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/TargetFrameInfo.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)54 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
55 unsigned FunctionNum, MachineModuleInfo &mmi)
56 : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi) {
57 if (TM.getRegisterInfo())
58 RegInfo = new (Allocator) MachineRegisterInfo(*TM.getRegisterInfo());
59 else
60 RegInfo = 0;
61 MFInfo = 0;
62 FrameInfo = new (Allocator) MachineFrameInfo(*TM.getFrameInfo());
63 if (Fn->hasFnAttr(Attribute::StackAlignment))
64 FrameInfo->setMaxAlignment(Attribute::getStackAlignmentFromAttrs(
65 Fn->getAttributes().getFnAttributes()));
66 ConstantPool = new (Allocator) MachineConstantPool(TM.getTargetData());
67 Alignment = TM.getTargetLowering()->getFunctionAlignment(F);
68 FunctionNumber = FunctionNum;
69 JumpTableInfo = 0;
70 }
71
~MachineFunction()72 MachineFunction::~MachineFunction() {
73 BasicBlocks.clear();
74 InstructionRecycler.clear(Allocator);
75 BasicBlockRecycler.clear(Allocator);
76 if (RegInfo) {
77 RegInfo->~MachineRegisterInfo();
78 Allocator.Deallocate(RegInfo);
79 }
80 if (MFInfo) {
81 MFInfo->~MachineFunctionInfo();
82 Allocator.Deallocate(MFInfo);
83 }
84 FrameInfo->~MachineFrameInfo(); Allocator.Deallocate(FrameInfo);
85 ConstantPool->~MachineConstantPool(); Allocator.Deallocate(ConstantPool);
86
87 if (JumpTableInfo) {
88 JumpTableInfo->~MachineJumpTableInfo();
89 Allocator.Deallocate(JumpTableInfo);
90 }
91 }
92
93 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
94 /// does already exist, allocate one.
95 MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind)96 getOrCreateJumpTableInfo(unsigned EntryKind) {
97 if (JumpTableInfo) return JumpTableInfo;
98
99 JumpTableInfo = new (Allocator)
100 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
101 return JumpTableInfo;
102 }
103
104 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
105 /// recomputes them. This guarantees that the MBB numbers are sequential,
106 /// dense, and match the ordering of the blocks within the function. If a
107 /// specific MachineBasicBlock is specified, only that block and those after
108 /// it are renumbered.
RenumberBlocks(MachineBasicBlock * MBB)109 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
110 if (empty()) { MBBNumbering.clear(); return; }
111 MachineFunction::iterator MBBI, E = end();
112 if (MBB == 0)
113 MBBI = begin();
114 else
115 MBBI = MBB;
116
117 // Figure out the block number this should have.
118 unsigned BlockNo = 0;
119 if (MBBI != begin())
120 BlockNo = prior(MBBI)->getNumber()+1;
121
122 for (; MBBI != E; ++MBBI, ++BlockNo) {
123 if (MBBI->getNumber() != (int)BlockNo) {
124 // Remove use of the old number.
125 if (MBBI->getNumber() != -1) {
126 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
127 "MBB number mismatch!");
128 MBBNumbering[MBBI->getNumber()] = 0;
129 }
130
131 // If BlockNo is already taken, set that block's number to -1.
132 if (MBBNumbering[BlockNo])
133 MBBNumbering[BlockNo]->setNumber(-1);
134
135 MBBNumbering[BlockNo] = MBBI;
136 MBBI->setNumber(BlockNo);
137 }
138 }
139
140 // Okay, all the blocks are renumbered. If we have compactified the block
141 // numbering, shrink MBBNumbering now.
142 assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
143 MBBNumbering.resize(BlockNo);
144 }
145
146 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
147 /// of `new MachineInstr'.
148 ///
149 MachineInstr *
CreateMachineInstr(const TargetInstrDesc & TID,DebugLoc DL,bool NoImp)150 MachineFunction::CreateMachineInstr(const TargetInstrDesc &TID,
151 DebugLoc DL, bool NoImp) {
152 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
153 MachineInstr(TID, DL, NoImp);
154 }
155
156 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
157 /// 'Orig' instruction, identical in all ways except the instruction
158 /// has no parent, prev, or next.
159 ///
160 MachineInstr *
CloneMachineInstr(const MachineInstr * Orig)161 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
162 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
163 MachineInstr(*this, *Orig);
164 }
165
166 /// DeleteMachineInstr - Delete the given MachineInstr.
167 ///
168 void
DeleteMachineInstr(MachineInstr * MI)169 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
170 MI->~MachineInstr();
171 InstructionRecycler.Deallocate(Allocator, MI);
172 }
173
174 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
175 /// instead of `new MachineBasicBlock'.
176 ///
177 MachineBasicBlock *
CreateMachineBasicBlock(const BasicBlock * bb)178 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
179 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
180 MachineBasicBlock(*this, bb);
181 }
182
183 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
184 ///
185 void
DeleteMachineBasicBlock(MachineBasicBlock * MBB)186 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
187 assert(MBB->getParent() == this && "MBB parent mismatch!");
188 MBB->~MachineBasicBlock();
189 BasicBlockRecycler.Deallocate(Allocator, MBB);
190 }
191
192 MachineMemOperand *
getMachineMemOperand(const Value * v,unsigned f,int64_t o,uint64_t s,unsigned base_alignment)193 MachineFunction::getMachineMemOperand(const Value *v, unsigned f,
194 int64_t o, uint64_t s,
195 unsigned base_alignment) {
196 return new (Allocator) MachineMemOperand(v, f, o, s, base_alignment);
197 }
198
199 MachineMemOperand *
getMachineMemOperand(const MachineMemOperand * MMO,int64_t Offset,uint64_t Size)200 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
201 int64_t Offset, uint64_t Size) {
202 return new (Allocator)
203 MachineMemOperand(MMO->getValue(), MMO->getFlags(),
204 int64_t(uint64_t(MMO->getOffset()) +
205 uint64_t(Offset)),
206 Size, MMO->getBaseAlignment());
207 }
208
209 MachineInstr::mmo_iterator
allocateMemRefsArray(unsigned long Num)210 MachineFunction::allocateMemRefsArray(unsigned long Num) {
211 return Allocator.Allocate<MachineMemOperand *>(Num);
212 }
213
214 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractLoadMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)215 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
216 MachineInstr::mmo_iterator End) {
217 // Count the number of load mem refs.
218 unsigned Num = 0;
219 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
220 if ((*I)->isLoad())
221 ++Num;
222
223 // Allocate a new array and populate it with the load information.
224 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
225 unsigned Index = 0;
226 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
227 if ((*I)->isLoad()) {
228 if (!(*I)->isStore())
229 // Reuse the MMO.
230 Result[Index] = *I;
231 else {
232 // Clone the MMO and unset the store flag.
233 MachineMemOperand *JustLoad =
234 getMachineMemOperand((*I)->getValue(),
235 (*I)->getFlags() & ~MachineMemOperand::MOStore,
236 (*I)->getOffset(), (*I)->getSize(),
237 (*I)->getBaseAlignment());
238 Result[Index] = JustLoad;
239 }
240 ++Index;
241 }
242 }
243 return std::make_pair(Result, Result + Num);
244 }
245
246 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractStoreMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)247 MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
248 MachineInstr::mmo_iterator End) {
249 // Count the number of load mem refs.
250 unsigned Num = 0;
251 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
252 if ((*I)->isStore())
253 ++Num;
254
255 // Allocate a new array and populate it with the store information.
256 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
257 unsigned Index = 0;
258 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
259 if ((*I)->isStore()) {
260 if (!(*I)->isLoad())
261 // Reuse the MMO.
262 Result[Index] = *I;
263 else {
264 // Clone the MMO and unset the load flag.
265 MachineMemOperand *JustStore =
266 getMachineMemOperand((*I)->getValue(),
267 (*I)->getFlags() & ~MachineMemOperand::MOLoad,
268 (*I)->getOffset(), (*I)->getSize(),
269 (*I)->getBaseAlignment());
270 Result[Index] = JustStore;
271 }
272 ++Index;
273 }
274 }
275 return std::make_pair(Result, Result + Num);
276 }
277
dump() const278 void MachineFunction::dump() const {
279 print(dbgs());
280 }
281
print(raw_ostream & OS) const282 void MachineFunction::print(raw_ostream &OS) const {
283 OS << "# Machine code for function " << Fn->getName() << ":\n";
284
285 // Print Frame Information
286 FrameInfo->print(*this, OS);
287
288 // Print JumpTable Information
289 if (JumpTableInfo)
290 JumpTableInfo->print(OS);
291
292 // Print Constant Pool
293 ConstantPool->print(OS);
294
295 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
296
297 if (RegInfo && !RegInfo->livein_empty()) {
298 OS << "Function Live Ins: ";
299 for (MachineRegisterInfo::livein_iterator
300 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
301 if (TRI)
302 OS << "%" << TRI->getName(I->first);
303 else
304 OS << " %physreg" << I->first;
305
306 if (I->second)
307 OS << " in reg%" << I->second;
308
309 if (llvm::next(I) != E)
310 OS << ", ";
311 }
312 OS << '\n';
313 }
314 if (RegInfo && !RegInfo->liveout_empty()) {
315 OS << "Function Live Outs: ";
316 for (MachineRegisterInfo::liveout_iterator
317 I = RegInfo->liveout_begin(), E = RegInfo->liveout_end(); I != E; ++I){
318 if (TRI)
319 OS << '%' << TRI->getName(*I);
320 else
321 OS << "%physreg" << *I;
322
323 if (llvm::next(I) != E)
324 OS << " ";
325 }
326 OS << '\n';
327 }
328
329 for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
330 OS << '\n';
331 BB->print(OS);
332 }
333
334 OS << "\n# End machine code for function " << Fn->getName() << ".\n\n";
335 }
336
337 namespace llvm {
338 template<>
339 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
340
DOTGraphTraitsllvm::DOTGraphTraits341 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
342
getGraphNamellvm::DOTGraphTraits343 static std::string getGraphName(const MachineFunction *F) {
344 return "CFG for '" + F->getFunction()->getNameStr() + "' function";
345 }
346
getNodeLabelllvm::DOTGraphTraits347 std::string getNodeLabel(const MachineBasicBlock *Node,
348 const MachineFunction *Graph) {
349 if (isSimple () && Node->getBasicBlock() &&
350 !Node->getBasicBlock()->getName().empty())
351 return Node->getBasicBlock()->getNameStr() + ":";
352
353 std::string OutStr;
354 {
355 raw_string_ostream OSS(OutStr);
356
357 if (isSimple())
358 OSS << Node->getNumber() << ':';
359 else
360 Node->print(OSS);
361 }
362
363 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
364
365 // Process string output to make it nicer...
366 for (unsigned i = 0; i != OutStr.length(); ++i)
367 if (OutStr[i] == '\n') { // Left justify
368 OutStr[i] = '\\';
369 OutStr.insert(OutStr.begin()+i+1, 'l');
370 }
371 return OutStr;
372 }
373 };
374 }
375
viewCFG() const376 void MachineFunction::viewCFG() const
377 {
378 #ifndef NDEBUG
379 ViewGraph(this, "mf" + getFunction()->getNameStr());
380 #else
381 errs() << "MachineFunction::viewCFG is only available in debug builds on "
382 << "systems with Graphviz or gv!\n";
383 #endif // NDEBUG
384 }
385
viewCFGOnly() const386 void MachineFunction::viewCFGOnly() const
387 {
388 #ifndef NDEBUG
389 ViewGraph(this, "mf" + getFunction()->getNameStr(), true);
390 #else
391 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
392 << "systems with Graphviz or gv!\n";
393 #endif // NDEBUG
394 }
395
396 /// addLiveIn - Add the specified physical register as a live-in value and
397 /// create a corresponding virtual register for it.
addLiveIn(unsigned PReg,const TargetRegisterClass * RC)398 unsigned MachineFunction::addLiveIn(unsigned PReg,
399 const TargetRegisterClass *RC) {
400 MachineRegisterInfo &MRI = getRegInfo();
401 unsigned VReg = MRI.getLiveInVirtReg(PReg);
402 if (VReg) {
403 assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
404 return VReg;
405 }
406 VReg = MRI.createVirtualRegister(RC);
407 MRI.addLiveIn(PReg, VReg);
408 return VReg;
409 }
410
411 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
412 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
413 /// normal 'L' label is returned.
getJTISymbol(unsigned JTI,MCContext & Ctx,bool isLinkerPrivate) const414 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
415 bool isLinkerPrivate) const {
416 assert(JumpTableInfo && "No jump tables");
417
418 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
419 const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
420
421 const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
422 MAI.getPrivateGlobalPrefix();
423 SmallString<60> Name;
424 raw_svector_ostream(Name)
425 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
426 return Ctx.GetOrCreateSymbol(Name.str());
427 }
428
429
430 //===----------------------------------------------------------------------===//
431 // MachineFrameInfo implementation
432 //===----------------------------------------------------------------------===//
433
434 /// CreateFixedObject - Create a new object at a fixed location on the stack.
435 /// All fixed objects should be created before other objects are created for
436 /// efficiency. By default, fixed objects are immutable. This returns an
437 /// index with a negative value.
438 ///
CreateFixedObject(uint64_t Size,int64_t SPOffset,bool Immutable)439 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
440 bool Immutable) {
441 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
442 // The alignment of the frame index can be determined from its offset from
443 // the incoming frame position. If the frame object is at offset 32 and
444 // the stack is guaranteed to be 16-byte aligned, then we know that the
445 // object is 16-byte aligned.
446 unsigned StackAlign = TFI.getStackAlignment();
447 unsigned Align = MinAlign(SPOffset, StackAlign);
448 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
449 /*isSS*/false, false));
450 return -++NumFixedObjects;
451 }
452
453
454 BitVector
getPristineRegs(const MachineBasicBlock * MBB) const455 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
456 assert(MBB && "MBB must be valid");
457 const MachineFunction *MF = MBB->getParent();
458 assert(MF && "MBB must be part of a MachineFunction");
459 const TargetMachine &TM = MF->getTarget();
460 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
461 BitVector BV(TRI->getNumRegs());
462
463 // Before CSI is calculated, no registers are considered pristine. They can be
464 // freely used and PEI will make sure they are saved.
465 if (!isCalleeSavedInfoValid())
466 return BV;
467
468 for (const unsigned *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
469 BV.set(*CSR);
470
471 // The entry MBB always has all CSRs pristine.
472 if (MBB == &MF->front())
473 return BV;
474
475 // On other MBBs the saved CSRs are not pristine.
476 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
477 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
478 E = CSI.end(); I != E; ++I)
479 BV.reset(I->getReg());
480
481 return BV;
482 }
483
484
print(const MachineFunction & MF,raw_ostream & OS) const485 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
486 if (Objects.empty()) return;
487
488 const TargetFrameInfo *FI = MF.getTarget().getFrameInfo();
489 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
490
491 OS << "Frame Objects:\n";
492
493 for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
494 const StackObject &SO = Objects[i];
495 OS << " fi#" << (int)(i-NumFixedObjects) << ": ";
496 if (SO.Size == ~0ULL) {
497 OS << "dead\n";
498 continue;
499 }
500 if (SO.Size == 0)
501 OS << "variable sized";
502 else
503 OS << "size=" << SO.Size;
504 OS << ", align=" << SO.Alignment;
505
506 if (i < NumFixedObjects)
507 OS << ", fixed";
508 if (i < NumFixedObjects || SO.SPOffset != -1) {
509 int64_t Off = SO.SPOffset - ValOffset;
510 OS << ", at location [SP";
511 if (Off > 0)
512 OS << "+" << Off;
513 else if (Off < 0)
514 OS << Off;
515 OS << "]";
516 }
517 OS << "\n";
518 }
519 }
520
dump(const MachineFunction & MF) const521 void MachineFrameInfo::dump(const MachineFunction &MF) const {
522 print(MF, dbgs());
523 }
524
525 //===----------------------------------------------------------------------===//
526 // MachineJumpTableInfo implementation
527 //===----------------------------------------------------------------------===//
528
529 /// getEntrySize - Return the size of each entry in the jump table.
getEntrySize(const TargetData & TD) const530 unsigned MachineJumpTableInfo::getEntrySize(const TargetData &TD) const {
531 // The size of a jump table entry is 4 bytes unless the entry is just the
532 // address of a block, in which case it is the pointer size.
533 switch (getEntryKind()) {
534 case MachineJumpTableInfo::EK_BlockAddress:
535 return TD.getPointerSize();
536 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
537 case MachineJumpTableInfo::EK_LabelDifference32:
538 case MachineJumpTableInfo::EK_Custom32:
539 return 4;
540 case MachineJumpTableInfo::EK_Inline:
541 return 0;
542 }
543 assert(0 && "Unknown jump table encoding!");
544 return ~0;
545 }
546
547 /// getEntryAlignment - Return the alignment of each entry in the jump table.
getEntryAlignment(const TargetData & TD) const548 unsigned MachineJumpTableInfo::getEntryAlignment(const TargetData &TD) const {
549 // The alignment of a jump table entry is the alignment of int32 unless the
550 // entry is just the address of a block, in which case it is the pointer
551 // alignment.
552 switch (getEntryKind()) {
553 case MachineJumpTableInfo::EK_BlockAddress:
554 return TD.getPointerABIAlignment();
555 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
556 case MachineJumpTableInfo::EK_LabelDifference32:
557 case MachineJumpTableInfo::EK_Custom32:
558 return TD.getABIIntegerTypeAlignment(32);
559 case MachineJumpTableInfo::EK_Inline:
560 return 1;
561 }
562 assert(0 && "Unknown jump table encoding!");
563 return ~0;
564 }
565
566 /// createJumpTableIndex - Create a new jump table entry in the jump table info.
567 ///
createJumpTableIndex(const std::vector<MachineBasicBlock * > & DestBBs)568 unsigned MachineJumpTableInfo::createJumpTableIndex(
569 const std::vector<MachineBasicBlock*> &DestBBs) {
570 assert(!DestBBs.empty() && "Cannot create an empty jump table!");
571 JumpTables.push_back(MachineJumpTableEntry(DestBBs));
572 return JumpTables.size()-1;
573 }
574
575 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
576 /// the jump tables to branch to New instead.
ReplaceMBBInJumpTables(MachineBasicBlock * Old,MachineBasicBlock * New)577 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
578 MachineBasicBlock *New) {
579 assert(Old != New && "Not making a change?");
580 bool MadeChange = false;
581 for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
582 ReplaceMBBInJumpTable(i, Old, New);
583 return MadeChange;
584 }
585
586 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
587 /// the jump table to branch to New instead.
ReplaceMBBInJumpTable(unsigned Idx,MachineBasicBlock * Old,MachineBasicBlock * New)588 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
589 MachineBasicBlock *Old,
590 MachineBasicBlock *New) {
591 assert(Old != New && "Not making a change?");
592 bool MadeChange = false;
593 MachineJumpTableEntry &JTE = JumpTables[Idx];
594 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
595 if (JTE.MBBs[j] == Old) {
596 JTE.MBBs[j] = New;
597 MadeChange = true;
598 }
599 return MadeChange;
600 }
601
print(raw_ostream & OS) const602 void MachineJumpTableInfo::print(raw_ostream &OS) const {
603 if (JumpTables.empty()) return;
604
605 OS << "Jump Tables:\n";
606
607 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
608 OS << " jt#" << i << ": ";
609 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
610 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
611 }
612
613 OS << '\n';
614 }
615
dump() const616 void MachineJumpTableInfo::dump() const { print(dbgs()); }
617
618
619 //===----------------------------------------------------------------------===//
620 // MachineConstantPool implementation
621 //===----------------------------------------------------------------------===//
622
getType() const623 const Type *MachineConstantPoolEntry::getType() const {
624 if (isMachineConstantPoolEntry())
625 return Val.MachineCPVal->getType();
626 return Val.ConstVal->getType();
627 }
628
629
getRelocationInfo() const630 unsigned MachineConstantPoolEntry::getRelocationInfo() const {
631 if (isMachineConstantPoolEntry())
632 return Val.MachineCPVal->getRelocationInfo();
633 return Val.ConstVal->getRelocationInfo();
634 }
635
~MachineConstantPool()636 MachineConstantPool::~MachineConstantPool() {
637 for (unsigned i = 0, e = Constants.size(); i != e; ++i)
638 if (Constants[i].isMachineConstantPoolEntry())
639 delete Constants[i].Val.MachineCPVal;
640 }
641
642 /// CanShareConstantPoolEntry - Test whether the given two constants
643 /// can be allocated the same constant pool entry.
CanShareConstantPoolEntry(const Constant * A,const Constant * B,const TargetData * TD)644 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
645 const TargetData *TD) {
646 // Handle the trivial case quickly.
647 if (A == B) return true;
648
649 // If they have the same type but weren't the same constant, quickly
650 // reject them.
651 if (A->getType() == B->getType()) return false;
652
653 // For now, only support constants with the same size.
654 if (TD->getTypeStoreSize(A->getType()) != TD->getTypeStoreSize(B->getType()))
655 return false;
656
657 // If a floating-point value and an integer value have the same encoding,
658 // they can share a constant-pool entry.
659 if (const ConstantFP *AFP = dyn_cast<ConstantFP>(A))
660 if (const ConstantInt *BI = dyn_cast<ConstantInt>(B))
661 return AFP->getValueAPF().bitcastToAPInt() == BI->getValue();
662 if (const ConstantFP *BFP = dyn_cast<ConstantFP>(B))
663 if (const ConstantInt *AI = dyn_cast<ConstantInt>(A))
664 return BFP->getValueAPF().bitcastToAPInt() == AI->getValue();
665
666 // Two vectors can share an entry if each pair of corresponding
667 // elements could.
668 if (const ConstantVector *AV = dyn_cast<ConstantVector>(A))
669 if (const ConstantVector *BV = dyn_cast<ConstantVector>(B)) {
670 if (AV->getType()->getNumElements() != BV->getType()->getNumElements())
671 return false;
672 for (unsigned i = 0, e = AV->getType()->getNumElements(); i != e; ++i)
673 if (!CanShareConstantPoolEntry(AV->getOperand(i),
674 BV->getOperand(i), TD))
675 return false;
676 return true;
677 }
678
679 // TODO: Handle other cases.
680
681 return false;
682 }
683
684 /// getConstantPoolIndex - Create a new entry in the constant pool or return
685 /// an existing one. User must specify the log2 of the minimum required
686 /// alignment for the object.
687 ///
getConstantPoolIndex(const Constant * C,unsigned Alignment)688 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
689 unsigned Alignment) {
690 assert(Alignment && "Alignment must be specified!");
691 if (Alignment > PoolAlignment) PoolAlignment = Alignment;
692
693 // Check to see if we already have this constant.
694 //
695 // FIXME, this could be made much more efficient for large constant pools.
696 for (unsigned i = 0, e = Constants.size(); i != e; ++i)
697 if (!Constants[i].isMachineConstantPoolEntry() &&
698 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C, TD)) {
699 if ((unsigned)Constants[i].getAlignment() < Alignment)
700 Constants[i].Alignment = Alignment;
701 return i;
702 }
703
704 Constants.push_back(MachineConstantPoolEntry(C, Alignment));
705 return Constants.size()-1;
706 }
707
getConstantPoolIndex(MachineConstantPoolValue * V,unsigned Alignment)708 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
709 unsigned Alignment) {
710 assert(Alignment && "Alignment must be specified!");
711 if (Alignment > PoolAlignment) PoolAlignment = Alignment;
712
713 // Check to see if we already have this constant.
714 //
715 // FIXME, this could be made much more efficient for large constant pools.
716 int Idx = V->getExistingMachineCPValue(this, Alignment);
717 if (Idx != -1)
718 return (unsigned)Idx;
719
720 Constants.push_back(MachineConstantPoolEntry(V, Alignment));
721 return Constants.size()-1;
722 }
723
print(raw_ostream & OS) const724 void MachineConstantPool::print(raw_ostream &OS) const {
725 if (Constants.empty()) return;
726
727 OS << "Constant Pool:\n";
728 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
729 OS << " cp#" << i << ": ";
730 if (Constants[i].isMachineConstantPoolEntry())
731 Constants[i].Val.MachineCPVal->print(OS);
732 else
733 OS << *(Value*)Constants[i].Val.ConstVal;
734 OS << ", align=" << Constants[i].getAlignment();
735 OS << "\n";
736 }
737 }
738
dump() const739 void MachineConstantPool::dump() const { print(dbgs()); }
740