• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 //===-- MachineFunction.cpp -----------------------------------------------===//
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 information for a function.  This allows
11 // target-specific information about the generated code to be stored with each
12 // function.
13 //
14 //===----------------------------------------------------------------------===//
15 
16 #include "llvm/CodeGen/MachineFunction.h"
17 #include "llvm/Function.h"
18 #include "llvm/CodeGen/MachineConstantPool.h"
19 #include "llvm/CodeGen/MachineFunctionPass.h"
20 #include "llvm/CodeGen/MachineFrameInfo.h"
21 #include "llvm/CodeGen/MachineInstr.h"
22 #include "llvm/CodeGen/MachineJumpTableInfo.h"
23 #include "llvm/CodeGen/MachineModuleInfo.h"
24 #include "llvm/CodeGen/MachineRegisterInfo.h"
25 #include "llvm/CodeGen/Passes.h"
26 #include "llvm/MC/MCAsmInfo.h"
27 #include "llvm/MC/MCContext.h"
28 #include "llvm/Analysis/ConstantFolding.h"
29 #include "llvm/Analysis/DebugInfo.h"
30 #include "llvm/Support/Debug.h"
31 #include "llvm/Target/TargetData.h"
32 #include "llvm/Target/TargetLowering.h"
33 #include "llvm/Target/TargetMachine.h"
34 #include "llvm/Target/TargetFrameLowering.h"
35 #include "llvm/ADT/SmallString.h"
36 #include "llvm/ADT/STLExtras.h"
37 #include "llvm/Support/GraphWriter.h"
38 #include "llvm/Support/raw_ostream.h"
39 using namespace llvm;
40 
41 //===----------------------------------------------------------------------===//
42 // MachineFunction implementation
43 //===----------------------------------------------------------------------===//
44 
45 // Out of line virtual method.
~MachineFunctionInfo()46 MachineFunctionInfo::~MachineFunctionInfo() {}
47 
deleteNode(MachineBasicBlock * MBB)48 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
49   MBB->getParent()->DeleteMachineBasicBlock(MBB);
50 }
51 
MachineFunction(const Function * F,const TargetMachine & TM,unsigned FunctionNum,MachineModuleInfo & mmi,GCModuleInfo * gmi)52 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
53                                  unsigned FunctionNum, MachineModuleInfo &mmi,
54                                  GCModuleInfo* gmi)
55   : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
56   if (TM.getRegisterInfo())
57     RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
58   else
59     RegInfo = 0;
60   MFInfo = 0;
61   FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering());
62   if (Fn->hasFnAttr(Attribute::StackAlignment))
63     FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
64         Fn->getAttributes().getFnAttributes()));
65   ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
66   Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
67   // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
68   if (!Fn->hasFnAttr(Attribute::OptimizeForSize))
69     Alignment = std::max(Alignment,
70                          TM.getTargetLowering()->getPrefFunctionAlignment());
71   FunctionNumber = FunctionNum;
72   JumpTableInfo = 0;
73 }
74 
~MachineFunction()75 MachineFunction::~MachineFunction() {
76   BasicBlocks.clear();
77   InstructionRecycler.clear(Allocator);
78   BasicBlockRecycler.clear(Allocator);
79   if (RegInfo) {
80     RegInfo->~MachineRegisterInfo();
81     Allocator.Deallocate(RegInfo);
82   }
83   if (MFInfo) {
84     MFInfo->~MachineFunctionInfo();
85     Allocator.Deallocate(MFInfo);
86   }
87   FrameInfo->~MachineFrameInfo();         Allocator.Deallocate(FrameInfo);
88   ConstantPool->~MachineConstantPool();   Allocator.Deallocate(ConstantPool);
89 
90   if (JumpTableInfo) {
91     JumpTableInfo->~MachineJumpTableInfo();
92     Allocator.Deallocate(JumpTableInfo);
93   }
94 }
95 
96 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
97 /// does already exist, allocate one.
98 MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind)99 getOrCreateJumpTableInfo(unsigned EntryKind) {
100   if (JumpTableInfo) return JumpTableInfo;
101 
102   JumpTableInfo = new (Allocator)
103     MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
104   return JumpTableInfo;
105 }
106 
107 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
108 /// recomputes them.  This guarantees that the MBB numbers are sequential,
109 /// dense, and match the ordering of the blocks within the function.  If a
110 /// specific MachineBasicBlock is specified, only that block and those after
111 /// it are renumbered.
RenumberBlocks(MachineBasicBlock * MBB)112 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
113   if (empty()) { MBBNumbering.clear(); return; }
114   MachineFunction::iterator MBBI, E = end();
115   if (MBB == 0)
116     MBBI = begin();
117   else
118     MBBI = MBB;
119 
120   // Figure out the block number this should have.
121   unsigned BlockNo = 0;
122   if (MBBI != begin())
123     BlockNo = prior(MBBI)->getNumber()+1;
124 
125   for (; MBBI != E; ++MBBI, ++BlockNo) {
126     if (MBBI->getNumber() != (int)BlockNo) {
127       // Remove use of the old number.
128       if (MBBI->getNumber() != -1) {
129         assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
130                "MBB number mismatch!");
131         MBBNumbering[MBBI->getNumber()] = 0;
132       }
133 
134       // If BlockNo is already taken, set that block's number to -1.
135       if (MBBNumbering[BlockNo])
136         MBBNumbering[BlockNo]->setNumber(-1);
137 
138       MBBNumbering[BlockNo] = MBBI;
139       MBBI->setNumber(BlockNo);
140     }
141   }
142 
143   // Okay, all the blocks are renumbered.  If we have compactified the block
144   // numbering, shrink MBBNumbering now.
145   assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
146   MBBNumbering.resize(BlockNo);
147 }
148 
149 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
150 /// of `new MachineInstr'.
151 ///
152 MachineInstr *
CreateMachineInstr(const MCInstrDesc & MCID,DebugLoc DL,bool NoImp)153 MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
154                                     DebugLoc DL, bool NoImp) {
155   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
156     MachineInstr(MCID, DL, NoImp);
157 }
158 
159 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
160 /// 'Orig' instruction, identical in all ways except the instruction
161 /// has no parent, prev, or next.
162 ///
163 MachineInstr *
CloneMachineInstr(const MachineInstr * Orig)164 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
165   return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
166              MachineInstr(*this, *Orig);
167 }
168 
169 /// DeleteMachineInstr - Delete the given MachineInstr.
170 ///
171 void
DeleteMachineInstr(MachineInstr * MI)172 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
173   MI->~MachineInstr();
174   InstructionRecycler.Deallocate(Allocator, MI);
175 }
176 
177 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
178 /// instead of `new MachineBasicBlock'.
179 ///
180 MachineBasicBlock *
CreateMachineBasicBlock(const BasicBlock * bb)181 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
182   return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
183              MachineBasicBlock(*this, bb);
184 }
185 
186 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
187 ///
188 void
DeleteMachineBasicBlock(MachineBasicBlock * MBB)189 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
190   assert(MBB->getParent() == this && "MBB parent mismatch!");
191   MBB->~MachineBasicBlock();
192   BasicBlockRecycler.Deallocate(Allocator, MBB);
193 }
194 
195 MachineMemOperand *
getMachineMemOperand(MachinePointerInfo PtrInfo,unsigned f,uint64_t s,unsigned base_alignment,const MDNode * TBAAInfo,const MDNode * Ranges)196 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
197                                       uint64_t s, unsigned base_alignment,
198                                       const MDNode *TBAAInfo,
199                                       const MDNode *Ranges) {
200   return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
201                                            TBAAInfo, Ranges);
202 }
203 
204 MachineMemOperand *
getMachineMemOperand(const MachineMemOperand * MMO,int64_t Offset,uint64_t Size)205 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
206                                       int64_t Offset, uint64_t Size) {
207   return new (Allocator)
208              MachineMemOperand(MachinePointerInfo(MMO->getValue(),
209                                                   MMO->getOffset()+Offset),
210                                MMO->getFlags(), Size,
211                                MMO->getBaseAlignment(), 0);
212 }
213 
214 MachineInstr::mmo_iterator
allocateMemRefsArray(unsigned long Num)215 MachineFunction::allocateMemRefsArray(unsigned long Num) {
216   return Allocator.Allocate<MachineMemOperand *>(Num);
217 }
218 
219 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractLoadMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)220 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
221                                     MachineInstr::mmo_iterator End) {
222   // Count the number of load mem refs.
223   unsigned Num = 0;
224   for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
225     if ((*I)->isLoad())
226       ++Num;
227 
228   // Allocate a new array and populate it with the load information.
229   MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
230   unsigned Index = 0;
231   for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
232     if ((*I)->isLoad()) {
233       if (!(*I)->isStore())
234         // Reuse the MMO.
235         Result[Index] = *I;
236       else {
237         // Clone the MMO and unset the store flag.
238         MachineMemOperand *JustLoad =
239           getMachineMemOperand((*I)->getPointerInfo(),
240                                (*I)->getFlags() & ~MachineMemOperand::MOStore,
241                                (*I)->getSize(), (*I)->getBaseAlignment(),
242                                (*I)->getTBAAInfo());
243         Result[Index] = JustLoad;
244       }
245       ++Index;
246     }
247   }
248   return std::make_pair(Result, Result + Num);
249 }
250 
251 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractStoreMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)252 MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
253                                      MachineInstr::mmo_iterator End) {
254   // Count the number of load mem refs.
255   unsigned Num = 0;
256   for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
257     if ((*I)->isStore())
258       ++Num;
259 
260   // Allocate a new array and populate it with the store information.
261   MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
262   unsigned Index = 0;
263   for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
264     if ((*I)->isStore()) {
265       if (!(*I)->isLoad())
266         // Reuse the MMO.
267         Result[Index] = *I;
268       else {
269         // Clone the MMO and unset the load flag.
270         MachineMemOperand *JustStore =
271           getMachineMemOperand((*I)->getPointerInfo(),
272                                (*I)->getFlags() & ~MachineMemOperand::MOLoad,
273                                (*I)->getSize(), (*I)->getBaseAlignment(),
274                                (*I)->getTBAAInfo());
275         Result[Index] = JustStore;
276       }
277       ++Index;
278     }
279   }
280   return std::make_pair(Result, Result + Num);
281 }
282 
dump() const283 void MachineFunction::dump() const {
284   print(dbgs());
285 }
286 
print(raw_ostream & OS,SlotIndexes * Indexes) const287 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
288   OS << "# Machine code for function " << Fn->getName() << ": ";
289   if (RegInfo) {
290     OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
291     if (!RegInfo->tracksLiveness())
292       OS << ", not tracking liveness";
293   }
294   OS << '\n';
295 
296   // Print Frame Information
297   FrameInfo->print(*this, OS);
298 
299   // Print JumpTable Information
300   if (JumpTableInfo)
301     JumpTableInfo->print(OS);
302 
303   // Print Constant Pool
304   ConstantPool->print(OS);
305 
306   const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
307 
308   if (RegInfo && !RegInfo->livein_empty()) {
309     OS << "Function Live Ins: ";
310     for (MachineRegisterInfo::livein_iterator
311          I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
312       OS << PrintReg(I->first, TRI);
313       if (I->second)
314         OS << " in " << PrintReg(I->second, TRI);
315       if (llvm::next(I) != E)
316         OS << ", ";
317     }
318     OS << '\n';
319   }
320   if (RegInfo && !RegInfo->liveout_empty()) {
321     OS << "Function Live Outs:";
322     for (MachineRegisterInfo::liveout_iterator
323          I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
324       OS << ' ' << PrintReg(*I, TRI);
325     OS << '\n';
326   }
327 
328   for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
329     OS << '\n';
330     BB->print(OS, Indexes);
331   }
332 
333   OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
334 }
335 
336 namespace llvm {
337   template<>
338   struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
339 
DOTGraphTraitsllvm::DOTGraphTraits340   DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
341 
getGraphNamellvm::DOTGraphTraits342     static std::string getGraphName(const MachineFunction *F) {
343       return "CFG for '" + F->getFunction()->getName().str() + "' function";
344     }
345 
getNodeLabelllvm::DOTGraphTraits346     std::string getNodeLabel(const MachineBasicBlock *Node,
347                              const MachineFunction *Graph) {
348       std::string OutStr;
349       {
350         raw_string_ostream OSS(OutStr);
351 
352         if (isSimple()) {
353           OSS << "BB#" << Node->getNumber();
354           if (const BasicBlock *BB = Node->getBasicBlock())
355             OSS << ": " << BB->getName();
356         } else
357           Node->print(OSS);
358       }
359 
360       if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
361 
362       // Process string output to make it nicer...
363       for (unsigned i = 0; i != OutStr.length(); ++i)
364         if (OutStr[i] == '\n') {                            // Left justify
365           OutStr[i] = '\\';
366           OutStr.insert(OutStr.begin()+i+1, 'l');
367         }
368       return OutStr;
369     }
370   };
371 }
372 
viewCFG() const373 void MachineFunction::viewCFG() const
374 {
375 #ifndef NDEBUG
376   ViewGraph(this, "mf" + getFunction()->getName());
377 #else
378   errs() << "MachineFunction::viewCFG is only available in debug builds on "
379          << "systems with Graphviz or gv!\n";
380 #endif // NDEBUG
381 }
382 
viewCFGOnly() const383 void MachineFunction::viewCFGOnly() const
384 {
385 #ifndef NDEBUG
386   ViewGraph(this, "mf" + getFunction()->getName(), true);
387 #else
388   errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
389          << "systems with Graphviz or gv!\n";
390 #endif // NDEBUG
391 }
392 
393 /// addLiveIn - Add the specified physical register as a live-in value and
394 /// create a corresponding virtual register for it.
addLiveIn(unsigned PReg,const TargetRegisterClass * RC)395 unsigned MachineFunction::addLiveIn(unsigned PReg,
396                                     const TargetRegisterClass *RC) {
397   MachineRegisterInfo &MRI = getRegInfo();
398   unsigned VReg = MRI.getLiveInVirtReg(PReg);
399   if (VReg) {
400     assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
401     return VReg;
402   }
403   VReg = MRI.createVirtualRegister(RC);
404   MRI.addLiveIn(PReg, VReg);
405   return VReg;
406 }
407 
408 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
409 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
410 /// normal 'L' label is returned.
getJTISymbol(unsigned JTI,MCContext & Ctx,bool isLinkerPrivate) const411 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
412                                         bool isLinkerPrivate) const {
413   assert(JumpTableInfo && "No jump tables");
414 
415   assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
416   const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
417 
418   const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
419                                          MAI.getPrivateGlobalPrefix();
420   SmallString<60> Name;
421   raw_svector_ostream(Name)
422     << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
423   return Ctx.GetOrCreateSymbol(Name.str());
424 }
425 
426 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
427 /// base.
getPICBaseSymbol() const428 MCSymbol *MachineFunction::getPICBaseSymbol() const {
429   const MCAsmInfo &MAI = *Target.getMCAsmInfo();
430   return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
431                                Twine(getFunctionNumber())+"$pb");
432 }
433 
434 //===----------------------------------------------------------------------===//
435 //  MachineFrameInfo implementation
436 //===----------------------------------------------------------------------===//
437 
438 /// CreateFixedObject - Create a new object at a fixed location on the stack.
439 /// All fixed objects should be created before other objects are created for
440 /// efficiency. By default, fixed objects are immutable. This returns an
441 /// index with a negative value.
442 ///
CreateFixedObject(uint64_t Size,int64_t SPOffset,bool Immutable)443 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
444                                         bool Immutable) {
445   assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
446   // The alignment of the frame index can be determined from its offset from
447   // the incoming frame position.  If the frame object is at offset 32 and
448   // the stack is guaranteed to be 16-byte aligned, then we know that the
449   // object is 16-byte aligned.
450   unsigned StackAlign = TFI.getStackAlignment();
451   unsigned Align = MinAlign(SPOffset, StackAlign);
452   Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
453                                               /*isSS*/false, false));
454   return -++NumFixedObjects;
455 }
456 
457 
458 BitVector
getPristineRegs(const MachineBasicBlock * MBB) const459 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
460   assert(MBB && "MBB must be valid");
461   const MachineFunction *MF = MBB->getParent();
462   assert(MF && "MBB must be part of a MachineFunction");
463   const TargetMachine &TM = MF->getTarget();
464   const TargetRegisterInfo *TRI = TM.getRegisterInfo();
465   BitVector BV(TRI->getNumRegs());
466 
467   // Before CSI is calculated, no registers are considered pristine. They can be
468   // freely used and PEI will make sure they are saved.
469   if (!isCalleeSavedInfoValid())
470     return BV;
471 
472   for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
473     BV.set(*CSR);
474 
475   // The entry MBB always has all CSRs pristine.
476   if (MBB == &MF->front())
477     return BV;
478 
479   // On other MBBs the saved CSRs are not pristine.
480   const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
481   for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
482          E = CSI.end(); I != E; ++I)
483     BV.reset(I->getReg());
484 
485   return BV;
486 }
487 
488 
print(const MachineFunction & MF,raw_ostream & OS) const489 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
490   if (Objects.empty()) return;
491 
492   const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
493   int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
494 
495   OS << "Frame Objects:\n";
496 
497   for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
498     const StackObject &SO = Objects[i];
499     OS << "  fi#" << (int)(i-NumFixedObjects) << ": ";
500     if (SO.Size == ~0ULL) {
501       OS << "dead\n";
502       continue;
503     }
504     if (SO.Size == 0)
505       OS << "variable sized";
506     else
507       OS << "size=" << SO.Size;
508     OS << ", align=" << SO.Alignment;
509 
510     if (i < NumFixedObjects)
511       OS << ", fixed";
512     if (i < NumFixedObjects || SO.SPOffset != -1) {
513       int64_t Off = SO.SPOffset - ValOffset;
514       OS << ", at location [SP";
515       if (Off > 0)
516         OS << "+" << Off;
517       else if (Off < 0)
518         OS << Off;
519       OS << "]";
520     }
521     OS << "\n";
522   }
523 }
524 
dump(const MachineFunction & MF) const525 void MachineFrameInfo::dump(const MachineFunction &MF) const {
526   print(MF, dbgs());
527 }
528 
529 //===----------------------------------------------------------------------===//
530 //  MachineJumpTableInfo implementation
531 //===----------------------------------------------------------------------===//
532 
533 /// getEntrySize - Return the size of each entry in the jump table.
getEntrySize(const TargetData & TD) const534 unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
535   // The size of a jump table entry is 4 bytes unless the entry is just the
536   // address of a block, in which case it is the pointer size.
537   switch (getEntryKind()) {
538   case MachineJumpTableInfo::EK_BlockAddress:
539     return TD.getPointerSize();
540   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
541     return 8;
542   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
543   case MachineJumpTableInfo::EK_LabelDifference32:
544   case MachineJumpTableInfo::EK_Custom32:
545     return 4;
546   case MachineJumpTableInfo::EK_Inline:
547     return 0;
548   }
549   llvm_unreachable("Unknown jump table encoding!");
550 }
551 
552 /// getEntryAlignment - Return the alignment of each entry in the jump table.
getEntryAlignment(const TargetData & TD) const553 unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
554   // The alignment of a jump table entry is the alignment of int32 unless the
555   // entry is just the address of a block, in which case it is the pointer
556   // alignment.
557   switch (getEntryKind()) {
558   case MachineJumpTableInfo::EK_BlockAddress:
559     return TD.getPointerABIAlignment();
560   case MachineJumpTableInfo::EK_GPRel64BlockAddress:
561     return TD.getABIIntegerTypeAlignment(64);
562   case MachineJumpTableInfo::EK_GPRel32BlockAddress:
563   case MachineJumpTableInfo::EK_LabelDifference32:
564   case MachineJumpTableInfo::EK_Custom32:
565     return TD.getABIIntegerTypeAlignment(32);
566   case MachineJumpTableInfo::EK_Inline:
567     return 1;
568   }
569   llvm_unreachable("Unknown jump table encoding!");
570 }
571 
572 /// createJumpTableIndex - Create a new jump table entry in the jump table info.
573 ///
createJumpTableIndex(const std::vector<MachineBasicBlock * > & DestBBs)574 unsigned MachineJumpTableInfo::createJumpTableIndex(
575                                const std::vector<MachineBasicBlock*> &DestBBs) {
576   assert(!DestBBs.empty() && "Cannot create an empty jump table!");
577   JumpTables.push_back(MachineJumpTableEntry(DestBBs));
578   return JumpTables.size()-1;
579 }
580 
581 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
582 /// the jump tables to branch to New instead.
ReplaceMBBInJumpTables(MachineBasicBlock * Old,MachineBasicBlock * New)583 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
584                                                   MachineBasicBlock *New) {
585   assert(Old != New && "Not making a change?");
586   bool MadeChange = false;
587   for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
588     ReplaceMBBInJumpTable(i, Old, New);
589   return MadeChange;
590 }
591 
592 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
593 /// the jump table to branch to New instead.
ReplaceMBBInJumpTable(unsigned Idx,MachineBasicBlock * Old,MachineBasicBlock * New)594 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
595                                                  MachineBasicBlock *Old,
596                                                  MachineBasicBlock *New) {
597   assert(Old != New && "Not making a change?");
598   bool MadeChange = false;
599   MachineJumpTableEntry &JTE = JumpTables[Idx];
600   for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
601     if (JTE.MBBs[j] == Old) {
602       JTE.MBBs[j] = New;
603       MadeChange = true;
604     }
605   return MadeChange;
606 }
607 
print(raw_ostream & OS) const608 void MachineJumpTableInfo::print(raw_ostream &OS) const {
609   if (JumpTables.empty()) return;
610 
611   OS << "Jump Tables:\n";
612 
613   for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
614     OS << "  jt#" << i << ": ";
615     for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
616       OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
617   }
618 
619   OS << '\n';
620 }
621 
dump() const622 void MachineJumpTableInfo::dump() const { print(dbgs()); }
623 
624 
625 //===----------------------------------------------------------------------===//
626 //  MachineConstantPool implementation
627 //===----------------------------------------------------------------------===//
628 
anchor()629 void MachineConstantPoolValue::anchor() { }
630 
getType() const631 Type *MachineConstantPoolEntry::getType() const {
632   if (isMachineConstantPoolEntry())
633     return Val.MachineCPVal->getType();
634   return Val.ConstVal->getType();
635 }
636 
637 
getRelocationInfo() const638 unsigned MachineConstantPoolEntry::getRelocationInfo() const {
639   if (isMachineConstantPoolEntry())
640     return Val.MachineCPVal->getRelocationInfo();
641   return Val.ConstVal->getRelocationInfo();
642 }
643 
~MachineConstantPool()644 MachineConstantPool::~MachineConstantPool() {
645   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
646     if (Constants[i].isMachineConstantPoolEntry())
647       delete Constants[i].Val.MachineCPVal;
648   for (DenseSet<MachineConstantPoolValue*>::iterator I =
649        MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
650        I != E; ++I)
651     delete *I;
652 }
653 
654 /// CanShareConstantPoolEntry - Test whether the given two constants
655 /// can be allocated the same constant pool entry.
CanShareConstantPoolEntry(const Constant * A,const Constant * B,const TargetData * TD)656 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
657                                       const TargetData *TD) {
658   // Handle the trivial case quickly.
659   if (A == B) return true;
660 
661   // If they have the same type but weren't the same constant, quickly
662   // reject them.
663   if (A->getType() == B->getType()) return false;
664 
665   // We can't handle structs or arrays.
666   if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
667       isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
668     return false;
669 
670   // For now, only support constants with the same size.
671   uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
672   if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
673       StoreSize > 128)
674     return false;
675 
676   Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
677 
678   // Try constant folding a bitcast of both instructions to an integer.  If we
679   // get two identical ConstantInt's, then we are good to share them.  We use
680   // the constant folding APIs to do this so that we get the benefit of
681   // TargetData.
682   if (isa<PointerType>(A->getType()))
683     A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
684                                  const_cast<Constant*>(A), TD);
685   else if (A->getType() != IntTy)
686     A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
687                                  const_cast<Constant*>(A), TD);
688   if (isa<PointerType>(B->getType()))
689     B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
690                                  const_cast<Constant*>(B), TD);
691   else if (B->getType() != IntTy)
692     B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
693                                  const_cast<Constant*>(B), TD);
694 
695   return A == B;
696 }
697 
698 /// getConstantPoolIndex - Create a new entry in the constant pool or return
699 /// an existing one.  User must specify the log2 of the minimum required
700 /// alignment for the object.
701 ///
getConstantPoolIndex(const Constant * C,unsigned Alignment)702 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
703                                                    unsigned Alignment) {
704   assert(Alignment && "Alignment must be specified!");
705   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
706 
707   // Check to see if we already have this constant.
708   //
709   // FIXME, this could be made much more efficient for large constant pools.
710   for (unsigned i = 0, e = Constants.size(); i != e; ++i)
711     if (!Constants[i].isMachineConstantPoolEntry() &&
712         CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
713       if ((unsigned)Constants[i].getAlignment() < Alignment)
714         Constants[i].Alignment = Alignment;
715       return i;
716     }
717 
718   Constants.push_back(MachineConstantPoolEntry(C, Alignment));
719   return Constants.size()-1;
720 }
721 
getConstantPoolIndex(MachineConstantPoolValue * V,unsigned Alignment)722 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
723                                                    unsigned Alignment) {
724   assert(Alignment && "Alignment must be specified!");
725   if (Alignment > PoolAlignment) PoolAlignment = Alignment;
726 
727   // Check to see if we already have this constant.
728   //
729   // FIXME, this could be made much more efficient for large constant pools.
730   int Idx = V->getExistingMachineCPValue(this, Alignment);
731   if (Idx != -1) {
732     MachineCPVsSharingEntries.insert(V);
733     return (unsigned)Idx;
734   }
735 
736   Constants.push_back(MachineConstantPoolEntry(V, Alignment));
737   return Constants.size()-1;
738 }
739 
print(raw_ostream & OS) const740 void MachineConstantPool::print(raw_ostream &OS) const {
741   if (Constants.empty()) return;
742 
743   OS << "Constant Pool:\n";
744   for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
745     OS << "  cp#" << i << ": ";
746     if (Constants[i].isMachineConstantPoolEntry())
747       Constants[i].Val.MachineCPVal->print(OS);
748     else
749       OS << *(Value*)Constants[i].Val.ConstVal;
750     OS << ", align=" << Constants[i].getAlignment();
751     OS << "\n";
752   }
753 }
754 
dump() const755 void MachineConstantPool::dump() const { print(dbgs()); }
756