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;
85 // RegInfo - Information about each register in use in the function.
86 MachineRegisterInfo *RegInfo;
88 // Used to keep track of target-specific per-machine function information for
89 // the target implementation.
90 MachineFunctionInfo *MFInfo;
92 // Keep track of objects allocated on the stack.
93 MachineFrameInfo *FrameInfo;
95 // Keep track of constants which are spilled to memory
96 MachineConstantPool *ConstantPool;
98 // Keep track of jump tables for switch instructions
99 MachineJumpTableInfo *JumpTableInfo;
101 // Function-level unique numbering for MachineBasicBlocks. When a
102 // MachineBasicBlock is inserted into a MachineFunction is it automatically
103 // numbered and this vector keeps track of the mapping from ID's to MBB's.
104 std::vector<MachineBasicBlock*> MBBNumbering;
106 // Pool-allocate MachineFunction-lifetime and IR objects.
107 BumpPtrAllocator Allocator;
109 // Allocation management for instructions in function.
110 Recycler<MachineInstr> InstructionRecycler;
112 // Allocation management for operand arrays on instructions.
113 ArrayRecycler<MachineOperand> OperandRecycler;
115 // Allocation management for basic blocks in function.
116 Recycler<MachineBasicBlock> BasicBlockRecycler;
118 // List of machine basic blocks in function
119 typedef ilist<MachineBasicBlock> BasicBlockListType;
120 BasicBlockListType BasicBlocks;
122 /// FunctionNumber - This provides a unique ID for each function emitted in
123 /// this translation unit.
125 unsigned FunctionNumber;
127 /// Alignment - The alignment of the function.
130 /// ExposesReturnsTwice - True if the function calls setjmp or related
131 /// functions with attribute "returns twice", but doesn't have
132 /// the attribute itself.
133 /// This is used to limit optimizations which cannot reason
134 /// about the control flow of such functions.
135 bool ExposesReturnsTwice;
137 /// True if the function includes any inline assembly.
140 MachineFunction(const MachineFunction &) LLVM_DELETED_FUNCTION;
141 void operator=(const MachineFunction&) LLVM_DELETED_FUNCTION;
143 MachineFunction(const Function *Fn, const TargetMachine &TM,
144 unsigned FunctionNum, MachineModuleInfo &MMI,
148 MachineModuleInfo &getMMI() const { return MMI; }
149 GCModuleInfo *getGMI() const { return GMI; }
150 MCContext &getContext() const { return Ctx; }
152 /// getFunction - Return the LLVM function that this machine code represents
154 const Function *getFunction() const { return Fn; }
156 /// getName - Return the name of the corresponding LLVM function.
158 StringRef getName() const;
160 /// getFunctionNumber - Return a unique ID for the current function.
162 unsigned getFunctionNumber() const { return FunctionNumber; }
164 /// getTarget - Return the target machine this machine code is compiled with
166 const TargetMachine &getTarget() const { return Target; }
168 /// getSubtarget - Return the subtarget for which this machine code is being
170 const TargetSubtargetInfo &getSubtarget() const { return *STI; }
171 void setSubtarget(TargetSubtargetInfo *ST) { STI = ST; }
173 /// getRegInfo - Return information about the registers currently in use.
175 MachineRegisterInfo &getRegInfo() { return *RegInfo; }
176 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
178 /// getFrameInfo - Return the frame info object for the current function.
179 /// This object contains information about objects allocated on the stack
180 /// frame of the current function in an abstract way.
182 MachineFrameInfo *getFrameInfo() { return FrameInfo; }
183 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
185 /// getJumpTableInfo - Return the jump table info object for the current
186 /// function. This object contains information about jump tables in the
187 /// current function. If the current function has no jump tables, this will
189 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
190 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
192 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
193 /// does already exist, allocate one.
194 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
197 /// getConstantPool - Return the constant pool object for the current
200 MachineConstantPool *getConstantPool() { return ConstantPool; }
201 const MachineConstantPool *getConstantPool() const { return ConstantPool; }
203 /// getAlignment - Return the alignment (log2, not bytes) of the function.
205 unsigned getAlignment() const { return Alignment; }
207 /// setAlignment - Set the alignment (log2, not bytes) of the function.
209 void setAlignment(unsigned A) { Alignment = A; }
211 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
212 void ensureAlignment(unsigned A) {
213 if (Alignment < A) Alignment = A;
216 /// exposesReturnsTwice - Returns true if the function calls setjmp or
217 /// any other similar functions with attribute "returns twice" without
218 /// having the attribute itself.
219 bool exposesReturnsTwice() const {
220 return ExposesReturnsTwice;
223 /// setCallsSetJmp - Set a flag that indicates if there's a call to
224 /// a "returns twice" function.
225 void setExposesReturnsTwice(bool B) {
226 ExposesReturnsTwice = B;
229 /// Returns true if the function contains any inline assembly.
230 bool hasInlineAsm() const {
234 /// Set a flag that indicates that the function contains inline assembly.
235 void setHasInlineAsm(bool B) {
239 /// getInfo - Keep track of various per-function pieces of information for
240 /// backends that would like to do so.
242 template<typename Ty>
245 MFInfo = new (Allocator.Allocate<Ty>()) Ty(*this);
246 return static_cast<Ty*>(MFInfo);
249 template<typename Ty>
250 const Ty *getInfo() const {
251 return const_cast<MachineFunction*>(this)->getInfo<Ty>();
254 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
255 /// are inserted into the machine function. The block number for a machine
256 /// basic block can be found by using the MBB::getBlockNumber method, this
257 /// method provides the inverse mapping.
259 MachineBasicBlock *getBlockNumbered(unsigned N) const {
260 assert(N < MBBNumbering.size() && "Illegal block number");
261 assert(MBBNumbering[N] && "Block was removed from the machine function!");
262 return MBBNumbering[N];
265 /// Should we be emitting segmented stack stuff for the function
266 bool shouldSplitStack();
268 /// getNumBlockIDs - Return the number of MBB ID's allocated.
270 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
272 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
273 /// recomputes them. This guarantees that the MBB numbers are sequential,
274 /// dense, and match the ordering of the blocks within the function. If a
275 /// specific MachineBasicBlock is specified, only that block and those after
276 /// it are renumbered.
277 void RenumberBlocks(MachineBasicBlock *MBBFrom = nullptr);
279 /// print - Print out the MachineFunction in a format suitable for debugging
280 /// to the specified stream.
282 void print(raw_ostream &OS, SlotIndexes* = nullptr) const;
284 /// viewCFG - This function is meant for use from the debugger. You can just
285 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
286 /// program, displaying the CFG of the current function with the code for each
287 /// basic block inside. This depends on there being a 'dot' and 'gv' program
290 void viewCFG() const;
292 /// viewCFGOnly - This function is meant for use from the debugger. It works
293 /// just like viewCFG, but it does not include the contents of basic blocks
294 /// into the nodes, just the label. If you are only interested in the CFG
295 /// this can make the graph smaller.
297 void viewCFGOnly() const;
299 /// dump - Print the current MachineFunction to cerr, useful for debugger use.
303 /// verify - Run the current MachineFunction through the machine code
304 /// verifier, useful for debugger use.
305 void verify(Pass *p = nullptr, const char *Banner = nullptr) const;
307 // Provide accessors for the MachineBasicBlock list...
308 typedef BasicBlockListType::iterator iterator;
309 typedef BasicBlockListType::const_iterator const_iterator;
310 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
311 typedef std::reverse_iterator<iterator> reverse_iterator;
313 /// addLiveIn - Add the specified physical register as a live-in value and
314 /// create a corresponding virtual register for it.
315 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
317 //===--------------------------------------------------------------------===//
318 // BasicBlock accessor functions.
320 iterator begin() { return BasicBlocks.begin(); }
321 const_iterator begin() const { return BasicBlocks.begin(); }
322 iterator end () { return BasicBlocks.end(); }
323 const_iterator end () const { return BasicBlocks.end(); }
325 reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
326 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
327 reverse_iterator rend () { return BasicBlocks.rend(); }
328 const_reverse_iterator rend () const { return BasicBlocks.rend(); }
330 unsigned size() const { return (unsigned)BasicBlocks.size();}
331 bool empty() const { return BasicBlocks.empty(); }
332 const MachineBasicBlock &front() const { return BasicBlocks.front(); }
333 MachineBasicBlock &front() { return BasicBlocks.front(); }
334 const MachineBasicBlock & back() const { return BasicBlocks.back(); }
335 MachineBasicBlock & back() { return BasicBlocks.back(); }
337 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
338 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
339 void insert(iterator MBBI, MachineBasicBlock *MBB) {
340 BasicBlocks.insert(MBBI, MBB);
342 void splice(iterator InsertPt, iterator MBBI) {
343 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
345 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
346 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
349 void remove(iterator MBBI) {
350 BasicBlocks.remove(MBBI);
352 void erase(iterator MBBI) {
353 BasicBlocks.erase(MBBI);
356 //===--------------------------------------------------------------------===//
357 // Internal functions used to automatically number MachineBasicBlocks
360 /// \brief Adds the MBB to the internal numbering. Returns the unique number
361 /// assigned to the MBB.
363 unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
364 MBBNumbering.push_back(MBB);
365 return (unsigned)MBBNumbering.size()-1;
368 /// removeFromMBBNumbering - Remove the specific machine basic block from our
369 /// tracker, this is only really to be used by the MachineBasicBlock
371 void removeFromMBBNumbering(unsigned N) {
372 assert(N < MBBNumbering.size() && "Illegal basic block #");
373 MBBNumbering[N] = nullptr;
376 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
377 /// of `new MachineInstr'.
379 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
383 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
384 /// 'Orig' instruction, identical in all ways except the instruction
385 /// has no parent, prev, or next.
387 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
389 MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
391 /// DeleteMachineInstr - Delete the given MachineInstr.
393 void DeleteMachineInstr(MachineInstr *MI);
395 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
396 /// instead of `new MachineBasicBlock'.
398 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = nullptr);
400 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
402 void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
404 /// getMachineMemOperand - Allocate a new MachineMemOperand.
405 /// MachineMemOperands are owned by the MachineFunction and need not be
406 /// explicitly deallocated.
407 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
408 unsigned f, uint64_t s,
409 unsigned base_alignment,
410 const AAMDNodes &AAInfo = AAMDNodes(),
411 const MDNode *Ranges = nullptr);
413 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
414 /// an existing one, adjusting by an offset and using the given size.
415 /// MachineMemOperands are owned by the MachineFunction and need not be
416 /// explicitly deallocated.
417 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
418 int64_t Offset, uint64_t Size);
420 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
422 /// Allocate an array of MachineOperands. This is only intended for use by
423 /// internal MachineInstr functions.
424 MachineOperand *allocateOperandArray(OperandCapacity Cap) {
425 return OperandRecycler.allocate(Cap, Allocator);
428 /// Dellocate an array of MachineOperands and recycle the memory. This is
429 /// only intended for use by internal MachineInstr functions.
430 /// Cap must be the same capacity that was used to allocate the array.
431 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
432 OperandRecycler.deallocate(Cap, Array);
435 /// \brief Allocate and initialize a register mask with @p NumRegister bits.
436 uint32_t *allocateRegisterMask(unsigned NumRegister) {
437 unsigned Size = (NumRegister + 31) / 32;
438 uint32_t *Mask = Allocator.Allocate<uint32_t>(Size);
439 for (unsigned i = 0; i != Size; ++i)
444 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
445 /// pointers. This array is owned by the MachineFunction.
446 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
448 /// extractLoadMemRefs - Allocate an array and populate it with just the
449 /// load information from the given MachineMemOperand sequence.
450 std::pair<MachineInstr::mmo_iterator,
451 MachineInstr::mmo_iterator>
452 extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
453 MachineInstr::mmo_iterator End);
455 /// extractStoreMemRefs - Allocate an array and populate it with just the
456 /// store information from the given MachineMemOperand sequence.
457 std::pair<MachineInstr::mmo_iterator,
458 MachineInstr::mmo_iterator>
459 extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
460 MachineInstr::mmo_iterator End);
462 //===--------------------------------------------------------------------===//
463 // Label Manipulation.
466 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
467 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
468 /// normal 'L' label is returned.
469 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
470 bool isLinkerPrivate = false) const;
472 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
474 MCSymbol *getPICBaseSymbol() const;
477 //===--------------------------------------------------------------------===//
478 // GraphTraits specializations for function basic block graphs (CFGs)
479 //===--------------------------------------------------------------------===//
481 // Provide specializations of GraphTraits to be able to treat a
482 // machine function as a graph of machine basic blocks... these are
483 // the same as the machine basic block iterators, except that the root
484 // node is implicitly the first node of the function.
486 template <> struct GraphTraits<MachineFunction*> :
487 public GraphTraits<MachineBasicBlock*> {
488 static NodeType *getEntryNode(MachineFunction *F) {
492 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
493 typedef MachineFunction::iterator nodes_iterator;
494 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
495 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
496 static unsigned size (MachineFunction *F) { return F->size(); }
498 template <> struct GraphTraits<const MachineFunction*> :
499 public GraphTraits<const MachineBasicBlock*> {
500 static NodeType *getEntryNode(const MachineFunction *F) {
504 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
505 typedef MachineFunction::const_iterator nodes_iterator;
506 static nodes_iterator nodes_begin(const MachineFunction *F) {
509 static nodes_iterator nodes_end (const MachineFunction *F) {
512 static unsigned size (const MachineFunction *F) {
518 // Provide specializations of GraphTraits to be able to treat a function as a
519 // graph of basic blocks... and to walk it in inverse order. Inverse order for
520 // a function is considered to be when traversing the predecessor edges of a BB
521 // instead of the successor edges.
523 template <> struct GraphTraits<Inverse<MachineFunction*> > :
524 public GraphTraits<Inverse<MachineBasicBlock*> > {
525 static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
526 return &G.Graph->front();
529 template <> struct GraphTraits<Inverse<const MachineFunction*> > :
530 public GraphTraits<Inverse<const MachineBasicBlock*> > {
531 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
532 return &G.Graph->front();
536 } // End llvm namespace