocator Allocator;
108 // Allocation management for instructions in function.
109 Recycler<MachineInstr> InstructionRecycler;
111 // Allocation management for operand arrays on instructions.
112 ArrayRecycler<MachineOperand> OperandRecycler;
114 // Allocation management for basic blocks in function.
115 Recycler<MachineBasicBlock> BasicBlockRecycler;
117 // List of machine basic blocks in function
118 typedef ilist<MachineBasicBlock> BasicBlockListType;
119 BasicBlockListType BasicBlocks;
121 /// FunctionNumber - This provides a unique ID for each function emitted in
122 /// this translation unit.
124 unsigned FunctionNumber;
126 /// Alignment - The alignment of the function.
129 /// ExposesReturnsTwice - True if the function calls setjmp or related
130 /// functions with attribute "returns twice", but doesn't have
131 /// the attribute itself.
132 /// This is used to limit optimizations which cannot reason
133 /// about the control flow of such functions.
134 bool ExposesReturnsTwice;
136 /// True if the function includes any inline assembly.
139 MachineFunction(const MachineFunction &) LLVM_DELETED_FUNCTION;
140 void operator=(const MachineFunction&) LLVM_DELETED_FUNCTION;
142 MachineFunction(const Function *Fn, const TargetMachine &TM,
143 unsigned FunctionNum, MachineModuleInfo &MMI);
146 MachineModuleInfo &getMMI() const { return MMI; }
147 MCContext &getContext() const { return Ctx; }
149 /// getFunction - Return the LLVM function that this machine code represents
151 const Function *getFunction() const { return Fn; }
153 /// getName - Return the name of the corresponding LLVM function.
155 StringRef getName() const;
157 /// getFunctionNumber - Return a unique ID for the current function.
159 unsigned getFunctionNumber() const { return FunctionNumber; }
161 /// getTarget - Return the target machine this machine code is compiled with
163 const TargetMachine &getTarget() const { return Target; }
165 /// getSubtarget - Return the subtarget for which this machine code is being
167 const TargetSubtargetInfo &getSubtarget() const { return *STI; }
168 void setSubtarget(const TargetSubtargetInfo *ST) { STI = ST; }
170 /// getRegInfo - Return information about the registers currently in use.
172 MachineRegisterInfo &getRegInfo() { return *RegInfo; }
173 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
175 /// getFrameInfo - Return the frame info object for the current function.
176 /// This object contains information about objects allocated on the stack
177 /// frame of the current function in an abstract way.
179 MachineFrameInfo *getFrameInfo() { return FrameInfo; }
180 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
182 /// getJumpTableInfo - Return the jump table info object for the current
183 /// function. This object contains information about jump tables in the
184 /// current function. If the current function has no jump tables, this will
186 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
187 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
189 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
190 /// does already exist, allocate one.
191 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
194 /// getConstantPool - Return the constant pool object for the current
197 MachineConstantPool *getConstantPool() { return ConstantPool; }
198 const MachineConstantPool *getConstantPool() const { return ConstantPool; }
200 /// getAlignment - Return the alignment (log2, not bytes) of the function.
202 unsigned getAlignment() const { return Alignment; }
204 /// setAlignment - Set the alignment (log2, not bytes) of the function.
206 void setAlignment(unsigned A) { Alignment = A; }
208 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
209 void ensureAlignment(unsigned A) {
210 if (Alignment < A) Alignment = A;
213 /// exposesReturnsTwice - Returns true if the function calls setjmp or
214 /// any other similar functions with attribute "returns twice" without
215 /// having the attribute itself.
216 bool exposesReturnsTwice() const {
217 return ExposesReturnsTwice;
220 /// setCallsSetJmp - Set a flag that indicates if there's a call to
221 /// a "returns twice" function.
222 void setExposesReturnsTwice(bool B) {
223 ExposesReturnsTwice = B;
226 /// Returns true if the function contains any inline assembly.
227 bool hasInlineAsm() const {
231 /// Set a flag that indicates that the function contains inline assembly.
232 void setHasInlineAsm(bool B) {
236 /// getInfo - Keep track of various per-function pieces of information for
237 /// backends that would like to do so.
239 template<typename Ty>
242 MFInfo = new (Allocator.Allocate<Ty>()) Ty(*this);
243 return static_cast<Ty*>(MFInfo);
246 template<typename Ty>
247 const Ty *getInfo() const {
248 return const_cast<MachineFunction*>(this)->getInfo<Ty>();
251 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
252 /// are inserted into the machine function. The block number for a machine
253 /// basic block can be found by using the MBB::getBlockNumber method, this
254 /// method provides the inverse mapping.
256 MachineBasicBlock *getBlockNumbered(unsigned N) const {
257 assert(N < MBBNumbering.size() && "Illegal block number");
258 assert(MBBNumbering[N] && "Block was removed from the machine function!");
259 return MBBNumbering[N];
262 /// Should we be emitting segmented stack stuff for the function
263 bool shouldSplitStack();
265 /// getNumBlockIDs - Return the number of MBB ID's allocated.
267 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
269 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
270 /// recomputes them. This guarantees that the MBB numbers are sequential,
271 /// dense, and match the ordering of the blocks within the function. If a
272 /// specific MachineBasicBlock is specified, only that block and those after
273 /// it are renumbered.
274 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);
276 /// print - Print out the MachineFunction in a format suitable for debugging
277 /// to the specified stream.
279 void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
281 /// viewCFG - This function is meant for use from the debugger. You can just
282 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
283 /// program, displaying the CFG of the current function with the code for each
284 /// basic block inside. This depends on there being a 'dot' and 'gv' program
287 void viewCFG() const;
289 /// viewCFGOnly - This function is meant for use from the debugger. It works
290 /// just like viewCFG, but it does not include the contents of basic blocks
291 /// into the nodes, just the label. If you are only interested in the CFG
292 /// this can make the graph smaller.
294 void viewCFGOnly() const;
296 /// dump - Print the current MachineFunction to cerr, useful for debugger use.
300 /// verify - Run the current MachineFunction through the machine code
301 /// verifier, useful for debugger use.
302 void verify(Pass *p = nullptr, const char *Banner = nullptr) const;
304 // Provide accessors for the MachineBasicBlock list...
305 typedef BasicBlockListType::iterator iterator;
306 typedef BasicBlockListType::const_iterator const_iterator;
307 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
308 typedef std::reverse_iterator<iterator> reverse_iterator;
310 /// addLiveIn - Add the specified physical register as a live-in value and
311 /// create a corresponding virtual register for it.
312 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
314 //===--------------------------------------------------------------------===//
315 // BasicBlock accessor functions.
317 iterator begin() { return BasicBlocks.begin(); }
318 const_iterator begin() const { return BasicBlocks.begin(); }
319 iterator end () { return BasicBlocks.end(); }
320 const_iterator end () const { return BasicBlocks.end(); }
322 reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
323 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
324 reverse_iterator rend () { return BasicBlocks.rend(); }
325 const_reverse_iterator rend () const { return BasicBlocks.rend(); }
327 unsigned size() const { return (unsigned)BasicBlocks.size();}
328 bool empty() const { return BasicBlocks.empty(); }
329 const MachineBasicBlock &front() const { return BasicBlocks.front(); }
330 MachineBasicBlock &front() { return BasicBlocks.front(); }
331 const MachineBasicBlock & back() const { return BasicBlocks.back(); }
332 MachineBasicBlock & back() { return BasicBlocks.back(); }
334 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
335 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
336 void insert(iterator MBBI, MachineBasicBlock *MBB) {
337 BasicBlocks.insert(MBBI, MBB);
339 void splice(iterator InsertPt, iterator MBBI) {
340 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
342 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
343 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
346 void remove(iterator MBBI) {
347 BasicBlocks.remove(MBBI);
349 void erase(iterator MBBI) {
350 BasicBlocks.erase(MBBI);
353 //===--------------------------------------------------------------------===//
354 // Internal functions used to automatically number MachineBasicBlocks
357 /// \brief Adds the MBB to the internal numbering. Returns the unique number
358 /// assigned to the MBB.
360 unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
361 MBBNumbering.push_back(MBB);
362 return (unsigned)MBBNumbering.size()-1;
365 /// removeFromMBBNumbering - Remove the specific machine basic block from our
366 /// tracker, this is only really to be used by the MachineBasicBlock
368 void removeFromMBBNumbering(unsigned N) {
369 assert(N < MBBNumbering.size() && "Illegal basic block #");
370 MBBNumbering[N] = nullptr;
373 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
374 /// of `new MachineInstr'.
376 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
380 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
381 /// 'Orig' instruction, identical in all ways except the instruction
382 /// has no parent, prev, or next.
384 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
386 MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
388 /// DeleteMachineInstr - Delete the given MachineInstr.
390 void DeleteMachineInstr(MachineInstr *MI);
392 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
393 /// instead of `new MachineBasicBlock'.
395 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr);
397 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
399 void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
401 /// getMachineMemOperand - Allocate a new MachineMemOperand.
402 /// MachineMemOperands are owned by the MachineFunction and need not be
403 /// explicitly deallocated.
404 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
405 unsigned f, uint64_t s,
406 unsigned base_alignment,
407 const AAMDNodes &AAInfo = AAMDNodes(),
408 const MDNode *Ranges = nullptr);
410 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
411 /// an existing one, adjusting by an offset and using the given size.
412 /// MachineMemOperands are owned by the MachineFunction and need not be
413 /// explicitly deallocated.
414 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
415 int64_t Offset, uint64_t Size);
417 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
419 /// Allocate an array of MachineOperands. This is only intended for use by
420 /// internal MachineInstr functions.
421 MachineOperand *allocateOperandArray(OperandCapacity Cap) {
422 return OperandRecycler.allocate(Cap, Allocator);
425 /// Dellocate an array of MachineOperands and recycle the memory. This is
426 /// only intended for use by internal MachineInstr functions.
427 /// Cap must be the same capacity that was used to allocate the array.
428 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
429 OperandRecycler.deallocate(Cap, Array);
432 /// \brief Allocate and initialize a register mask with @p NumRegister bits.
433 uint32_t *allocateRegisterMask(unsigned NumRegister) {
434 unsigned Size = (NumRegister + 31) / 32;
435 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
436 for (unsigned i = 0; i != Size; ++i)
441 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
442 /// pointers. This array is owned by the MachineFunction.
443 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
445 /// extractLoadMemRefs - Allocate an array and populate it with just the
446 /// load information from the given MachineMemOperand sequence.
447 std::pair<MachineInstr::mmo_iterator,
448 MachineInstr::mmo_iterator>
449 extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
450 MachineInstr::mmo_iterator End);
452 /// extractStoreMemRefs - Allocate an array and populate it with just the
453 /// store information from the given MachineMemOperand sequence.
454 std::pair<MachineInstr::mmo_iterator,
455 MachineInstr::mmo_iterator>
456 extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
457 MachineInstr::mmo_iterator End);
459 //===--------------------------------------------------------------------===//
460 // Label Manipulation.
463 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
464 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
465 /// normal 'L' label is returned.
466 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
467 bool isLinkerPrivate = false) const;
469 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
471 MCSymbol *getPICBaseSymbol() const;
474 //===--------------------------------------------------------------------===//
475 // GraphTraits specializations for function basic block graphs (CFGs)
476 //===--------------------------------------------------------------------===//
478 // Provide specializations of GraphTraits to be able to treat a
479 // machine function as a graph of machine basic blocks... these are
480 // the same as the machine basic block iterators, except that the root
481 // node is implicitly the first node of the function.
483 template <> struct GraphTraits<MachineFunction*> :
484 public GraphTraits<MachineBasicBlock*> {
485 static NodeType *getEntryNode(MachineFunction *F) {
489 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
490 typedef MachineFunction::iterator nodes_iterator;
491 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
492 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
493 static unsigned size (MachineFunction *F) { return F->size(); }
495 template <> struct GraphTraits<const MachineFunction*> :
496 public GraphTraits<const MachineBasicBlock*> {
497 static NodeType *getEntryNode(const MachineFunction *F) {
501 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
502 typedef MachineFunction::const_iterator nodes_iterator;
503 static nodes_iterator nodes_begin(const MachineFunction *F) {
506 static nodes_iterator nodes_end (const MachineFunction *F) {
509 static unsigned size (const MachineFunction *F) {
515 // Provide specializations of GraphTraits to be able to treat a function as a
516 // graph of basic blocks... and to walk it in inverse order. Inverse order for
517 // a function is considered to be when traversing the predecessor edges of a BB
518 // instead of the successor edges.
520 template <> struct GraphTraits<Inverse<MachineFunction*> > :
521 public GraphTraits<Inverse<MachineBasicBlock*> > {
522 static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
523 return &G.Graph->front();
526 template <> struct GraphTraits<Inverse<const MachineFunction*> > :
527 public GraphTraits<Inverse<const MachineBasicBlock*> > {
528 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
529 return &G.Graph->front();
533 } // End llvm namespace