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/DerivedTypes.h"
17 #include "llvm/Function.h"
18 #include "llvm/Instructions.h"
19 #include "llvm/Config/config.h"
20 #include "llvm/CodeGen/MachineConstantPool.h"
21 #include "llvm/CodeGen/MachineFunction.h"
22 #include "llvm/CodeGen/MachineFunctionPass.h"
23 #include "llvm/CodeGen/MachineFrameInfo.h"
24 #include "llvm/CodeGen/MachineInstr.h"
25 #include "llvm/CodeGen/MachineJumpTableInfo.h"
26 #include "llvm/CodeGen/MachineModuleInfo.h"
27 #include "llvm/CodeGen/MachineRegisterInfo.h"
28 #include "llvm/CodeGen/Passes.h"
29 #include "llvm/MC/MCAsmInfo.h"
30 #include "llvm/MC/MCContext.h"
31 #include "llvm/Analysis/DebugInfo.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Target/TargetData.h"
34 #include "llvm/Target/TargetLowering.h"
35 #include "llvm/Target/TargetMachine.h"
36 #include "llvm/Target/TargetFrameLowering.h"
37 #include "llvm/ADT/SmallString.h"
38 #include "llvm/ADT/STLExtras.h"
39 #include "llvm/Support/GraphWriter.h"
40 #include "llvm/Support/raw_ostream.h"
41 using namespace llvm;
42
43 //===----------------------------------------------------------------------===//
44 // MachineFunction implementation
45 //===----------------------------------------------------------------------===//
46
47 // Out of line virtual method.
~MachineFunctionInfo()48 MachineFunctionInfo::~MachineFunctionInfo() {}
49
deleteNode(MachineBasicBlock * MBB)50 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
51 MBB->getParent()->DeleteMachineBasicBlock(MBB);
52 }
53
MachineFunction(const Function * F,const TargetMachine & TM,unsigned FunctionNum,MachineModuleInfo & mmi,GCModuleInfo * gmi)54 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
55 unsigned FunctionNum, MachineModuleInfo &mmi,
56 GCModuleInfo* gmi)
57 : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
58 if (TM.getRegisterInfo())
59 RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
60 else
61 RegInfo = 0;
62 MFInfo = 0;
63 FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameLowering());
64 if (Fn->hasFnAttr(Attribute::StackAlignment))
65 FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
66 Fn->getAttributes().getFnAttributes()));
67 ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
68 Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
69 // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
70 if (!Fn->hasFnAttr(Attribute::OptimizeForSize))
71 Alignment = std::max(Alignment,
72 TM.getTargetLowering()->getPrefFunctionAlignment());
73 FunctionNumber = FunctionNum;
74 JumpTableInfo = 0;
75 }
76
~MachineFunction()77 MachineFunction::~MachineFunction() {
78 BasicBlocks.clear();
79 InstructionRecycler.clear(Allocator);
80 BasicBlockRecycler.clear(Allocator);
81 if (RegInfo) {
82 RegInfo->~MachineRegisterInfo();
83 Allocator.Deallocate(RegInfo);
84 }
85 if (MFInfo) {
86 MFInfo->~MachineFunctionInfo();
87 Allocator.Deallocate(MFInfo);
88 }
89 FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo);
90 ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool);
91
92 if (JumpTableInfo) {
93 JumpTableInfo->~MachineJumpTableInfo();
94 Allocator.Deallocate(JumpTableInfo);
95 }
96 }
97
98 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
99 /// does already exist, allocate one.
100 MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind)101 getOrCreateJumpTableInfo(unsigned EntryKind) {
102 if (JumpTableInfo) return JumpTableInfo;
103
104 JumpTableInfo = new (Allocator)
105 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
106 return JumpTableInfo;
107 }
108
109 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
110 /// recomputes them. This guarantees that the MBB numbers are sequential,
111 /// dense, and match the ordering of the blocks within the function. If a
112 /// specific MachineBasicBlock is specified, only that block and those after
113 /// it are renumbered.
RenumberBlocks(MachineBasicBlock * MBB)114 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
115 if (empty()) { MBBNumbering.clear(); return; }
116 MachineFunction::iterator MBBI, E = end();
117 if (MBB == 0)
118 MBBI = begin();
119 else
120 MBBI = MBB;
121
122 // Figure out the block number this should have.
123 unsigned BlockNo = 0;
124 if (MBBI != begin())
125 BlockNo = prior(MBBI)->getNumber()+1;
126
127 for (; MBBI != E; ++MBBI, ++BlockNo) {
128 if (MBBI->getNumber() != (int)BlockNo) {
129 // Remove use of the old number.
130 if (MBBI->getNumber() != -1) {
131 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
132 "MBB number mismatch!");
133 MBBNumbering[MBBI->getNumber()] = 0;
134 }
135
136 // If BlockNo is already taken, set that block's number to -1.
137 if (MBBNumbering[BlockNo])
138 MBBNumbering[BlockNo]->setNumber(-1);
139
140 MBBNumbering[BlockNo] = MBBI;
141 MBBI->setNumber(BlockNo);
142 }
143 }
144
145 // Okay, all the blocks are renumbered. If we have compactified the block
146 // numbering, shrink MBBNumbering now.
147 assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
148 MBBNumbering.resize(BlockNo);
149 }
150
151 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
152 /// of `new MachineInstr'.
153 ///
154 MachineInstr *
CreateMachineInstr(const MCInstrDesc & MCID,DebugLoc DL,bool NoImp)155 MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
156 DebugLoc DL, bool NoImp) {
157 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
158 MachineInstr(MCID, DL, NoImp);
159 }
160
161 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
162 /// 'Orig' instruction, identical in all ways except the instruction
163 /// has no parent, prev, or next.
164 ///
165 MachineInstr *
CloneMachineInstr(const MachineInstr * Orig)166 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
167 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
168 MachineInstr(*this, *Orig);
169 }
170
171 /// DeleteMachineInstr - Delete the given MachineInstr.
172 ///
173 void
DeleteMachineInstr(MachineInstr * MI)174 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
175 MI->~MachineInstr();
176 InstructionRecycler.Deallocate(Allocator, MI);
177 }
178
179 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
180 /// instead of `new MachineBasicBlock'.
181 ///
182 MachineBasicBlock *
CreateMachineBasicBlock(const BasicBlock * bb)183 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
184 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
185 MachineBasicBlock(*this, bb);
186 }
187
188 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
189 ///
190 void
DeleteMachineBasicBlock(MachineBasicBlock * MBB)191 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
192 assert(MBB->getParent() == this && "MBB parent mismatch!");
193 MBB->~MachineBasicBlock();
194 BasicBlockRecycler.Deallocate(Allocator, MBB);
195 }
196
197 MachineMemOperand *
getMachineMemOperand(MachinePointerInfo PtrInfo,unsigned f,uint64_t s,unsigned base_alignment,const MDNode * TBAAInfo)198 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
199 uint64_t s, unsigned base_alignment,
200 const MDNode *TBAAInfo) {
201 return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
202 TBAAInfo);
203 }
204
205 MachineMemOperand *
getMachineMemOperand(const MachineMemOperand * MMO,int64_t Offset,uint64_t Size)206 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
207 int64_t Offset, uint64_t Size) {
208 return new (Allocator)
209 MachineMemOperand(MachinePointerInfo(MMO->getValue(),
210 MMO->getOffset()+Offset),
211 MMO->getFlags(), Size,
212 MMO->getBaseAlignment(), 0);
213 }
214
215 MachineInstr::mmo_iterator
allocateMemRefsArray(unsigned long Num)216 MachineFunction::allocateMemRefsArray(unsigned long Num) {
217 return Allocator.Allocate<MachineMemOperand *>(Num);
218 }
219
220 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractLoadMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)221 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
222 MachineInstr::mmo_iterator End) {
223 // Count the number of load mem refs.
224 unsigned Num = 0;
225 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
226 if ((*I)->isLoad())
227 ++Num;
228
229 // Allocate a new array and populate it with the load information.
230 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
231 unsigned Index = 0;
232 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
233 if ((*I)->isLoad()) {
234 if (!(*I)->isStore())
235 // Reuse the MMO.
236 Result[Index] = *I;
237 else {
238 // Clone the MMO and unset the store flag.
239 MachineMemOperand *JustLoad =
240 getMachineMemOperand((*I)->getPointerInfo(),
241 (*I)->getFlags() & ~MachineMemOperand::MOStore,
242 (*I)->getSize(), (*I)->getBaseAlignment(),
243 (*I)->getTBAAInfo());
244 Result[Index] = JustLoad;
245 }
246 ++Index;
247 }
248 }
249 return std::make_pair(Result, Result + Num);
250 }
251
252 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractStoreMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)253 MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
254 MachineInstr::mmo_iterator End) {
255 // Count the number of load mem refs.
256 unsigned Num = 0;
257 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
258 if ((*I)->isStore())
259 ++Num;
260
261 // Allocate a new array and populate it with the store information.
262 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
263 unsigned Index = 0;
264 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
265 if ((*I)->isStore()) {
266 if (!(*I)->isLoad())
267 // Reuse the MMO.
268 Result[Index] = *I;
269 else {
270 // Clone the MMO and unset the load flag.
271 MachineMemOperand *JustStore =
272 getMachineMemOperand((*I)->getPointerInfo(),
273 (*I)->getFlags() & ~MachineMemOperand::MOLoad,
274 (*I)->getSize(), (*I)->getBaseAlignment(),
275 (*I)->getTBAAInfo());
276 Result[Index] = JustStore;
277 }
278 ++Index;
279 }
280 }
281 return std::make_pair(Result, Result + Num);
282 }
283
dump() const284 void MachineFunction::dump() const {
285 print(dbgs());
286 }
287
print(raw_ostream & OS,SlotIndexes * Indexes) const288 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
289 OS << "# Machine code for function " << Fn->getName() << ":\n";
290
291 // Print Frame Information
292 FrameInfo->print(*this, OS);
293
294 // Print JumpTable Information
295 if (JumpTableInfo)
296 JumpTableInfo->print(OS);
297
298 // Print Constant Pool
299 ConstantPool->print(OS);
300
301 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
302
303 if (RegInfo && !RegInfo->livein_empty()) {
304 OS << "Function Live Ins: ";
305 for (MachineRegisterInfo::livein_iterator
306 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
307 OS << PrintReg(I->first, TRI);
308 if (I->second)
309 OS << " in " << PrintReg(I->second, TRI);
310 if (llvm::next(I) != E)
311 OS << ", ";
312 }
313 OS << '\n';
314 }
315 if (RegInfo && !RegInfo->liveout_empty()) {
316 OS << "Function Live Outs:";
317 for (MachineRegisterInfo::liveout_iterator
318 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I)
319 OS << ' ' << PrintReg(*I, TRI);
320 OS << '\n';
321 }
322
323 for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
324 OS << '\n';
325 BB->print(OS, Indexes);
326 }
327
328 OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
329 }
330
331 namespace llvm {
332 template<>
333 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
334
DOTGraphTraitsllvm::DOTGraphTraits335 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
336
getGraphNamellvm::DOTGraphTraits337 static std::string getGraphName(const MachineFunction *F) {
338 return "CFG for '" + F->getFunction()->getNameStr() + "' function";
339 }
340
getNodeLabelllvm::DOTGraphTraits341 std::string getNodeLabel(const MachineBasicBlock *Node,
342 const MachineFunction *Graph) {
343 std::string OutStr;
344 {
345 raw_string_ostream OSS(OutStr);
346
347 if (isSimple()) {
348 OSS << "BB#" << Node->getNumber();
349 if (const BasicBlock *BB = Node->getBasicBlock())
350 OSS << ": " << BB->getName();
351 } else
352 Node->print(OSS);
353 }
354
355 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
356
357 // Process string output to make it nicer...
358 for (unsigned i = 0; i != OutStr.length(); ++i)
359 if (OutStr[i] == '\n') { // Left justify
360 OutStr[i] = '\\';
361 OutStr.insert(OutStr.begin()+i+1, 'l');
362 }
363 return OutStr;
364 }
365 };
366 }
367
viewCFG() const368 void MachineFunction::viewCFG() const
369 {
370 #ifndef NDEBUG
371 ViewGraph(this, "mf" + getFunction()->getNameStr());
372 #else
373 errs() << "MachineFunction::viewCFG is only available in debug builds on "
374 << "systems with Graphviz or gv!\n";
375 #endif // NDEBUG
376 }
377
viewCFGOnly() const378 void MachineFunction::viewCFGOnly() const
379 {
380 #ifndef NDEBUG
381 ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
382 #else
383 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
384 << "systems with Graphviz or gv!\n";
385 #endif // NDEBUG
386 }
387
388 /// addLiveIn - Add the specified physical register as a live-in value and
389 /// create a corresponding virtual register for it.
addLiveIn(unsigned PReg,const TargetRegisterClass * RC)390 unsigned MachineFunction::addLiveIn(unsigned PReg,
391 const TargetRegisterClass *RC) {
392 MachineRegisterInfo &MRI = getRegInfo();
393 unsigned VReg = MRI.getLiveInVirtReg(PReg);
394 if (VReg) {
395 assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
396 return VReg;
397 }
398 VReg = MRI.createVirtualRegister(RC);
399 MRI.addLiveIn(PReg, VReg);
400 return VReg;
401 }
402
403 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
404 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
405 /// normal 'L' label is returned.
getJTISymbol(unsigned JTI,MCContext & Ctx,bool isLinkerPrivate) const406 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
407 bool isLinkerPrivate) const {
408 assert(JumpTableInfo && "No jump tables");
409
410 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
411 const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
412
413 const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
414 MAI.getPrivateGlobalPrefix();
415 SmallString<60> Name;
416 raw_svector_ostream(Name)
417 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
418 return Ctx.GetOrCreateSymbol(Name.str());
419 }
420
421 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
422 /// base.
getPICBaseSymbol() const423 MCSymbol *MachineFunction::getPICBaseSymbol() const {
424 const MCAsmInfo &MAI = *Target.getMCAsmInfo();
425 return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
426 Twine(getFunctionNumber())+"$pb");
427 }
428
429 //===----------------------------------------------------------------------===//
430 // MachineFrameInfo implementation
431 //===----------------------------------------------------------------------===//
432
433 /// CreateFixedObject - Create a new object at a fixed location on the stack.
434 /// All fixed objects should be created before other objects are created for
435 /// efficiency. By default, fixed objects are immutable. This returns an
436 /// index with a negative value.
437 ///
CreateFixedObject(uint64_t Size,int64_t SPOffset,bool Immutable)438 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
439 bool Immutable) {
440 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
441 // The alignment of the frame index can be determined from its offset from
442 // the incoming frame position. If the frame object is at offset 32 and
443 // the stack is guaranteed to be 16-byte aligned, then we know that the
444 // object is 16-byte aligned.
445 unsigned StackAlign = TFI.getStackAlignment();
446 unsigned Align = MinAlign(SPOffset, StackAlign);
447 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
448 /*isSS*/false, false));
449 return -++NumFixedObjects;
450 }
451
452
453 BitVector
getPristineRegs(const MachineBasicBlock * MBB) const454 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
455 assert(MBB && "MBB must be valid");
456 const MachineFunction *MF = MBB->getParent();
457 assert(MF && "MBB must be part of a MachineFunction");
458 const TargetMachine &TM = MF->getTarget();
459 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
460 BitVector BV(TRI->getNumRegs());
461
462 // Before CSI is calculated, no registers are considered pristine. They can be
463 // freely used and PEI will make sure they are saved.
464 if (!isCalleeSavedInfoValid())
465 return BV;
466
467 for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
468 BV.set(*CSR);
469
470 // The entry MBB always has all CSRs pristine.
471 if (MBB == &MF->front())
472 return BV;
473
474 // On other MBBs the saved CSRs are not pristine.
475 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
476 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
477 E = CSI.end(); I != E; ++I)
478 BV.reset(I->getReg());
479
480 return BV;
481 }
482
483
print(const MachineFunction & MF,raw_ostream & OS) const484 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
485 if (Objects.empty()) return;
486
487 const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
488 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
489
490 OS << "Frame Objects:\n";
491
492 for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
493 const StackObject &SO = Objects[i];
494 OS << " fi#" << (int)(i-NumFixedObjects) << ": ";
495 if (SO.Size == ~0ULL) {
496 OS << "dead\n";
497 continue;
498 }
499 if (SO.Size == 0)
500 OS << "variable sized";
501 else
502 OS << "size=" << SO.Size;
503 OS << ", align=" << SO.Alignment;
504
505 if (i < NumFixedObjects)
506 OS << ", fixed";
507 if (i < NumFixedObjects || SO.SPOffset != -1) {
508 int64_t Off = SO.SPOffset - ValOffset;
509 OS << ", at location [SP";
510 if (Off > 0)
511 OS << "+" << Off;
512 else if (Off < 0)
513 OS << Off;
514 OS << "]";
515 }
516 OS << "\n";
517 }
518 }
519
dump(const MachineFunction & MF) const520 void MachineFrameInfo::dump(const MachineFunction &MF) const {
521 print(MF, dbgs());
522 }
523
524 //===----------------------------------------------------------------------===//
525 // MachineJumpTableInfo implementation
526 //===----------------------------------------------------------------------===//
527
528 /// getEntrySize - Return the size of each entry in the jump table.
getEntrySize(const TargetData & TD) const529 unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
530 // The size of a jump table entry is 4 bytes unless the entry is just the
531 // address of a block, in which case it is the pointer size.
532 switch (getEntryKind()) {
533 case MachineJumpTableInfo::EK_BlockAddress:
534 return TD.getPointerSize();
535 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
536 case MachineJumpTableInfo::EK_LabelDifference32:
537 case MachineJumpTableInfo::EK_Custom32:
538 return 4;
539 case MachineJumpTableInfo::EK_Inline:
540 return 0;
541 }
542 assert(0 && "Unknown jump table encoding!");
543 return ~0;
544 }
545
546 /// getEntryAlignment - Return the alignment of each entry in the jump table.
getEntryAlignment(const TargetData & TD) const547 unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
548 // The alignment of a jump table entry is the alignment of int32 unless the
549 // entry is just the address of a block, in which case it is the pointer
550 // alignment.
551 switch (getEntryKind()) {
552 case MachineJumpTableInfo::EK_BlockAddress:
553 return TD.getPointerABIAlignment();
554 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
555 case MachineJumpTableInfo::EK_LabelDifference32:
556 case MachineJumpTableInfo::EK_Custom32:
557 return TD.getABIIntegerTypeAlignment(32);
558 case MachineJumpTableInfo::EK_Inline:
559 return 1;
560 }
561 assert(0 && "Unknown jump table encoding!");
562 return ~0;
563 }
564
565 /// createJumpTableIndex - Create a new jump table entry in the jump table info.
566 ///
createJumpTableIndex(const std::vector<MachineBasicBlock * > & DestBBs)567 unsigned MachineJumpTableInfo::createJumpTableIndex(
568 const std::vector<MachineBasicBlock*> &DestBBs) {
569 assert(!DestBBs.empty() && "Cannot create an empty jump table!");
570 JumpTables.push_back(MachineJumpTableEntry(DestBBs));
571 return JumpTables.size()-1;
572 }
573
574 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
575 /// the jump tables to branch to New instead.
ReplaceMBBInJumpTables(MachineBasicBlock * Old,MachineBasicBlock * New)576 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
577 MachineBasicBlock *New) {
578 assert(Old != New && "Not making a change?");
579 bool MadeChange = false;
580 for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
581 ReplaceMBBInJumpTable(i, Old, New);
582 return MadeChange;
583 }
584
585 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
586 /// the jump table to branch to New instead.
ReplaceMBBInJumpTable(unsigned Idx,MachineBasicBlock * Old,MachineBasicBlock * New)587 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
588 MachineBasicBlock *Old,
589 MachineBasicBlock *New) {
590 assert(Old != New && "Not making a change?");
591 bool MadeChange = false;
592 MachineJumpTableEntry &JTE = JumpTables[Idx];
593 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
594 if (JTE.MBBs[j] == Old) {
595 JTE.MBBs[j] = New;
596 MadeChange = true;
597 }
598 return MadeChange;
599 }
600
print(raw_ostream & OS) const601 void MachineJumpTableInfo::print(raw_ostream &OS) const {
602 if (JumpTables.empty()) return;
603
604 OS << "Jump Tables:\n";
605
606 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
607 OS << " jt#" << i << ": ";
608 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
609 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
610 }
611
612 OS << '\n';
613 }
614
dump() const615 void MachineJumpTableInfo::dump() const { print(dbgs()); }
616
617
618 //===----------------------------------------------------------------------===//
619 // MachineConstantPool implementation
620 //===----------------------------------------------------------------------===//
621
getType() const622 Type *MachineConstantPoolEntry::getType() const {
623 if (isMachineConstantPoolEntry())
624 return Val.MachineCPVal->getType();
625 return Val.ConstVal->getType();
626 }
627
628
getRelocationInfo() const629 unsigned MachineConstantPoolEntry::getRelocationInfo() const {
630 if (isMachineConstantPoolEntry())
631 return Val.MachineCPVal->getRelocationInfo();
632 return Val.ConstVal->getRelocationInfo();
633 }
634
~MachineConstantPool()635 MachineConstantPool::~MachineConstantPool() {
636 for (unsigned i = 0, e = Constants.size(); i != e; ++i)
637 if (Constants[i].isMachineConstantPoolEntry())
638 delete Constants[i].Val.MachineCPVal;
639 for (DenseSet<MachineConstantPoolValue*>::iterator I =
640 MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
641 I != E; ++I)
642 delete *I;
643 }
644
645 /// CanShareConstantPoolEntry - Test whether the given two constants
646 /// can be allocated the same constant pool entry.
CanShareConstantPoolEntry(const Constant * A,const Constant * B,const TargetData * TD)647 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
648 const TargetData *TD) {
649 // Handle the trivial case quickly.
650 if (A == B) return true;
651
652 // If they have the same type but weren't the same constant, quickly
653 // reject them.
654 if (A->getType() == B->getType()) return false;
655
656 // For now, only support constants with the same size.
657 if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
658 return false;
659
660 // If a floating-point value and an integer value have the same encoding,
661 // they can share a constant-pool entry.
662 if (const ConstantFP *AFP = dyn_cast<ConstantFP>(A))
663 if (const ConstantInt *BI = dyn_cast<ConstantInt>(B))
664 return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
665 if (const ConstantFP *BFP = dyn_cast<ConstantFP>(B))
666 if (const ConstantInt *AI = dyn_cast<ConstantInt>(A))
667 return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
668
669 // Two vectors can share an entry if each pair of corresponding
670 // elements could.
671 if (const ConstantVector *AV = dyn_cast<ConstantVector>(A))
672 if (const ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
673 if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
674 return false;
675 for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
676 if (!CanShareConstantPoolEntry(AV->getOperand(i),
677 BV->getOperand(i), TD))
678 return false;
679 return true;
680 }
681
682 // TODO: Handle other cases.
683
684 return false;
685 }
686
687 /// getConstantPoolIndex - Create a new entry in the constant pool or return
688 /// an existing one. User must specify the log2 of the minimum required
689 /// alignment for the object.
690 ///
getConstantPoolIndex(const Constant * C,unsigned Alignment)691 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
692 unsigned Alignment) {
693 assert(Alignment && "Alignment must be specified!");
694 if (Alignment > PoolAlignment) PoolAlignment = Alignment;
695
696 // Check to see if we already have this constant.
697 //
698 // FIXME, this could be made much more efficient for large constant pools.
699 for (unsigned i = 0, e = Constants.size(); i != e; ++i)
700 if (!Constants[i].isMachineConstantPoolEntry() &&
701 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
702 if ((unsigned)Constants[i].getAlignment() < Alignment)
703 Constants[i].Alignment = Alignment;
704 return i;
705 }
706
707 Constants.push_back(MachineConstantPoolEntry(C, Alignment));
708 return Constants.size()-1;
709 }
710
getConstantPoolIndex(MachineConstantPoolValue * V,unsigned Alignment)711 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
712 unsigned Alignment) {
713 assert(Alignment && "Alignment must be specified!");
714 if (Alignment > PoolAlignment) PoolAlignment = Alignment;
715
716 // Check to see if we already have this constant.
717 //
718 // FIXME, this could be made much more efficient for large constant pools.
719 int Idx = V->getExistingMachineCPValue(this, Alignment);
720 if (Idx != -1) {
721 MachineCPVsSharingEntries.insert(V);
722 return (unsigned)Idx;
723 }
724
725 Constants.push_back(MachineConstantPoolEntry(V, Alignment));
726 return Constants.size()-1;
727 }
728
print(raw_ostream & OS) const729 void MachineConstantPool::print(raw_ostream &OS) const {
730 if (Constants.empty()) return;
731
732 OS << "Constant Pool:\n";
733 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
734 OS << " cp#" << i << ": ";
735 if (Constants[i].isMachineConstantPoolEntry())
736 Constants[i].Val.MachineCPVal->print(OS);
737 else
738 OS << *(Value*)Constants[i].Val.ConstVal;
739 OS << ", align=" << Constants[i].getAlignment();
740 OS << "\n";
741 }
742 }
743
dump() const744 void MachineConstantPool::dump() const { print(dbgs()); }
745