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/ADT/STLExtras.h"
18 #include "llvm/ADT/SmallString.h"
19 #include "llvm/Analysis/ConstantFolding.h"
20 #include "llvm/Assembly/Writer.h"
21 #include "llvm/CodeGen/MachineConstantPool.h"
22 #include "llvm/CodeGen/MachineFrameInfo.h"
23 #include "llvm/CodeGen/MachineFunctionPass.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/DebugInfo.h"
30 #include "llvm/IR/DataLayout.h"
31 #include "llvm/IR/Function.h"
32 #include "llvm/MC/MCAsmInfo.h"
33 #include "llvm/MC/MCContext.h"
34 #include "llvm/Support/Debug.h"
35 #include "llvm/Support/GraphWriter.h"
36 #include "llvm/Support/raw_ostream.h"
37 #include "llvm/Target/TargetFrameLowering.h"
38 #include "llvm/Target/TargetLowering.h"
39 #include "llvm/Target/TargetMachine.h"
40 using namespace llvm;
41
42 //===----------------------------------------------------------------------===//
43 // MachineFunction implementation
44 //===----------------------------------------------------------------------===//
45
46 // Out of line virtual method.
~MachineFunctionInfo()47 MachineFunctionInfo::~MachineFunctionInfo() {}
48
deleteNode(MachineBasicBlock * MBB)49 void ilist_traits<MachineBasicBlock>::deleteNode(MachineBasicBlock *MBB) {
50 MBB->getParent()->DeleteMachineBasicBlock(MBB);
51 }
52
MachineFunction(const Function * F,const TargetMachine & TM,unsigned FunctionNum,MachineModuleInfo & mmi,GCModuleInfo * gmi)53 MachineFunction::MachineFunction(const Function *F, const TargetMachine &TM,
54 unsigned FunctionNum, MachineModuleInfo &mmi,
55 GCModuleInfo* gmi)
56 : Fn(F), Target(TM), Ctx(mmi.getContext()), MMI(mmi), GMI(gmi) {
57 if (TM.getRegisterInfo())
58 RegInfo = new (Allocator) MachineRegisterInfo(TM);
59 else
60 RegInfo = 0;
61
62 MFInfo = 0;
63 FrameInfo =
64 new (Allocator) MachineFrameInfo(TM,!F->hasFnAttribute("no-realign-stack"));
65
66 if (Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
67 Attribute::StackAlignment))
68 FrameInfo->ensureMaxAlignment(Fn->getAttributes().
69 getStackAlignment(AttributeSet::FunctionIndex));
70
71 ConstantPool = new (Allocator) MachineConstantPool(TM);
72 Alignment = TM.getTargetLowering()->getMinFunctionAlignment();
73
74 // FIXME: Shouldn't use pref alignment if explicit alignment is set on Fn.
75 if (!Fn->getAttributes().hasAttribute(AttributeSet::FunctionIndex,
76 Attribute::OptimizeForSize))
77 Alignment = std::max(Alignment,
78 TM.getTargetLowering()->getPrefFunctionAlignment());
79
80 FunctionNumber = FunctionNum;
81 JumpTableInfo = 0;
82 }
83
~MachineFunction()84 MachineFunction::~MachineFunction() {
85 // Don't call destructors on MachineInstr and MachineOperand. All of their
86 // memory comes from the BumpPtrAllocator which is about to be purged.
87 //
88 // Do call MachineBasicBlock destructors, it contains std::vectors.
89 for (iterator I = begin(), E = end(); I != E; I = BasicBlocks.erase(I))
90 I->Insts.clearAndLeakNodesUnsafely();
91
92 InstructionRecycler.clear(Allocator);
93 OperandRecycler.clear(Allocator);
94 BasicBlockRecycler.clear(Allocator);
95 if (RegInfo) {
96 RegInfo->~MachineRegisterInfo();
97 Allocator.Deallocate(RegInfo);
98 }
99 if (MFInfo) {
100 MFInfo->~MachineFunctionInfo();
101 Allocator.Deallocate(MFInfo);
102 }
103
104 FrameInfo->~MachineFrameInfo();
105 Allocator.Deallocate(FrameInfo);
106
107 ConstantPool->~MachineConstantPool();
108 Allocator.Deallocate(ConstantPool);
109
110 if (JumpTableInfo) {
111 JumpTableInfo->~MachineJumpTableInfo();
112 Allocator.Deallocate(JumpTableInfo);
113 }
114 }
115
116 /// getOrCreateJumpTableInfo - Get the JumpTableInfo for this function, if it
117 /// does already exist, allocate one.
118 MachineJumpTableInfo *MachineFunction::
getOrCreateJumpTableInfo(unsigned EntryKind)119 getOrCreateJumpTableInfo(unsigned EntryKind) {
120 if (JumpTableInfo) return JumpTableInfo;
121
122 JumpTableInfo = new (Allocator)
123 MachineJumpTableInfo((MachineJumpTableInfo::JTEntryKind)EntryKind);
124 return JumpTableInfo;
125 }
126
127 /// RenumberBlocks - This discards all of the MachineBasicBlock numbers and
128 /// recomputes them. This guarantees that the MBB numbers are sequential,
129 /// dense, and match the ordering of the blocks within the function. If a
130 /// specific MachineBasicBlock is specified, only that block and those after
131 /// it are renumbered.
RenumberBlocks(MachineBasicBlock * MBB)132 void MachineFunction::RenumberBlocks(MachineBasicBlock *MBB) {
133 if (empty()) { MBBNumbering.clear(); return; }
134 MachineFunction::iterator MBBI, E = end();
135 if (MBB == 0)
136 MBBI = begin();
137 else
138 MBBI = MBB;
139
140 // Figure out the block number this should have.
141 unsigned BlockNo = 0;
142 if (MBBI != begin())
143 BlockNo = prior(MBBI)->getNumber()+1;
144
145 for (; MBBI != E; ++MBBI, ++BlockNo) {
146 if (MBBI->getNumber() != (int)BlockNo) {
147 // Remove use of the old number.
148 if (MBBI->getNumber() != -1) {
149 assert(MBBNumbering[MBBI->getNumber()] == &*MBBI &&
150 "MBB number mismatch!");
151 MBBNumbering[MBBI->getNumber()] = 0;
152 }
153
154 // If BlockNo is already taken, set that block's number to -1.
155 if (MBBNumbering[BlockNo])
156 MBBNumbering[BlockNo]->setNumber(-1);
157
158 MBBNumbering[BlockNo] = MBBI;
159 MBBI->setNumber(BlockNo);
160 }
161 }
162
163 // Okay, all the blocks are renumbered. If we have compactified the block
164 // numbering, shrink MBBNumbering now.
165 assert(BlockNo <= MBBNumbering.size() && "Mismatch!");
166 MBBNumbering.resize(BlockNo);
167 }
168
169 /// CreateMachineInstr - Allocate a new MachineInstr. Use this instead
170 /// of `new MachineInstr'.
171 ///
172 MachineInstr *
CreateMachineInstr(const MCInstrDesc & MCID,DebugLoc DL,bool NoImp)173 MachineFunction::CreateMachineInstr(const MCInstrDesc &MCID,
174 DebugLoc DL, bool NoImp) {
175 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
176 MachineInstr(*this, MCID, DL, NoImp);
177 }
178
179 /// CloneMachineInstr - Create a new MachineInstr which is a copy of the
180 /// 'Orig' instruction, identical in all ways except the instruction
181 /// has no parent, prev, or next.
182 ///
183 MachineInstr *
CloneMachineInstr(const MachineInstr * Orig)184 MachineFunction::CloneMachineInstr(const MachineInstr *Orig) {
185 return new (InstructionRecycler.Allocate<MachineInstr>(Allocator))
186 MachineInstr(*this, *Orig);
187 }
188
189 /// DeleteMachineInstr - Delete the given MachineInstr.
190 ///
191 /// This function also serves as the MachineInstr destructor - the real
192 /// ~MachineInstr() destructor must be empty.
193 void
DeleteMachineInstr(MachineInstr * MI)194 MachineFunction::DeleteMachineInstr(MachineInstr *MI) {
195 // Strip it for parts. The operand array and the MI object itself are
196 // independently recyclable.
197 if (MI->Operands)
198 deallocateOperandArray(MI->CapOperands, MI->Operands);
199 // Don't call ~MachineInstr() which must be trivial anyway because
200 // ~MachineFunction drops whole lists of MachineInstrs wihout calling their
201 // destructors.
202 InstructionRecycler.Deallocate(Allocator, MI);
203 }
204
205 /// CreateMachineBasicBlock - Allocate a new MachineBasicBlock. Use this
206 /// instead of `new MachineBasicBlock'.
207 ///
208 MachineBasicBlock *
CreateMachineBasicBlock(const BasicBlock * bb)209 MachineFunction::CreateMachineBasicBlock(const BasicBlock *bb) {
210 return new (BasicBlockRecycler.Allocate<MachineBasicBlock>(Allocator))
211 MachineBasicBlock(*this, bb);
212 }
213
214 /// DeleteMachineBasicBlock - Delete the given MachineBasicBlock.
215 ///
216 void
DeleteMachineBasicBlock(MachineBasicBlock * MBB)217 MachineFunction::DeleteMachineBasicBlock(MachineBasicBlock *MBB) {
218 assert(MBB->getParent() == this && "MBB parent mismatch!");
219 MBB->~MachineBasicBlock();
220 BasicBlockRecycler.Deallocate(Allocator, MBB);
221 }
222
223 MachineMemOperand *
getMachineMemOperand(MachinePointerInfo PtrInfo,unsigned f,uint64_t s,unsigned base_alignment,const MDNode * TBAAInfo,const MDNode * Ranges)224 MachineFunction::getMachineMemOperand(MachinePointerInfo PtrInfo, unsigned f,
225 uint64_t s, unsigned base_alignment,
226 const MDNode *TBAAInfo,
227 const MDNode *Ranges) {
228 return new (Allocator) MachineMemOperand(PtrInfo, f, s, base_alignment,
229 TBAAInfo, Ranges);
230 }
231
232 MachineMemOperand *
getMachineMemOperand(const MachineMemOperand * MMO,int64_t Offset,uint64_t Size)233 MachineFunction::getMachineMemOperand(const MachineMemOperand *MMO,
234 int64_t Offset, uint64_t Size) {
235 return new (Allocator)
236 MachineMemOperand(MachinePointerInfo(MMO->getValue(),
237 MMO->getOffset()+Offset),
238 MMO->getFlags(), Size,
239 MMO->getBaseAlignment(), 0);
240 }
241
242 MachineInstr::mmo_iterator
allocateMemRefsArray(unsigned long Num)243 MachineFunction::allocateMemRefsArray(unsigned long Num) {
244 return Allocator.Allocate<MachineMemOperand *>(Num);
245 }
246
247 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractLoadMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)248 MachineFunction::extractLoadMemRefs(MachineInstr::mmo_iterator Begin,
249 MachineInstr::mmo_iterator End) {
250 // Count the number of load mem refs.
251 unsigned Num = 0;
252 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
253 if ((*I)->isLoad())
254 ++Num;
255
256 // Allocate a new array and populate it with the load information.
257 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
258 unsigned Index = 0;
259 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
260 if ((*I)->isLoad()) {
261 if (!(*I)->isStore())
262 // Reuse the MMO.
263 Result[Index] = *I;
264 else {
265 // Clone the MMO and unset the store flag.
266 MachineMemOperand *JustLoad =
267 getMachineMemOperand((*I)->getPointerInfo(),
268 (*I)->getFlags() & ~MachineMemOperand::MOStore,
269 (*I)->getSize(), (*I)->getBaseAlignment(),
270 (*I)->getTBAAInfo());
271 Result[Index] = JustLoad;
272 }
273 ++Index;
274 }
275 }
276 return std::make_pair(Result, Result + Num);
277 }
278
279 std::pair<MachineInstr::mmo_iterator, MachineInstr::mmo_iterator>
extractStoreMemRefs(MachineInstr::mmo_iterator Begin,MachineInstr::mmo_iterator End)280 MachineFunction::extractStoreMemRefs(MachineInstr::mmo_iterator Begin,
281 MachineInstr::mmo_iterator End) {
282 // Count the number of load mem refs.
283 unsigned Num = 0;
284 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I)
285 if ((*I)->isStore())
286 ++Num;
287
288 // Allocate a new array and populate it with the store information.
289 MachineInstr::mmo_iterator Result = allocateMemRefsArray(Num);
290 unsigned Index = 0;
291 for (MachineInstr::mmo_iterator I = Begin; I != End; ++I) {
292 if ((*I)->isStore()) {
293 if (!(*I)->isLoad())
294 // Reuse the MMO.
295 Result[Index] = *I;
296 else {
297 // Clone the MMO and unset the load flag.
298 MachineMemOperand *JustStore =
299 getMachineMemOperand((*I)->getPointerInfo(),
300 (*I)->getFlags() & ~MachineMemOperand::MOLoad,
301 (*I)->getSize(), (*I)->getBaseAlignment(),
302 (*I)->getTBAAInfo());
303 Result[Index] = JustStore;
304 }
305 ++Index;
306 }
307 }
308 return std::make_pair(Result, Result + Num);
309 }
310
311 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const312 void MachineFunction::dump() const {
313 print(dbgs());
314 }
315 #endif
316
getName() const317 StringRef MachineFunction::getName() const {
318 assert(getFunction() && "No function!");
319 return getFunction()->getName();
320 }
321
print(raw_ostream & OS,SlotIndexes * Indexes) const322 void MachineFunction::print(raw_ostream &OS, SlotIndexes *Indexes) const {
323 OS << "# Machine code for function " << getName() << ": ";
324 if (RegInfo) {
325 OS << (RegInfo->isSSA() ? "SSA" : "Post SSA");
326 if (!RegInfo->tracksLiveness())
327 OS << ", not tracking liveness";
328 }
329 OS << '\n';
330
331 // Print Frame Information
332 FrameInfo->print(*this, OS);
333
334 // Print JumpTable Information
335 if (JumpTableInfo)
336 JumpTableInfo->print(OS);
337
338 // Print Constant Pool
339 ConstantPool->print(OS);
340
341 const TargetRegisterInfo *TRI = getTarget().getRegisterInfo();
342
343 if (RegInfo && !RegInfo->livein_empty()) {
344 OS << "Function Live Ins: ";
345 for (MachineRegisterInfo::livein_iterator
346 I = RegInfo->livein_begin(), E = RegInfo->livein_end(); I != E; ++I) {
347 OS << PrintReg(I->first, TRI);
348 if (I->second)
349 OS << " in " << PrintReg(I->second, TRI);
350 if (llvm::next(I) != E)
351 OS << ", ";
352 }
353 OS << '\n';
354 }
355
356 for (const_iterator BB = begin(), E = end(); BB != E; ++BB) {
357 OS << '\n';
358 BB->print(OS, Indexes);
359 }
360
361 OS << "\n# End machine code for function " << getName() << ".\n\n";
362 }
363
364 namespace llvm {
365 template<>
366 struct DOTGraphTraits<const MachineFunction*> : public DefaultDOTGraphTraits {
367
DOTGraphTraitsllvm::DOTGraphTraits368 DOTGraphTraits (bool isSimple=false) : DefaultDOTGraphTraits(isSimple) {}
369
getGraphNamellvm::DOTGraphTraits370 static std::string getGraphName(const MachineFunction *F) {
371 return "CFG for '" + F->getName().str() + "' function";
372 }
373
getNodeLabelllvm::DOTGraphTraits374 std::string getNodeLabel(const MachineBasicBlock *Node,
375 const MachineFunction *Graph) {
376 std::string OutStr;
377 {
378 raw_string_ostream OSS(OutStr);
379
380 if (isSimple()) {
381 OSS << "BB#" << Node->getNumber();
382 if (const BasicBlock *BB = Node->getBasicBlock())
383 OSS << ": " << BB->getName();
384 } else
385 Node->print(OSS);
386 }
387
388 if (OutStr[0] == '\n') OutStr.erase(OutStr.begin());
389
390 // Process string output to make it nicer...
391 for (unsigned i = 0; i != OutStr.length(); ++i)
392 if (OutStr[i] == '\n') { // Left justify
393 OutStr[i] = '\\';
394 OutStr.insert(OutStr.begin()+i+1, 'l');
395 }
396 return OutStr;
397 }
398 };
399 }
400
viewCFG() const401 void MachineFunction::viewCFG() const
402 {
403 #ifndef NDEBUG
404 ViewGraph(this, "mf" + getName());
405 #else
406 errs() << "MachineFunction::viewCFG is only available in debug builds on "
407 << "systems with Graphviz or gv!\n";
408 #endif // NDEBUG
409 }
410
viewCFGOnly() const411 void MachineFunction::viewCFGOnly() const
412 {
413 #ifndef NDEBUG
414 ViewGraph(this, "mf" + getName(), true);
415 #else
416 errs() << "MachineFunction::viewCFGOnly is only available in debug builds on "
417 << "systems with Graphviz or gv!\n";
418 #endif // NDEBUG
419 }
420
421 /// addLiveIn - Add the specified physical register as a live-in value and
422 /// create a corresponding virtual register for it.
addLiveIn(unsigned PReg,const TargetRegisterClass * RC)423 unsigned MachineFunction::addLiveIn(unsigned PReg,
424 const TargetRegisterClass *RC) {
425 MachineRegisterInfo &MRI = getRegInfo();
426 unsigned VReg = MRI.getLiveInVirtReg(PReg);
427 if (VReg) {
428 assert(MRI.getRegClass(VReg) == RC && "Register class mismatch!");
429 return VReg;
430 }
431 VReg = MRI.createVirtualRegister(RC);
432 MRI.addLiveIn(PReg, VReg);
433 return VReg;
434 }
435
436 /// getJTISymbol - Return the MCSymbol for the specified non-empty jump table.
437 /// If isLinkerPrivate is specified, an 'l' label is returned, otherwise a
438 /// normal 'L' label is returned.
getJTISymbol(unsigned JTI,MCContext & Ctx,bool isLinkerPrivate) const439 MCSymbol *MachineFunction::getJTISymbol(unsigned JTI, MCContext &Ctx,
440 bool isLinkerPrivate) const {
441 assert(JumpTableInfo && "No jump tables");
442 assert(JTI < JumpTableInfo->getJumpTables().size() && "Invalid JTI!");
443 const MCAsmInfo &MAI = *getTarget().getMCAsmInfo();
444
445 const char *Prefix = isLinkerPrivate ? MAI.getLinkerPrivateGlobalPrefix() :
446 MAI.getPrivateGlobalPrefix();
447 SmallString<60> Name;
448 raw_svector_ostream(Name)
449 << Prefix << "JTI" << getFunctionNumber() << '_' << JTI;
450 return Ctx.GetOrCreateSymbol(Name.str());
451 }
452
453 /// getPICBaseSymbol - Return a function-local symbol to represent the PIC
454 /// base.
getPICBaseSymbol() const455 MCSymbol *MachineFunction::getPICBaseSymbol() const {
456 const MCAsmInfo &MAI = *Target.getMCAsmInfo();
457 return Ctx.GetOrCreateSymbol(Twine(MAI.getPrivateGlobalPrefix())+
458 Twine(getFunctionNumber())+"$pb");
459 }
460
461 //===----------------------------------------------------------------------===//
462 // MachineFrameInfo implementation
463 //===----------------------------------------------------------------------===//
464
getFrameLowering() const465 const TargetFrameLowering *MachineFrameInfo::getFrameLowering() const {
466 return TM.getFrameLowering();
467 }
468
469 /// ensureMaxAlignment - Make sure the function is at least Align bytes
470 /// aligned.
ensureMaxAlignment(unsigned Align)471 void MachineFrameInfo::ensureMaxAlignment(unsigned Align) {
472 if (!getFrameLowering()->isStackRealignable() || !RealignOption)
473 assert(Align <= getFrameLowering()->getStackAlignment() &&
474 "For targets without stack realignment, Align is out of limit!");
475 if (MaxAlignment < Align) MaxAlignment = Align;
476 }
477
478 /// clampStackAlignment - Clamp the alignment if requested and emit a warning.
clampStackAlignment(bool ShouldClamp,unsigned Align,unsigned StackAlign)479 static inline unsigned clampStackAlignment(bool ShouldClamp, unsigned Align,
480 unsigned StackAlign) {
481 if (!ShouldClamp || Align <= StackAlign)
482 return Align;
483 DEBUG(dbgs() << "Warning: requested alignment " << Align
484 << " exceeds the stack alignment " << StackAlign
485 << " when stack realignment is off" << '\n');
486 return StackAlign;
487 }
488
489 /// CreateStackObject - Create a new statically sized stack object, returning
490 /// a nonnegative identifier to represent it.
491 ///
CreateStackObject(uint64_t Size,unsigned Alignment,bool isSS,bool MayNeedSP,const AllocaInst * Alloca)492 int MachineFrameInfo::CreateStackObject(uint64_t Size, unsigned Alignment,
493 bool isSS, bool MayNeedSP, const AllocaInst *Alloca) {
494 assert(Size != 0 && "Cannot allocate zero size stack objects!");
495 Alignment =
496 clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
497 !RealignOption,
498 Alignment, getFrameLowering()->getStackAlignment());
499 Objects.push_back(StackObject(Size, Alignment, 0, false, isSS, MayNeedSP,
500 Alloca));
501 int Index = (int)Objects.size() - NumFixedObjects - 1;
502 assert(Index >= 0 && "Bad frame index!");
503 ensureMaxAlignment(Alignment);
504 return Index;
505 }
506
507 /// CreateSpillStackObject - Create a new statically sized stack object that
508 /// represents a spill slot, returning a nonnegative identifier to represent
509 /// it.
510 ///
CreateSpillStackObject(uint64_t Size,unsigned Alignment)511 int MachineFrameInfo::CreateSpillStackObject(uint64_t Size,
512 unsigned Alignment) {
513 Alignment =
514 clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
515 !RealignOption,
516 Alignment, getFrameLowering()->getStackAlignment());
517 CreateStackObject(Size, Alignment, true, false);
518 int Index = (int)Objects.size() - NumFixedObjects - 1;
519 ensureMaxAlignment(Alignment);
520 return Index;
521 }
522
523 /// CreateVariableSizedObject - Notify the MachineFrameInfo object that a
524 /// variable sized object has been created. This must be created whenever a
525 /// variable sized object is created, whether or not the index returned is
526 /// actually used.
527 ///
CreateVariableSizedObject(unsigned Alignment)528 int MachineFrameInfo::CreateVariableSizedObject(unsigned Alignment) {
529 HasVarSizedObjects = true;
530 Alignment =
531 clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
532 !RealignOption,
533 Alignment, getFrameLowering()->getStackAlignment());
534 Objects.push_back(StackObject(0, Alignment, 0, false, false, true, 0));
535 ensureMaxAlignment(Alignment);
536 return (int)Objects.size()-NumFixedObjects-1;
537 }
538
539 /// CreateFixedObject - Create a new object at a fixed location on the stack.
540 /// All fixed objects should be created before other objects are created for
541 /// efficiency. By default, fixed objects are immutable. This returns an
542 /// index with a negative value.
543 ///
CreateFixedObject(uint64_t Size,int64_t SPOffset,bool Immutable)544 int MachineFrameInfo::CreateFixedObject(uint64_t Size, int64_t SPOffset,
545 bool Immutable) {
546 assert(Size != 0 && "Cannot allocate zero size fixed stack objects!");
547 // The alignment of the frame index can be determined from its offset from
548 // the incoming frame position. If the frame object is at offset 32 and
549 // the stack is guaranteed to be 16-byte aligned, then we know that the
550 // object is 16-byte aligned.
551 unsigned StackAlign = getFrameLowering()->getStackAlignment();
552 unsigned Align = MinAlign(SPOffset, StackAlign);
553 Align =
554 clampStackAlignment(!getFrameLowering()->isStackRealignable() ||
555 !RealignOption,
556 Align, getFrameLowering()->getStackAlignment());
557 Objects.insert(Objects.begin(), StackObject(Size, Align, SPOffset, Immutable,
558 /*isSS*/ false,
559 /*NeedSP*/ false,
560 /*Alloca*/ 0));
561 return -++NumFixedObjects;
562 }
563
564
565 BitVector
getPristineRegs(const MachineBasicBlock * MBB) const566 MachineFrameInfo::getPristineRegs(const MachineBasicBlock *MBB) const {
567 assert(MBB && "MBB must be valid");
568 const MachineFunction *MF = MBB->getParent();
569 assert(MF && "MBB must be part of a MachineFunction");
570 const TargetMachine &TM = MF->getTarget();
571 const TargetRegisterInfo *TRI = TM.getRegisterInfo();
572 BitVector BV(TRI->getNumRegs());
573
574 // Before CSI is calculated, no registers are considered pristine. They can be
575 // freely used and PEI will make sure they are saved.
576 if (!isCalleeSavedInfoValid())
577 return BV;
578
579 for (const uint16_t *CSR = TRI->getCalleeSavedRegs(MF); CSR && *CSR; ++CSR)
580 BV.set(*CSR);
581
582 // The entry MBB always has all CSRs pristine.
583 if (MBB == &MF->front())
584 return BV;
585
586 // On other MBBs the saved CSRs are not pristine.
587 const std::vector<CalleeSavedInfo> &CSI = getCalleeSavedInfo();
588 for (std::vector<CalleeSavedInfo>::const_iterator I = CSI.begin(),
589 E = CSI.end(); I != E; ++I)
590 BV.reset(I->getReg());
591
592 return BV;
593 }
594
estimateStackSize(const MachineFunction & MF) const595 unsigned MachineFrameInfo::estimateStackSize(const MachineFunction &MF) const {
596 const TargetFrameLowering *TFI = MF.getTarget().getFrameLowering();
597 const TargetRegisterInfo *RegInfo = MF.getTarget().getRegisterInfo();
598 unsigned MaxAlign = getMaxAlignment();
599 int Offset = 0;
600
601 // This code is very, very similar to PEI::calculateFrameObjectOffsets().
602 // It really should be refactored to share code. Until then, changes
603 // should keep in mind that there's tight coupling between the two.
604
605 for (int i = getObjectIndexBegin(); i != 0; ++i) {
606 int FixedOff = -getObjectOffset(i);
607 if (FixedOff > Offset) Offset = FixedOff;
608 }
609 for (unsigned i = 0, e = getObjectIndexEnd(); i != e; ++i) {
610 if (isDeadObjectIndex(i))
611 continue;
612 Offset += getObjectSize(i);
613 unsigned Align = getObjectAlignment(i);
614 // Adjust to alignment boundary
615 Offset = (Offset+Align-1)/Align*Align;
616
617 MaxAlign = std::max(Align, MaxAlign);
618 }
619
620 if (adjustsStack() && TFI->hasReservedCallFrame(MF))
621 Offset += getMaxCallFrameSize();
622
623 // Round up the size to a multiple of the alignment. If the function has
624 // any calls or alloca's, align to the target's StackAlignment value to
625 // ensure that the callee's frame or the alloca data is suitably aligned;
626 // otherwise, for leaf functions, align to the TransientStackAlignment
627 // value.
628 unsigned StackAlign;
629 if (adjustsStack() || hasVarSizedObjects() ||
630 (RegInfo->needsStackRealignment(MF) && getObjectIndexEnd() != 0))
631 StackAlign = TFI->getStackAlignment();
632 else
633 StackAlign = TFI->getTransientStackAlignment();
634
635 // If the frame pointer is eliminated, all frame offsets will be relative to
636 // SP not FP. Align to MaxAlign so this works.
637 StackAlign = std::max(StackAlign, MaxAlign);
638 unsigned AlignMask = StackAlign - 1;
639 Offset = (Offset + AlignMask) & ~uint64_t(AlignMask);
640
641 return (unsigned)Offset;
642 }
643
print(const MachineFunction & MF,raw_ostream & OS) const644 void MachineFrameInfo::print(const MachineFunction &MF, raw_ostream &OS) const{
645 if (Objects.empty()) return;
646
647 const TargetFrameLowering *FI = MF.getTarget().getFrameLowering();
648 int ValOffset = (FI ? FI->getOffsetOfLocalArea() : 0);
649
650 OS << "Frame Objects:\n";
651
652 for (unsigned i = 0, e = Objects.size(); i != e; ++i) {
653 const StackObject &SO = Objects[i];
654 OS << " fi#" << (int)(i-NumFixedObjects) << ": ";
655 if (SO.Size == ~0ULL) {
656 OS << "dead\n";
657 continue;
658 }
659 if (SO.Size == 0)
660 OS << "variable sized";
661 else
662 OS << "size=" << SO.Size;
663 OS << ", align=" << SO.Alignment;
664
665 if (i < NumFixedObjects)
666 OS << ", fixed";
667 if (i < NumFixedObjects || SO.SPOffset != -1) {
668 int64_t Off = SO.SPOffset - ValOffset;
669 OS << ", at location [SP";
670 if (Off > 0)
671 OS << "+" << Off;
672 else if (Off < 0)
673 OS << Off;
674 OS << "]";
675 }
676 OS << "\n";
677 }
678 }
679
680 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump(const MachineFunction & MF) const681 void MachineFrameInfo::dump(const MachineFunction &MF) const {
682 print(MF, dbgs());
683 }
684 #endif
685
686 //===----------------------------------------------------------------------===//
687 // MachineJumpTableInfo implementation
688 //===----------------------------------------------------------------------===//
689
690 /// getEntrySize - Return the size of each entry in the jump table.
getEntrySize(const DataLayout & TD) const691 unsigned MachineJumpTableInfo::getEntrySize(const DataLayout &TD) const {
692 // The size of a jump table entry is 4 bytes unless the entry is just the
693 // address of a block, in which case it is the pointer size.
694 switch (getEntryKind()) {
695 case MachineJumpTableInfo::EK_BlockAddress:
696 return TD.getPointerSize();
697 case MachineJumpTableInfo::EK_GPRel64BlockAddress:
698 return 8;
699 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
700 case MachineJumpTableInfo::EK_LabelDifference32:
701 case MachineJumpTableInfo::EK_Custom32:
702 return 4;
703 case MachineJumpTableInfo::EK_Inline:
704 return 0;
705 }
706 llvm_unreachable("Unknown jump table encoding!");
707 }
708
709 /// getEntryAlignment - Return the alignment of each entry in the jump table.
getEntryAlignment(const DataLayout & TD) const710 unsigned MachineJumpTableInfo::getEntryAlignment(const DataLayout &TD) const {
711 // The alignment of a jump table entry is the alignment of int32 unless the
712 // entry is just the address of a block, in which case it is the pointer
713 // alignment.
714 switch (getEntryKind()) {
715 case MachineJumpTableInfo::EK_BlockAddress:
716 return TD.getPointerABIAlignment();
717 case MachineJumpTableInfo::EK_GPRel64BlockAddress:
718 return TD.getABIIntegerTypeAlignment(64);
719 case MachineJumpTableInfo::EK_GPRel32BlockAddress:
720 case MachineJumpTableInfo::EK_LabelDifference32:
721 case MachineJumpTableInfo::EK_Custom32:
722 return TD.getABIIntegerTypeAlignment(32);
723 case MachineJumpTableInfo::EK_Inline:
724 return 1;
725 }
726 llvm_unreachable("Unknown jump table encoding!");
727 }
728
729 /// createJumpTableIndex - Create a new jump table entry in the jump table info.
730 ///
createJumpTableIndex(const std::vector<MachineBasicBlock * > & DestBBs)731 unsigned MachineJumpTableInfo::createJumpTableIndex(
732 const std::vector<MachineBasicBlock*> &DestBBs) {
733 assert(!DestBBs.empty() && "Cannot create an empty jump table!");
734 JumpTables.push_back(MachineJumpTableEntry(DestBBs));
735 return JumpTables.size()-1;
736 }
737
738 /// ReplaceMBBInJumpTables - If Old is the target of any jump tables, update
739 /// the jump tables to branch to New instead.
ReplaceMBBInJumpTables(MachineBasicBlock * Old,MachineBasicBlock * New)740 bool MachineJumpTableInfo::ReplaceMBBInJumpTables(MachineBasicBlock *Old,
741 MachineBasicBlock *New) {
742 assert(Old != New && "Not making a change?");
743 bool MadeChange = false;
744 for (size_t i = 0, e = JumpTables.size(); i != e; ++i)
745 ReplaceMBBInJumpTable(i, Old, New);
746 return MadeChange;
747 }
748
749 /// ReplaceMBBInJumpTable - If Old is a target of the jump tables, update
750 /// the jump table to branch to New instead.
ReplaceMBBInJumpTable(unsigned Idx,MachineBasicBlock * Old,MachineBasicBlock * New)751 bool MachineJumpTableInfo::ReplaceMBBInJumpTable(unsigned Idx,
752 MachineBasicBlock *Old,
753 MachineBasicBlock *New) {
754 assert(Old != New && "Not making a change?");
755 bool MadeChange = false;
756 MachineJumpTableEntry &JTE = JumpTables[Idx];
757 for (size_t j = 0, e = JTE.MBBs.size(); j != e; ++j)
758 if (JTE.MBBs[j] == Old) {
759 JTE.MBBs[j] = New;
760 MadeChange = true;
761 }
762 return MadeChange;
763 }
764
print(raw_ostream & OS) const765 void MachineJumpTableInfo::print(raw_ostream &OS) const {
766 if (JumpTables.empty()) return;
767
768 OS << "Jump Tables:\n";
769
770 for (unsigned i = 0, e = JumpTables.size(); i != e; ++i) {
771 OS << " jt#" << i << ": ";
772 for (unsigned j = 0, f = JumpTables[i].MBBs.size(); j != f; ++j)
773 OS << " BB#" << JumpTables[i].MBBs[j]->getNumber();
774 }
775
776 OS << '\n';
777 }
778
779 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const780 void MachineJumpTableInfo::dump() const { print(dbgs()); }
781 #endif
782
783
784 //===----------------------------------------------------------------------===//
785 // MachineConstantPool implementation
786 //===----------------------------------------------------------------------===//
787
anchor()788 void MachineConstantPoolValue::anchor() { }
789
getDataLayout() const790 const DataLayout *MachineConstantPool::getDataLayout() const {
791 return TM.getDataLayout();
792 }
793
getType() const794 Type *MachineConstantPoolEntry::getType() const {
795 if (isMachineConstantPoolEntry())
796 return Val.MachineCPVal->getType();
797 return Val.ConstVal->getType();
798 }
799
800
getRelocationInfo() const801 unsigned MachineConstantPoolEntry::getRelocationInfo() const {
802 if (isMachineConstantPoolEntry())
803 return Val.MachineCPVal->getRelocationInfo();
804 return Val.ConstVal->getRelocationInfo();
805 }
806
~MachineConstantPool()807 MachineConstantPool::~MachineConstantPool() {
808 for (unsigned i = 0, e = Constants.size(); i != e; ++i)
809 if (Constants[i].isMachineConstantPoolEntry())
810 delete Constants[i].Val.MachineCPVal;
811 for (DenseSet<MachineConstantPoolValue*>::iterator I =
812 MachineCPVsSharingEntries.begin(), E = MachineCPVsSharingEntries.end();
813 I != E; ++I)
814 delete *I;
815 }
816
817 /// CanShareConstantPoolEntry - Test whether the given two constants
818 /// can be allocated the same constant pool entry.
CanShareConstantPoolEntry(const Constant * A,const Constant * B,const DataLayout * TD)819 static bool CanShareConstantPoolEntry(const Constant *A, const Constant *B,
820 const DataLayout *TD) {
821 // Handle the trivial case quickly.
822 if (A == B) return true;
823
824 // If they have the same type but weren't the same constant, quickly
825 // reject them.
826 if (A->getType() == B->getType()) return false;
827
828 // We can't handle structs or arrays.
829 if (isa<StructType>(A->getType()) || isa<ArrayType>(A->getType()) ||
830 isa<StructType>(B->getType()) || isa<ArrayType>(B->getType()))
831 return false;
832
833 // For now, only support constants with the same size.
834 uint64_t StoreSize = TD->getTypeStoreSize(A->getType());
835 if (StoreSize != TD->getTypeStoreSize(B->getType()) ||
836 StoreSize > 128)
837 return false;
838
839 Type *IntTy = IntegerType::get(A->getContext(), StoreSize*8);
840
841 // Try constant folding a bitcast of both instructions to an integer. If we
842 // get two identical ConstantInt's, then we are good to share them. We use
843 // the constant folding APIs to do this so that we get the benefit of
844 // DataLayout.
845 if (isa<PointerType>(A->getType()))
846 A = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
847 const_cast<Constant*>(A), TD);
848 else if (A->getType() != IntTy)
849 A = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
850 const_cast<Constant*>(A), TD);
851 if (isa<PointerType>(B->getType()))
852 B = ConstantFoldInstOperands(Instruction::PtrToInt, IntTy,
853 const_cast<Constant*>(B), TD);
854 else if (B->getType() != IntTy)
855 B = ConstantFoldInstOperands(Instruction::BitCast, IntTy,
856 const_cast<Constant*>(B), TD);
857
858 return A == B;
859 }
860
861 /// getConstantPoolIndex - Create a new entry in the constant pool or return
862 /// an existing one. User must specify the log2 of the minimum required
863 /// alignment for the object.
864 ///
getConstantPoolIndex(const Constant * C,unsigned Alignment)865 unsigned MachineConstantPool::getConstantPoolIndex(const Constant *C,
866 unsigned Alignment) {
867 assert(Alignment && "Alignment must be specified!");
868 if (Alignment > PoolAlignment) PoolAlignment = Alignment;
869
870 // Check to see if we already have this constant.
871 //
872 // FIXME, this could be made much more efficient for large constant pools.
873 for (unsigned i = 0, e = Constants.size(); i != e; ++i)
874 if (!Constants[i].isMachineConstantPoolEntry() &&
875 CanShareConstantPoolEntry(Constants[i].Val.ConstVal, C,
876 getDataLayout())) {
877 if ((unsigned)Constants[i].getAlignment() < Alignment)
878 Constants[i].Alignment = Alignment;
879 return i;
880 }
881
882 Constants.push_back(MachineConstantPoolEntry(C, Alignment));
883 return Constants.size()-1;
884 }
885
getConstantPoolIndex(MachineConstantPoolValue * V,unsigned Alignment)886 unsigned MachineConstantPool::getConstantPoolIndex(MachineConstantPoolValue *V,
887 unsigned Alignment) {
888 assert(Alignment && "Alignment must be specified!");
889 if (Alignment > PoolAlignment) PoolAlignment = Alignment;
890
891 // Check to see if we already have this constant.
892 //
893 // FIXME, this could be made much more efficient for large constant pools.
894 int Idx = V->getExistingMachineCPValue(this, Alignment);
895 if (Idx != -1) {
896 MachineCPVsSharingEntries.insert(V);
897 return (unsigned)Idx;
898 }
899
900 Constants.push_back(MachineConstantPoolEntry(V, Alignment));
901 return Constants.size()-1;
902 }
903
print(raw_ostream & OS) const904 void MachineConstantPool::print(raw_ostream &OS) const {
905 if (Constants.empty()) return;
906
907 OS << "Constant Pool:\n";
908 for (unsigned i = 0, e = Constants.size(); i != e; ++i) {
909 OS << " cp#" << i << ": ";
910 if (Constants[i].isMachineConstantPoolEntry())
911 Constants[i].Val.MachineCPVal->print(OS);
912 else
913 WriteAsOperand(OS, Constants[i].Val.ConstVal, /*PrintType=*/false);
914 OS << ", align=" << Constants[i].getAlignment();
915 OS << "\n";
916 }
917 }
918
919 #if !defined(NDEBUG) || defined(LLVM_ENABLE_DUMP)
dump() const920 void MachineConstantPool::dump() const { print(dbgs()); }
921 #endif
922