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