//===----------------------------------------------------------------------===//
#include "llvm/Transforms/Utils/Cloning.h"
+#include "llvm/ADT/SmallSet.h"
#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/StringExtras.h"
+#include "llvm/Analysis/AliasAnalysis.h"
+#include "llvm/Analysis/AssumptionCache.h"
#include "llvm/Analysis/CallGraph.h"
+#include "llvm/Analysis/CaptureTracking.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/ValueTracking.h"
#include "llvm/IR/Attributes.h"
#include "llvm/IR/CallSite.h"
+#include "llvm/IR/CFG.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/DebugInfo.h"
#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/DIBuilder.h"
+#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Instructions.h"
#include "llvm/IR/IntrinsicInst.h"
#include "llvm/IR/Intrinsics.h"
+#include "llvm/IR/MDBuilder.h"
#include "llvm/IR/Module.h"
#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Support/CommandLine.h"
+#include <algorithm>
using namespace llvm;
+static cl::opt<bool>
+EnableNoAliasConversion("enable-noalias-to-md-conversion", cl::init(true),
+ cl::Hidden,
+ cl::desc("Convert noalias attributes to metadata during inlining."));
+
+static cl::opt<bool>
+PreserveAlignmentAssumptions("preserve-alignment-assumptions-during-inlining",
+ cl::init(true), cl::Hidden,
+ cl::desc("Convert align attributes to assumptions during inlining."));
+
bool llvm::InlineFunction(CallInst *CI, InlineFunctionInfo &IFI,
bool InsertLifetime) {
return InlineFunction(CallSite(CI), IFI, InsertLifetime);
public:
InvokeInliningInfo(InvokeInst *II)
- : OuterResumeDest(II->getUnwindDest()), InnerResumeDest(0),
- CallerLPad(0), InnerEHValuesPHI(0) {
+ : OuterResumeDest(II->getUnwindDest()), InnerResumeDest(nullptr),
+ CallerLPad(nullptr), InnerEHValuesPHI(nullptr) {
// If there are PHI nodes in the unwind destination block, we need to keep
// track of which values came into them from the invoke before removing
// the edge from this block.
/// split the landing pad block after the landingpad instruction and jump
/// to there.
void forwardResume(ResumeInst *RI,
- SmallPtrSet<LandingPadInst*, 16> &InlinedLPads);
+ SmallPtrSetImpl<LandingPadInst*> &InlinedLPads);
/// addIncomingPHIValuesFor - Add incoming-PHI values to the unwind
/// destination block for the given basic block, using the values for the
/// branch. When there is more than one predecessor, we need to split the
/// landing pad block after the landingpad instruction and jump to there.
void InvokeInliningInfo::forwardResume(ResumeInst *RI,
- SmallPtrSet<LandingPadInst*, 16> &InlinedLPads) {
+ SmallPtrSetImpl<LandingPadInst*> &InlinedLPads) {
BasicBlock *Dest = getInnerResumeDest();
BasicBlock *Src = RI->getParent();
InvokeInst *II = InvokeInst::Create(CI->getCalledValue(), Split,
Invoke.getOuterResumeDest(),
InvokeArgs, CI->getName(), BB);
+ II->setDebugLoc(CI->getDebugLoc());
II->setCallingConv(CI->getCallingConv());
II->setAttributes(CI->getAttributes());
// Append the clauses from the outer landing pad instruction into the inlined
// landing pad instructions.
LandingPadInst *OuterLPad = Invoke.getLandingPadInst();
- for (SmallPtrSet<LandingPadInst*, 16>::iterator I = InlinedLPads.begin(),
- E = InlinedLPads.end(); I != E; ++I) {
- LandingPadInst *InlinedLPad = *I;
+ for (LandingPadInst *InlinedLPad : InlinedLPads) {
unsigned OuterNum = OuterLPad->getNumClauses();
InlinedLPad->reserveClauses(OuterNum);
for (unsigned OuterIdx = 0; OuterIdx != OuterNum; ++OuterIdx)
InvokeDest->removePredecessor(II->getParent());
}
+/// CloneAliasScopeMetadata - When inlining a function that contains noalias
+/// scope metadata, this metadata needs to be cloned so that the inlined blocks
+/// have different "unqiue scopes" at every call site. Were this not done, then
+/// aliasing scopes from a function inlined into a caller multiple times could
+/// not be differentiated (and this would lead to miscompiles because the
+/// non-aliasing property communicated by the metadata could have
+/// call-site-specific control dependencies).
+static void CloneAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap) {
+ const Function *CalledFunc = CS.getCalledFunction();
+ SetVector<const MDNode *> MD;
+
+ // Note: We could only clone the metadata if it is already used in the
+ // caller. I'm omitting that check here because it might confuse
+ // inter-procedural alias analysis passes. We can revisit this if it becomes
+ // an efficiency or overhead problem.
+
+ for (Function::const_iterator I = CalledFunc->begin(), IE = CalledFunc->end();
+ I != IE; ++I)
+ for (BasicBlock::const_iterator J = I->begin(), JE = I->end(); J != JE; ++J) {
+ if (const MDNode *M = J->getMetadata(LLVMContext::MD_alias_scope))
+ MD.insert(M);
+ if (const MDNode *M = J->getMetadata(LLVMContext::MD_noalias))
+ MD.insert(M);
+ }
+
+ if (MD.empty())
+ return;
+
+ // Walk the existing metadata, adding the complete (perhaps cyclic) chain to
+ // the set.
+ SmallVector<const Metadata *, 16> Queue(MD.begin(), MD.end());
+ while (!Queue.empty()) {
+ const MDNode *M = cast<MDNode>(Queue.pop_back_val());
+ for (unsigned i = 0, ie = M->getNumOperands(); i != ie; ++i)
+ if (const MDNode *M1 = dyn_cast<MDNode>(M->getOperand(i)))
+ if (MD.insert(M1))
+ Queue.push_back(M1);
+ }
+
+ // Now we have a complete set of all metadata in the chains used to specify
+ // the noalias scopes and the lists of those scopes.
+ SmallVector<TempMDTuple, 16> DummyNodes;
+ DenseMap<const MDNode *, TrackingMDNodeRef> MDMap;
+ for (SetVector<const MDNode *>::iterator I = MD.begin(), IE = MD.end();
+ I != IE; ++I) {
+ DummyNodes.push_back(MDTuple::getTemporary(CalledFunc->getContext(), None));
+ MDMap[*I].reset(DummyNodes.back().get());
+ }
+
+ // Create new metadata nodes to replace the dummy nodes, replacing old
+ // metadata references with either a dummy node or an already-created new
+ // node.
+ for (SetVector<const MDNode *>::iterator I = MD.begin(), IE = MD.end();
+ I != IE; ++I) {
+ SmallVector<Metadata *, 4> NewOps;
+ for (unsigned i = 0, ie = (*I)->getNumOperands(); i != ie; ++i) {
+ const Metadata *V = (*I)->getOperand(i);
+ if (const MDNode *M = dyn_cast<MDNode>(V))
+ NewOps.push_back(MDMap[M]);
+ else
+ NewOps.push_back(const_cast<Metadata *>(V));
+ }
+
+ MDNode *NewM = MDNode::get(CalledFunc->getContext(), NewOps);
+ MDTuple *TempM = cast<MDTuple>(MDMap[*I]);
+ assert(TempM->isTemporary() && "Expected temporary node");
+
+ TempM->replaceAllUsesWith(NewM);
+ }
+
+ // Now replace the metadata in the new inlined instructions with the
+ // repacements from the map.
+ for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end();
+ VMI != VMIE; ++VMI) {
+ if (!VMI->second)
+ continue;
+
+ Instruction *NI = dyn_cast<Instruction>(VMI->second);
+ if (!NI)
+ continue;
+
+ if (MDNode *M = NI->getMetadata(LLVMContext::MD_alias_scope)) {
+ MDNode *NewMD = MDMap[M];
+ // If the call site also had alias scope metadata (a list of scopes to
+ // which instructions inside it might belong), propagate those scopes to
+ // the inlined instructions.
+ if (MDNode *CSM =
+ CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope))
+ NewMD = MDNode::concatenate(NewMD, CSM);
+ NI->setMetadata(LLVMContext::MD_alias_scope, NewMD);
+ } else if (NI->mayReadOrWriteMemory()) {
+ if (MDNode *M =
+ CS.getInstruction()->getMetadata(LLVMContext::MD_alias_scope))
+ NI->setMetadata(LLVMContext::MD_alias_scope, M);
+ }
+
+ if (MDNode *M = NI->getMetadata(LLVMContext::MD_noalias)) {
+ MDNode *NewMD = MDMap[M];
+ // If the call site also had noalias metadata (a list of scopes with
+ // which instructions inside it don't alias), propagate those scopes to
+ // the inlined instructions.
+ if (MDNode *CSM =
+ CS.getInstruction()->getMetadata(LLVMContext::MD_noalias))
+ NewMD = MDNode::concatenate(NewMD, CSM);
+ NI->setMetadata(LLVMContext::MD_noalias, NewMD);
+ } else if (NI->mayReadOrWriteMemory()) {
+ if (MDNode *M = CS.getInstruction()->getMetadata(LLVMContext::MD_noalias))
+ NI->setMetadata(LLVMContext::MD_noalias, M);
+ }
+ }
+}
+
+/// AddAliasScopeMetadata - If the inlined function has noalias arguments, then
+/// add new alias scopes for each noalias argument, tag the mapped noalias
+/// parameters with noalias metadata specifying the new scope, and tag all
+/// non-derived loads, stores and memory intrinsics with the new alias scopes.
+static void AddAliasScopeMetadata(CallSite CS, ValueToValueMapTy &VMap,
+ const DataLayout *DL, AliasAnalysis *AA) {
+ if (!EnableNoAliasConversion)
+ return;
+
+ const Function *CalledFunc = CS.getCalledFunction();
+ SmallVector<const Argument *, 4> NoAliasArgs;
+
+ for (Function::const_arg_iterator I = CalledFunc->arg_begin(),
+ E = CalledFunc->arg_end(); I != E; ++I) {
+ if (I->hasNoAliasAttr() && !I->hasNUses(0))
+ NoAliasArgs.push_back(I);
+ }
+
+ if (NoAliasArgs.empty())
+ return;
+
+ // To do a good job, if a noalias variable is captured, we need to know if
+ // the capture point dominates the particular use we're considering.
+ DominatorTree DT;
+ DT.recalculate(const_cast<Function&>(*CalledFunc));
+
+ // noalias indicates that pointer values based on the argument do not alias
+ // pointer values which are not based on it. So we add a new "scope" for each
+ // noalias function argument. Accesses using pointers based on that argument
+ // become part of that alias scope, accesses using pointers not based on that
+ // argument are tagged as noalias with that scope.
+
+ DenseMap<const Argument *, MDNode *> NewScopes;
+ MDBuilder MDB(CalledFunc->getContext());
+
+ // Create a new scope domain for this function.
+ MDNode *NewDomain =
+ MDB.createAnonymousAliasScopeDomain(CalledFunc->getName());
+ for (unsigned i = 0, e = NoAliasArgs.size(); i != e; ++i) {
+ const Argument *A = NoAliasArgs[i];
+
+ std::string Name = CalledFunc->getName();
+ if (A->hasName()) {
+ Name += ": %";
+ Name += A->getName();
+ } else {
+ Name += ": argument ";
+ Name += utostr(i);
+ }
+
+ // Note: We always create a new anonymous root here. This is true regardless
+ // of the linkage of the callee because the aliasing "scope" is not just a
+ // property of the callee, but also all control dependencies in the caller.
+ MDNode *NewScope = MDB.createAnonymousAliasScope(NewDomain, Name);
+ NewScopes.insert(std::make_pair(A, NewScope));
+ }
+
+ // Iterate over all new instructions in the map; for all memory-access
+ // instructions, add the alias scope metadata.
+ for (ValueToValueMapTy::iterator VMI = VMap.begin(), VMIE = VMap.end();
+ VMI != VMIE; ++VMI) {
+ if (const Instruction *I = dyn_cast<Instruction>(VMI->first)) {
+ if (!VMI->second)
+ continue;
+
+ Instruction *NI = dyn_cast<Instruction>(VMI->second);
+ if (!NI)
+ continue;
+
+ bool IsArgMemOnlyCall = false, IsFuncCall = false;
+ SmallVector<const Value *, 2> PtrArgs;
+
+ if (const LoadInst *LI = dyn_cast<LoadInst>(I))
+ PtrArgs.push_back(LI->getPointerOperand());
+ else if (const StoreInst *SI = dyn_cast<StoreInst>(I))
+ PtrArgs.push_back(SI->getPointerOperand());
+ else if (const VAArgInst *VAAI = dyn_cast<VAArgInst>(I))
+ PtrArgs.push_back(VAAI->getPointerOperand());
+ else if (const AtomicCmpXchgInst *CXI = dyn_cast<AtomicCmpXchgInst>(I))
+ PtrArgs.push_back(CXI->getPointerOperand());
+ else if (const AtomicRMWInst *RMWI = dyn_cast<AtomicRMWInst>(I))
+ PtrArgs.push_back(RMWI->getPointerOperand());
+ else if (ImmutableCallSite ICS = ImmutableCallSite(I)) {
+ // If we know that the call does not access memory, then we'll still
+ // know that about the inlined clone of this call site, and we don't
+ // need to add metadata.
+ if (ICS.doesNotAccessMemory())
+ continue;
+
+ IsFuncCall = true;
+ if (AA) {
+ AliasAnalysis::ModRefBehavior MRB = AA->getModRefBehavior(ICS);
+ if (MRB == AliasAnalysis::OnlyAccessesArgumentPointees ||
+ MRB == AliasAnalysis::OnlyReadsArgumentPointees)
+ IsArgMemOnlyCall = true;
+ }
+
+ for (ImmutableCallSite::arg_iterator AI = ICS.arg_begin(),
+ AE = ICS.arg_end(); AI != AE; ++AI) {
+ // We need to check the underlying objects of all arguments, not just
+ // the pointer arguments, because we might be passing pointers as
+ // integers, etc.
+ // However, if we know that the call only accesses pointer arguments,
+ // then we only need to check the pointer arguments.
+ if (IsArgMemOnlyCall && !(*AI)->getType()->isPointerTy())
+ continue;
+
+ PtrArgs.push_back(*AI);
+ }
+ }
+
+ // If we found no pointers, then this instruction is not suitable for
+ // pairing with an instruction to receive aliasing metadata.
+ // However, if this is a call, this we might just alias with none of the
+ // noalias arguments.
+ if (PtrArgs.empty() && !IsFuncCall)
+ continue;
+
+ // It is possible that there is only one underlying object, but you
+ // need to go through several PHIs to see it, and thus could be
+ // repeated in the Objects list.
+ SmallPtrSet<const Value *, 4> ObjSet;
+ SmallVector<Metadata *, 4> Scopes, NoAliases;
+
+ SmallSetVector<const Argument *, 4> NAPtrArgs;
+ for (unsigned i = 0, ie = PtrArgs.size(); i != ie; ++i) {
+ SmallVector<Value *, 4> Objects;
+ GetUnderlyingObjects(const_cast<Value*>(PtrArgs[i]),
+ Objects, DL, /* MaxLookup = */ 0);
+
+ for (Value *O : Objects)
+ ObjSet.insert(O);
+ }
+
+ // Figure out if we're derived from anything that is not a noalias
+ // argument.
+ bool CanDeriveViaCapture = false, UsesAliasingPtr = false;
+ for (const Value *V : ObjSet) {
+ // Is this value a constant that cannot be derived from any pointer
+ // value (we need to exclude constant expressions, for example, that
+ // are formed from arithmetic on global symbols).
+ bool IsNonPtrConst = isa<ConstantInt>(V) || isa<ConstantFP>(V) ||
+ isa<ConstantPointerNull>(V) ||
+ isa<ConstantDataVector>(V) || isa<UndefValue>(V);
+ if (IsNonPtrConst)
+ continue;
+
+ // If this is anything other than a noalias argument, then we cannot
+ // completely describe the aliasing properties using alias.scope
+ // metadata (and, thus, won't add any).
+ if (const Argument *A = dyn_cast<Argument>(V)) {
+ if (!A->hasNoAliasAttr())
+ UsesAliasingPtr = true;
+ } else {
+ UsesAliasingPtr = true;
+ }
+
+ // If this is not some identified function-local object (which cannot
+ // directly alias a noalias argument), or some other argument (which,
+ // by definition, also cannot alias a noalias argument), then we could
+ // alias a noalias argument that has been captured).
+ if (!isa<Argument>(V) &&
+ !isIdentifiedFunctionLocal(const_cast<Value*>(V)))
+ CanDeriveViaCapture = true;
+ }
+
+ // A function call can always get captured noalias pointers (via other
+ // parameters, globals, etc.).
+ if (IsFuncCall && !IsArgMemOnlyCall)
+ CanDeriveViaCapture = true;
+
+ // First, we want to figure out all of the sets with which we definitely
+ // don't alias. Iterate over all noalias set, and add those for which:
+ // 1. The noalias argument is not in the set of objects from which we
+ // definitely derive.
+ // 2. The noalias argument has not yet been captured.
+ // An arbitrary function that might load pointers could see captured
+ // noalias arguments via other noalias arguments or globals, and so we
+ // must always check for prior capture.
+ for (const Argument *A : NoAliasArgs) {
+ if (!ObjSet.count(A) && (!CanDeriveViaCapture ||
+ // It might be tempting to skip the
+ // PointerMayBeCapturedBefore check if
+ // A->hasNoCaptureAttr() is true, but this is
+ // incorrect because nocapture only guarantees
+ // that no copies outlive the function, not
+ // that the value cannot be locally captured.
+ !PointerMayBeCapturedBefore(A,
+ /* ReturnCaptures */ false,
+ /* StoreCaptures */ false, I, &DT)))
+ NoAliases.push_back(NewScopes[A]);
+ }
+
+ if (!NoAliases.empty())
+ NI->setMetadata(LLVMContext::MD_noalias,
+ MDNode::concatenate(
+ NI->getMetadata(LLVMContext::MD_noalias),
+ MDNode::get(CalledFunc->getContext(), NoAliases)));
+
+ // Next, we want to figure out all of the sets to which we might belong.
+ // We might belong to a set if the noalias argument is in the set of
+ // underlying objects. If there is some non-noalias argument in our list
+ // of underlying objects, then we cannot add a scope because the fact
+ // that some access does not alias with any set of our noalias arguments
+ // cannot itself guarantee that it does not alias with this access
+ // (because there is some pointer of unknown origin involved and the
+ // other access might also depend on this pointer). We also cannot add
+ // scopes to arbitrary functions unless we know they don't access any
+ // non-parameter pointer-values.
+ bool CanAddScopes = !UsesAliasingPtr;
+ if (CanAddScopes && IsFuncCall)
+ CanAddScopes = IsArgMemOnlyCall;
+
+ if (CanAddScopes)
+ for (const Argument *A : NoAliasArgs) {
+ if (ObjSet.count(A))
+ Scopes.push_back(NewScopes[A]);
+ }
+
+ if (!Scopes.empty())
+ NI->setMetadata(
+ LLVMContext::MD_alias_scope,
+ MDNode::concatenate(NI->getMetadata(LLVMContext::MD_alias_scope),
+ MDNode::get(CalledFunc->getContext(), Scopes)));
+ }
+ }
+}
+
+/// If the inlined function has non-byval align arguments, then
+/// add @llvm.assume-based alignment assumptions to preserve this information.
+static void AddAlignmentAssumptions(CallSite CS, InlineFunctionInfo &IFI) {
+ if (!PreserveAlignmentAssumptions || !IFI.DL)
+ return;
+
+ // To avoid inserting redundant assumptions, we should check for assumptions
+ // already in the caller. To do this, we might need a DT of the caller.
+ DominatorTree DT;
+ bool DTCalculated = false;
+
+ Function *CalledFunc = CS.getCalledFunction();
+ for (Function::arg_iterator I = CalledFunc->arg_begin(),
+ E = CalledFunc->arg_end();
+ I != E; ++I) {
+ unsigned Align = I->getType()->isPointerTy() ? I->getParamAlignment() : 0;
+ if (Align && !I->hasByValOrInAllocaAttr() && !I->hasNUses(0)) {
+ if (!DTCalculated) {
+ DT.recalculate(const_cast<Function&>(*CS.getInstruction()->getParent()
+ ->getParent()));
+ DTCalculated = true;
+ }
+
+ // If we can already prove the asserted alignment in the context of the
+ // caller, then don't bother inserting the assumption.
+ Value *Arg = CS.getArgument(I->getArgNo());
+ if (getKnownAlignment(Arg, IFI.DL,
+ &IFI.ACT->getAssumptionCache(*CalledFunc),
+ CS.getInstruction(), &DT) >= Align)
+ continue;
+
+ IRBuilder<>(CS.getInstruction()).CreateAlignmentAssumption(*IFI.DL, Arg,
+ Align);
+ }
+ }
+}
+
/// UpdateCallGraphAfterInlining - Once we have cloned code over from a callee
/// into the caller, update the specified callgraph to reflect the changes we
/// made. Note that it's possible that not all code was copied over, so only
ValueToValueMapTy::iterator VMI = VMap.find(OrigCall);
// Only copy the edge if the call was inlined!
- if (VMI == VMap.end() || VMI->second == 0)
+ if (VMI == VMap.end() || VMI->second == nullptr)
continue;
// If the call was inlined, but then constant folded, there is no edge to
// add. Check for this case.
Instruction *NewCall = dyn_cast<Instruction>(VMI->second);
- if (NewCall == 0) continue;
+ if (!NewCall) continue;
// Remember that this call site got inlined for the client of
// InlineFunction.
// happens, set the callee of the new call site to a more precise
// destination. This can also happen if the call graph node of the caller
// was just unnecessarily imprecise.
- if (I->second->getFunction() == 0)
+ if (!I->second->getFunction())
if (Function *F = CallSite(NewCall).getCalledFunction()) {
// Indirect call site resolved to direct call.
CallerNode->addCalledFunction(CallSite(NewCall), CG[F]);
static void HandleByValArgumentInit(Value *Dst, Value *Src, Module *M,
BasicBlock *InsertBlock,
InlineFunctionInfo &IFI) {
- LLVMContext &Context = Src->getContext();
- Type *VoidPtrTy = Type::getInt8PtrTy(Context);
Type *AggTy = cast<PointerType>(Src->getType())->getElementType();
- Type *Tys[3] = { VoidPtrTy, VoidPtrTy, Type::getInt64Ty(Context) };
- Function *MemCpyFn = Intrinsic::getDeclaration(M, Intrinsic::memcpy, Tys);
- IRBuilder<> builder(InsertBlock->begin());
- Value *DstCast = builder.CreateBitCast(Dst, VoidPtrTy, "tmp");
- Value *SrcCast = builder.CreateBitCast(Src, VoidPtrTy, "tmp");
+ IRBuilder<> Builder(InsertBlock->begin());
Value *Size;
- if (IFI.DL == 0)
+ if (IFI.DL == nullptr)
Size = ConstantExpr::getSizeOf(AggTy);
else
- Size = ConstantInt::get(Type::getInt64Ty(Context),
- IFI.DL->getTypeStoreSize(AggTy));
+ Size = Builder.getInt64(IFI.DL->getTypeStoreSize(AggTy));
// Always generate a memcpy of alignment 1 here because we don't know
// the alignment of the src pointer. Other optimizations can infer
// better alignment.
- Value *CallArgs[] = {
- DstCast, SrcCast, Size,
- ConstantInt::get(Type::getInt32Ty(Context), 1),
- ConstantInt::getFalse(Context) // isVolatile
- };
- builder.CreateCall(MemCpyFn, CallArgs);
+ Builder.CreateMemCpy(Dst, Src, Size, /*Align=*/1);
}
/// HandleByValArgument - When inlining a call site that has a byval argument,
PointerType *ArgTy = cast<PointerType>(Arg->getType());
Type *AggTy = ArgTy->getElementType();
+ Function *Caller = TheCall->getParent()->getParent();
+
// If the called function is readonly, then it could not mutate the caller's
// copy of the byval'd memory. In this case, it is safe to elide the copy and
// temporary.
// If the pointer is already known to be sufficiently aligned, or if we can
// round it up to a larger alignment, then we don't need a temporary.
- if (getOrEnforceKnownAlignment(Arg, ByValAlignment,
- IFI.DL) >= ByValAlignment)
+ if (getOrEnforceKnownAlignment(Arg, ByValAlignment, IFI.DL,
+ &IFI.ACT->getAssumptionCache(*Caller),
+ TheCall) >= ByValAlignment)
return Arg;
// Otherwise, we have to make a memcpy to get a safe alignment. This is bad
// pointer inside the callee).
Align = std::max(Align, ByValAlignment);
- Function *Caller = TheCall->getParent()->getParent();
-
- Value *NewAlloca = new AllocaInst(AggTy, 0, Align, Arg->getName(),
+ Value *NewAlloca = new AllocaInst(AggTy, nullptr, Align, Arg->getName(),
&*Caller->begin()->begin());
IFI.StaticAllocas.push_back(cast<AllocaInst>(NewAlloca));
return false;
}
-/// updateInlinedAtInfo - Helper function used by fixupLineNumbers to
-/// recursively update InlinedAtEntry of a DebugLoc.
-static DebugLoc updateInlinedAtInfo(const DebugLoc &DL,
- const DebugLoc &InlinedAtDL,
- LLVMContext &Ctx) {
- if (MDNode *IA = DL.getInlinedAt(Ctx)) {
- DebugLoc NewInlinedAtDL
- = updateInlinedAtInfo(DebugLoc::getFromDILocation(IA), InlinedAtDL, Ctx);
- return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(Ctx),
- NewInlinedAtDL.getAsMDNode(Ctx));
+/// Rebuild the entire inlined-at chain for this instruction so that the top of
+/// the chain now is inlined-at the new call site.
+static DebugLoc
+updateInlinedAtInfo(DebugLoc DL, MDLocation *InlinedAtNode,
+ LLVMContext &Ctx,
+ DenseMap<const MDLocation *, MDLocation *> &IANodes) {
+ SmallVector<MDLocation*, 3> InlinedAtLocations;
+ MDLocation *Last = InlinedAtNode;
+ DebugLoc CurInlinedAt = DL;
+
+ // Gather all the inlined-at nodes
+ while (MDLocation *IA =
+ cast_or_null<MDLocation>(CurInlinedAt.getInlinedAt(Ctx))) {
+ // Skip any we've already built nodes for
+ if (MDLocation *Found = IANodes[IA]) {
+ Last = Found;
+ break;
+ }
+
+ InlinedAtLocations.push_back(IA);
+ CurInlinedAt = DebugLoc::getFromDILocation(IA);
}
- return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(Ctx),
- InlinedAtDL.getAsMDNode(Ctx));
+ // Starting from the top, rebuild the nodes to point to the new inlined-at
+ // location (then rebuilding the rest of the chain behind it) and update the
+ // map of already-constructed inlined-at nodes.
+ for (auto I = InlinedAtLocations.rbegin(), E = InlinedAtLocations.rend();
+ I != E; ++I) {
+ const MDLocation *MD = *I;
+ Last = IANodes[MD] = MDLocation::getDistinct(
+ Ctx, MD->getLine(), MD->getColumn(), MD->getScope(), Last);
+ }
+
+ // And finally create the normal location for this instruction, referring to
+ // the new inlined-at chain.
+ return DebugLoc::get(DL.getLine(), DL.getCol(), DL.getScope(Ctx), Last);
}
/// fixupLineNumbers - Update inlined instructions' line numbers to
if (TheCallDL.isUnknown())
return;
+ auto &Ctx = Fn->getContext();
+ auto *InlinedAtNode = cast<MDLocation>(TheCallDL.getAsMDNode(Ctx));
+
+ // Create a unique call site, not to be confused with any other call from the
+ // same location.
+ InlinedAtNode = MDLocation::getDistinct(
+ Ctx, InlinedAtNode->getLine(), InlinedAtNode->getColumn(),
+ InlinedAtNode->getScope(), InlinedAtNode->getInlinedAt());
+
+ // Cache the inlined-at nodes as they're built so they are reused, without
+ // this every instruction's inlined-at chain would become distinct from each
+ // other.
+ DenseMap<const MDLocation *, MDLocation *> IANodes;
+
for (; FI != Fn->end(); ++FI) {
for (BasicBlock::iterator BI = FI->begin(), BE = FI->end();
BI != BE; ++BI) {
DebugLoc DL = BI->getDebugLoc();
- if (!DL.isUnknown()) {
- BI->setDebugLoc(updateInlinedAtInfo(DL, TheCallDL, BI->getContext()));
+ if (DL.isUnknown()) {
+ // If the inlined instruction has no line number, make it look as if it
+ // originates from the call location. This is important for
+ // ((__always_inline__, __nodebug__)) functions which must use caller
+ // location for all instructions in their function body.
+
+ // Don't update static allocas, as they may get moved later.
+ if (auto *AI = dyn_cast<AllocaInst>(BI))
+ if (isa<Constant>(AI->getArraySize()))
+ continue;
+
+ BI->setDebugLoc(TheCallDL);
+ } else {
+ BI->setDebugLoc(updateInlinedAtInfo(DL, InlinedAtNode, BI->getContext(), IANodes));
if (DbgValueInst *DVI = dyn_cast<DbgValueInst>(BI)) {
LLVMContext &Ctx = BI->getContext();
MDNode *InlinedAt = BI->getDebugLoc().getInlinedAt(Ctx);
- DVI->setOperand(2, createInlinedVariable(DVI->getVariable(),
- InlinedAt, Ctx));
+ DVI->setOperand(2, MetadataAsValue::get(
+ Ctx, createInlinedVariable(DVI->getVariable(),
+ InlinedAt, Ctx)));
+ } else if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(BI)) {
+ LLVMContext &Ctx = BI->getContext();
+ MDNode *InlinedAt = BI->getDebugLoc().getInlinedAt(Ctx);
+ DDI->setOperand(1, MetadataAsValue::get(
+ Ctx, createInlinedVariable(DDI->getVariable(),
+ InlinedAt, Ctx)));
}
}
}
IFI.reset();
const Function *CalledFunc = CS.getCalledFunction();
- if (CalledFunc == 0 || // Can't inline external function or indirect
+ if (!CalledFunc || // Can't inline external function or indirect
CalledFunc->isDeclaration() || // call, or call to a vararg function!
CalledFunc->getFunctionType()->isVarArg()) return false;
- // If the call to the callee is not a tail call, we must clear the 'tail'
- // flags on any calls that we inline.
- bool MustClearTailCallFlags =
- !(isa<CallInst>(TheCall) && cast<CallInst>(TheCall)->isTailCall());
-
// If the call to the callee cannot throw, set the 'nounwind' flag on any
// calls that we inline.
bool MarkNoUnwind = CS.doesNotThrow();
}
// Get the personality function from the callee if it contains a landing pad.
- Value *CalleePersonality = 0;
+ Value *CalleePersonality = nullptr;
for (Function::const_iterator I = CalledFunc->begin(), E = CalledFunc->end();
I != E; ++I)
if (const InvokeInst *II = dyn_cast<InvokeInst>(I->getTerminator())) {
VMap[I] = ActualArg;
}
+ // Add alignment assumptions if necessary. We do this before the inlined
+ // instructions are actually cloned into the caller so that we can easily
+ // check what will be known at the start of the inlined code.
+ AddAlignmentAssumptions(CS, IFI);
+
// We want the inliner to prune the code as it copies. We would LOVE to
// have no dead or constant instructions leftover after inlining occurs
// (which can happen, e.g., because an argument was constant), but we'll be
// Update inlined instructions' line number information.
fixupLineNumbers(Caller, FirstNewBlock, TheCall);
+
+ // Clone existing noalias metadata if necessary.
+ CloneAliasScopeMetadata(CS, VMap);
+
+ // Add noalias metadata if necessary.
+ AddAliasScopeMetadata(CS, VMap, IFI.DL, IFI.AA);
+
+ // FIXME: We could register any cloned assumptions instead of clearing the
+ // whole function's cache.
+ if (IFI.ACT)
+ IFI.ACT->getAssumptionCache(*Caller).clear();
}
// If there are any alloca instructions in the block that used to be the entry
for (BasicBlock::iterator I = FirstNewBlock->begin(),
E = FirstNewBlock->end(); I != E; ) {
AllocaInst *AI = dyn_cast<AllocaInst>(I++);
- if (AI == 0) continue;
+ if (!AI) continue;
// If the alloca is now dead, remove it. This often occurs due to code
// specialization.
FirstNewBlock->getInstList(),
AI, I);
}
+ // Move any dbg.declares describing the allocas into the entry basic block.
+ DIBuilder DIB(*Caller->getParent());
+ for (auto &AI : IFI.StaticAllocas)
+ replaceDbgDeclareForAlloca(AI, AI, DIB, /*Deref=*/false);
+ }
+
+ bool InlinedMustTailCalls = false;
+ if (InlinedFunctionInfo.ContainsCalls) {
+ CallInst::TailCallKind CallSiteTailKind = CallInst::TCK_None;
+ if (CallInst *CI = dyn_cast<CallInst>(TheCall))
+ CallSiteTailKind = CI->getTailCallKind();
+
+ for (Function::iterator BB = FirstNewBlock, E = Caller->end(); BB != E;
+ ++BB) {
+ for (Instruction &I : *BB) {
+ CallInst *CI = dyn_cast<CallInst>(&I);
+ if (!CI)
+ continue;
+
+ // We need to reduce the strength of any inlined tail calls. For
+ // musttail, we have to avoid introducing potential unbounded stack
+ // growth. For example, if functions 'f' and 'g' are mutually recursive
+ // with musttail, we can inline 'g' into 'f' so long as we preserve
+ // musttail on the cloned call to 'f'. If either the inlined call site
+ // or the cloned call site is *not* musttail, the program already has
+ // one frame of stack growth, so it's safe to remove musttail. Here is
+ // a table of example transformations:
+ //
+ // f -> musttail g -> musttail f ==> f -> musttail f
+ // f -> musttail g -> tail f ==> f -> tail f
+ // f -> g -> musttail f ==> f -> f
+ // f -> g -> tail f ==> f -> f
+ CallInst::TailCallKind ChildTCK = CI->getTailCallKind();
+ ChildTCK = std::min(CallSiteTailKind, ChildTCK);
+ CI->setTailCallKind(ChildTCK);
+ InlinedMustTailCalls |= CI->isMustTailCall();
+
+ // Calls inlined through a 'nounwind' call site should be marked
+ // 'nounwind'.
+ if (MarkNoUnwind)
+ CI->setDoesNotThrow();
+ }
+ }
}
// Leave lifetime markers for the static alloca's, scoping them to the
continue;
// Try to determine the size of the allocation.
- ConstantInt *AllocaSize = 0;
+ ConstantInt *AllocaSize = nullptr;
if (ConstantInt *AIArraySize =
dyn_cast<ConstantInt>(AI->getArraySize())) {
if (IFI.DL) {
}
builder.CreateLifetimeStart(AI, AllocaSize);
- for (unsigned ri = 0, re = Returns.size(); ri != re; ++ri) {
- IRBuilder<> builder(Returns[ri]);
- builder.CreateLifetimeEnd(AI, AllocaSize);
+ for (ReturnInst *RI : Returns) {
+ // Don't insert llvm.lifetime.end calls between a musttail call and a
+ // return. The return kills all local allocas.
+ if (InlinedMustTailCalls &&
+ RI->getParent()->getTerminatingMustTailCall())
+ continue;
+ IRBuilder<>(RI).CreateLifetimeEnd(AI, AllocaSize);
}
}
}
// Insert a call to llvm.stackrestore before any return instructions in the
// inlined function.
- for (unsigned i = 0, e = Returns.size(); i != e; ++i) {
- IRBuilder<>(Returns[i]).CreateCall(StackRestore, SavedPtr);
+ for (ReturnInst *RI : Returns) {
+ // Don't insert llvm.stackrestore calls between a musttail call and a
+ // return. The return will restore the stack pointer.
+ if (InlinedMustTailCalls && RI->getParent()->getTerminatingMustTailCall())
+ continue;
+ IRBuilder<>(RI).CreateCall(StackRestore, SavedPtr);
}
}
- // If we are inlining tail call instruction through a call site that isn't
- // marked 'tail', we must remove the tail marker for any calls in the inlined
- // code. Also, calls inlined through a 'nounwind' call site should be marked
- // 'nounwind'.
- if (InlinedFunctionInfo.ContainsCalls &&
- (MustClearTailCallFlags || MarkNoUnwind)) {
- for (Function::iterator BB = FirstNewBlock, E = Caller->end();
- BB != E; ++BB)
- for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I)
- if (CallInst *CI = dyn_cast<CallInst>(I)) {
- if (MustClearTailCallFlags)
- CI->setTailCall(false);
- if (MarkNoUnwind)
- CI->setDoesNotThrow();
- }
- }
-
// If we are inlining for an invoke instruction, we must make sure to rewrite
// any call instructions into invoke instructions.
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall))
HandleInlinedInvoke(II, FirstNewBlock, InlinedFunctionInfo);
+ // Handle any inlined musttail call sites. In order for a new call site to be
+ // musttail, the source of the clone and the inlined call site must have been
+ // musttail. Therefore it's safe to return without merging control into the
+ // phi below.
+ if (InlinedMustTailCalls) {
+ // Check if we need to bitcast the result of any musttail calls.
+ Type *NewRetTy = Caller->getReturnType();
+ bool NeedBitCast = !TheCall->use_empty() && TheCall->getType() != NewRetTy;
+
+ // Handle the returns preceded by musttail calls separately.
+ SmallVector<ReturnInst *, 8> NormalReturns;
+ for (ReturnInst *RI : Returns) {
+ CallInst *ReturnedMustTail =
+ RI->getParent()->getTerminatingMustTailCall();
+ if (!ReturnedMustTail) {
+ NormalReturns.push_back(RI);
+ continue;
+ }
+ if (!NeedBitCast)
+ continue;
+
+ // Delete the old return and any preceding bitcast.
+ BasicBlock *CurBB = RI->getParent();
+ auto *OldCast = dyn_cast_or_null<BitCastInst>(RI->getReturnValue());
+ RI->eraseFromParent();
+ if (OldCast)
+ OldCast->eraseFromParent();
+
+ // Insert a new bitcast and return with the right type.
+ IRBuilder<> Builder(CurBB);
+ Builder.CreateRet(Builder.CreateBitCast(ReturnedMustTail, NewRetTy));
+ }
+
+ // Leave behind the normal returns so we can merge control flow.
+ std::swap(Returns, NormalReturns);
+ }
+
// If we cloned in _exactly one_ basic block, and if that block ends in a
// return instruction, we splice the body of the inlined callee directly into
// the calling basic block.
// "starter" and "ender" blocks. How we accomplish this depends on whether
// this is an invoke instruction or a call instruction.
BasicBlock *AfterCallBB;
- BranchInst *CreatedBranchToNormalDest = NULL;
+ BranchInst *CreatedBranchToNormalDest = nullptr;
if (InvokeInst *II = dyn_cast<InvokeInst>(TheCall)) {
// Add an unconditional branch to make this look like the CallInst case...
// any users of the original call/invoke instruction.
Type *RTy = CalledFunc->getReturnType();
- PHINode *PHI = 0;
+ PHINode *PHI = nullptr;
if (Returns.size() > 1) {
// The PHI node should go at the front of the new basic block to merge all
// possible incoming values.
// Since we are now done with the Call/Invoke, we can delete it.
TheCall->eraseFromParent();
+ // If we inlined any musttail calls and the original return is now
+ // unreachable, delete it. It can only contain a bitcast and ret.
+ if (InlinedMustTailCalls && pred_begin(AfterCallBB) == pred_end(AfterCallBB))
+ AfterCallBB->eraseFromParent();
+
// We should always be able to fold the entry block of the function into the
// single predecessor of the block...
assert(cast<BranchInst>(Br)->isUnconditional() && "splitBasicBlock broken!");
// the entries are the same or undef). If so, remove the PHI so it doesn't
// block other optimizations.
if (PHI) {
- if (Value *V = SimplifyInstruction(PHI, IFI.DL)) {
+ if (Value *V = SimplifyInstruction(PHI, IFI.DL, nullptr, nullptr,
+ &IFI.ACT->getAssumptionCache(*Caller))) {
PHI->replaceAllUsesWith(V);
PHI->eraseFromParent();
}