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 // FIXME: This should be revisited when we want to throw inside a catch
305 TBME.CatchHigh = INT_MAX;
306 assert(TBME.TryLow <= TBME.TryHigh);
307 assert(TBME.CatchHigh > TBME.TryHigh);
308 for (CatchHandler *CH : Handlers) {
310 if (CH->getSelector()->isNullValue()) {
311 HT.Adjectives = 0x40;
312 HT.TypeDescriptor = nullptr;
314 auto *GV = cast<GlobalVariable>(CH->getSelector()->stripPointerCasts());
315 // Selectors are always pointers to GlobalVariables with 'struct' type.
316 // The struct has two fields, adjectives and a type descriptor.
317 auto *CS = cast<ConstantStruct>(GV->getInitializer());
319 cast<ConstantInt>(CS->getAggregateElement(0U))->getZExtValue();
321 cast<GlobalVariable>(CS->getAggregateElement(1)->stripPointerCasts());
323 HT.Handler = cast<Function>(CH->getHandlerBlockOrFunc());
324 // FIXME: We don't support catching objects yet!
325 HT.CatchObjIdx = INT_MAX;
326 HT.CatchObjOffset = 0;
327 TBME.HandlerArray.push_back(HT);
329 FuncInfo.TryBlockMap.push_back(TBME);
332 static void print_name(const Value *V) {
335 DEBUG(dbgs() << "null");
339 if (const auto *F = dyn_cast<Function>(V))
340 DEBUG(dbgs() << F->getName());
346 void WinEHNumbering::processCallSite(ArrayRef<ActionHandler *> Actions,
347 ImmutableCallSite CS) {
348 int FirstMismatch = 0;
349 for (int E = std::min(HandlerStack.size(), Actions.size()); FirstMismatch < E;
351 if (HandlerStack[FirstMismatch]->getHandlerBlockOrFunc() !=
352 Actions[FirstMismatch]->getHandlerBlockOrFunc())
354 delete Actions[FirstMismatch];
357 bool EnteringScope = (int)Actions.size() > FirstMismatch;
359 // Don't recurse while we are looping over the handler stack. Instead, defer
360 // the numbering of the catch handlers until we are done popping.
361 SmallVector<CatchHandler *, 4> PoppedCatches;
362 for (int I = HandlerStack.size() - 1; I >= FirstMismatch; --I) {
363 if (auto *CH = dyn_cast<CatchHandler>(HandlerStack.back())) {
364 PoppedCatches.push_back(CH);
366 // Delete cleanup handlers
367 delete HandlerStack.back();
369 HandlerStack.pop_back();
372 // We need to create a new state number if we are exiting a try scope and we
373 // will not push any more actions.
374 int TryHigh = NextState - 1;
375 if (!EnteringScope && !PoppedCatches.empty()) {
376 createUnwindMapEntry(currentEHNumber(), nullptr);
380 int LastTryLowIdx = 0;
381 for (int I = 0, E = PoppedCatches.size(); I != E; ++I) {
382 CatchHandler *CH = PoppedCatches[I];
383 if (I + 1 == E || CH->getEHState() != PoppedCatches[I + 1]->getEHState()) {
384 int TryLow = CH->getEHState();
386 makeArrayRef(&PoppedCatches[LastTryLowIdx], I - LastTryLowIdx + 1);
387 createTryBlockMapEntry(TryLow, TryHigh, Handlers);
388 LastTryLowIdx = I + 1;
392 for (CatchHandler *CH : PoppedCatches) {
393 if (auto *F = dyn_cast<Function>(CH->getHandlerBlockOrFunc()))
394 calculateStateNumbers(*F);
398 bool LastActionWasCatch = false;
399 for (size_t I = FirstMismatch; I != Actions.size(); ++I) {
400 // We can reuse eh states when pushing two catches for the same invoke.
401 bool CurrActionIsCatch = isa<CatchHandler>(Actions[I]);
402 // FIXME: Reenable this optimization!
403 if (CurrActionIsCatch && LastActionWasCatch && false) {
404 Actions[I]->setEHState(currentEHNumber());
406 createUnwindMapEntry(currentEHNumber(), Actions[I]);
407 Actions[I]->setEHState(NextState);
409 DEBUG(dbgs() << "Creating unwind map entry for: (");
410 print_name(Actions[I]->getHandlerBlockOrFunc());
411 DEBUG(dbgs() << ", " << currentEHNumber() << ")\n");
413 HandlerStack.push_back(Actions[I]);
414 LastActionWasCatch = CurrActionIsCatch;
417 DEBUG(dbgs() << "In EHState " << currentEHNumber() << " for CallSite: ");
418 print_name(CS ? CS.getCalledValue() : nullptr);
419 DEBUG(dbgs() << '\n');
422 void WinEHNumbering::calculateStateNumbers(const Function &F) {
423 auto I = VisitedHandlers.insert(&F);
425 return; // We've already visited this handler, don't renumber it.
427 DEBUG(dbgs() << "Calculating state numbers for: " << F.getName() << '\n');
428 SmallVector<ActionHandler *, 4> ActionList;
429 for (const BasicBlock &BB : F) {
430 for (const Instruction &I : BB) {
431 const auto *CI = dyn_cast<CallInst>(&I);
432 if (!CI || CI->doesNotThrow())
434 processCallSite(None, CI);
436 const auto *II = dyn_cast<InvokeInst>(BB.getTerminator());
439 const LandingPadInst *LPI = II->getLandingPadInst();
440 auto *ActionsCall = dyn_cast<IntrinsicInst>(LPI->getNextNode());
443 assert(ActionsCall->getIntrinsicID() == Intrinsic::eh_actions);
444 parseEHActions(ActionsCall, ActionList);
445 processCallSite(ActionList, II);
447 FuncInfo.LandingPadStateMap[LPI] = currentEHNumber();
451 /// clear - Clear out all the function-specific state. This returns this
452 /// FunctionLoweringInfo to an empty state, ready to be used for a
453 /// different function.
454 void FunctionLoweringInfo::clear() {
455 assert(CatchInfoFound.size() == CatchInfoLost.size() &&
456 "Not all catch info was assigned to a landing pad!");
460 StaticAllocaMap.clear();
462 CatchInfoLost.clear();
463 CatchInfoFound.clear();
465 LiveOutRegInfo.clear();
467 ArgDbgValues.clear();
468 ByValArgFrameIndexMap.clear();
470 StatepointStackSlots.clear();
471 PreferredExtendType.clear();
474 /// CreateReg - Allocate a single virtual register for the given type.
475 unsigned FunctionLoweringInfo::CreateReg(MVT VT) {
476 return RegInfo->createVirtualRegister(
477 MF->getSubtarget().getTargetLowering()->getRegClassFor(VT));
480 /// CreateRegs - Allocate the appropriate number of virtual registers of
481 /// the correctly promoted or expanded types. Assign these registers
482 /// consecutive vreg numbers and return the first assigned number.
484 /// In the case that the given value has struct or array type, this function
485 /// will assign registers for each member or element.
487 unsigned FunctionLoweringInfo::CreateRegs(Type *Ty) {
488 const TargetLowering *TLI = MF->getSubtarget().getTargetLowering();
490 SmallVector<EVT, 4> ValueVTs;
491 ComputeValueVTs(*TLI, Ty, ValueVTs);
493 unsigned FirstReg = 0;
494 for (unsigned Value = 0, e = ValueVTs.size(); Value != e; ++Value) {
495 EVT ValueVT = ValueVTs[Value];
496 MVT RegisterVT = TLI->getRegisterType(Ty->getContext(), ValueVT);
498 unsigned NumRegs = TLI->getNumRegisters(Ty->getContext(), ValueVT);
499 for (unsigned i = 0; i != NumRegs; ++i) {
500 unsigned R = CreateReg(RegisterVT);
501 if (!FirstReg) FirstReg = R;
507 /// GetLiveOutRegInfo - Gets LiveOutInfo for a register, returning NULL if the
508 /// register is a PHI destination and the PHI's LiveOutInfo is not valid. If
509 /// the register's LiveOutInfo is for a smaller bit width, it is extended to
510 /// the larger bit width by zero extension. The bit width must be no smaller
511 /// than the LiveOutInfo's existing bit width.
512 const FunctionLoweringInfo::LiveOutInfo *
513 FunctionLoweringInfo::GetLiveOutRegInfo(unsigned Reg, unsigned BitWidth) {
514 if (!LiveOutRegInfo.inBounds(Reg))
517 LiveOutInfo *LOI = &LiveOutRegInfo[Reg];
521 if (BitWidth > LOI->KnownZero.getBitWidth()) {
522 LOI->NumSignBits = 1;
523 LOI->KnownZero = LOI->KnownZero.zextOrTrunc(BitWidth);
524 LOI->KnownOne = LOI->KnownOne.zextOrTrunc(BitWidth);
530 /// ComputePHILiveOutRegInfo - Compute LiveOutInfo for a PHI's destination
531 /// register based on the LiveOutInfo of its operands.
532 void FunctionLoweringInfo::ComputePHILiveOutRegInfo(const PHINode *PN) {
533 Type *Ty = PN->getType();
534 if (!Ty->isIntegerTy() || Ty->isVectorTy())
537 SmallVector<EVT, 1> ValueVTs;
538 ComputeValueVTs(*TLI, Ty, ValueVTs);
539 assert(ValueVTs.size() == 1 &&
540 "PHIs with non-vector integer types should have a single VT.");
541 EVT IntVT = ValueVTs[0];
543 if (TLI->getNumRegisters(PN->getContext(), IntVT) != 1)
545 IntVT = TLI->getTypeToTransformTo(PN->getContext(), IntVT);
546 unsigned BitWidth = IntVT.getSizeInBits();
548 unsigned DestReg = ValueMap[PN];
549 if (!TargetRegisterInfo::isVirtualRegister(DestReg))
551 LiveOutRegInfo.grow(DestReg);
552 LiveOutInfo &DestLOI = LiveOutRegInfo[DestReg];
554 Value *V = PN->getIncomingValue(0);
555 if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
556 DestLOI.NumSignBits = 1;
557 APInt Zero(BitWidth, 0);
558 DestLOI.KnownZero = Zero;
559 DestLOI.KnownOne = Zero;
563 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
564 APInt Val = CI->getValue().zextOrTrunc(BitWidth);
565 DestLOI.NumSignBits = Val.getNumSignBits();
566 DestLOI.KnownZero = ~Val;
567 DestLOI.KnownOne = Val;
569 assert(ValueMap.count(V) && "V should have been placed in ValueMap when its"
570 "CopyToReg node was created.");
571 unsigned SrcReg = ValueMap[V];
572 if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
573 DestLOI.IsValid = false;
576 const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
578 DestLOI.IsValid = false;
584 assert(DestLOI.KnownZero.getBitWidth() == BitWidth &&
585 DestLOI.KnownOne.getBitWidth() == BitWidth &&
586 "Masks should have the same bit width as the type.");
588 for (unsigned i = 1, e = PN->getNumIncomingValues(); i != e; ++i) {
589 Value *V = PN->getIncomingValue(i);
590 if (isa<UndefValue>(V) || isa<ConstantExpr>(V)) {
591 DestLOI.NumSignBits = 1;
592 APInt Zero(BitWidth, 0);
593 DestLOI.KnownZero = Zero;
594 DestLOI.KnownOne = Zero;
598 if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
599 APInt Val = CI->getValue().zextOrTrunc(BitWidth);
600 DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, Val.getNumSignBits());
601 DestLOI.KnownZero &= ~Val;
602 DestLOI.KnownOne &= Val;
606 assert(ValueMap.count(V) && "V should have been placed in ValueMap when "
607 "its CopyToReg node was created.");
608 unsigned SrcReg = ValueMap[V];
609 if (!TargetRegisterInfo::isVirtualRegister(SrcReg)) {
610 DestLOI.IsValid = false;
613 const LiveOutInfo *SrcLOI = GetLiveOutRegInfo(SrcReg, BitWidth);
615 DestLOI.IsValid = false;
618 DestLOI.NumSignBits = std::min(DestLOI.NumSignBits, SrcLOI->NumSignBits);
619 DestLOI.KnownZero &= SrcLOI->KnownZero;
620 DestLOI.KnownOne &= SrcLOI->KnownOne;
624 /// setArgumentFrameIndex - Record frame index for the byval
625 /// argument. This overrides previous frame index entry for this argument,
627 void FunctionLoweringInfo::setArgumentFrameIndex(const Argument *A,
629 ByValArgFrameIndexMap[A] = FI;
632 /// getArgumentFrameIndex - Get frame index for the byval argument.
633 /// If the argument does not have any assigned frame index then 0 is
635 int FunctionLoweringInfo::getArgumentFrameIndex(const Argument *A) {
636 DenseMap<const Argument *, int>::iterator I =
637 ByValArgFrameIndexMap.find(A);
638 if (I != ByValArgFrameIndexMap.end())
640 DEBUG(dbgs() << "Argument does not have assigned frame index!\n");
644 /// ComputeUsesVAFloatArgument - Determine if any floating-point values are
645 /// being passed to this variadic function, and set the MachineModuleInfo's
646 /// usesVAFloatArgument flag if so. This flag is used to emit an undefined
647 /// reference to _fltused on Windows, which will link in MSVCRT's
648 /// floating-point support.
649 void llvm::ComputeUsesVAFloatArgument(const CallInst &I,
650 MachineModuleInfo *MMI)
652 FunctionType *FT = cast<FunctionType>(
653 I.getCalledValue()->getType()->getContainedType(0));
654 if (FT->isVarArg() && !MMI->usesVAFloatArgument()) {
655 for (unsigned i = 0, e = I.getNumArgOperands(); i != e; ++i) {
656 Type* T = I.getArgOperand(i)->getType();
657 for (po_iterator<Type*> i = po_begin(T), e = po_end(T);
659 if (i->isFloatingPointTy()) {
660 MMI->setUsesVAFloatArgument(true);
668 /// AddLandingPadInfo - Extract the exception handling information from the
669 /// landingpad instruction and add them to the specified machine module info.
670 void llvm::AddLandingPadInfo(const LandingPadInst &I, MachineModuleInfo &MMI,
671 MachineBasicBlock *MBB) {
672 MMI.addPersonality(MBB,
673 cast<Function>(I.getPersonalityFn()->stripPointerCasts()));
678 // FIXME: New EH - Add the clauses in reverse order. This isn't 100% correct,
679 // but we need to do it this way because of how the DWARF EH emitter
680 // processes the clauses.
681 for (unsigned i = I.getNumClauses(); i != 0; --i) {
682 Value *Val = I.getClause(i - 1);
683 if (I.isCatch(i - 1)) {
684 MMI.addCatchTypeInfo(MBB,
685 dyn_cast<GlobalValue>(Val->stripPointerCasts()));
687 // Add filters in a list.
688 Constant *CVal = cast<Constant>(Val);
689 SmallVector<const GlobalValue*, 4> FilterList;
690 for (User::op_iterator
691 II = CVal->op_begin(), IE = CVal->op_end(); II != IE; ++II)
692 FilterList.push_back(cast<GlobalValue>((*II)->stripPointerCasts()));
694 MMI.addFilterTypeInfo(MBB, FilterList);