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/Support/Allocator.h"
24 #include "llvm/Support/ArrayRecycler.h"
25 #include "llvm/Support/DebugLoc.h"
26 #include "llvm/Support/Recycler.h"
33 class MachineRegisterInfo;
34 class MachineFrameInfo;
35 class MachineConstantPool;
36 class MachineJumpTableInfo;
37 class MachineModuleInfo;
41 class TargetRegisterClass;
42 struct MachinePointerInfo;
45 struct ilist_traits<MachineBasicBlock>
46 : public ilist_default_traits<MachineBasicBlock> {
47 mutable ilist_half_node<MachineBasicBlock> Sentinel;
49 MachineBasicBlock *createSentinel() const {
50 return static_cast<MachineBasicBlock*>(&Sentinel);
52 void destroySentinel(MachineBasicBlock *) const {}
54 MachineBasicBlock *provideInitialHead() const { return createSentinel(); }
55 MachineBasicBlock *ensureHead(MachineBasicBlock*) const {
56 return createSentinel();
58 static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {}
60 void addNodeToList(MachineBasicBlock* MBB);
61 void removeNodeFromList(MachineBasicBlock* MBB);
62 void deleteNode(MachineBasicBlock *MBB);
64 void createNode(const MachineBasicBlock &);
67 /// MachineFunctionInfo - This class can be derived from and used by targets to
68 /// hold private target-specific information for each MachineFunction. Objects
69 /// of type are accessed/created with MF::getInfo and destroyed when the
70 /// MachineFunction is destroyed.
71 struct MachineFunctionInfo {
72 virtual ~MachineFunctionInfo();
75 class MachineFunction {
77 const TargetMachine &Target;
79 MachineModuleInfo &MMI;
82 // RegInfo - Information about each register in use in the function.
83 MachineRegisterInfo *RegInfo;
85 // Used to keep track of target-specific per-machine function information for
86 // the target implementation.
87 MachineFunctionInfo *MFInfo;
89 // Keep track of objects allocated on the stack.
90 MachineFrameInfo *FrameInfo;
92 // Keep track of constants which are spilled to memory
93 MachineConstantPool *ConstantPool;
95 // Keep track of jump tables for switch instructions
96 MachineJumpTableInfo *JumpTableInfo;
98 // Function-level unique numbering for MachineBasicBlocks. When a
99 // MachineBasicBlock is inserted into a MachineFunction is it automatically
100 // numbered and this vector keeps track of the mapping from ID's to MBB's.
101 std::vector<MachineBasicBlock*> MBBNumbering;
103 // Pool-allocate MachineFunction-lifetime and IR objects.
104 BumpPtrAllocator Allocator;
106 // Allocation management for instructions in function.
107 Recycler<MachineInstr> InstructionRecycler;
109 // Allocation management for operand arrays on instructions.
110 ArrayRecycler<MachineOperand> OperandRecycler;
112 // Allocation management for basic blocks in function.
113 Recycler<MachineBasicBlock> BasicBlockRecycler;
115 // List of machine basic blocks in function
116 typedef ilist<MachineBasicBlock> BasicBlockListType;
117 BasicBlockListType BasicBlocks;
119 /// FunctionNumber - This provides a unique ID for each function emitted in
120 /// this translation unit.
122 unsigned FunctionNumber;
124 /// Alignment - The alignment of the function.
127 /// ExposesReturnsTwice - True if the function calls setjmp or related
128 /// functions with attribute "returns twice", but doesn't have
129 /// the attribute itself.
130 /// This is used to limit optimizations which cannot reason
131 /// about the control flow of such functions.
132 bool ExposesReturnsTwice;
134 MachineFunction(const MachineFunction &) LLVM_DELETED_FUNCTION;
135 void operator=(const MachineFunction&) LLVM_DELETED_FUNCTION;
137 MachineFunction(const Function *Fn, const TargetMachine &TM,
138 unsigned FunctionNum, MachineModuleInfo &MMI,
142 MachineModuleInfo &getMMI() const { return MMI; }
143 GCModuleInfo *getGMI() const { return GMI; }
144 MCContext &getContext() const { return Ctx; }
146 /// getFunction - Return the LLVM function that this machine code represents
148 const Function *getFunction() const { return Fn; }
150 /// getName - Return the name of the corresponding LLVM function.
152 StringRef getName() const;
154 /// getFunctionNumber - Return a unique ID for the current function.
156 unsigned getFunctionNumber() const { return FunctionNumber; }
158 /// getTarget - Return the target machine this machine code is compiled with
160 const TargetMachine &getTarget() const { return Target; }
162 /// getRegInfo - Return information about the registers currently in use.
164 MachineRegisterInfo &getRegInfo() { return *RegInfo; }
165 const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
167 /// getFrameInfo - Return the frame info object for the current function.
168 /// This object contains information about objects allocated on the stack
169 /// frame of the current function in an abstract way.
171 MachineFrameInfo *getFrameInfo() { return FrameInfo; }
172 const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
174 /// getJumpTableInfo - Return the jump table info object for the current
175 /// function. This object contains information about jump tables in the
176 /// current function. If the current function has no jump tables, this will
178 const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
179 MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
181 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
182 /// does already exist, allocate one.
183 MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
186 /// getConstantPool - Return the constant pool object for the current
189 MachineConstantPool *getConstantPool() { return ConstantPool; }
190 const MachineConstantPool *getConstantPool() const { return ConstantPool; }
192 /// getAlignment - Return the alignment (log2, not bytes) of the function.
194 unsigned getAlignment() const { return Alignment; }
196 /// setAlignment - Set the alignment (log2, not bytes) of the function.
198 void setAlignment(unsigned A) { Alignment = A; }
200 /// ensureAlignment - Make sure the function is at least 1 << A bytes aligned.
201 void ensureAlignment(unsigned A) {
202 if (Alignment < A) Alignment = A;
205 /// exposesReturnsTwice - Returns true if the function calls setjmp or
206 /// any other similar functions with attribute "returns twice" without
207 /// having the attribute itself.
208 bool exposesReturnsTwice() const {
209 return ExposesReturnsTwice;
212 /// setCallsSetJmp - Set a flag that indicates if there's a call to
213 /// a "returns twice" function.
214 void setExposesReturnsTwice(bool B) {
215 ExposesReturnsTwice = B;
218 /// getInfo - Keep track of various per-function pieces of information for
219 /// backends that would like to do so.
221 template<typename Ty>
224 // This should be just `new (Allocator.Allocate<Ty>()) Ty(*this)', but
225 // that apparently breaks GCC 3.3.
226 Ty *Loc = static_cast<Ty*>(Allocator.Allocate(sizeof(Ty),
227 AlignOf<Ty>::Alignment));
228 MFInfo = new (Loc) Ty(*this);
230 return static_cast<Ty*>(MFInfo);
233 template<typename Ty>
234 const Ty *getInfo() const {
235 return const_cast<MachineFunction*>(this)->getInfo<Ty>();
238 /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
239 /// are inserted into the machine function. The block number for a machine
240 /// basic block can be found by using the MBB::getBlockNumber method, this
241 /// method provides the inverse mapping.
243 MachineBasicBlock *getBlockNumbered(unsigned N) const {
244 assert(N < MBBNumbering.size() && "Illegal block number");
245 assert(MBBNumbering[N] && "Block was removed from the machine function!");
246 return MBBNumbering[N];
249 /// getNumBlockIDs - Return the number of MBB ID's allocated.
251 unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
253 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
254 /// recomputes them. This guarantees that the MBB numbers are sequential,
255 /// dense, and match the ordering of the blocks within the function. If a
256 /// specific MachineBasicBlock is specified, only that block and those after
257 /// it are renumbered.
258 void RenumberBlocks(MachineBasicBlock *MBBFrom = 0);
260 /// print - Print out the MachineFunction in a format suitable for debugging
261 /// to the specified stream.
263 void print(raw_ostream &OS, SlotIndexes* = 0) const;
265 /// viewCFG - This function is meant for use from the debugger. You can just
266 /// say 'call F->viewCFG()' and a ghostview window should pop up from the
267 /// program, displaying the CFG of the current function with the code for each
268 /// basic block inside. This depends on there being a 'dot' and 'gv' program
271 void viewCFG() const;
273 /// viewCFGOnly - This function is meant for use from the debugger. It works
274 /// just like viewCFG, but it does not include the contents of basic blocks
275 /// into the nodes, just the label. If you are only interested in the CFG
276 /// this can make the graph smaller.
278 void viewCFGOnly() const;
280 /// dump - Print the current MachineFunction to cerr, useful for debugger use.
284 /// verify - Run the current MachineFunction through the machine code
285 /// verifier, useful for debugger use.
286 void verify(Pass *p = NULL, const char *Banner = NULL) const;
288 // Provide accessors for the MachineBasicBlock list...
289 typedef BasicBlockListType::iterator iterator;
290 typedef BasicBlockListType::const_iterator const_iterator;
291 typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
292 typedef std::reverse_iterator<iterator> reverse_iterator;
294 /// addLiveIn - Add the specified physical register as a live-in value and
295 /// create a corresponding virtual register for it.
296 unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
298 //===--------------------------------------------------------------------===//
299 // BasicBlock accessor functions.
301 iterator begin() { return BasicBlocks.begin(); }
302 const_iterator begin() const { return BasicBlocks.begin(); }
303 iterator end () { return BasicBlocks.end(); }
304 const_iterator end () const { return BasicBlocks.end(); }
306 reverse_iterator rbegin() { return BasicBlocks.rbegin(); }
307 const_reverse_iterator rbegin() const { return BasicBlocks.rbegin(); }
308 reverse_iterator rend () { return BasicBlocks.rend(); }
309 const_reverse_iterator rend () const { return BasicBlocks.rend(); }
311 unsigned size() const { return (unsigned)BasicBlocks.size();}
312 bool empty() const { return BasicBlocks.empty(); }
313 const MachineBasicBlock &front() const { return BasicBlocks.front(); }
314 MachineBasicBlock &front() { return BasicBlocks.front(); }
315 const MachineBasicBlock & back() const { return BasicBlocks.back(); }
316 MachineBasicBlock & back() { return BasicBlocks.back(); }
318 void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
319 void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
320 void insert(iterator MBBI, MachineBasicBlock *MBB) {
321 BasicBlocks.insert(MBBI, MBB);
323 void splice(iterator InsertPt, iterator MBBI) {
324 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
326 void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
327 BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
330 void remove(iterator MBBI) {
331 BasicBlocks.remove(MBBI);
333 void erase(iterator MBBI) {
334 BasicBlocks.erase(MBBI);
337 //===--------------------------------------------------------------------===//
338 // Internal functions used to automatically number MachineBasicBlocks
341 /// getNextMBBNumber - Returns the next unique number to be assigned
342 /// to a MachineBasicBlock in this MachineFunction.
344 unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
345 MBBNumbering.push_back(MBB);
346 return (unsigned)MBBNumbering.size()-1;
349 /// removeFromMBBNumbering - Remove the specific machine basic block from our
350 /// tracker, this is only really to be used by the MachineBasicBlock
352 void removeFromMBBNumbering(unsigned N) {
353 assert(N < MBBNumbering.size() && "Illegal basic block #");
357 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
358 /// of `new MachineInstr'.
360 MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
364 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
365 /// 'Orig' instruction, identical in all ways except the instruction
366 /// has no parent, prev, or next.
368 /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
370 MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
372 /// DeleteMachineInstr - Delete the given MachineInstr.
374 void DeleteMachineInstr(MachineInstr *MI);
376 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
377 /// instead of `new MachineBasicBlock'.
379 MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = 0);
381 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
383 void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
385 /// getMachineMemOperand - Allocate a new MachineMemOperand.
386 /// MachineMemOperands are owned by the MachineFunction and need not be
387 /// explicitly deallocated.
388 MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
389 unsigned f, uint64_t s,
390 unsigned base_alignment,
391 const MDNode *TBAAInfo = 0,
392 const MDNode *Ranges = 0);
394 /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
395 /// an existing one, adjusting by an offset and using the given size.
396 /// MachineMemOperands are owned by the MachineFunction and need not be
397 /// explicitly deallocated.
398 MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
399 int64_t Offset, uint64_t Size);
401 typedef ArrayRecycler<MachineOperand>::Capacity OperandCapacity;
403 /// Allocate an array of MachineOperands. This is only intended for use by
404 /// internal MachineInstr functions.
405 MachineOperand *allocateOperandArray(OperandCapacity Cap) {
406 return OperandRecycler.allocate(Cap, Allocator);
409 /// Dellocate an array of MachineOperands and recycle the memory. This is
410 /// only intended for use by internal MachineInstr functions.
411 /// Cap must be the same capacity that was used to allocate the array.
412 void deallocateOperandArray(OperandCapacity Cap, MachineOperand *Array) {
413 OperandRecycler.deallocate(Cap, Array);
416 /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
417 /// pointers. This array is owned by the MachineFunction.
418 MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
420 /// extractLoadMemRefs - Allocate an array and populate it with just the
421 /// load information from the given MachineMemOperand sequence.
422 std::pair<MachineInstr::mmo_iterator,
423 MachineInstr::mmo_iterator>
424 extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
425 MachineInstr::mmo_iterator End);
427 /// extractStoreMemRefs - Allocate an array and populate it with just the
428 /// store information from the given MachineMemOperand sequence.
429 std::pair<MachineInstr::mmo_iterator,
430 MachineInstr::mmo_iterator>
431 extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
432 MachineInstr::mmo_iterator End);
434 //===--------------------------------------------------------------------===//
435 // Label Manipulation.
438 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
439 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
440 /// normal 'L' label is returned.
441 MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
442 bool isLinkerPrivate = false) const;
444 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
446 MCSymbol *getPICBaseSymbol() const;
449 //===--------------------------------------------------------------------===//
450 // GraphTraits specializations for function basic block graphs (CFGs)
451 //===--------------------------------------------------------------------===//
453 // Provide specializations of GraphTraits to be able to treat a
454 // machine function as a graph of machine basic blocks... these are
455 // the same as the machine basic block iterators, except that the root
456 // node is implicitly the first node of the function.
458 template <> struct GraphTraits<MachineFunction*> :
459 public GraphTraits<MachineBasicBlock*> {
460 static NodeType *getEntryNode(MachineFunction *F) {
464 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
465 typedef MachineFunction::iterator nodes_iterator;
466 static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
467 static nodes_iterator nodes_end (MachineFunction *F) { return F->end(); }
468 static unsigned size (MachineFunction *F) { return F->size(); }
470 template <> struct GraphTraits<const MachineFunction*> :
471 public GraphTraits<const MachineBasicBlock*> {
472 static NodeType *getEntryNode(const MachineFunction *F) {
476 // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
477 typedef MachineFunction::const_iterator nodes_iterator;
478 static nodes_iterator nodes_begin(const MachineFunction *F) {
481 static nodes_iterator nodes_end (const MachineFunction *F) {
484 static unsigned size (const MachineFunction *F) {
490 // Provide specializations of GraphTraits to be able to treat a function as a
491 // graph of basic blocks... and to walk it in inverse order. Inverse order for
492 // a function is considered to be when traversing the predecessor edges of a BB
493 // instead of the successor edges.
495 template <> struct GraphTraits<Inverse<MachineFunction*> > :
496 public GraphTraits<Inverse<MachineBasicBlock*> > {
497 static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
498 return &G.Graph->front();
501 template <> struct GraphTraits<Inverse<const MachineFunction*> > :
502 public GraphTraits<Inverse<const MachineBasicBlock*> > {
503 static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
504 return &G.Graph->front();
508 } // End llvm namespace