1//===-- llvm/CodeGen/MachineFunction.h --------------------------*- C++ -*-===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10// Collect native machine code for a function.  This class contains a list of
11// MachineBasicBlock instances that make up the current compiled function.
12//
13// This class also contains pointers to various classes which hold
14// target-specific information about the generated code.
15//
16//===----------------------------------------------------------------------===//
17
18#ifndef LLVM_CODEGEN_MACHINEFUNCTION_H
19#define LLVM_CODEGEN_MACHINEFUNCTION_H
20
21#include "llvm/CodeGen/MachineBasicBlock.h"
22#include "llvm/ADT/ilist.h"
23#include "llvm/Support/DebugLoc.h"
24#include "llvm/Support/Allocator.h"
25#include "llvm/Support/Recycler.h"
26
27namespace llvm {
28
29class Value;
30class Function;
31class GCModuleInfo;
32class MachineRegisterInfo;
33class MachineFrameInfo;
34class MachineConstantPool;
35class MachineJumpTableInfo;
36class MachineModuleInfo;
37class MCContext;
38class Pass;
39class TargetMachine;
40class TargetRegisterClass;
41struct MachinePointerInfo;
42
43template <>
44struct ilist_traits<MachineBasicBlock>
45    : public ilist_default_traits<MachineBasicBlock> {
46  mutable ilist_half_node<MachineBasicBlock> Sentinel;
47public:
48  MachineBasicBlock *createSentinel() const {
49    return static_cast<MachineBasicBlock*>(&Sentinel);
50  }
51  void destroySentinel(MachineBasicBlock *) const {}
52
53  MachineBasicBlock *provideInitialHead() const { return createSentinel(); }
54  MachineBasicBlock *ensureHead(MachineBasicBlock*) const {
55    return createSentinel();
56  }
57  static void noteHead(MachineBasicBlock*, MachineBasicBlock*) {}
58
59  void addNodeToList(MachineBasicBlock* MBB);
60  void removeNodeFromList(MachineBasicBlock* MBB);
61  void deleteNode(MachineBasicBlock *MBB);
62private:
63  void createNode(const MachineBasicBlock &);
64};
65
66/// MachineFunctionInfo - This class can be derived from and used by targets to
67/// hold private target-specific information for each MachineFunction.  Objects
68/// of type are accessed/created with MF::getInfo and destroyed when the
69/// MachineFunction is destroyed.
70struct MachineFunctionInfo {
71  virtual ~MachineFunctionInfo();
72};
73
74class MachineFunction {
75  const Function *Fn;
76  const TargetMachine &Target;
77  MCContext &Ctx;
78  MachineModuleInfo &MMI;
79  GCModuleInfo *GMI;
80
81  // RegInfo - Information about each register in use in the function.
82  MachineRegisterInfo *RegInfo;
83
84  // Used to keep track of target-specific per-machine function information for
85  // the target implementation.
86  MachineFunctionInfo *MFInfo;
87
88  // Keep track of objects allocated on the stack.
89  MachineFrameInfo *FrameInfo;
90
91  // Keep track of constants which are spilled to memory
92  MachineConstantPool *ConstantPool;
93
94  // Keep track of jump tables for switch instructions
95  MachineJumpTableInfo *JumpTableInfo;
96
97  // Function-level unique numbering for MachineBasicBlocks.  When a
98  // MachineBasicBlock is inserted into a MachineFunction is it automatically
99  // numbered and this vector keeps track of the mapping from ID's to MBB's.
100  std::vector<MachineBasicBlock*> MBBNumbering;
101
102  // Pool-allocate MachineFunction-lifetime and IR objects.
103  BumpPtrAllocator Allocator;
104
105  // Allocation management for instructions in function.
106  Recycler<MachineInstr> InstructionRecycler;
107
108  // Allocation management for basic blocks in function.
109  Recycler<MachineBasicBlock> BasicBlockRecycler;
110
111  // List of machine basic blocks in function
112  typedef ilist<MachineBasicBlock> BasicBlockListType;
113  BasicBlockListType BasicBlocks;
114
115  /// FunctionNumber - This provides a unique ID for each function emitted in
116  /// this translation unit.
117  ///
118  unsigned FunctionNumber;
119
120  /// Alignment - The alignment of the function.
121  unsigned Alignment;
122
123  /// CallsSetJmp - True if the function calls setjmp or sigsetjmp. This is used
124  /// to limit optimizations which cannot reason about the control flow of
125  /// setjmp.
126  bool CallsSetJmp;
127
128  MachineFunction(const MachineFunction &); // DO NOT IMPLEMENT
129  void operator=(const MachineFunction&);   // DO NOT IMPLEMENT
130public:
131  MachineFunction(const Function *Fn, const TargetMachine &TM,
132                  unsigned FunctionNum, MachineModuleInfo &MMI,
133                  GCModuleInfo* GMI);
134  ~MachineFunction();
135
136  MachineModuleInfo &getMMI() const { return MMI; }
137  GCModuleInfo *getGMI() const { return GMI; }
138  MCContext &getContext() const { return Ctx; }
139
140  /// getFunction - Return the LLVM function that this machine code represents
141  ///
142  const Function *getFunction() const { return Fn; }
143
144  /// getFunctionNumber - Return a unique ID for the current function.
145  ///
146  unsigned getFunctionNumber() const { return FunctionNumber; }
147
148  /// getTarget - Return the target machine this machine code is compiled with
149  ///
150  const TargetMachine &getTarget() const { return Target; }
151
152  /// getRegInfo - Return information about the registers currently in use.
153  ///
154  MachineRegisterInfo &getRegInfo() { return *RegInfo; }
155  const MachineRegisterInfo &getRegInfo() const { return *RegInfo; }
156
157  /// getFrameInfo - Return the frame info object for the current function.
158  /// This object contains information about objects allocated on the stack
159  /// frame of the current function in an abstract way.
160  ///
161  MachineFrameInfo *getFrameInfo() { return FrameInfo; }
162  const MachineFrameInfo *getFrameInfo() const { return FrameInfo; }
163
164  /// getJumpTableInfo - Return the jump table info object for the current
165  /// function.  This object contains information about jump tables in the
166  /// current function.  If the current function has no jump tables, this will
167  /// return null.
168  const MachineJumpTableInfo *getJumpTableInfo() const { return JumpTableInfo; }
169  MachineJumpTableInfo *getJumpTableInfo() { return JumpTableInfo; }
170
171  /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
172  /// does already exist, allocate one.
173  MachineJumpTableInfo *getOrCreateJumpTableInfo(unsigned JTEntryKind);
174
175
176  /// getConstantPool - Return the constant pool object for the current
177  /// function.
178  ///
179  MachineConstantPool *getConstantPool() { return ConstantPool; }
180  const MachineConstantPool *getConstantPool() const { return ConstantPool; }
181
182  /// getAlignment - Return the alignment (log2, not bytes) of the function.
183  ///
184  unsigned getAlignment() const { return Alignment; }
185
186  /// setAlignment - Set the alignment (log2, not bytes) of the function.
187  ///
188  void setAlignment(unsigned A) { Alignment = A; }
189
190  /// EnsureAlignment - Make sure the function is at least 'A' bits aligned.
191  void EnsureAlignment(unsigned A) {
192    if (Alignment < A) Alignment = A;
193  }
194
195  /// callsSetJmp - Returns true if the function calls setjmp or sigsetjmp.
196  bool callsSetJmp() const {
197    return CallsSetJmp;
198  }
199
200  /// setCallsSetJmp - Set a flag that indicates if there's a call to setjmp or
201  /// sigsetjmp.
202  void setCallsSetJmp(bool B) {
203    CallsSetJmp = B;
204  }
205
206  /// getInfo - Keep track of various per-function pieces of information for
207  /// backends that would like to do so.
208  ///
209  template<typename Ty>
210  Ty *getInfo() {
211    if (!MFInfo) {
212        // This should be just `new (Allocator.Allocate<Ty>()) Ty(*this)', but
213        // that apparently breaks GCC 3.3.
214        Ty *Loc = static_cast<Ty*>(Allocator.Allocate(sizeof(Ty),
215                                                      AlignOf<Ty>::Alignment));
216        MFInfo = new (Loc) Ty(*this);
217    }
218    return static_cast<Ty*>(MFInfo);
219  }
220
221  template<typename Ty>
222  const Ty *getInfo() const {
223     return const_cast<MachineFunction*>(this)->getInfo<Ty>();
224  }
225
226  /// getBlockNumbered - MachineBasicBlocks are automatically numbered when they
227  /// are inserted into the machine function.  The block number for a machine
228  /// basic block can be found by using the MBB::getBlockNumber method, this
229  /// method provides the inverse mapping.
230  ///
231  MachineBasicBlock *getBlockNumbered(unsigned N) const {
232    assert(N < MBBNumbering.size() && "Illegal block number");
233    assert(MBBNumbering[N] && "Block was removed from the machine function!");
234    return MBBNumbering[N];
235  }
236
237  /// getNumBlockIDs - Return the number of MBB ID's allocated.
238  ///
239  unsigned getNumBlockIDs() const { return (unsigned)MBBNumbering.size(); }
240
241  /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
242  /// recomputes them.  This guarantees that the MBB numbers are sequential,
243  /// dense, and match the ordering of the blocks within the function.  If a
244  /// specific MachineBasicBlock is specified, only that block and those after
245  /// it are renumbered.
246  void RenumberBlocks(MachineBasicBlock *MBBFrom = 0);
247
248  /// print - Print out the MachineFunction in a format suitable for debugging
249  /// to the specified stream.
250  ///
251  void print(raw_ostream &OS, SlotIndexes* = 0) const;
252
253  /// viewCFG - This function is meant for use from the debugger.  You can just
254  /// say 'call F->viewCFG()' and a ghostview window should pop up from the
255  /// program, displaying the CFG of the current function with the code for each
256  /// basic block inside.  This depends on there being a 'dot' and 'gv' program
257  /// in your path.
258  ///
259  void viewCFG() const;
260
261  /// viewCFGOnly - This function is meant for use from the debugger.  It works
262  /// just like viewCFG, but it does not include the contents of basic blocks
263  /// into the nodes, just the label.  If you are only interested in the CFG
264  /// this can make the graph smaller.
265  ///
266  void viewCFGOnly() const;
267
268  /// dump - Print the current MachineFunction to cerr, useful for debugger use.
269  ///
270  void dump() const;
271
272  /// verify - Run the current MachineFunction through the machine code
273  /// verifier, useful for debugger use.
274  void verify(Pass *p = NULL, const char *Banner = NULL) const;
275
276  // Provide accessors for the MachineBasicBlock list...
277  typedef BasicBlockListType::iterator iterator;
278  typedef BasicBlockListType::const_iterator const_iterator;
279  typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
280  typedef std::reverse_iterator<iterator>             reverse_iterator;
281
282  /// addLiveIn - Add the specified physical register as a live-in value and
283  /// create a corresponding virtual register for it.
284  unsigned addLiveIn(unsigned PReg, const TargetRegisterClass *RC);
285
286  //===--------------------------------------------------------------------===//
287  // BasicBlock accessor functions.
288  //
289  iterator                 begin()       { return BasicBlocks.begin(); }
290  const_iterator           begin() const { return BasicBlocks.begin(); }
291  iterator                 end  ()       { return BasicBlocks.end();   }
292  const_iterator           end  () const { return BasicBlocks.end();   }
293
294  reverse_iterator        rbegin()       { return BasicBlocks.rbegin(); }
295  const_reverse_iterator  rbegin() const { return BasicBlocks.rbegin(); }
296  reverse_iterator        rend  ()       { return BasicBlocks.rend();   }
297  const_reverse_iterator  rend  () const { return BasicBlocks.rend();   }
298
299  unsigned                  size() const { return (unsigned)BasicBlocks.size();}
300  bool                     empty() const { return BasicBlocks.empty(); }
301  const MachineBasicBlock &front() const { return BasicBlocks.front(); }
302        MachineBasicBlock &front()       { return BasicBlocks.front(); }
303  const MachineBasicBlock & back() const { return BasicBlocks.back(); }
304        MachineBasicBlock & back()       { return BasicBlocks.back(); }
305
306  void push_back (MachineBasicBlock *MBB) { BasicBlocks.push_back (MBB); }
307  void push_front(MachineBasicBlock *MBB) { BasicBlocks.push_front(MBB); }
308  void insert(iterator MBBI, MachineBasicBlock *MBB) {
309    BasicBlocks.insert(MBBI, MBB);
310  }
311  void splice(iterator InsertPt, iterator MBBI) {
312    BasicBlocks.splice(InsertPt, BasicBlocks, MBBI);
313  }
314  void splice(iterator InsertPt, iterator MBBI, iterator MBBE) {
315    BasicBlocks.splice(InsertPt, BasicBlocks, MBBI, MBBE);
316  }
317
318  void remove(iterator MBBI) {
319    BasicBlocks.remove(MBBI);
320  }
321  void erase(iterator MBBI) {
322    BasicBlocks.erase(MBBI);
323  }
324
325  //===--------------------------------------------------------------------===//
326  // Internal functions used to automatically number MachineBasicBlocks
327  //
328
329  /// getNextMBBNumber - Returns the next unique number to be assigned
330  /// to a MachineBasicBlock in this MachineFunction.
331  ///
332  unsigned addToMBBNumbering(MachineBasicBlock *MBB) {
333    MBBNumbering.push_back(MBB);
334    return (unsigned)MBBNumbering.size()-1;
335  }
336
337  /// removeFromMBBNumbering - Remove the specific machine basic block from our
338  /// tracker, this is only really to be used by the MachineBasicBlock
339  /// implementation.
340  void removeFromMBBNumbering(unsigned N) {
341    assert(N < MBBNumbering.size() && "Illegal basic block #");
342    MBBNumbering[N] = 0;
343  }
344
345  /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
346  /// of `new MachineInstr'.
347  ///
348  MachineInstr *CreateMachineInstr(const MCInstrDesc &MCID,
349                                   DebugLoc DL,
350                                   bool NoImp = false);
351
352  /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
353  /// 'Orig' instruction, identical in all ways except the instruction
354  /// has no parent, prev, or next.
355  ///
356  /// See also TargetInstrInfo::duplicate() for target-specific fixes to cloned
357  /// instructions.
358  MachineInstr *CloneMachineInstr(const MachineInstr *Orig);
359
360  /// DeleteMachineInstr - Delete the given MachineInstr.
361  ///
362  void DeleteMachineInstr(MachineInstr *MI);
363
364  /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
365  /// instead of `new MachineBasicBlock'.
366  ///
367  MachineBasicBlock *CreateMachineBasicBlock(const BasicBlock *bb = 0);
368
369  /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
370  ///
371  void DeleteMachineBasicBlock(MachineBasicBlock *MBB);
372
373  /// getMachineMemOperand - Allocate a new MachineMemOperand.
374  /// MachineMemOperands are owned by the MachineFunction and need not be
375  /// explicitly deallocated.
376  MachineMemOperand *getMachineMemOperand(MachinePointerInfo PtrInfo,
377                                          unsigned f, uint64_t s,
378                                          unsigned base_alignment,
379                                          const MDNode *TBAAInfo = 0);
380
381  /// getMachineMemOperand - Allocate a new MachineMemOperand by copying
382  /// an existing one, adjusting by an offset and using the given size.
383  /// MachineMemOperands are owned by the MachineFunction and need not be
384  /// explicitly deallocated.
385  MachineMemOperand *getMachineMemOperand(const MachineMemOperand *MMO,
386                                          int64_t Offset, uint64_t Size);
387
388  /// allocateMemRefsArray - Allocate an array to hold MachineMemOperand
389  /// pointers.  This array is owned by the MachineFunction.
390  MachineInstr::mmo_iterator allocateMemRefsArray(unsigned long Num);
391
392  /// extractLoadMemRefs - Allocate an array and populate it with just the
393  /// load information from the given MachineMemOperand sequence.
394  std::pair<MachineInstr::mmo_iterator,
395            MachineInstr::mmo_iterator>
396    extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
397                       MachineInstr::mmo_iterator End);
398
399  /// extractStoreMemRefs - Allocate an array and populate it with just the
400  /// store information from the given MachineMemOperand sequence.
401  std::pair<MachineInstr::mmo_iterator,
402            MachineInstr::mmo_iterator>
403    extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
404                        MachineInstr::mmo_iterator End);
405
406  //===--------------------------------------------------------------------===//
407  // Label Manipulation.
408  //
409
410  /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
411  /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
412  /// normal 'L' label is returned.
413  MCSymbol *getJTISymbol(unsigned JTI, MCContext &Ctx,
414                         bool isLinkerPrivate = false) const;
415
416  /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
417  /// base.
418  MCSymbol *getPICBaseSymbol() const;
419};
420
421//===--------------------------------------------------------------------===//
422// GraphTraits specializations for function basic block graphs (CFGs)
423//===--------------------------------------------------------------------===//
424
425// Provide specializations of GraphTraits to be able to treat a
426// machine function as a graph of machine basic blocks... these are
427// the same as the machine basic block iterators, except that the root
428// node is implicitly the first node of the function.
429//
430template <> struct GraphTraits<MachineFunction*> :
431  public GraphTraits<MachineBasicBlock*> {
432  static NodeType *getEntryNode(MachineFunction *F) {
433    return &F->front();
434  }
435
436  // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
437  typedef MachineFunction::iterator nodes_iterator;
438  static nodes_iterator nodes_begin(MachineFunction *F) { return F->begin(); }
439  static nodes_iterator nodes_end  (MachineFunction *F) { return F->end(); }
440};
441template <> struct GraphTraits<const MachineFunction*> :
442  public GraphTraits<const MachineBasicBlock*> {
443  static NodeType *getEntryNode(const MachineFunction *F) {
444    return &F->front();
445  }
446
447  // nodes_iterator/begin/end - Allow iteration over all nodes in the graph
448  typedef MachineFunction::const_iterator nodes_iterator;
449  static nodes_iterator nodes_begin(const MachineFunction *F) {
450    return F->begin();
451  }
452  static nodes_iterator nodes_end  (const MachineFunction *F) {
453    return F->end();
454  }
455};
456
457
458// Provide specializations of GraphTraits to be able to treat a function as a
459// graph of basic blocks... and to walk it in inverse order.  Inverse order for
460// a function is considered to be when traversing the predecessor edges of a BB
461// instead of the successor edges.
462//
463template <> struct GraphTraits<Inverse<MachineFunction*> > :
464  public GraphTraits<Inverse<MachineBasicBlock*> > {
465  static NodeType *getEntryNode(Inverse<MachineFunction*> G) {
466    return &G.Graph->front();
467  }
468};
469template <> struct GraphTraits<Inverse<const MachineFunction*> > :
470  public GraphTraits<Inverse<const MachineBasicBlock*> > {
471  static NodeType *getEntryNode(Inverse<const MachineFunction *> G) {
472    return &G.Graph->front();
473  }
474};
475
476} // End llvm namespace
477
478#endif
479