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 createUnwindMapEntry(int ToState, ActionHandler *AH);
98 void createTryBlockMapEntry(int TryLow, int TryHigh,
99 ArrayRef<CatchHandler *> Handlers);
100 void processCallSite(ArrayRef<ActionHandler *> Actions, ImmutableCallSite CS);
101 void calculateStateNumbers(const Function &F);
105 void FunctionLoweringInfo::set(const Function &fn, MachineFunction &mf,
109 TLI = MF->getSubtarget().getTargetLowering();
110 RegInfo = &MF->getRegInfo();
111 MachineModuleInfo &MMI = MF->getMMI();
113 // Check whether the function can return without sret-demotion.
114 SmallVector<ISD::OutputArg, 4> Outs;
115 GetReturnInfo(Fn->getReturnType(), Fn->getAttributes(), Outs, *TLI);
116 CanLowerReturn = TLI->CanLowerReturn(Fn->getCallingConv(), *MF,
117 Fn->isVarArg(), Outs, Fn->getContext());
119 // Initialize the mapping of values to registers. This is only set up for
120 // instruction values that are used outside of the block that defines
122 Function::const_iterator BB = Fn->begin(), EB = Fn->end();
123 for (; BB != EB; ++BB)
124 for (BasicBlock::const_iterator I = BB->begin(), E = BB->end();
126 if (const AllocaInst *AI = dyn_cast<AllocaInst>(I)) {
127 // Static allocas can be folded into the initial stack frame adjustment.
128 if (AI->isStaticAlloca()) {
129 const ConstantInt *CUI = cast<ConstantInt>(AI->getArraySize());
130 Type *Ty = AI->getAllocatedType();
131 uint64_t TySize = TLI->getDataLayout()->getTypeAllocSize(Ty);
133 std::max((unsigned)TLI->getDataLayout()->getPrefTypeAlignment(Ty),
136 TySize *= CUI->getZExtValue(); // Get total allocated size.
137 if (TySize == 0) TySize = 1; // Don't create zero-sized stack objects.
139 StaticAllocaMap[AI] =
140 MF->getFrameInfo()->CreateStackObject(TySize, Align, false, AI);
143 unsigned Align = std::max(
144 (unsigned)TLI->getDataLayout()->getPrefTypeAlignment(
145 AI->getAllocatedType()),
147 unsigned StackAlign =
148 MF->getSubtarget().getFrameLowering()->getStackAlignment();
149 if (Align <= StackAlign)
151 // Inform the Frame Information that we have variable-sized objects.
152 MF->getFrameInfo()->CreateVariableSizedObject(Align ? Align : 1, AI);
156 // Look for inline asm that clobbers the SP register.
157 if (isa<CallInst>(I) || isa<InvokeInst>(I)) {
158 ImmutableCallSite CS(I);
159 if (isa<InlineAsm>(CS.getCalledValue())) {
160 unsigned SP = TLI->getStackPointerRegisterToSaveRestore();
161 const TargetRegisterInfo *TRI = MF->getSubtarget().getRegisterInfo();
162 std::vector<TargetLowering::AsmOperandInfo> Ops =
163 TLI->ParseConstraints(TRI, CS);
164 for (size_t I = 0, E = Ops.size(); I != E; ++I) {
165 TargetLowering::AsmOperandInfo &Op = Ops[I];
166 if (Op.Type == InlineAsm::isClobber) {
167 // Clobbers don't have SDValue operands, hence SDValue().
168 TLI->ComputeConstraintToUse(Op, SDValue(), DAG);
169 std::pair<unsigned, const TargetRegisterClass *> PhysReg =
170 TLI->getRegForInlineAsmConstraint(TRI, Op.ConstraintCode,
172 if (PhysReg.first == SP)
173 MF->getFrameInfo()->setHasInlineAsmWithSPAdjust(true);
179 // Look for calls to the @llvm.va_start intrinsic. We can omit some
180 // prologue boilerplate for variadic functions that don't examine their
182 if (const auto *II = dyn_cast<IntrinsicInst>(I)) {
183 if (II->getIntrinsicID() == Intrinsic::vastart)
184 MF->getFrameInfo()->setHasVAStart(true);
187 // If we have a musttail call in a variadic funciton, we need to ensure we
188 // forward implicit register parameters.
189 if (const auto *CI = dyn_cast<CallInst>(I)) {
190 if (CI->isMustTailCall() && Fn->isVarArg())
191 MF->getFrameInfo()->setHasMustTailInVarArgFunc(true);
194 // Mark values used outside their block as exported, by allocating
195 // a virtual register for them.
196 if (isUsedOutsideOfDefiningBlock(I))
197 if (!isa<AllocaInst>(I) ||
198 !StaticAllocaMap.count(cast<AllocaInst>(I)))
199 InitializeRegForValue(I);
201 // Collect llvm.dbg.declare information. This is done now instead of
202 // during the initial isel pass through the IR so that it is done
203 // in a predictable order.
204 if (const DbgDeclareInst *DI = dyn_cast<DbgDeclareInst>(I)) {
205 DIVariable DIVar(DI->getVariable());
206 assert((!DIVar || DIVar.isVariable()) &&
207 "Variable in DbgDeclareInst should be either null or a DIVariable.");
208 if (MMI.hasDebugInfo() && DIVar && DI->getDebugLoc()) {
209 // Don't handle byval struct arguments or VLAs, for example.
210 // Non-byval arguments are handled here (they refer to the stack
211 // temporary alloca at this point).
212 const Value *Address = DI->getAddress();
214 if (const BitCastInst *BCI = dyn_cast<BitCastInst>(Address))
215 Address = BCI->getOperand(0);
216 if (const AllocaInst *AI = dyn_cast<AllocaInst>(Address)) {
217 DenseMap<const AllocaInst *, int>::iterator SI =
218 StaticAllocaMap.find(AI);
219 if (SI != StaticAllocaMap.end()) { // Check for VLAs.
221 MMI.setVariableDbgInfo(DI->getVariable(), DI->getExpression(),
222 FI, DI->getDebugLoc());
229 // Decide the preferred extend type for a value.
230 PreferredExtendType[I] = getPreferredExtendForValue(I);
233 // Create an initial MachineBasicBlock for each LLVM BasicBlock in F. This
234 // also creates the initial PHI MachineInstrs, though none of the input
235 // operands are populated.
236 for (BB = Fn->begin(); BB != EB; ++BB) {
237 MachineBasicBlock *MBB = mf.CreateMachineBasicBlock(BB);
241 // Transfer the address-taken flag. This is necessary because there could
242 // be multiple MachineBasicBlocks corresponding to one BasicBlock, and only
243 // the first one should be marked.
244 if (BB->hasAddressTaken())
245 MBB->setHasAddressTaken();
247 // Create Machine PHI nodes for LLVM PHI nodes, lowering them as
249 for (BasicBlock::const_iterator I = BB->begin();
250 const PHINode *PN = dyn_cast<PHINode>(I); ++I) {
251 if (PN->use_empty()) continue;
254 if (PN->getType()->isEmptyTy())
257 DebugLoc DL = PN->getDebugLoc();
258 unsigned PHIReg = ValueMap[PN];
259 assert(PHIReg && "PHI node does not have an assigned virtual register!");
261 SmallVector<EVT, 4> ValueVTs;
262 ComputeValueVTs(*TLI, PN->getType(), ValueVTs);
263 for (unsigned vti = 0, vte = ValueVTs.size(); vti != vte; ++vti) {
264 EVT VT = ValueVTs[vti];
265 unsigned NumRegisters = TLI->getNumRegisters(Fn->getContext(), VT);
266 const TargetInstrInfo *TII = MF->getSubtarget().getInstrInfo();
267 for (unsigned i = 0; i != NumRegisters; ++i)
268 BuildMI(MBB, DL, TII->get(TargetOpcode::PHI), PHIReg + i);
269 PHIReg += NumRegisters;
274 // Mark landing pad blocks.
275 for (BB = Fn->begin(); BB != EB; ++BB)
276 if (const auto *Invoke = dyn_cast<InvokeInst>(BB->getTerminator()))
277 MBBMap[Invoke->getSuccessor(1)]->setIsLandingPad();
279 // Calculate EH numbers for WinEH.
280 if (fn.getFnAttribute("wineh-parent").getValueAsString() == fn.getName()) {
281 WinEHNumbering Num(MMI.getWinEHFuncInfo(&fn));
282 Num.calculateStateNumbers(fn);
283 // Pop everything on the handler stack.
284 Num.processCallSite(None, ImmutableCallSite());
288 void WinEHNumbering::createUnwindMapEntry(int ToState, ActionHandler *AH) {
289 WinEHUnwindMapEntry UME;
290 UME.ToState = ToState;
291 if (auto *CH = dyn_cast_or_null<CleanupHandler>(AH))
292 UME.Cleanup = cast<Function>(CH->getHandlerBlockOrFunc());
294 UME.Cleanup = nullptr;
295 FuncInfo.UnwindMap.push_back(UME);
298 void WinEHNumbering::createTryBlockMapEntry(int TryLow, int TryHigh,
299 ArrayRef<CatchHandler *> Handlers) {
300 WinEHTryBlockMapEntry TBME;
301 TBME.TryLow = TryLow;
302 TBME.TryHigh = TryHigh;
303 assert(TBME.TryLow <= TBME.TryHigh);
304 for (CatchHandler *CH : Handlers) {
306 if (CH->getSelector()->isNullValue()) {
307 HT.Adjectives = 0x40;
308 HT.TypeDescriptor = nullptr;
310 auto *GV = cast<GlobalVariable>(CH->getSelector()->stripPointerCasts());
311 // Selectors are always pointers to GlobalVariables with 'struct' type.
312 // The struct has two fields, adjectives and a type descriptor.
313 auto *CS = cast<ConstantStruct>(GV->getInitializer());
315 cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
317 cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
319 HT.Handler = cast<Function>(CH->getHandlerBlockOrFunc());
320 HT.CatchObjRecoverIdx = CH->getExceptionVarIndex();
321 TBME.HandlerArray.push_back(HT);
323 FuncInfo.TryBlockMap.push_back(TBME);
326 static void print_name(const Value *V) {
329 DEBUG(dbgs() << "null");
333 if (const auto *F = dyn_cast<Function>(V))
334 DEBUG(dbgs() << F->getName());
340 void WinEHNumbering::processCallSite(ArrayRef<ActionHandler *> Actions,
341 ImmutableCallSite CS) {
342 int FirstMismatch = 0;
343 for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E;
345 if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
346 Actions[FirstMismatch]->getHandlerBlockOrFunc())
348 delete Actions[FirstMismatch];
351 bool EnteringScope = (int)Actions.size() > FirstMismatch;
353 // Don't recurse while we are looping over the handler stack. Instead, defer
354 // the numbering of the catch handlers until we are done popping.
355 SmallVector<CatchHandler *, 4> PoppedCatches;
356 for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) {
357 if (auto *CH = dyn_cast<CatchHandler>(HandlerStack.back())) {
358 PoppedCatches.push_back(CH);
360 // Delete cleanup handlers
361 delete HandlerStack.back();
363 HandlerStack.pop_back();
366 // We need to create a new state number if we are exiting a try scope and we
367 // will not push any more actions.
368 int TryHigh = NextState - 1;
369 if (!EnteringScope && !PoppedCatches.empty()) {
370 createUnwindMapEntry(currentEHNumber(), nullptr);
374 int LastTryLowIdx = 0;
375 for (int I = 0, E = PoppedCatches.size(); I != E; ++I) {
376 CatchHandler *CH = PoppedCatches[I];
377 if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) {
378 int TryLow = CH->getEHState();
380 makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1);
381 createTryBlockMapEntry(TryLow, TryHigh, Handlers);
382 LastTryLowIdx = I + 1;
386 for (CatchHandler *CH : PoppedCatches) {
387 if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc()))
388 calculateStateNumbers(*F);
392 bool LastActionWasCatch = false;
393 for (size_t I = FirstMismatch; I != Actions.size(); ++I) {
394 // We can reuse eh states when pushing two catches for the same invoke.
395 bool CurrActionIsCatch = isa<CatchHandler>(Actions[I]);
396 // FIXME: Reenable this optimization!
397 if (CurrActionIsCatch && LastActionWasCatch && false) {
398 Actions[I]->setEHState(currentEHNumber());
400 createUnwindMapEntry(currentEHNumber(), Actions[I]);
401 Actions[I]->setEHState(NextState);
403 DEBUG(dbgs() << "Creating unwind map entry for: (");
404 print_name(Actions[I]->getHandlerBlockOrFunc());
405 DEBUG(dbgs() << ", " << currentEHNumber() << ")\n");
407 HandlerStack.push_back(Actions[I]);
408 LastActionWasCatch = CurrActionIsCatch;
411 DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: ");
412 print_name(CS ? CS.getCalledValue() : nullptr);
413 DEBUG(dbgs() << '\n');
416 void WinEHNumbering::calculateStateNumbers(const Function &F) {
417 auto I = VisitedHandlers.insert(&F);
419 return; // We've already visited this handler, don't renumber it.
421 DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n');
422 SmallVector<ActionHandler *, 4> ActionList;
423 for (const BasicBlock &BB : F) {
424 for (const Instruction &I : BB) {
425 const auto *CI = dyn_cast<CallInst>(&I);
426 if (!CI || CI->doesNotThrow())
428 processCallSite(None, CI);
430 const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
433 const LandingPadInst *LPI = II->getLandingPadInst();
434 auto *ActionsCall = dyn_cast<IntrinsicInst>(LPI->getNextNode());
437 assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions);
438 parseEHActions(ActionsCall, ActionList);
439 processCallSite(ActionList, II);
441 FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
444 FuncInfo.CatchHandlerMaxState[&F] = NextState - 1;
447 /// clear - Clear out all the function-specific state. This returns this
448 /// FunctionLoweringInfo to an empty state, ready to be used for a
449 /// different function.
450 void FunctionLoweringInfo::clear() {
451 assert(CatchInfoFound.size() == CatchInfoLost.size() &&
452 "Not all catch info was assigned to a landing pad!");
456 StaticAllocaMap.clear();
458 CatchInfoLost.clear();
459 CatchInfoFound.clear();
461 LiveOutRegInfo.clear();
463 ArgDbgValues.clear();
464 ByValArgFrameIndexMap.clear();
466 StatepointStackSlots.clear();
467 PreferredExtendType.clear();
470 /// CreateReg - Allocate a single virtual register for the given type.
471 unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
472 return RegInfo->createVirtualRegister(
473 MF->getSubtarget().getTargetLowering()->getRegClassFor(VT));
476 /// CreateRegs - Allocate the appropriate number of virtual registers of
477 /// the correctly promoted or expanded types. Assign these registers
478 /// consecutive vreg numbers and return the first assigned number.
480 /// In the case that the given value has struct or array type, this function
481 /// will assign registers for each member or element.
483 unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
484 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
486 SmallVector<EVT, 4> ValueVTs;
487 ComputeValueVTs(*TLI, Ty, ValueVTs);
489 unsigned FirstReg = 0;
490 for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
491 EVT ValueVT = ValueVTs[Value];
492 MVT RegisterVT = TLI->getRegisterType(Ty->getContext(), ValueVT);
494 unsigned NumRegs = TLI->getNumRegisters(Ty->getContext(), ValueVT);
495 for (unsigned i = 0; i != NumRegs; ++i) {
496 unsigned R = CreateReg(RegisterVT);
497 if (!FirstReg) FirstReg = R;
503 /// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the
504 /// register is a PHI destination and the PHI's LiveOutInfo is not valid. If
505 /// the register's LiveOutInfo is for a smaller bit width, it is extended to
506 /// the larger bit width by zero extension. The bit width must be no smaller
507 /// than the LiveOutInfo's existing bit width.
508 const FunctionLoweringInfo::LiveOutInfo *
509 FunctionLoweringInfo::GetLiveOutRegInfo(unsigned Reg, unsigned BitWidth) {
510 if (!LiveOutRegInfo.inBounds(Reg))
513 LiveOutInfo *LOI = &LiveOutRegInfo[Reg];
517 if (BitWidth > LOI->KnownZero.getBitWidth()) {
518 LOI->NumSignBits = 1;
519 LOI->KnownZero = LOI->KnownZero.zextOrTrunc(BitWidth);
520 LOI->KnownOne = LOI->KnownOne.zextOrTrunc(BitWidth);
526 /// ComputePHILiveOutRegInfo - Compute LiveOutInfo for a PHI's destination
527 /// register based on the LiveOutInfo of its operands.
528 void FunctionLoweringInfo::ComputePHILiveOutRegInfo(const PHINode *PN) {
529 Type *Ty = PN->getType();
530 if (!Ty->isIntegerTy() || Ty->isVectorTy())
533 SmallVector<EVT, 1> ValueVTs;
534 ComputeValueVTs(*TLI, Ty, ValueVTs);
535 assert(ValueVTs.size() == 1 &&
536 "PHIs with non-vector integer types should have a single VT.");
537 EVT IntVT = ValueVTs[0];
539 if (TLI->getNumRegisters(PN->getContext(), IntVT) != 1)
541 IntVT = TLI->getTypeToTransformTo(PN->getContext(), IntVT);
542 unsigned BitWidth = IntVT.getSizeInBits();
544 unsigned DestReg = ValueMap[PN];
545 if (!TargetRegisterInfo::isVirtualRegister(DestReg))
547 LiveOutRegInfo.grow(DestReg);
548 LiveOutInfo &DestLOI = LiveOutRegInfo[DestReg];
550 Value *V = PN->getIncomingValue(0);
551 if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
552 DestLOI.NumSignBits = 1;
553 APInt Zero(BitWidth, 0);
554 DestLOI.KnownZero = Zero;
555 DestLOI.KnownOne = Zero;
559 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
560 APInt Val = CI->getValue().zextOrTrunc(BitWidth);
561 DestLOI.NumSignBits = Val.getNumSignBits();
562 DestLOI.KnownZero = ~Val;
563 DestLOI.KnownOne = Val;
565 assert(ValueMap.count(V) && "V should have been placed in ValueMap when its"
566 "CopyToReg node was created.");
567 unsigned SrcReg = ValueMap[V];
568 if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
569 DestLOI.IsValid = false;
572 const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
574 DestLOI.IsValid = false;
580 assert(DestLOI.KnownZero.getBitWidth() == BitWidth &&
581 DestLOI.KnownOne.getBitWidth() == BitWidth &&
582 "Masks should have the same bit width as the type.");
584 for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) {
585 Value *V = PN->getIncomingValue(i);
586 if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
587 DestLOI.NumSignBits = 1;
588 APInt Zero(BitWidth, 0);
589 DestLOI.KnownZero = Zero;
590 DestLOI.KnownOne = Zero;
594 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
595 APInt Val = CI->getValue().zextOrTrunc(BitWidth);
596 DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, Val.getNumSignBits());
597 DestLOI.KnownZero &= ~Val;
598 DestLOI.KnownOne &= Val;
602 assert(ValueMap.count(V) && "V should have been placed in ValueMap when "
603 "its CopyToReg node was created.");
604 unsigned SrcReg = ValueMap[V];
605 if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
606 DestLOI.IsValid = false;
609 const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
611 DestLOI.IsValid = false;
614 DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, SrcLOI->NumSignBits);
615 DestLOI.KnownZero &= SrcLOI->KnownZero;
616 DestLOI.KnownOne &= SrcLOI->KnownOne;
620 /// setArgumentFrameIndex - Record frame index for the byval
621 /// argument. This overrides previous frame index entry for this argument,
623 void FunctionLoweringInfo::setArgumentFrameIndex(const Argument *A,
625 ByValArgFrameIndexMap[A] = FI;
628 /// getArgumentFrameIndex - Get frame index for the byval argument.
629 /// If the argument does not have any assigned frame index then 0 is
631 int FunctionLoweringInfo::getArgumentFrameIndex(const Argument *A) {
632 DenseMap<const Argument *, int>::iterator I =
633 ByValArgFrameIndexMap.find(A);
634 if (I != ByValArgFrameIndexMap.end())
636 DEBUG(dbgs() << "Argument does not have assigned frame index!\n");
640 /// ComputeUsesVAFloatArgument - Determine if any floating-point values are
641 /// being passed to this variadic function, and set the MachineModuleInfo's
642 /// usesVAFloatArgument flag if so. This flag is used to emit an undefined
643 /// reference to _fltused on Windows, which will link in MSVCRT's
644 /// floating-point support.
645 void llvm::ComputeUsesVAFloatArgument(const CallInst &I,
646 MachineModuleInfo *MMI)
648 FunctionType *FT = cast<FunctionType>(
649 I.getCalledValue()->getType()->getContainedType(0));
650 if (FT->isVarArg() && !MMI->usesVAFloatArgument()) {
651 for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
652 Type* T = I.getArgOperand(i)->getType();
653 for (po_iterator<Type*> i = po_begin(T), e = po_end(T);
655 if (i->isFloatingPointTy()) {
656 MMI->setUsesVAFloatArgument(true);
664 /// AddLandingPadInfo - Extract the exception handling information from the
665 /// landingpad instruction and add them to the specified machine module info.
666 void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
667 MachineBasicBlock *MBB) {
668 MMI.addPersonality(MBB,
669 cast<Function>(I.getPersonalityFn()->stripPointerCasts()));
674 // FIXME: New EH - Add the clauses in reverse order. This isn't 100% correct,
675 // but we need to do it this way because of how the DWARF EH emitter
676 // processes the clauses.
677 for (unsigned i = I.getNumClauses(); i != 0; --i) {
678 Value *Val = I.getClause(i - 1);
679 if (I.isCatch(i - 1)) {
680 MMI.addCatchTypeInfo(MBB,
681 dyn_cast<GlobalValue>(Val->stripPointerCasts()));
683 // Add filters in a list.
684 Constant *CVal = cast<Constant>(Val);
685 SmallVector<const GlobalValue*, 4> FilterList;
686 for (User::op_iterator
687 II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II)
688 FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
690 MMI.addFilterTypeInfo(MBB, FilterList);