1 //===-- FunctionLoweringInfo.cpp ------------------------------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This implements routines for translating functions from LLVM IR into
13 //===----------------------------------------------------------------------===//
15 #include "llvm/CodeGen/FunctionLoweringInfo.h"
16 #include "llvm/ADT/PostOrderIterator.h"
17 #include "llvm/CodeGen/Analysis.h"
18 #include "llvm/CodeGen/MachineFrameInfo.h"
19 #include "llvm/CodeGen/MachineFunction.h"
20 #include "llvm/CodeGen/MachineInstrBuilder.h"
21 #include "llvm/CodeGen/MachineModuleInfo.h"
22 #include "llvm/CodeGen/MachineRegisterInfo.h"
23 #include "llvm/CodeGen/WinEHFuncInfo.h"
24 #include "llvm/IR/DataLayout.h"
25 #include "llvm/IR/DebugInfo.h"
26 #include "llvm/IR/DerivedTypes.h"
27 #include "llvm/IR/Function.h"
28 #include "llvm/IR/Instructions.h"
29 #include "llvm/IR/IntrinsicInst.h"
30 #include "llvm/IR/LLVMContext.h"
31 #include "llvm/IR/Module.h"
32 #include "llvm/Support/Debug.h"
33 #include "llvm/Support/ErrorHandling.h"
34 #include "llvm/Support/MathExtras.h"
35 #include "llvm/Support/raw_ostream.h"
36 #include "llvm/Target/TargetFrameLowering.h"
37 #include "llvm/Target/TargetInstrInfo.h"
38 #include "llvm/Target/TargetLowering.h"
39 #include "llvm/Target/TargetOptions.h"
40 #include "llvm/Target/TargetRegisterInfo.h"
41 #include "llvm/Target/TargetSubtargetInfo.h"
45 #define DEBUG_TYPE "function-lowering-info"
47 /// isUsedOutsideOfDefiningBlock - Return true if this instruction is used by
48 /// PHI nodes or outside of the basic block that defines it, or used by a
49 /// switch or atomic instruction, which may expand to multiple basic blocks.
50 static bool isUsedOutsideOfDefiningBlock(const Instruction *I) {
51 if (I->use_empty()) return false;
52 if (isa<PHINode>(I)) return true;
53 const BasicBlock *BB = I->getParent();
54 for (const User *U : I->users())
55 if (cast<Instruction>(U)->getParent() != BB || isa<PHINode>(U))
61 static ISD::NodeType getPreferredExtendForValue(const Value *V) {
62 // For the users of the source value being used for compare instruction, if
63 // the number of signed predicate is greater than unsigned predicate, we
64 // prefer to use SIGN_EXTEND.
66 // With this optimization, we would be able to reduce some redundant sign or
67 // zero extension instruction, and eventually more machine CSE opportunities
69 ISD::NodeType ExtendKind = ISD::ANY_EXTEND;
70 unsigned NumOfSigned = 0, NumOfUnsigned = 0;
71 for (const User *U : V->users()) {
72 if (const auto *CI = dyn_cast<CmpInst>(U)) {
73 NumOfSigned += CI->isSigned();
74 NumOfUnsigned += CI->isUnsigned();
77 if (NumOfSigned > NumOfUnsigned)
78 ExtendKind = ISD::SIGN_EXTEND;
84 struct WinEHNumbering {
85 WinEHNumbering(WinEHFuncInfo &FuncInfo) : FuncInfo(FuncInfo), NextState(0) {}
87 WinEHFuncInfo &FuncInfo;
90 SmallVector<ActionHandler *, 4> HandlerStack;
91 SmallPtrSet<const Function *, 4> VisitedHandlers;
93 int currentEHNumber() const {
94 return HandlerStack.empty() ? -1 : HandlerStack.back()->getEHState();
97 void parseEHActions(const IntrinsicInst *II,
98 SmallVectorImpl<ActionHandler *> &Actions);
99 void createUnwindMapEntry(int ToState, ActionHandler *AH);
100 void createTryBlockMapEntry(int TryLow, int TryHigh,
101 ArrayRef<CatchHandler *> Handlers);
102 void processCallSite(ArrayRef<ActionHandler *> Actions, ImmutableCallSite CS);
103 void calculateStateNumbers(const Function &F);
107 void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
111 TLI = MF->getSubtarget().getTargetLowering();
112 RegInfo = &MF->getRegInfo();
113 MachineModuleInfo &MMI = MF->getMMI();
115 // Check whether the function can return without sret-demotion.
116 SmallVector<ISD::OutputArg, 4> Outs;
117 GetReturnInfo(Fn->getReturnType(), Fn->getAttributes(), Outs, *TLI);
118 CanLowerReturn = TLI->CanLowerReturn(Fn->getCallingConv(), *MF,
119 Fn->isVarArg(), Outs, Fn->getContext());
121 // Initialize the mapping of values to registers. This is only set up for
122 // instruction values that are used outside of the block that defines
124 Function::const_iterator BB = Fn->begin(), EB = Fn->end();
125 for (; BB != EB; ++BB)
126 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
128 if (const AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
129 // Static allocas can be folded into the initial stack frame adjustment.
130 if (AI->isStaticAlloca()) {
131 const ConstantInt *CUI = cast<ConstantInt>(AI->getArraySize());
132 Type *Ty = AI->getAllocatedType();
133 uint64_t TySize = TLI->getDataLayout()->getTypeAllocSize(Ty);
135 std::max((unsigned)TLI->getDataLayout()->getPrefTypeAlignment(Ty),
138 TySize *= CUI->getZExtValue(); // Get total allocated size.
139 if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
141 StaticAllocaMap[AI] =
142 MF->getFrameInfo()->CreateStackObject(TySize, Align, false, AI);
145 unsigned Align = std::max(
146 (unsigned)TLI->getDataLayout()->getPrefTypeAlignment(
147 AI->getAllocatedType()),
149 unsigned StackAlign =
150 MF->getSubtarget().getFrameLowering()->getStackAlignment();
151 if (Align <= StackAlign)
153 // Inform the Frame Information that we have variable-sized objects.
154 MF->getFrameInfo()->CreateVariableSizedObject(Align ? Align : 1, AI);
158 // Look for inline asm that clobbers the SP register.
159 if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
160 ImmutableCallSite CS(I);
161 if (isa<InlineAsm>(CS.getCalledValue())) {
162 unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
163 const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
164 std::vector<TargetLowering::AsmOperandInfo> Ops =
165 TLI->ParseConstraints(TRI, CS);
166 for (size_t I = 0, E = Ops.size(); I != E; ++I) {
167 TargetLowering::AsmOperandInfo &Op = Ops[I];
168 if (Op.Type == InlineAsm::isClobber) {
169 // Clobbers don't have SDValue operands, hence SDValue().
170 TLI->ComputeConstraintToUse(Op, SDValue(), DAG);
171 std::pair<unsigned, const TargetRegisterClass *> PhysReg =
172 TLI->getRegForInlineAsmConstraint(TRI, Op.ConstraintCode,
174 if (PhysReg.first == SP)
175 MF->getFrameInfo()->setHasInlineAsmWithSPAdjust(true);
181 // Look for calls to the @llvm.va_start intrinsic. We can omit some
182 // prologue boilerplate for variadic functions that don't examine their
184 if (const auto *II = dyn_cast<IntrinsicInst>(I)) {
185 if (II->getIntrinsicID() == Intrinsic::vastart)
186 MF->getFrameInfo()->setHasVAStart(true);
189 // If we have a musttail call in a variadic funciton, we need to ensure we
190 // forward implicit register parameters.
191 if (const auto *CI = dyn_cast<CallInst>(I)) {
192 if (CI->isMustTailCall() && Fn->isVarArg())
193 MF->getFrameInfo()->setHasMustTailInVarArgFunc(true);
196 // Mark values used outside their block as exported, by allocating
197 // a virtual register for them.
198 if (isUsedOutsideOfDefiningBlock(I))
199 if (!isa<AllocaInst>(I) ||
200 !StaticAllocaMap.count(cast<AllocaInst>(I)))
201 InitializeRegForValue(I);
203 // Collect llvm.dbg.declare information. This is done now instead of
204 // during the initial isel pass through the IR so that it is done
205 // in a predictable order.
206 if (const DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(I)) {
207 DIVariable DIVar(DI->getVariable());
208 assert((!DIVar || DIVar.isVariable()) &&
209 "Variable in DbgDeclareInst should be either null or a DIVariable.");
210 if (MMI.hasDebugInfo() && DIVar && DI->getDebugLoc()) {
211 // Don't handle byval struct arguments or VLAs, for example.
212 // Non-byval arguments are handled here (they refer to the stack
213 // temporary alloca at this point).
214 const Value *Address = DI->getAddress();
216 if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
217 Address = BCI->getOperand(0);
218 if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
219 DenseMap<const AllocaInst *, int>::iterator SI =
220 StaticAllocaMap.find(AI);
221 if (SI != StaticAllocaMap.end()) { // Check for VLAs.
223 MMI.setVariableDbgInfo(DI->getVariable(), DI->getExpression(),
224 FI, DI->getDebugLoc());
231 // Decide the preferred extend type for a value.
232 PreferredExtendType[I] = getPreferredExtendForValue(I);
235 // Create an initial MachineBasicBlock for each LLVM BasicBlock in F. This
236 // also creates the initial PHI MachineInstrs, though none of the input
237 // operands are populated.
238 for (BB = Fn->begin(); BB != EB; ++BB) {
239 MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
243 // Transfer the address-taken flag. This is necessary because there could
244 // be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
245 // the first one should be marked.
246 if (BB->hasAddressTaken())
247 MBB->setHasAddressTaken();
249 // Create Machine PHI nodes for LLVM PHI nodes, lowering them as
251 for (BasicBlock::const_iterator I = BB->begin();
252 const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
253 if (PN->use_empty()) continue;
256 if (PN->getType()->isEmptyTy())
259 DebugLoc DL = PN->getDebugLoc();
260 unsigned PHIReg = ValueMap[PN];
261 assert(PHIReg && "PHI node does not have an assigned virtual register!");
263 SmallVector<EVT, 4> ValueVTs;
264 ComputeValueVTs(*TLI, PN->getType(), ValueVTs);
265 for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
266 EVT VT = ValueVTs[vti];
267 unsigned NumRegisters = TLI->getNumRegisters(Fn->getContext(), VT);
268 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
269 for (unsigned i = 0; i != NumRegisters; ++i)
270 BuildMI(MBB, DL, TII->get(TargetOpcode::PHI), PHIReg + i);
271 PHIReg += NumRegisters;
276 // Mark landing pad blocks.
277 for (BB = Fn->begin(); BB != EB; ++BB)
278 if (const auto *Invoke = dyn_cast<InvokeInst>(BB->getTerminator()))
279 MBBMap[Invoke->getSuccessor(1)]->setIsLandingPad();
281 // Calculate EH numbers for WinEH.
282 if (fn.getFnAttribute("wineh-parent").getValueAsString() == fn.getName()) {
283 WinEHNumbering Num(MMI.getWinEHFuncInfo(&fn));
284 Num.calculateStateNumbers(fn);
285 // Pop everything on the handler stack.
286 Num.processCallSite(None, ImmutableCallSite());
290 void WinEHNumbering::parseEHActions(const IntrinsicInst *II,
291 SmallVectorImpl<ActionHandler *> &Actions) {
292 for (unsigned I = 0, E = II->getNumArgOperands(); I != E;) {
293 uint64_t ActionKind =
294 cast<ConstantInt>(II->getArgOperand(I))->getZExtValue();
295 if (ActionKind == /*catch=*/1) {
296 auto *Selector = cast<Constant>(II->getArgOperand(I + 1));
297 Value *CatchObject = II->getArgOperand(I + 2);
298 Constant *Handler = cast<Constant>(II->getArgOperand(I + 3));
300 auto *CH = new CatchHandler(/*BB=*/nullptr, Selector, /*NextBB=*/nullptr);
301 CH->setExceptionVar(CatchObject);
302 CH->setHandlerBlockOrFunc(Handler);
303 Actions.push_back(CH);
305 assert(ActionKind == 0 && "expected a cleanup or a catch action!");
306 Constant *Handler = cast<Constant>(II->getArgOperand(I + 1));
308 auto *CH = new CleanupHandler(/*BB=*/nullptr);
309 CH->setHandlerBlockOrFunc(Handler);
310 Actions.push_back(CH);
313 std::reverse(Actions.begin(), Actions.end());
316 void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
317 WinEHUnwindMapEntry UME;
318 UME.ToState = ToState;
319 if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
320 UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
322 UME.Cleanup = nullptr;
323 FuncInfo.UnwindMap.push_back(UME);
326 void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
327 ArrayRef<CatchHandler *> Handlers) {
328 WinEHTryBlockMapEntry TBME;
329 TBME.TryLow = TryLow;
330 TBME.TryHigh = TryHigh;
331 // FIXME: This should be revisited when we want to throw inside a catch
333 TBME.CatchHigh = INT_MAX;
334 assert(TBME.TryLow <= TBME.TryHigh);
335 assert(TBME.CatchHigh > TBME.TryHigh);
336 for (CatchHandler *CH : Handlers) {
338 auto *GV = cast<GlobalVariable>(CH->getSelector()->stripPointerCasts());
339 // Selectors are always pointers to GlobalVariables with 'struct' type.
340 // The struct has two fields, adjectives and a type descriptor.
341 auto *CS = cast<ConstantStruct>(GV->getInitializer());
343 cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
344 HT.TypeDescriptor = cast<GlobalVariable>(
345 CS->getAggregateElement(1)->stripPointerCasts());
346 HT.Handler = cast<Function>(CH->getHandlerBlockOrFunc());
347 // FIXME: We don't support catching objects yet!
348 HT.CatchObjIdx = INT_MAX;
349 HT.CatchObjOffset = 0;
350 TBME.HandlerArray.push_back(HT);
352 FuncInfo.TryBlockMap.push_back(TBME);
355 static void print_name(const Value *V) {
358 DEBUG(dbgs() << "null");
362 if (const auto *F = dyn_cast<Function>(V))
363 DEBUG(dbgs() << F->getName());
369 void WinEHNumbering::processCallSite(ArrayRef<ActionHandler *> Actions,
370 ImmutableCallSite CS) {
371 int FirstMismatch = 0;
372 for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E;
374 if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
375 Actions[FirstMismatch]->getHandlerBlockOrFunc())
377 delete Actions[FirstMismatch];
380 bool EnteringScope = (int)Actions.size() > FirstMismatch;
381 bool ExitingScope = (int)HandlerStack.size() > FirstMismatch;
383 // Don't recurse while we are looping over the handler stack. Instead, defer
384 // the numbering of the catch handlers until we are done popping.
385 SmallVector<CatchHandler *, 4> PoppedCatches;
386 for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) {
387 if (auto *CH = dyn_cast<CatchHandler>(HandlerStack.back())) {
388 PoppedCatches.push_back(CH);
390 // Delete cleanup handlers
391 delete HandlerStack.back();
393 HandlerStack.pop_back();
396 // We need to create a new state number if we are exiting a try scope and we
397 // will not push any more actions.
398 int TryHigh = NextState - 1;
399 if (ExitingScope && !EnteringScope && !PoppedCatches.empty()) {
400 createUnwindMapEntry(currentEHNumber(), nullptr);
404 int LastTryLowIdx = 0;
405 for (int I = 0, E = PoppedCatches.size(); I != E; ++I) {
406 CatchHandler *CH = PoppedCatches[I];
407 if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) {
408 int TryLow = CH->getEHState();
410 makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1);
411 createTryBlockMapEntry(TryLow, TryHigh, Handlers);
412 LastTryLowIdx = I + 1;
416 for (CatchHandler *CH : PoppedCatches) {
417 if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc()))
418 calculateStateNumbers(*F);
422 bool LastActionWasCatch = false;
423 for (size_t I = FirstMismatch; I != Actions.size(); ++I) {
424 // We can reuse eh states when pushing two catches for the same invoke.
425 bool CurrActionIsCatch = isa<CatchHandler>(Actions[I]);
426 // FIXME: Reenable this optimization!
427 if (CurrActionIsCatch && LastActionWasCatch && false) {
428 Actions[I]->setEHState(currentEHNumber());
430 createUnwindMapEntry(currentEHNumber(), Actions[I]);
431 Actions[I]->setEHState(NextState);
433 DEBUG(dbgs() << "Creating unwind map entry for: (");
434 print_name(Actions[I]->getHandlerBlockOrFunc());
435 DEBUG(dbgs() << ", " << currentEHNumber() << ")\n");
437 HandlerStack.push_back(Actions[I]);
438 LastActionWasCatch = CurrActionIsCatch;
441 DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: ");
442 print_name(CS ? CS.getCalledValue() : nullptr);
443 DEBUG(dbgs() << '\n');
446 void WinEHNumbering::calculateStateNumbers(const Function &F) {
447 auto I = VisitedHandlers.insert(&F);
449 return; // We've already visited this handler, don't renumber it.
451 DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n');
452 SmallVector<ActionHandler *, 4> ActionList;
453 for (const BasicBlock &BB : F) {
454 for (const Instruction &I : BB) {
455 const auto *CI = dyn_cast<CallInst>(&I);
456 if (!CI || CI->doesNotThrow())
458 processCallSite(None, CI);
460 const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
463 const LandingPadInst *LPI = II->getLandingPadInst();
464 auto *ActionsCall = dyn_cast<IntrinsicInst>(LPI->getNextNode());
467 assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions);
468 parseEHActions(ActionsCall, ActionList);
469 processCallSite(ActionList, II);
471 FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
475 /// clear - Clear out all the function-specific state. This returns this
476 /// FunctionLoweringInfo to an empty state, ready to be used for a
477 /// different function.
478 void FunctionLoweringInfo::clear() {
479 assert(CatchInfoFound.size() == CatchInfoLost.size() &&
480 "Not all catch info was assigned to a landing pad!");
484 StaticAllocaMap.clear();
486 CatchInfoLost.clear();
487 CatchInfoFound.clear();
489 LiveOutRegInfo.clear();
491 ArgDbgValues.clear();
492 ByValArgFrameIndexMap.clear();
494 StatepointStackSlots.clear();
495 PreferredExtendType.clear();
498 /// CreateReg - Allocate a single virtual register for the given type.
499 unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
500 return RegInfo->createVirtualRegister(
501 MF->getSubtarget().getTargetLowering()->getRegClassFor(VT));
504 /// CreateRegs - Allocate the appropriate number of virtual registers of
505 /// the correctly promoted or expanded types. Assign these registers
506 /// consecutive vreg numbers and return the first assigned number.
508 /// In the case that the given value has struct or array type, this function
509 /// will assign registers for each member or element.
511 unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
512 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
514 SmallVector<EVT, 4> ValueVTs;
515 ComputeValueVTs(*TLI, Ty, ValueVTs);
517 unsigned FirstReg = 0;
518 for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
519 EVT ValueVT = ValueVTs[Value];
520 MVT RegisterVT = TLI->getRegisterType(Ty->getContext(), ValueVT);
522 unsigned NumRegs = TLI->getNumRegisters(Ty->getContext(), ValueVT);
523 for (unsigned i = 0; i != NumRegs; ++i) {
524 unsigned R = CreateReg(RegisterVT);
525 if (!FirstReg) FirstReg = R;
531 /// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the
532 /// register is a PHI destination and the PHI's LiveOutInfo is not valid. If
533 /// the register's LiveOutInfo is for a smaller bit width, it is extended to
534 /// the larger bit width by zero extension. The bit width must be no smaller
535 /// than the LiveOutInfo's existing bit width.
536 const FunctionLoweringInfo::LiveOutInfo *
537 FunctionLoweringInfo::GetLiveOutRegInfo(unsigned Reg, unsigned BitWidth) {
538 if (!LiveOutRegInfo.inBounds(Reg))
541 LiveOutInfo *LOI = &LiveOutRegInfo[Reg];
545 if (BitWidth > LOI->KnownZero.getBitWidth()) {
546 LOI->NumSignBits = 1;
547 LOI->KnownZero = LOI->KnownZero.zextOrTrunc(BitWidth);
548 LOI->KnownOne = LOI->KnownOne.zextOrTrunc(BitWidth);
554 /// ComputePHILiveOutRegInfo - Compute LiveOutInfo for a PHI's destination
555 /// register based on the LiveOutInfo of its operands.
556 void FunctionLoweringInfo::ComputePHILiveOutRegInfo(const PHINode *PN) {
557 Type *Ty = PN->getType();
558 if (!Ty->isIntegerTy() || Ty->isVectorTy())
561 SmallVector<EVT, 1> ValueVTs;
562 ComputeValueVTs(*TLI, Ty, ValueVTs);
563 assert(ValueVTs.size() == 1 &&
564 "PHIs with non-vector integer types should have a single VT.");
565 EVT IntVT = ValueVTs[0];
567 if (TLI->getNumRegisters(PN->getContext(), IntVT) != 1)
569 IntVT = TLI->getTypeToTransformTo(PN->getContext(), IntVT);
570 unsigned BitWidth = IntVT.getSizeInBits();
572 unsigned DestReg = ValueMap[PN];
573 if (!TargetRegisterInfo::isVirtualRegister(DestReg))
575 LiveOutRegInfo.grow(DestReg);
576 LiveOutInfo &DestLOI = LiveOutRegInfo[DestReg];
578 Value *V = PN->getIncomingValue(0);
579 if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
580 DestLOI.NumSignBits = 1;
581 APInt Zero(BitWidth, 0);
582 DestLOI.KnownZero = Zero;
583 DestLOI.KnownOne = Zero;
587 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
588 APInt Val = CI->getValue().zextOrTrunc(BitWidth);
589 DestLOI.NumSignBits = Val.getNumSignBits();
590 DestLOI.KnownZero = ~Val;
591 DestLOI.KnownOne = Val;
593 assert(ValueMap.count(V) && "V should have been placed in ValueMap when its"
594 "CopyToReg node was created.");
595 unsigned SrcReg = ValueMap[V];
596 if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
597 DestLOI.IsValid = false;
600 const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
602 DestLOI.IsValid = false;
608 assert(DestLOI.KnownZero.getBitWidth() == BitWidth &&
609 DestLOI.KnownOne.getBitWidth() == BitWidth &&
610 "Masks should have the same bit width as the type.");
612 for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) {
613 Value *V = PN->getIncomingValue(i);
614 if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
615 DestLOI.NumSignBits = 1;
616 APInt Zero(BitWidth, 0);
617 DestLOI.KnownZero = Zero;
618 DestLOI.KnownOne = Zero;
622 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
623 APInt Val = CI->getValue().zextOrTrunc(BitWidth);
624 DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, Val.getNumSignBits());
625 DestLOI.KnownZero &= ~Val;
626 DestLOI.KnownOne &= Val;
630 assert(ValueMap.count(V) && "V should have been placed in ValueMap when "
631 "its CopyToReg node was created.");
632 unsigned SrcReg = ValueMap[V];
633 if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
634 DestLOI.IsValid = false;
637 const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
639 DestLOI.IsValid = false;
642 DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, SrcLOI->NumSignBits);
643 DestLOI.KnownZero &= SrcLOI->KnownZero;
644 DestLOI.KnownOne &= SrcLOI->KnownOne;
648 /// setArgumentFrameIndex - Record frame index for the byval
649 /// argument. This overrides previous frame index entry for this argument,
651 void FunctionLoweringInfo::setArgumentFrameIndex(const Argument *A,
653 ByValArgFrameIndexMap[A] = FI;
656 /// getArgumentFrameIndex - Get frame index for the byval argument.
657 /// If the argument does not have any assigned frame index then 0 is
659 int FunctionLoweringInfo::getArgumentFrameIndex(const Argument *A) {
660 DenseMap<const Argument *, int>::iterator I =
661 ByValArgFrameIndexMap.find(A);
662 if (I != ByValArgFrameIndexMap.end())
664 DEBUG(dbgs() << "Argument does not have assigned frame index!\n");
668 /// ComputeUsesVAFloatArgument - Determine if any floating-point values are
669 /// being passed to this variadic function, and set the MachineModuleInfo's
670 /// usesVAFloatArgument flag if so. This flag is used to emit an undefined
671 /// reference to _fltused on Windows, which will link in MSVCRT's
672 /// floating-point support.
673 void llvm::ComputeUsesVAFloatArgument(const CallInst &I,
674 MachineModuleInfo *MMI)
676 FunctionType *FT = cast<FunctionType>(
677 I.getCalledValue()->getType()->getContainedType(0));
678 if (FT->isVarArg() && !MMI->usesVAFloatArgument()) {
679 for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
680 Type* T = I.getArgOperand(i)->getType();
681 for (po_iterator<Type*> i = po_begin(T), e = po_end(T);
683 if (i->isFloatingPointTy()) {
684 MMI->setUsesVAFloatArgument(true);
692 /// AddLandingPadInfo - Extract the exception handling information from the
693 /// landingpad instruction and add them to the specified machine module info.
694 void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
695 MachineBasicBlock *MBB) {
696 MMI.addPersonality(MBB,
697 cast<Function>(I.getPersonalityFn()->stripPointerCasts()));
702 // FIXME: New EH - Add the clauses in reverse order. This isn't 100% correct,
703 // but we need to do it this way because of how the DWARF EH emitter
704 // processes the clauses.
705 for (unsigned i = I.getNumClauses(); i != 0; --i) {
706 Value *Val = I.getClause(i - 1);
707 if (I.isCatch(i - 1)) {
708 MMI.addCatchTypeInfo(MBB,
709 dyn_cast<GlobalValue>(Val->stripPointerCasts()));
711 // Add filters in a list.
712 Constant *CVal = cast<Constant>(Val);
713 SmallVector<const GlobalValue*, 4> FilterList;
714 for (User::op_iterator
715 II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II)
716 FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
718 MMI.addFilterTypeInfo(MBB, FilterList);