// This file also defines a simple ARC-aware AliasAnalysis.
//
// WARNING: This file knows about certain library functions. It recognizes them
-// by name, and hardwires knowedge of their semantics.
+// by name, and hardwires knowledge of their semantics.
//
// WARNING: This file knows about how certain Objective-C library functions are
// used. Naive LLVM IR transformations which would otherwise be
//===----------------------------------------------------------------------===//
#define DEBUG_TYPE "objc-arc"
-#include "llvm/Function.h"
-#include "llvm/Intrinsics.h"
-#include "llvm/GlobalVariable.h"
-#include "llvm/DerivedTypes.h"
-#include "llvm/Module.h"
-#include "llvm/Analysis/ValueTracking.h"
-#include "llvm/Transforms/Utils/Local.h"
-#include "llvm/Support/CallSite.h"
+#include "llvm/Support/raw_ostream.h"
#include "llvm/Support/CommandLine.h"
-#include "llvm/ADT/StringSwitch.h"
#include "llvm/ADT/DenseMap.h"
-#include "llvm/ADT/STLExtras.h"
using namespace llvm;
// A handy option to enable/disable all optimizations in this file.
// ARC Utilities.
//===----------------------------------------------------------------------===//
+#include "llvm/Intrinsics.h"
+#include "llvm/Module.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Transforms/Utils/Local.h"
+#include "llvm/Support/CallSite.h"
+#include "llvm/ADT/StringSwitch.h"
+
namespace {
/// InstructionClass - A simple classification for instructions.
enum InstructionClass {
// None of the intrinsic functions do objc_release. For intrinsics, the
// only question is whether or not they may be users.
switch (F->getIntrinsicID()) {
- case 0: break;
- case Intrinsic::bswap: case Intrinsic::ctpop:
- case Intrinsic::ctlz: case Intrinsic::cttz:
case Intrinsic::returnaddress: case Intrinsic::frameaddress:
case Intrinsic::stacksave: case Intrinsic::stackrestore:
case Intrinsic::vastart: case Intrinsic::vacopy: case Intrinsic::vaend:
+ case Intrinsic::objectsize: case Intrinsic::prefetch:
+ case Intrinsic::stackprotector:
+ case Intrinsic::eh_return_i32: case Intrinsic::eh_return_i64:
+ case Intrinsic::eh_typeid_for: case Intrinsic::eh_dwarf_cfa:
+ case Intrinsic::eh_sjlj_lsda: case Intrinsic::eh_sjlj_functioncontext:
+ case Intrinsic::init_trampoline: case Intrinsic::adjust_trampoline:
+ case Intrinsic::lifetime_start: case Intrinsic::lifetime_end:
+ case Intrinsic::invariant_start: case Intrinsic::invariant_end:
// Don't let dbg info affect our results.
case Intrinsic::dbg_declare: case Intrinsic::dbg_value:
// Short cut: Some intrinsics obviously don't use ObjC pointers.
return IC_None;
default:
- for (Function::const_arg_iterator AI = F->arg_begin(),
- AE = F->arg_end(); AI != AE; ++AI)
- if (IsPotentialUse(AI))
- return IC_User;
- return IC_None;
+ break;
}
}
return GetCallSiteClass(CI);
return isa<InvokeInst>(V) ? IC_CallOrUser : IC_User;
}
-/// IsRetain - Test if the the given class is objc_retain or
+/// IsRetain - Test if the given class is objc_retain or
/// equivalent.
static bool IsRetain(InstructionClass Class) {
return Class == IC_Retain ||
Class == IC_RetainRV;
}
-/// IsAutorelease - Test if the the given class is objc_autorelease or
+/// IsAutorelease - Test if the given class is objc_autorelease or
/// equivalent.
static bool IsAutorelease(InstructionClass Class) {
return Class == IC_Autorelease ||
Class == IC_AutoreleasepoolPop;
}
-/// EraseInstruction - Erase the given instruction. ObjC calls return their
+/// EraseInstruction - Erase the given instruction. Many ObjC calls return their
/// argument verbatim, so if it's such a call and the return value has users,
/// replace them with the argument value.
static void EraseInstruction(Instruction *CI) {
return Arg;
}
- // If we found an identifiable object but it has multiple uses, but they
- // are trivial uses, we can still consider this to be a single-use
- // value.
+ // If we found an identifiable object but it has multiple uses, but they are
+ // trivial uses, we can still consider this to be a single-use value.
if (IsObjCIdentifiedObject(Arg)) {
for (Value::const_use_iterator UI = Arg->use_begin(), UE = Arg->use_end();
UI != UE; ++UI) {
/// specified pass info.
virtual void *getAdjustedAnalysisPointer(const void *PI) {
if (PI == &AliasAnalysis::ID)
- return (AliasAnalysis*)this;
+ return static_cast<AliasAnalysis *>(this);
return this;
}
case IC_FusedRetainAutorelease:
case IC_FusedRetainAutoreleaseRV:
// These functions don't access any memory visible to the compiler.
- // Note that this doesn't include objc_retainBlock, becuase it updates
+ // Note that this doesn't include objc_retainBlock, because it updates
// pointers when it copies block data.
return NoModRef;
default:
//===----------------------------------------------------------------------===//
#include "llvm/Constants.h"
+#include "llvm/ADT/STLExtras.h"
namespace {
/// ObjCARCAPElim - Autorelease pool elimination.
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
virtual bool runOnModule(Module &M);
- bool MayAutorelease(CallSite CS, unsigned Depth = 0);
- bool OptimizeBB(BasicBlock *BB);
+ static bool MayAutorelease(ImmutableCallSite CS, unsigned Depth = 0);
+ static bool OptimizeBB(BasicBlock *BB);
public:
static char ID;
/// MayAutorelease - Interprocedurally determine if calls made by the
/// given call site can possibly produce autoreleases.
-bool ObjCARCAPElim::MayAutorelease(CallSite CS, unsigned Depth) {
- if (Function *Callee = CS.getCalledFunction()) {
+bool ObjCARCAPElim::MayAutorelease(ImmutableCallSite CS, unsigned Depth) {
+ if (const Function *Callee = CS.getCalledFunction()) {
if (Callee->isDeclaration() || Callee->mayBeOverridden())
return true;
- for (Function::iterator I = Callee->begin(), E = Callee->end();
+ for (Function::const_iterator I = Callee->begin(), E = Callee->end();
I != E; ++I) {
- BasicBlock *BB = I;
- for (BasicBlock::iterator J = BB->begin(), F = BB->end(); J != F; ++J)
- if (CallSite JCS = CallSite(J))
+ const BasicBlock *BB = I;
+ for (BasicBlock::const_iterator J = BB->begin(), F = BB->end();
+ J != F; ++J)
+ if (ImmutableCallSite JCS = ImmutableCallSite(J))
// This recursion depth limit is arbitrary. It's just great
// enough to cover known interesting testcases.
if (Depth < 3 &&
Push = 0;
break;
case IC_CallOrUser:
- if (MayAutorelease(CallSite(Inst)))
+ if (MayAutorelease(ImmutableCallSite(Inst)))
Push = 0;
break;
default:
Value *Op = *OI;
// llvm.global_ctors is an array of pairs where the second members
// are constructor functions.
- Function *F = cast<Function>(cast<ConstantStruct>(Op)->getOperand(1));
+ Function *F = dyn_cast<Function>(cast<ConstantStruct>(Op)->getOperand(1));
+ // If the user used a constructor function with the wrong signature and
+ // it got bitcasted or whatever, look the other way.
+ if (!F)
+ continue;
// Only look at function definitions.
if (F->isDeclaration())
continue;
// TODO: Delete release+retain pairs (rare).
-#include "llvm/GlobalAlias.h"
-#include "llvm/Constants.h"
#include "llvm/LLVMContext.h"
-#include "llvm/Support/ErrorHandling.h"
#include "llvm/Support/CFG.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/ADT/SmallPtrSet.h"
-#include "llvm/ADT/DenseSet.h"
STATISTIC(NumNoops, "Number of no-op objc calls eliminated");
STATISTIC(NumPartialNoops, "Number of partially no-op objc calls eliminated");
bool relatedSelect(const SelectInst *A, const Value *B);
bool relatedPHI(const PHINode *A, const Value *B);
- // Do not implement.
- void operator=(const ProvenanceAnalysis &);
- ProvenanceAnalysis(const ProvenanceAnalysis &);
+ void operator=(const ProvenanceAnalysis &) LLVM_DELETED_FUNCTION;
+ ProvenanceAnalysis(const ProvenanceAnalysis &) LLVM_DELETED_FUNCTION;
public:
ProvenanceAnalysis() {}
// If the values are Selects with the same condition, we can do a more precise
// check: just check for relations between the values on corresponding arms.
if (const SelectInst *SB = dyn_cast<SelectInst>(B))
- if (A->getCondition() == SB->getCondition()) {
- if (related(A->getTrueValue(), SB->getTrueValue()))
- return true;
- if (related(A->getFalseValue(), SB->getFalseValue()))
- return true;
- return false;
- }
+ if (A->getCondition() == SB->getCondition())
+ return related(A->getTrueValue(), SB->getTrueValue()) ||
+ related(A->getFalseValue(), SB->getFalseValue());
// Check both arms of the Select node individually.
- if (related(A->getTrueValue(), B))
- return true;
- if (related(A->getFalseValue(), B))
- return true;
-
- // The arms both checked out.
- return false;
+ return related(A->getTrueValue(), B) ||
+ related(A->getFalseValue(), B);
}
bool ProvenanceAnalysis::relatedPHI(const PHINode *A, const Value *B) {
// An ObjC-Identified object can't alias a load if it is never locally stored.
if (AIsIdentified) {
+ // Check for an obvious escape.
+ if (isa<LoadInst>(B))
+ return isStoredObjCPointer(A);
if (BIsIdentified) {
- // If both pointers have provenance, they can be directly compared.
- if (A != B)
- return false;
- } else {
- if (isa<LoadInst>(B))
- return isStoredObjCPointer(A);
+ // Check for an obvious escape.
+ if (isa<LoadInst>(A))
+ return isStoredObjCPointer(B);
+ // Both pointers are identified and escapes aren't an evident problem.
+ return false;
}
- } else {
- if (BIsIdentified && isa<LoadInst>(A))
+ } else if (BIsIdentified) {
+ // Check for an obvious escape.
+ if (isa<LoadInst>(A))
return isStoredObjCPointer(B);
}
/// with the "tail" keyword.
bool IsTailCallRelease;
- /// Partial - True of we've seen an opportunity for partial RR elimination,
- /// such as pushing calls into a CFG triangle or into one side of a
- /// CFG diamond.
- /// TODO: Consider moving this to PtrState.
- bool Partial;
-
/// ReleaseMetadata - If the Calls are objc_release calls and they all have
/// a clang.imprecise_release tag, this is the metadata tag.
MDNode *ReleaseMetadata;
RRInfo() :
KnownSafe(false), IsRetainBlock(false),
- IsTailCallRelease(false), Partial(false),
+ IsTailCallRelease(false),
ReleaseMetadata(0) {}
void clear();
KnownSafe = false;
IsRetainBlock = false;
IsTailCallRelease = false;
- Partial = false;
ReleaseMetadata = 0;
Calls.clear();
ReverseInsertPts.clear();
/// PtrState - This class summarizes several per-pointer runtime properties
/// which are propogated through the flow graph.
class PtrState {
- /// RefCount - The known minimum number of reference count increments.
- unsigned RefCount;
+ /// KnownPositiveRefCount - True if the reference count is known to
+ /// be incremented.
+ bool KnownPositiveRefCount;
- /// NestCount - The known minimum level of retain+release nesting.
- unsigned NestCount;
+ /// Partial - True of we've seen an opportunity for partial RR elimination,
+ /// such as pushing calls into a CFG triangle or into one side of a
+ /// CFG diamond.
+ bool Partial;
/// Seq - The current position in the sequence.
- Sequence Seq;
+ Sequence Seq : 8;
public:
/// RRI - Unidirectional information about the current sequence.
/// TODO: Encapsulate this better.
RRInfo RRI;
- PtrState() : RefCount(0), NestCount(0), Seq(S_None) {}
+ PtrState() : KnownPositiveRefCount(false), Partial(false),
+ Seq(S_None) {}
- void SetAtLeastOneRefCount() {
- if (RefCount == 0) RefCount = 1;
+ void SetKnownPositiveRefCount() {
+ KnownPositiveRefCount = true;
}
- void IncrementRefCount() {
- if (RefCount != UINT_MAX) ++RefCount;
- }
-
- void DecrementRefCount() {
- if (RefCount != 0) --RefCount;
+ void ClearRefCount() {
+ KnownPositiveRefCount = false;
}
bool IsKnownIncremented() const {
- return RefCount > 0;
- }
-
- void IncrementNestCount() {
- if (NestCount != UINT_MAX) ++NestCount;
- }
-
- void DecrementNestCount() {
- if (NestCount != 0) --NestCount;
- }
-
- bool IsKnownNested() const {
- return NestCount > 0;
+ return KnownPositiveRefCount;
}
void SetSeq(Sequence NewSeq) {
}
void ClearSequenceProgress() {
- Seq = S_None;
+ ResetSequenceProgress(S_None);
+ }
+
+ void ResetSequenceProgress(Sequence NewSeq) {
+ Seq = NewSeq;
+ Partial = false;
RRI.clear();
}
void
PtrState::Merge(const PtrState &Other, bool TopDown) {
Seq = MergeSeqs(Seq, Other.Seq, TopDown);
- RefCount = std::min(RefCount, Other.RefCount);
- NestCount = std::min(NestCount, Other.NestCount);
+ KnownPositiveRefCount = KnownPositiveRefCount && Other.KnownPositiveRefCount;
// We can't merge a plain objc_retain with an objc_retainBlock.
if (RRI.IsRetainBlock != Other.RRI.IsRetainBlock)
// If we're not in a sequence (anymore), drop all associated state.
if (Seq == S_None) {
+ Partial = false;
RRI.clear();
- } else if (RRI.Partial || Other.RRI.Partial) {
+ } else if (Partial || Other.Partial) {
// If we're doing a merge on a path that's previously seen a partial
// merge, conservatively drop the sequence, to avoid doing partial
// RR elimination. If the branch predicates for the two merge differ,
// mixing them is unsafe.
- Seq = S_None;
- RRI.clear();
+ ClearSequenceProgress();
} else {
// Conservatively merge the ReleaseMetadata information.
if (RRI.ReleaseMetadata != Other.RRI.ReleaseMetadata)
RRI.ReleaseMetadata = 0;
RRI.KnownSafe = RRI.KnownSafe && Other.RRI.KnownSafe;
- RRI.IsTailCallRelease = RRI.IsTailCallRelease && Other.RRI.IsTailCallRelease;
+ RRI.IsTailCallRelease = RRI.IsTailCallRelease &&
+ Other.RRI.IsTailCallRelease;
RRI.Calls.insert(Other.RRI.Calls.begin(), Other.RRI.Calls.end());
// Merge the insert point sets. If there are any differences,
// that makes this a partial merge.
- RRI.Partial = RRI.ReverseInsertPts.size() !=
- Other.RRI.ReverseInsertPts.size();
+ Partial = RRI.ReverseInsertPts.size() != Other.RRI.ReverseInsertPts.size();
for (SmallPtrSet<Instruction *, 2>::const_iterator
I = Other.RRI.ReverseInsertPts.begin(),
E = Other.RRI.ReverseInsertPts.end(); I != E; ++I)
- RRI.Partial |= RRI.ReverseInsertPts.insert(*I);
+ Partial |= RRI.ReverseInsertPts.insert(*I);
}
}
/// known about a pointer at the top of each block.
MapTy PerPtrBottomUp;
+ /// Preds, Succs - Effective successors and predecessors of the current
+ /// block (this ignores ignorable edges and ignored backedges).
+ SmallVector<BasicBlock *, 2> Preds;
+ SmallVector<BasicBlock *, 2> Succs;
+
public:
BBState() : TopDownPathCount(0), BottomUpPathCount(0) {}
/// entry to an exit which pass through this block. This is only valid
/// after both the top-down and bottom-up traversals are complete.
unsigned GetAllPathCount() const {
+ assert(TopDownPathCount != 0);
+ assert(BottomUpPathCount != 0);
return TopDownPathCount * BottomUpPathCount;
}
- /// IsVisitedTopDown - Test whether the block for this BBState has been
- /// visited by the top-down portion of the algorithm.
- bool isVisitedTopDown() const {
- return TopDownPathCount != 0;
- }
+ // Specialized CFG utilities.
+ typedef SmallVectorImpl<BasicBlock *>::const_iterator edge_iterator;
+ edge_iterator pred_begin() { return Preds.begin(); }
+ edge_iterator pred_end() { return Preds.end(); }
+ edge_iterator succ_begin() { return Succs.begin(); }
+ edge_iterator succ_end() { return Succs.end(); }
+
+ void addSucc(BasicBlock *Succ) { Succs.push_back(Succ); }
+ void addPred(BasicBlock *Pred) { Preds.push_back(Pred); }
+
+ bool isExit() const { return Succs.empty(); }
};
}
// loop backedge. Loop backedges are special.
TopDownPathCount += Other.TopDownPathCount;
+ // Check for overflow. If we have overflow, fall back to conservative behavior.
+ if (TopDownPathCount < Other.TopDownPathCount) {
+ clearTopDownPointers();
+ return;
+ }
+
// For each entry in the other set, if our set has an entry with the same key,
// merge the entries. Otherwise, copy the entry and merge it with an empty
// entry.
// loop backedge. Loop backedges are special.
BottomUpPathCount += Other.BottomUpPathCount;
+ // Check for overflow. If we have overflow, fall back to conservative behavior.
+ if (BottomUpPathCount < Other.BottomUpPathCount) {
+ clearBottomUpPointers();
+ return;
+ }
+
// For each entry in the other set, if our set has an entry with the
// same key, merge the entries. Otherwise, copy the entry and merge
// it with an empty entry.
if (!RetainRVCallee) {
LLVMContext &C = M->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
- std::vector<Type *> Params;
- Params.push_back(I8X);
- FunctionType *FTy =
- FunctionType::get(I8X, Params, /*isVarArg=*/false);
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { I8X };
+ FunctionType *FTy = FunctionType::get(I8X, Params, /*isVarArg=*/false);
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(M->getContext(), B));
RetainRVCallee =
M->getOrInsertFunction("objc_retainAutoreleasedReturnValue", FTy,
Attributes);
if (!AutoreleaseRVCallee) {
LLVMContext &C = M->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
- std::vector<Type *> Params;
- Params.push_back(I8X);
- FunctionType *FTy =
- FunctionType::get(I8X, Params, /*isVarArg=*/false);
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { I8X };
+ FunctionType *FTy = FunctionType::get(I8X, Params, /*isVarArg=*/false);
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, B));
AutoreleaseRVCallee =
M->getOrInsertFunction("objc_autoreleaseReturnValue", FTy,
Attributes);
Constant *ObjCARCOpt::getReleaseCallee(Module *M) {
if (!ReleaseCallee) {
LLVMContext &C = M->getContext();
- std::vector<Type *> Params;
- Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C)));
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { PointerType::getUnqual(Type::getInt8Ty(C)) };
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, B));
ReleaseCallee =
M->getOrInsertFunction(
"objc_release",
Constant *ObjCARCOpt::getRetainCallee(Module *M) {
if (!RetainCallee) {
LLVMContext &C = M->getContext();
- std::vector<Type *> Params;
- Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C)));
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { PointerType::getUnqual(Type::getInt8Ty(C)) };
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, B));
RetainCallee =
M->getOrInsertFunction(
"objc_retain",
Constant *ObjCARCOpt::getRetainBlockCallee(Module *M) {
if (!RetainBlockCallee) {
LLVMContext &C = M->getContext();
- std::vector<Type *> Params;
- Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C)));
- AttrListPtr Attributes;
+ Type *Params[] = { PointerType::getUnqual(Type::getInt8Ty(C)) };
// objc_retainBlock is not nounwind because it calls user copy constructors
// which could theoretically throw.
RetainBlockCallee =
M->getOrInsertFunction(
"objc_retainBlock",
FunctionType::get(Params[0], Params, /*isVarArg=*/false),
- Attributes);
+ AttrListPtr());
}
return RetainBlockCallee;
}
Constant *ObjCARCOpt::getAutoreleaseCallee(Module *M) {
if (!AutoreleaseCallee) {
LLVMContext &C = M->getContext();
- std::vector<Type *> Params;
- Params.push_back(PointerType::getUnqual(Type::getInt8Ty(C)));
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { PointerType::getUnqual(Type::getInt8Ty(C)) };
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, B));
AutoreleaseCallee =
M->getOrInsertFunction(
"objc_autorelease",
return AutoreleaseCallee;
}
+/// IsPotentialUse - Test whether the given value is possible a
+/// reference-counted pointer, including tests which utilize AliasAnalysis.
+static bool IsPotentialUse(const Value *Op, AliasAnalysis &AA) {
+ // First make the rudimentary check.
+ if (!IsPotentialUse(Op))
+ return false;
+
+ // Objects in constant memory are not reference-counted.
+ if (AA.pointsToConstantMemory(Op))
+ return false;
+
+ // Pointers in constant memory are not pointing to reference-counted objects.
+ if (const LoadInst *LI = dyn_cast<LoadInst>(Op))
+ if (AA.pointsToConstantMemory(LI->getPointerOperand()))
+ return false;
+
+ // Otherwise assume the worst.
+ return true;
+}
+
/// CanAlterRefCount - Test whether the given instruction can result in a
/// reference count modification (positive or negative) for the pointer's
/// object.
for (ImmutableCallSite::arg_iterator I = CS.arg_begin(), E = CS.arg_end();
I != E; ++I) {
const Value *Op = *I;
- if (IsPotentialUse(Op) && PA.related(Ptr, Op))
+ if (IsPotentialUse(Op, *PA.getAA()) && PA.related(Ptr, Op))
return true;
}
return false;
// Comparing a pointer with null, or any other constant, isn't really a use,
// because we don't care what the pointer points to, or about the values
// of any other dynamic reference-counted pointers.
- if (!IsPotentialUse(ICI->getOperand(1)))
+ if (!IsPotentialUse(ICI->getOperand(1), *PA.getAA()))
return false;
} else if (ImmutableCallSite CS = static_cast<const Value *>(Inst)) {
// For calls, just check the arguments (and not the callee operand).
for (ImmutableCallSite::arg_iterator OI = CS.arg_begin(),
OE = CS.arg_end(); OI != OE; ++OI) {
const Value *Op = *OI;
- if (IsPotentialUse(Op) && PA.related(Ptr, Op))
+ if (IsPotentialUse(Op, *PA.getAA()) && PA.related(Ptr, Op))
return true;
}
return false;
const Value *Op = GetUnderlyingObjCPtr(SI->getPointerOperand());
// If we can't tell what the underlying object was, assume there is a
// dependence.
- return IsPotentialUse(Op) && PA.related(Op, Ptr);
+ return IsPotentialUse(Op, *PA.getAA()) && PA.related(Op, Ptr);
}
// Check each operand for a match.
for (User::const_op_iterator OI = Inst->op_begin(), OE = Inst->op_end();
OI != OE; ++OI) {
const Value *Op = *OI;
- if (IsPotentialUse(Op) && PA.related(Ptr, Op))
+ if (IsPotentialUse(Op, *PA.getAA()) && PA.related(Ptr, Op))
return true;
}
return false;
/// objc_retainAutoreleasedReturnValue if the operand is a return value.
void
ObjCARCOpt::OptimizeRetainCall(Function &F, Instruction *Retain) {
- CallSite CS(GetObjCArg(Retain));
- Instruction *Call = CS.getInstruction();
+ ImmutableCallSite CS(GetObjCArg(Retain));
+ const Instruction *Call = CS.getInstruction();
if (!Call) return;
if (Call->getParent() != Retain->getParent()) return;
// Check that the call is next to the retain.
- BasicBlock::iterator I = Call;
+ BasicBlock::const_iterator I = Call;
++I;
while (isNoopInstruction(I)) ++I;
if (&*I != Retain)
}
/// OptimizeRetainRVCall - Turn objc_retainAutoreleasedReturnValue into
-/// objc_retain if the operand is not a return value. Or, if it can be
-/// paired with an objc_autoreleaseReturnValue, delete the pair and
-/// return true.
+/// objc_retain if the operand is not a return value. Or, if it can be paired
+/// with an objc_autoreleaseReturnValue, delete the pair and return true.
bool
ObjCARCOpt::OptimizeRetainRVCall(Function &F, Instruction *RetainRV) {
// Check for the argument being from an immediately preceding call or invoke.
- Value *Arg = GetObjCArg(RetainRV);
- CallSite CS(Arg);
- if (Instruction *Call = CS.getInstruction()) {
+ const Value *Arg = GetObjCArg(RetainRV);
+ ImmutableCallSite CS(Arg);
+ if (const Instruction *Call = CS.getInstruction()) {
if (Call->getParent() == RetainRV->getParent()) {
- BasicBlock::iterator I = Call;
+ BasicBlock::const_iterator I = Call;
++I;
while (isNoopInstruction(I)) ++I;
if (&*I == RetainRV)
return false;
- } else if (InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
+ } else if (const InvokeInst *II = dyn_cast<InvokeInst>(Call)) {
BasicBlock *RetainRVParent = RetainRV->getParent();
if (II->getNormalDest() == RetainRVParent) {
- BasicBlock::iterator I = RetainRVParent->begin();
+ BasicBlock::const_iterator I = RetainRVParent->begin();
while (isNoopInstruction(I)) ++I;
if (&*I == RetainRV)
return false;
// These can always be moved up.
break;
case IC_Release:
- // These can't be moved across things that care about the retain count.
+ // These can't be moved across things that care about the retain
+ // count.
FindDependencies(NeedsPositiveRetainCount, Arg,
Inst->getParent(), Inst,
DependingInstructions, Visited, PA);
for (; SI != SE; ++SI) {
Sequence SuccSSeq = S_None;
bool SuccSRRIKnownSafe = false;
- // If VisitBottomUp has visited this successor, take what we know about it.
- DenseMap<const BasicBlock *, BBState>::iterator BBI = BBStates.find(*SI);
- if (BBI != BBStates.end()) {
- const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
- SuccSSeq = SuccS.GetSeq();
- SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
- }
+ // If VisitBottomUp has pointer information for this successor, take
+ // what we know about it.
+ DenseMap<const BasicBlock *, BBState>::iterator BBI =
+ BBStates.find(*SI);
+ assert(BBI != BBStates.end());
+ const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
+ SuccSSeq = SuccS.GetSeq();
+ SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
switch (SuccSSeq) {
case S_None:
case S_CanRelease: {
for (; SI != SE; ++SI) {
Sequence SuccSSeq = S_None;
bool SuccSRRIKnownSafe = false;
- // If VisitBottomUp has visited this successor, take what we know about it.
- DenseMap<const BasicBlock *, BBState>::iterator BBI = BBStates.find(*SI);
- if (BBI != BBStates.end()) {
- const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
- SuccSSeq = SuccS.GetSeq();
- SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
- }
+ // If VisitBottomUp has pointer information for this successor, take
+ // what we know about it.
+ DenseMap<const BasicBlock *, BBState>::iterator BBI =
+ BBStates.find(*SI);
+ assert(BBI != BBStates.end());
+ const PtrState &SuccS = BBI->second.getPtrBottomUpState(Arg);
+ SuccSSeq = SuccS.GetSeq();
+ SuccSRRIKnownSafe = SuccS.RRI.KnownSafe;
switch (SuccSSeq) {
case S_None: {
if (!S.RRI.KnownSafe && !SuccSRRIKnownSafe) {
if (S.GetSeq() == S_Release || S.GetSeq() == S_MovableRelease)
NestingDetected = true;
- S.RRI.clear();
-
MDNode *ReleaseMetadata = Inst->getMetadata(ImpreciseReleaseMDKind);
- S.SetSeq(ReleaseMetadata ? S_MovableRelease : S_Release);
+ S.ResetSequenceProgress(ReleaseMetadata ? S_MovableRelease : S_Release);
S.RRI.ReleaseMetadata = ReleaseMetadata;
- S.RRI.KnownSafe = S.IsKnownNested() || S.IsKnownIncremented();
+ S.RRI.KnownSafe = S.IsKnownIncremented();
S.RRI.IsTailCallRelease = cast<CallInst>(Inst)->isTailCall();
S.RRI.Calls.insert(Inst);
- S.IncrementRefCount();
- S.IncrementNestCount();
+ S.SetKnownPositiveRefCount();
break;
}
case IC_RetainBlock:
Arg = GetObjCArg(Inst);
PtrState &S = MyStates.getPtrBottomUpState(Arg);
- S.DecrementRefCount();
- S.SetAtLeastOneRefCount();
- S.DecrementNestCount();
+ S.SetKnownPositiveRefCount();
switch (S.GetSeq()) {
case S_Stop:
// Check for possible releases.
if (CanAlterRefCount(Inst, Ptr, PA, Class)) {
- S.DecrementRefCount();
+ S.ClearRefCount();
switch (Seq) {
case S_Use:
S.SetSeq(S_CanRelease);
// Merge the states from each successor to compute the initial state
// for the current block.
- const TerminatorInst *TI = cast<TerminatorInst>(&BB->back());
- succ_const_iterator SI(TI), SE(TI, false);
- if (SI == SE)
- MyStates.SetAsExit();
- else {
- // If the terminator is an invoke marked with the
- // clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
- // ignored, for ARC purposes.
- if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind))
- --SE;
-
- do {
- const BasicBlock *Succ = *SI++;
- if (Succ == BB)
- continue;
- DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Succ);
- // If we haven't seen this node yet, then we've found a CFG cycle.
- // Be optimistic here; it's CheckForCFGHazards' job detect trouble.
- if (I == BBStates.end())
- continue;
- MyStates.InitFromSucc(I->second);
- while (SI != SE) {
- Succ = *SI++;
- if (Succ != BB) {
- I = BBStates.find(Succ);
- if (I != BBStates.end())
- MyStates.MergeSucc(I->second);
- }
- }
- break;
- } while (SI != SE);
+ BBState::edge_iterator SI(MyStates.succ_begin()),
+ SE(MyStates.succ_end());
+ if (SI != SE) {
+ const BasicBlock *Succ = *SI;
+ DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Succ);
+ assert(I != BBStates.end());
+ MyStates.InitFromSucc(I->second);
+ ++SI;
+ for (; SI != SE; ++SI) {
+ Succ = *SI;
+ I = BBStates.find(Succ);
+ assert(I != BBStates.end());
+ MyStates.MergeSucc(I->second);
+ }
}
// Visit all the instructions, bottom-up.
NestingDetected |= VisitInstructionBottomUp(Inst, BB, Retains, MyStates);
}
- // If there's a predecessor with an invoke, visit the invoke as
- // if it were part of this block, since we can't insert code after
- // an invoke in its own block, and we don't want to split critical
- // edges.
- for (pred_iterator PI(BB), PE(BB, false); PI != PE; ++PI) {
+ // If there's a predecessor with an invoke, visit the invoke as if it were
+ // part of this block, since we can't insert code after an invoke in its own
+ // block, and we don't want to split critical edges.
+ for (BBState::edge_iterator PI(MyStates.pred_begin()),
+ PE(MyStates.pred_end()); PI != PE; ++PI) {
BasicBlock *Pred = *PI;
- TerminatorInst *PredTI = cast<TerminatorInst>(&Pred->back());
- if (isa<InvokeInst>(PredTI))
- NestingDetected |= VisitInstructionBottomUp(PredTI, BB, Retains, MyStates);
+ if (InvokeInst *II = dyn_cast<InvokeInst>(&Pred->back()))
+ NestingDetected |= VisitInstructionBottomUp(II, BB, Retains, MyStates);
}
return NestingDetected;
if (S.GetSeq() == S_Retain)
NestingDetected = true;
- S.SetSeq(S_Retain);
- S.RRI.clear();
+ S.ResetSequenceProgress(S_Retain);
S.RRI.IsRetainBlock = Class == IC_RetainBlock;
- // Don't check S.IsKnownIncremented() here because it's not
- // sufficient.
- S.RRI.KnownSafe = S.IsKnownNested();
+ S.RRI.KnownSafe = S.IsKnownIncremented();
S.RRI.Calls.insert(Inst);
}
- S.SetAtLeastOneRefCount();
- S.IncrementRefCount();
- S.IncrementNestCount();
- return NestingDetected;
+ S.SetKnownPositiveRefCount();
+
+ // A retain can be a potential use; procede to the generic checking
+ // code below.
+ break;
}
case IC_Release: {
Arg = GetObjCArg(Inst);
PtrState &S = MyStates.getPtrTopDownState(Arg);
- S.DecrementRefCount();
- S.DecrementNestCount();
+ S.ClearRefCount();
switch (S.GetSeq()) {
case S_Retain:
// Check for possible releases.
if (CanAlterRefCount(Inst, Ptr, PA, Class)) {
- S.DecrementRefCount();
+ S.ClearRefCount();
switch (Seq) {
case S_Retain:
S.SetSeq(S_CanRelease);
// Merge the states from each predecessor to compute the initial state
// for the current block.
- const_pred_iterator PI(BB), PE(BB, false);
- if (PI == PE)
- MyStates.SetAsEntry();
- else
- do {
- unsigned OperandNo = PI.getOperandNo();
- const Use &Us = PI.getUse();
- ++PI;
-
- // Skip invoke unwind edges on invoke instructions marked with
- // clang.arc.no_objc_arc_exceptions.
- if (const InvokeInst *II = dyn_cast<InvokeInst>(Us.getUser()))
- if (OperandNo == II->getNumArgOperands() + 2 &&
- II->getMetadata(NoObjCARCExceptionsMDKind))
- continue;
-
- const BasicBlock *Pred = cast<TerminatorInst>(Us.getUser())->getParent();
- if (Pred == BB)
- continue;
- DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Pred);
- // If we haven't seen this node yet, then we've found a CFG cycle.
- // Be optimistic here; it's CheckForCFGHazards' job detect trouble.
- if (I == BBStates.end() || !I->second.isVisitedTopDown())
- continue;
- MyStates.InitFromPred(I->second);
- while (PI != PE) {
- Pred = *PI++;
- if (Pred != BB) {
- I = BBStates.find(Pred);
- if (I != BBStates.end() && I->second.isVisitedTopDown())
- MyStates.MergePred(I->second);
- }
- }
- break;
- } while (PI != PE);
+ BBState::edge_iterator PI(MyStates.pred_begin()),
+ PE(MyStates.pred_end());
+ if (PI != PE) {
+ const BasicBlock *Pred = *PI;
+ DenseMap<const BasicBlock *, BBState>::iterator I = BBStates.find(Pred);
+ assert(I != BBStates.end());
+ MyStates.InitFromPred(I->second);
+ ++PI;
+ for (; PI != PE; ++PI) {
+ Pred = *PI;
+ I = BBStates.find(Pred);
+ assert(I != BBStates.end());
+ MyStates.MergePred(I->second);
+ }
+ }
// Visit all the instructions, top-down.
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E; ++I) {
static void
ComputePostOrders(Function &F,
SmallVectorImpl<BasicBlock *> &PostOrder,
- SmallVectorImpl<BasicBlock *> &ReverseCFGPostOrder) {
- /// Backedges - Backedges detected in the DFS. These edges will be
- /// ignored in the reverse-CFG DFS, so that loops with multiple exits will be
- /// traversed in the desired order.
- DenseSet<std::pair<BasicBlock *, BasicBlock *> > Backedges;
-
+ SmallVectorImpl<BasicBlock *> &ReverseCFGPostOrder,
+ unsigned NoObjCARCExceptionsMDKind,
+ DenseMap<const BasicBlock *, BBState> &BBStates) {
/// Visited - The visited set, for doing DFS walks.
SmallPtrSet<BasicBlock *, 16> Visited;
// Do DFS, computing the PostOrder.
SmallPtrSet<BasicBlock *, 16> OnStack;
SmallVector<std::pair<BasicBlock *, succ_iterator>, 16> SuccStack;
+
+ // Functions always have exactly one entry block, and we don't have
+ // any other block that we treat like an entry block.
BasicBlock *EntryBB = &F.getEntryBlock();
- SuccStack.push_back(std::make_pair(EntryBB, succ_begin(EntryBB)));
+ BBState &MyStates = BBStates[EntryBB];
+ MyStates.SetAsEntry();
+ TerminatorInst *EntryTI = cast<TerminatorInst>(&EntryBB->back());
+ SuccStack.push_back(std::make_pair(EntryBB, succ_iterator(EntryTI)));
Visited.insert(EntryBB);
OnStack.insert(EntryBB);
do {
dfs_next_succ:
- TerminatorInst *TI = cast<TerminatorInst>(&SuccStack.back().first->back());
- succ_iterator End = succ_iterator(TI, true);
- while (SuccStack.back().second != End) {
- BasicBlock *BB = *SuccStack.back().second++;
- if (Visited.insert(BB)) {
- SuccStack.push_back(std::make_pair(BB, succ_begin(BB)));
- OnStack.insert(BB);
+ BasicBlock *CurrBB = SuccStack.back().first;
+ TerminatorInst *TI = cast<TerminatorInst>(&CurrBB->back());
+ succ_iterator SE(TI, false);
+
+ // If the terminator is an invoke marked with the
+ // clang.arc.no_objc_arc_exceptions metadata, the unwind edge can be
+ // ignored, for ARC purposes.
+ if (isa<InvokeInst>(TI) && TI->getMetadata(NoObjCARCExceptionsMDKind))
+ --SE;
+
+ while (SuccStack.back().second != SE) {
+ BasicBlock *SuccBB = *SuccStack.back().second++;
+ if (Visited.insert(SuccBB)) {
+ TerminatorInst *TI = cast<TerminatorInst>(&SuccBB->back());
+ SuccStack.push_back(std::make_pair(SuccBB, succ_iterator(TI)));
+ BBStates[CurrBB].addSucc(SuccBB);
+ BBState &SuccStates = BBStates[SuccBB];
+ SuccStates.addPred(CurrBB);
+ OnStack.insert(SuccBB);
goto dfs_next_succ;
}
- if (OnStack.count(BB))
- Backedges.insert(std::make_pair(SuccStack.back().first, BB));
+
+ if (!OnStack.count(SuccBB)) {
+ BBStates[CurrBB].addSucc(SuccBB);
+ BBStates[SuccBB].addPred(CurrBB);
+ }
}
- OnStack.erase(SuccStack.back().first);
- PostOrder.push_back(SuccStack.pop_back_val().first);
+ OnStack.erase(CurrBB);
+ PostOrder.push_back(CurrBB);
+ SuccStack.pop_back();
} while (!SuccStack.empty());
Visited.clear();
- // Compute the exits, which are the starting points for reverse-CFG DFS.
- // This includes blocks where all the successors are backedges that
- // we're skipping.
- SmallVector<BasicBlock *, 4> Exits;
+ // Do reverse-CFG DFS, computing the reverse-CFG PostOrder.
+ // Functions may have many exits, and there also blocks which we treat
+ // as exits due to ignored edges.
+ SmallVector<std::pair<BasicBlock *, BBState::edge_iterator>, 16> PredStack;
for (Function::iterator I = F.begin(), E = F.end(); I != E; ++I) {
- BasicBlock *BB = I;
- TerminatorInst *TI = cast<TerminatorInst>(&BB->back());
- for (succ_iterator SI(TI), SE(TI, true); SI != SE; ++SI)
- if (!Backedges.count(std::make_pair(BB, *SI)))
- goto HasNonBackedgeSucc;
- Exits.push_back(BB);
- HasNonBackedgeSucc:;
- }
+ BasicBlock *ExitBB = I;
+ BBState &MyStates = BBStates[ExitBB];
+ if (!MyStates.isExit())
+ continue;
- // Do reverse-CFG DFS, computing the reverse-CFG PostOrder.
- SmallVector<std::pair<BasicBlock *, pred_iterator>, 16> PredStack;
- for (SmallVectorImpl<BasicBlock *>::iterator I = Exits.begin(), E = Exits.end();
- I != E; ++I) {
- BasicBlock *ExitBB = *I;
- PredStack.push_back(std::make_pair(ExitBB, pred_begin(ExitBB)));
+ MyStates.SetAsExit();
+
+ PredStack.push_back(std::make_pair(ExitBB, MyStates.pred_begin()));
Visited.insert(ExitBB);
while (!PredStack.empty()) {
reverse_dfs_next_succ:
- pred_iterator End = pred_end(PredStack.back().first);
- while (PredStack.back().second != End) {
+ BBState::edge_iterator PE = BBStates[PredStack.back().first].pred_end();
+ while (PredStack.back().second != PE) {
BasicBlock *BB = *PredStack.back().second++;
- // Skip backedges detected in the forward-CFG DFS.
- if (Backedges.count(std::make_pair(BB, PredStack.back().first)))
- continue;
if (Visited.insert(BB)) {
- PredStack.push_back(std::make_pair(BB, pred_begin(BB)));
+ PredStack.push_back(std::make_pair(BB, BBStates[BB].pred_begin()));
goto reverse_dfs_next_succ;
}
}
// function exit point, and we want to ignore selected cycle edges.
SmallVector<BasicBlock *, 16> PostOrder;
SmallVector<BasicBlock *, 16> ReverseCFGPostOrder;
- ComputePostOrders(F, PostOrder, ReverseCFGPostOrder);
+ ComputePostOrders(F, PostOrder, ReverseCFGPostOrder,
+ NoObjCARCExceptionsMDKind,
+ BBStates);
// Use reverse-postorder on the reverse CFG for bottom-up.
bool BottomUpNestingDetected = false;
// not being managed by ObjC reference counting, so we can delete pairs
// regardless of what possible decrements or uses lie between them.
bool KnownSafe = isa<Constant>(Arg) || isa<AllocaInst>(Arg);
-
+
// A constant pointer can't be pointing to an object on the heap. It may
// be reference-counted, but it won't be deleted.
if (const LoadInst *LI = dyn_cast<LoadInst>(Arg))
// Ok, everything checks out and we're all set. Let's move some code!
Changed = true;
+ assert(OldCount != 0 && "Unreachable code?");
AnyPairsCompletelyEliminated = NewCount == 0;
NumRRs += OldCount - NewCount;
MoveCalls(Arg, RetainsToMove, ReleasesToMove,
if (AllocaInst *Alloca = dyn_cast<AllocaInst>(Arg)) {
for (Value::use_iterator UI = Alloca->use_begin(),
UE = Alloca->use_end(); UI != UE; ++UI) {
- Instruction *UserInst = cast<Instruction>(*UI);
+ const Instruction *UserInst = cast<Instruction>(*UI);
switch (GetBasicInstructionClass(UserInst)) {
case IC_InitWeak:
case IC_StoreWeak:
for (Value::use_iterator UI = Alloca->use_begin(),
UE = Alloca->use_end(); UI != UE; ) {
CallInst *UserInst = cast<CallInst>(*UI++);
- if (!UserInst->use_empty())
- UserInst->replaceAllUsesWith(UserInst->getArgOperand(0));
+ switch (GetBasicInstructionClass(UserInst)) {
+ case IC_InitWeak:
+ case IC_StoreWeak:
+ // These functions return their second argument.
+ UserInst->replaceAllUsesWith(UserInst->getArgOperand(1));
+ break;
+ case IC_DestroyWeak:
+ // No return value.
+ break;
+ default:
+ llvm_unreachable("alloca really is used!");
+ }
UserInst->eraseFromParent();
}
Alloca->eraseFromParent();
}
/// OptimizeReturns - Look for this pattern:
-///
+/// \code
/// %call = call i8* @something(...)
/// %2 = call i8* @objc_retain(i8* %call)
/// %3 = call i8* @objc_autorelease(i8* %2)
/// ret i8* %3
-///
+/// \endcode
/// And delete the retain and autorelease.
///
/// Otherwise if it's just this:
-///
+/// \code
/// %3 = call i8* @objc_autorelease(i8* %2)
/// ret i8* %3
-///
+/// \endcode
/// convert the autorelease to autoreleaseRV.
void ObjCARCOpt::OptimizeReturns(Function &F) {
if (!F.getReturnType()->isPointerTy())
dyn_cast_or_null<CallInst>(*DependingInstructions.begin());
if (!Autorelease)
goto next_block;
- InstructionClass AutoreleaseClass =
- GetBasicInstructionClass(Autorelease);
+ InstructionClass AutoreleaseClass = GetBasicInstructionClass(Autorelease);
if (!IsAutorelease(AutoreleaseClass))
goto next_block;
if (GetObjCArg(Autorelease) != Arg)
// Intuitively, objc_retain and others are nocapture, however in practice
// they are not, because they return their argument value. And objc_release
- // calls finalizers.
+ // calls finalizers which can have arbitrary side effects.
// These are initialized lazily.
RetainRVCallee = 0;
while (OptimizeSequences(F)) {}
// Optimizations if objc_autorelease is used.
- if (UsedInThisFunction &
- ((1 << IC_Autorelease) | (1 << IC_AutoreleaseRV)))
+ if (UsedInThisFunction & ((1 << IC_Autorelease) |
+ (1 << IC_AutoreleaseRV)))
OptimizeReturns(F);
return Changed;
/// StoreStrongCalls - The set of inserted objc_storeStrong calls. If
/// at the end of walking the function we have found no alloca
/// instructions, these calls can be marked "tail".
- DenseSet<CallInst *> StoreStrongCalls;
+ SmallPtrSet<CallInst *, 8> StoreStrongCalls;
Constant *getStoreStrongCallee(Module *M);
Constant *getRetainAutoreleaseCallee(Module *M);
LLVMContext &C = M->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
Type *I8XX = PointerType::getUnqual(I8X);
- std::vector<Type *> Params;
- Params.push_back(I8XX);
- Params.push_back(I8X);
+ Type *Params[] = { I8XX, I8X };
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
- Attributes.addAttr(1, Attribute::NoCapture);
+ Attributes::Builder BNoUnwind;
+ BNoUnwind.addAttribute(Attributes::NoUnwind);
+ Attributes::Builder BNoCapture;
+ BNoCapture.addAttribute(Attributes::NoCapture);
+ AttrListPtr Attributes = AttrListPtr()
+ .addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, BNoUnwind))
+ .addAttr(M->getContext(), 1, Attributes::get(C, BNoCapture));
StoreStrongCallee =
M->getOrInsertFunction(
if (!RetainAutoreleaseCallee) {
LLVMContext &C = M->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
- std::vector<Type *> Params;
- Params.push_back(I8X);
- FunctionType *FTy =
- FunctionType::get(I8X, Params, /*isVarArg=*/false);
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { I8X };
+ FunctionType *FTy = FunctionType::get(I8X, Params, /*isVarArg=*/false);
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, B));
RetainAutoreleaseCallee =
M->getOrInsertFunction("objc_retainAutorelease", FTy, Attributes);
}
if (!RetainAutoreleaseRVCallee) {
LLVMContext &C = M->getContext();
Type *I8X = PointerType::getUnqual(Type::getInt8Ty(C));
- std::vector<Type *> Params;
- Params.push_back(I8X);
- FunctionType *FTy =
- FunctionType::get(I8X, Params, /*isVarArg=*/false);
- AttrListPtr Attributes;
- Attributes.addAttr(~0u, Attribute::NoUnwind);
+ Type *Params[] = { I8X };
+ FunctionType *FTy = FunctionType::get(I8X, Params, /*isVarArg=*/false);
+ Attributes::Builder B;
+ B.addAttribute(Attributes::NoUnwind);
+ AttrListPtr Attributes =
+ AttrListPtr().addAttr(M->getContext(), AttrListPtr::FunctionIndex,
+ Attributes::get(C, B));
RetainAutoreleaseRVCallee =
M->getOrInsertFunction("objc_retainAutoreleaseReturnValue", FTy,
Attributes);
return RetainAutoreleaseRVCallee;
}
-/// ContractAutorelease - Merge an autorelease with a retain into a fused
-/// call.
+/// ContractAutorelease - Merge an autorelease with a retain into a fused call.
bool
ObjCARCContract::ContractAutorelease(Function &F, Instruction *Autorelease,
InstructionClass Class,
BasicBlock *BB = Release->getParent();
if (Load->getParent() != BB) return;
- // Walk down to find the store.
+ // Walk down to find the store and the release, which may be in either order.
BasicBlock::iterator I = Load, End = BB->end();
++I;
AliasAnalysis::Location Loc = AA->getLocation(Load);
- while (I != End &&
- (&*I == Release ||
- IsRetain(GetBasicInstructionClass(I)) ||
- !(AA->getModRefInfo(I, Loc) & AliasAnalysis::Mod)))
- ++I;
- StoreInst *Store = dyn_cast<StoreInst>(I);
- if (!Store || !Store->isSimple()) return;
- if (Store->getPointerOperand() != Loc.Ptr) return;
+ StoreInst *Store = 0;
+ bool SawRelease = false;
+ for (; !Store || !SawRelease; ++I) {
+ if (I == End)
+ return;
+
+ Instruction *Inst = I;
+ if (Inst == Release) {
+ SawRelease = true;
+ continue;
+ }
+
+ InstructionClass Class = GetBasicInstructionClass(Inst);
+
+ // Unrelated retains are harmless.
+ if (IsRetain(Class))
+ continue;
+
+ if (Store) {
+ // The store is the point where we're going to put the objc_storeStrong,
+ // so make sure there are no uses after it.
+ if (CanUse(Inst, Load, PA, Class))
+ return;
+ } else if (AA->getModRefInfo(Inst, Loc) & AliasAnalysis::Mod) {
+ // We are moving the load down to the store, so check for anything
+ // else which writes to the memory between the load and the store.
+ Store = dyn_cast<StoreInst>(Inst);
+ if (!Store || !Store->isSimple()) return;
+ if (Store->getPointerOperand() != Loc.Ptr) return;
+ }
+ }
Value *New = StripPointerCastsAndObjCCalls(Store->getValueOperand());
// It seems that functions which "return twice" are also unsafe for the
// "tail" argument, because they are setjmp, which could need to
// return to an earlier stack state.
- bool TailOkForStoreStrongs = !F.isVarArg() && !F.callsFunctionThatReturnsTwice();
+ bool TailOkForStoreStrongs = !F.isVarArg() &&
+ !F.callsFunctionThatReturnsTwice();
// For ObjC library calls which return their argument, replace uses of the
// argument with uses of the call return value, if it dominates the use. This
if (!RetainRVMarker)
break;
BasicBlock::iterator BBI = Inst;
- --BBI;
- while (isNoopInstruction(BBI)) --BBI;
+ BasicBlock *InstParent = Inst->getParent();
+
+ // Step up to see if the call immediately precedes the RetainRV call.
+ // If it's an invoke, we have to cross a block boundary. And we have
+ // to carefully dodge no-op instructions.
+ do {
+ if (&*BBI == InstParent->begin()) {
+ BasicBlock *Pred = InstParent->getSinglePredecessor();
+ if (!Pred)
+ goto decline_rv_optimization;
+ BBI = Pred->getTerminator();
+ break;
+ }
+ --BBI;
+ } while (isNoopInstruction(BBI));
+
if (&*BBI == GetObjCArg(Inst)) {
Changed = true;
InlineAsm *IA =
/*Constraints=*/"", /*hasSideEffects=*/true);
CallInst::Create(IA, "", Inst);
}
+ decline_rv_optimization:
break;
}
case IC_InitWeak: {
// trivially dominate itself, which would lead us to rewriting its
// argument in terms of its return value, which would lead to
// infinite loops in GetObjCArg.
- if (DT->isReachableFromEntry(U) &&
- DT->dominates(Inst, U)) {
+ if (DT->isReachableFromEntry(U) && DT->dominates(Inst, U)) {
Changed = true;
Instruction *Replacement = Inst;
Type *UseTy = U.get()->getType();
if (PHINode *PHI = dyn_cast<PHINode>(U.getUser())) {
// For PHI nodes, insert the bitcast in the predecessor block.
- unsigned ValNo =
- PHINode::getIncomingValueNumForOperand(OperandNo);
- BasicBlock *BB =
- PHI->getIncomingBlock(ValNo);
+ unsigned ValNo = PHINode::getIncomingValueNumForOperand(OperandNo);
+ BasicBlock *BB = PHI->getIncomingBlock(ValNo);
if (Replacement->getType() != UseTy)
Replacement = new BitCastInst(Replacement, UseTy, "",
&BB->back());
// While we're here, rewrite all edges for this PHI, rather
// than just one use at a time, to minimize the number of
// bitcasts we emit.
- for (unsigned i = 0, e = PHI->getNumIncomingValues();
- i != e; ++i)
+ for (unsigned i = 0, e = PHI->getNumIncomingValues(); i != e; ++i)
if (PHI->getIncomingBlock(i) == BB) {
// Keep the UI iterator valid.
if (&PHI->getOperandUse(
}
}
- // If Arg is a no-op casted pointer, strip one level of casts and
- // iterate.
+ // If Arg is a no-op casted pointer, strip one level of casts and iterate.
if (const BitCastInst *BI = dyn_cast<BitCastInst>(Arg))
Arg = BI->getOperand(0);
else if (isa<GEPOperator>(Arg) &&
// If this function has no escaping allocas or suspicious vararg usage,
// objc_storeStrong calls can be marked with the "tail" keyword.
if (TailOkForStoreStrongs)
- for (DenseSet<CallInst *>::iterator I = StoreStrongCalls.begin(),
+ for (SmallPtrSet<CallInst *, 8>::iterator I = StoreStrongCalls.begin(),
E = StoreStrongCalls.end(); I != E; ++I)
(*I)->setTailCall();
StoreStrongCalls.clear();
projects / oota-llvm.git / blobdiff