#include "llvm/Transforms/Utils/Local.h"
#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/Hashing.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SetVector.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/Statistic.h"
+#include "llvm/Analysis/EHPersonalities.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/Analysis/ValueTracking.h"
}
if (SwitchInst *SI = dyn_cast<SwitchInst>(T)) {
- // If we are switching on a constant, we can convert the switch into a
- // single branch instruction!
+ // If we are switching on a constant, we can convert the switch to an
+ // unconditional branch.
ConstantInt *CI = dyn_cast<ConstantInt>(SI->getCondition());
- BasicBlock *TheOnlyDest = SI->getDefaultDest();
- BasicBlock *DefaultDest = TheOnlyDest;
+ BasicBlock *DefaultDest = SI->getDefaultDest();
+ BasicBlock *TheOnlyDest = DefaultDest;
+
+ // If the default is unreachable, ignore it when searching for TheOnlyDest.
+ if (isa<UnreachableInst>(DefaultDest->getFirstNonPHIOrDbg()) &&
+ SI->getNumCases() > 0) {
+ TheOnlyDest = SI->case_begin().getCaseSuccessor();
+ }
// Figure out which case it goes to.
for (SwitchInst::CaseIt i = SI->case_begin(), e = SI->case_end();
// Check to see if this branch is going to the same place as the default
// dest. If so, eliminate it as an explicit compare.
if (i.getCaseSuccessor() == DefaultDest) {
- MDNode* MD = SI->getMetadata(LLVMContext::MD_prof);
+ MDNode *MD = SI->getMetadata(LLVMContext::MD_prof);
unsigned NCases = SI->getNumCases();
// Fold the case metadata into the default if there will be any branches
// left, unless the metadata doesn't match the switch.
SmallVector<uint32_t, 8> Weights;
for (unsigned MD_i = 1, MD_e = MD->getNumOperands(); MD_i < MD_e;
++MD_i) {
- ConstantInt* CI = dyn_cast<ConstantInt>(MD->getOperand(MD_i));
+ ConstantInt *CI =
+ mdconst::dyn_extract<ConstantInt>(MD->getOperand(MD_i));
assert(CI);
Weights.push_back(CI->getValue().getZExtValue());
}
// Otherwise, check to see if the switch only branches to one destination.
// We do this by reseting "TheOnlyDest" to null when we find two non-equal
// destinations.
- if (i.getCaseSuccessor() != TheOnlyDest) TheOnlyDest = 0;
+ if (i.getCaseSuccessor() != TheOnlyDest) TheOnlyDest = nullptr;
}
if (CI && !TheOnlyDest) {
BasicBlock *BB = SI->getParent();
// Remove entries from PHI nodes which we no longer branch to...
- for (unsigned i = 0, e = SI->getNumSuccessors(); i != e; ++i) {
+ for (BasicBlock *Succ : SI->successors()) {
// Found case matching a constant operand?
- BasicBlock *Succ = SI->getSuccessor(i);
if (Succ == TheOnlyDest)
- TheOnlyDest = 0; // Don't modify the first branch to TheOnlyDest
+ TheOnlyDest = nullptr; // Don't modify the first branch to TheOnlyDest
else
Succ->removePredecessor(BB);
}
BranchInst *NewBr = Builder.CreateCondBr(Cond,
FirstCase.getCaseSuccessor(),
SI->getDefaultDest());
- MDNode* MD = SI->getMetadata(LLVMContext::MD_prof);
+ MDNode *MD = SI->getMetadata(LLVMContext::MD_prof);
if (MD && MD->getNumOperands() == 3) {
- ConstantInt *SICase = dyn_cast<ConstantInt>(MD->getOperand(2));
- ConstantInt *SIDef = dyn_cast<ConstantInt>(MD->getOperand(1));
+ ConstantInt *SICase =
+ mdconst::dyn_extract<ConstantInt>(MD->getOperand(2));
+ ConstantInt *SIDef =
+ mdconst::dyn_extract<ConstantInt>(MD->getOperand(1));
assert(SICase && SIDef);
// The TrueWeight should be the weight for the single case of SI.
NewBr->setMetadata(LLVMContext::MD_prof,
SIDef->getValue().getZExtValue()));
}
+ // Update make.implicit metadata to the newly-created conditional branch.
+ MDNode *MakeImplicitMD = SI->getMetadata(LLVMContext::MD_make_implicit);
+ if (MakeImplicitMD)
+ NewBr->setMetadata(LLVMContext::MD_make_implicit, MakeImplicitMD);
+
// Delete the old switch.
SI->eraseFromParent();
return true;
for (unsigned i = 0, e = IBI->getNumDestinations(); i != e; ++i) {
if (IBI->getDestination(i) == TheOnlyDest)
- TheOnlyDest = 0;
+ TheOnlyDest = nullptr;
else
IBI->getDestination(i)->removePredecessor(IBI->getParent());
}
const TargetLibraryInfo *TLI) {
if (!I->use_empty() || isa<TerminatorInst>(I)) return false;
- // We don't want the landingpad instruction removed by anything this general.
- if (isa<LandingPadInst>(I))
+ // We don't want the landingpad-like instructions removed by anything this
+ // general.
+ if (I->isEHPad())
return false;
// We don't want debug info removed by anything this general, unless
if (II->getIntrinsicID() == Intrinsic::lifetime_start ||
II->getIntrinsicID() == Intrinsic::lifetime_end)
return isa<UndefValue>(II->getArgOperand(1));
+
+ // Assumptions are dead if their condition is trivially true.
+ if (II->getIntrinsicID() == Intrinsic::assume) {
+ if (ConstantInt *Cond = dyn_cast<ConstantInt>(II->getArgOperand(0)))
+ return !Cond->isZero();
+
+ return false;
+ }
}
if (isAllocLikeFn(I, TLI)) return true;
// dead as we go.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
Value *OpV = I->getOperand(i);
- I->setOperand(i, 0);
+ I->setOperand(i, nullptr);
if (!OpV->use_empty()) continue;
// If we find an instruction more than once, we're on a cycle that
// won't prove fruitful.
- if (!Visited.insert(I)) {
+ if (!Visited.insert(I).second) {
// Break the cycle and delete the instruction and its operands.
I->replaceAllUsesWith(UndefValue::get(I->getType()));
(void)RecursivelyDeleteTriviallyDeadInstructions(I, TLI);
return false;
}
+static bool
+simplifyAndDCEInstruction(Instruction *I,
+ SmallSetVector<Instruction *, 16> &WorkList,
+ const DataLayout &DL,
+ const TargetLibraryInfo *TLI) {
+ if (isInstructionTriviallyDead(I, TLI)) {
+ // Null out all of the instruction's operands to see if any operand becomes
+ // dead as we go.
+ for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
+ Value *OpV = I->getOperand(i);
+ I->setOperand(i, nullptr);
+
+ if (!OpV->use_empty() || I == OpV)
+ continue;
+
+ // If the operand is an instruction that became dead as we nulled out the
+ // operand, and if it is 'trivially' dead, delete it in a future loop
+ // iteration.
+ if (Instruction *OpI = dyn_cast<Instruction>(OpV))
+ if (isInstructionTriviallyDead(OpI, TLI))
+ WorkList.insert(OpI);
+ }
+
+ I->eraseFromParent();
+
+ return true;
+ }
+
+ if (Value *SimpleV = SimplifyInstruction(I, DL)) {
+ // Add the users to the worklist. CAREFUL: an instruction can use itself,
+ // in the case of a phi node.
+ for (User *U : I->users())
+ if (U != I)
+ WorkList.insert(cast<Instruction>(U));
+
+ // Replace the instruction with its simplified value.
+ I->replaceAllUsesWith(SimpleV);
+ I->eraseFromParent();
+ return true;
+ }
+ return false;
+}
+
/// SimplifyInstructionsInBlock - Scan the specified basic block and try to
/// simplify any instructions in it and recursively delete dead instructions.
///
/// This returns true if it changed the code, note that it can delete
/// instructions in other blocks as well in this block.
-bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB, const DataLayout *TD,
+bool llvm::SimplifyInstructionsInBlock(BasicBlock *BB,
const TargetLibraryInfo *TLI) {
bool MadeChange = false;
+ const DataLayout &DL = BB->getModule()->getDataLayout();
#ifndef NDEBUG
// In debug builds, ensure that the terminator of the block is never replaced
// or deleted by these simplifications. The idea of simplification is that it
// cannot introduce new instructions, and there is no way to replace the
// terminator of a block without introducing a new instruction.
- AssertingVH<Instruction> TerminatorVH(--BB->end());
+ AssertingVH<Instruction> TerminatorVH(&BB->back());
#endif
- for (BasicBlock::iterator BI = BB->begin(), E = --BB->end(); BI != E; ) {
+ SmallSetVector<Instruction *, 16> WorkList;
+ // Iterate over the original function, only adding insts to the worklist
+ // if they actually need to be revisited. This avoids having to pre-init
+ // the worklist with the entire function's worth of instructions.
+ for (BasicBlock::iterator BI = BB->begin(), E = std::prev(BB->end()); BI != E;) {
assert(!BI->isTerminator());
- Instruction *Inst = BI++;
+ Instruction *I = &*BI;
+ ++BI;
- WeakVH BIHandle(BI);
- if (recursivelySimplifyInstruction(Inst, TD, TLI)) {
- MadeChange = true;
- if (BIHandle != BI)
- BI = BB->begin();
- continue;
- }
+ // We're visiting this instruction now, so make sure it's not in the
+ // worklist from an earlier visit.
+ if (!WorkList.count(I))
+ MadeChange |= simplifyAndDCEInstruction(I, WorkList, DL, TLI);
+ }
- MadeChange |= RecursivelyDeleteTriviallyDeadInstructions(Inst, TLI);
- if (BIHandle != BI)
- BI = BB->begin();
+ while (!WorkList.empty()) {
+ Instruction *I = WorkList.pop_back_val();
+ MadeChange |= simplifyAndDCEInstruction(I, WorkList, DL, TLI);
}
return MadeChange;
}
///
/// .. and delete the predecessor corresponding to the '1', this will attempt to
/// recursively fold the and to 0.
-void llvm::RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred,
- DataLayout *TD) {
+void llvm::RemovePredecessorAndSimplify(BasicBlock *BB, BasicBlock *Pred) {
// This only adjusts blocks with PHI nodes.
if (!isa<PHINode>(BB->begin()))
return;
PhiIt = &*++BasicBlock::iterator(cast<Instruction>(PhiIt));
Value *OldPhiIt = PhiIt;
- if (!recursivelySimplifyInstruction(PN, TD))
+ if (!recursivelySimplifyInstruction(PN))
continue;
// If recursive simplification ended up deleting the next PHI node we would
/// between them, moving the instructions in the predecessor into DestBB and
/// deleting the predecessor block.
///
-void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, Pass *P) {
+void llvm::MergeBasicBlockIntoOnlyPred(BasicBlock *DestBB, DominatorTree *DT) {
// If BB has single-entry PHI nodes, fold them.
while (PHINode *PN = dyn_cast<PHINode>(DestBB->begin())) {
Value *NewVal = PN->getIncomingValue(0);
PredBB->getTerminator()->eraseFromParent();
DestBB->getInstList().splice(DestBB->begin(), PredBB->getInstList());
- if (P) {
- if (DominatorTreeWrapperPass *DTWP =
- P->getAnalysisIfAvailable<DominatorTreeWrapperPass>()) {
- DominatorTree &DT = DTWP->getDomTree();
- BasicBlock *PredBBIDom = DT.getNode(PredBB)->getIDom()->getBlock();
- DT.changeImmediateDominator(DestBB, PredBBIDom);
- DT.eraseNode(PredBB);
- }
+ // If the PredBB is the entry block of the function, move DestBB up to
+ // become the entry block after we erase PredBB.
+ if (PredBB == &DestBB->getParent()->getEntryBlock())
+ DestBB->moveAfter(PredBB);
+
+ if (DT) {
+ BasicBlock *PredBBIDom = DT->getNode(PredBB)->getIDom()->getBlock();
+ DT->changeImmediateDominator(DestBB, PredBBIDom);
+ DT->eraseNode(PredBB);
}
// Nuke BB.
PredBB->eraseFromParent();
// Copy over any phi, debug or lifetime instruction.
BB->getTerminator()->eraseFromParent();
- Succ->getInstList().splice(Succ->getFirstNonPHI(), BB->getInstList());
+ Succ->getInstList().splice(Succ->getFirstNonPHI()->getIterator(),
+ BB->getInstList());
} else {
while (PHINode *PN = dyn_cast<PHINode>(&BB->front())) {
// We explicitly check for such uses in CanPropagatePredecessorsForPHIs.
/// orders them so it usually won't matter.
///
bool llvm::EliminateDuplicatePHINodes(BasicBlock *BB) {
- bool Changed = false;
-
// This implementation doesn't currently consider undef operands
// specially. Theoretically, two phis which are identical except for
// one having an undef where the other doesn't could be collapsed.
- // Map from PHI hash values to PHI nodes. If multiple PHIs have
- // the same hash value, the element is the first PHI in the
- // linked list in CollisionMap.
- DenseMap<uintptr_t, PHINode *> HashMap;
+ struct PHIDenseMapInfo {
+ static PHINode *getEmptyKey() {
+ return DenseMapInfo<PHINode *>::getEmptyKey();
+ }
+ static PHINode *getTombstoneKey() {
+ return DenseMapInfo<PHINode *>::getTombstoneKey();
+ }
+ static unsigned getHashValue(PHINode *PN) {
+ // Compute a hash value on the operands. Instcombine will likely have
+ // sorted them, which helps expose duplicates, but we have to check all
+ // the operands to be safe in case instcombine hasn't run.
+ return static_cast<unsigned>(hash_combine(
+ hash_combine_range(PN->value_op_begin(), PN->value_op_end()),
+ hash_combine_range(PN->block_begin(), PN->block_end())));
+ }
+ static bool isEqual(PHINode *LHS, PHINode *RHS) {
+ if (LHS == getEmptyKey() || LHS == getTombstoneKey() ||
+ RHS == getEmptyKey() || RHS == getTombstoneKey())
+ return LHS == RHS;
+ return LHS->isIdenticalTo(RHS);
+ }
+ };
- // Maintain linked lists of PHI nodes with common hash values.
- DenseMap<PHINode *, PHINode *> CollisionMap;
+ // Set of unique PHINodes.
+ DenseSet<PHINode *, PHIDenseMapInfo> PHISet;
// Examine each PHI.
- for (BasicBlock::iterator I = BB->begin();
- PHINode *PN = dyn_cast<PHINode>(I++); ) {
- // Compute a hash value on the operands. Instcombine will likely have sorted
- // them, which helps expose duplicates, but we have to check all the
- // operands to be safe in case instcombine hasn't run.
- uintptr_t Hash = 0;
- // This hash algorithm is quite weak as hash functions go, but it seems
- // to do a good enough job for this particular purpose, and is very quick.
- for (User::op_iterator I = PN->op_begin(), E = PN->op_end(); I != E; ++I) {
- Hash ^= reinterpret_cast<uintptr_t>(static_cast<Value *>(*I));
- Hash = (Hash << 7) | (Hash >> (sizeof(uintptr_t) * CHAR_BIT - 7));
- }
- for (PHINode::block_iterator I = PN->block_begin(), E = PN->block_end();
- I != E; ++I) {
- Hash ^= reinterpret_cast<uintptr_t>(static_cast<BasicBlock *>(*I));
- Hash = (Hash << 7) | (Hash >> (sizeof(uintptr_t) * CHAR_BIT - 7));
- }
- // Avoid colliding with the DenseMap sentinels ~0 and ~0-1.
- Hash >>= 1;
- // If we've never seen this hash value before, it's a unique PHI.
- std::pair<DenseMap<uintptr_t, PHINode *>::iterator, bool> Pair =
- HashMap.insert(std::make_pair(Hash, PN));
- if (Pair.second) continue;
- // Otherwise it's either a duplicate or a hash collision.
- for (PHINode *OtherPN = Pair.first->second; ; ) {
- if (OtherPN->isIdenticalTo(PN)) {
- // A duplicate. Replace this PHI with its duplicate.
- PN->replaceAllUsesWith(OtherPN);
- PN->eraseFromParent();
- Changed = true;
- break;
- }
- // A non-duplicate hash collision.
- DenseMap<PHINode *, PHINode *>::iterator I = CollisionMap.find(OtherPN);
- if (I == CollisionMap.end()) {
- // Set this PHI to be the head of the linked list of colliding PHIs.
- PHINode *Old = Pair.first->second;
- Pair.first->second = PN;
- CollisionMap[PN] = Old;
- break;
- }
- // Proceed to the next PHI in the list.
- OtherPN = I->second;
+ bool Changed = false;
+ for (auto I = BB->begin(); PHINode *PN = dyn_cast<PHINode>(I++);) {
+ auto Inserted = PHISet.insert(PN);
+ if (!Inserted.second) {
+ // A duplicate. Replace this PHI with its duplicate.
+ PN->replaceAllUsesWith(*Inserted.first);
+ PN->eraseFromParent();
+ Changed = true;
+
+ // The RAUW can change PHIs that we already visited. Start over from the
+ // beginning.
+ PHISet.clear();
+ I = BB->begin();
}
}
/// their preferred alignment from the beginning.
///
static unsigned enforceKnownAlignment(Value *V, unsigned Align,
- unsigned PrefAlign, const DataLayout *TD) {
+ unsigned PrefAlign,
+ const DataLayout &DL) {
V = V->stripPointerCasts();
if (AllocaInst *AI = dyn_cast<AllocaInst>(V)) {
// If the preferred alignment is greater than the natural stack alignment
// then don't round up. This avoids dynamic stack realignment.
- if (TD && TD->exceedsNaturalStackAlignment(PrefAlign))
+ if (DL.exceedsNaturalStackAlignment(PrefAlign))
return Align;
// If there is a requested alignment and if this is an alloca, round up.
if (AI->getAlignment() >= PrefAlign)
return PrefAlign;
}
- if (GlobalValue *GV = dyn_cast<GlobalValue>(V)) {
+ if (auto *GO = dyn_cast<GlobalObject>(V)) {
// If there is a large requested alignment and we can, bump up the alignment
- // of the global.
- if (GV->isDeclaration()) return Align;
- // If the memory we set aside for the global may not be the memory used by
- // the final program then it is impossible for us to reliably enforce the
- // preferred alignment.
- if (GV->isWeakForLinker()) return Align;
-
- if (GV->getAlignment() >= PrefAlign)
- return GV->getAlignment();
+ // of the global. If the memory we set aside for the global may not be the
+ // memory used by the final program then it is impossible for us to reliably
+ // enforce the preferred alignment.
+ if (!GO->isStrongDefinitionForLinker())
+ return Align;
+
+ if (GO->getAlignment() >= PrefAlign)
+ return GO->getAlignment();
// We can only increase the alignment of the global if it has no alignment
// specified or if it is not assigned a section. If it is assigned a
// section, the global could be densely packed with other objects in the
// section, increasing the alignment could cause padding issues.
- if (!GV->hasSection() || GV->getAlignment() == 0)
- GV->setAlignment(PrefAlign);
- return GV->getAlignment();
+ if (!GO->hasSection() || GO->getAlignment() == 0)
+ GO->setAlignment(PrefAlign);
+ return GO->getAlignment();
}
return Align;
/// and it is more than the alignment of the ultimate object, see if we can
/// increase the alignment of the ultimate object, making this check succeed.
unsigned llvm::getOrEnforceKnownAlignment(Value *V, unsigned PrefAlign,
- const DataLayout *DL) {
+ const DataLayout &DL,
+ const Instruction *CxtI,
+ AssumptionCache *AC,
+ const DominatorTree *DT) {
assert(V->getType()->isPointerTy() &&
"getOrEnforceKnownAlignment expects a pointer!");
- unsigned BitWidth = DL ? DL->getPointerTypeSizeInBits(V->getType()) : 64;
+ unsigned BitWidth = DL.getPointerTypeSizeInBits(V->getType());
APInt KnownZero(BitWidth, 0), KnownOne(BitWidth, 0);
- ComputeMaskedBits(V, KnownZero, KnownOne, DL);
+ computeKnownBits(V, KnownZero, KnownOne, DL, 0, AC, CxtI, DT);
unsigned TrailZ = KnownZero.countTrailingOnes();
// Avoid trouble with ridiculously large TrailZ values, such as
///
/// See if there is a dbg.value intrinsic for DIVar before I.
-static bool LdStHasDebugValue(DIVariable &DIVar, Instruction *I) {
+static bool LdStHasDebugValue(const DILocalVariable *DIVar, Instruction *I) {
// Since we can't guarantee that the original dbg.declare instrinsic
// is removed by LowerDbgDeclare(), we need to make sure that we are
// not inserting the same dbg.value intrinsic over and over.
/// that has an associated llvm.dbg.decl intrinsic.
bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
StoreInst *SI, DIBuilder &Builder) {
- DIVariable DIVar(DDI->getVariable());
- assert((!DIVar || DIVar.isVariable()) &&
- "Variable in DbgDeclareInst should be either null or a DIVariable.");
- if (!DIVar)
- return false;
+ auto *DIVar = DDI->getVariable();
+ auto *DIExpr = DDI->getExpression();
+ assert(DIVar && "Missing variable");
if (LdStHasDebugValue(DIVar, SI))
return true;
- Instruction *DbgVal = NULL;
// If an argument is zero extended then use argument directly. The ZExt
// may be zapped by an optimization pass in future.
- Argument *ExtendedArg = NULL;
+ Argument *ExtendedArg = nullptr;
if (ZExtInst *ZExt = dyn_cast<ZExtInst>(SI->getOperand(0)))
ExtendedArg = dyn_cast<Argument>(ZExt->getOperand(0));
if (SExtInst *SExt = dyn_cast<SExtInst>(SI->getOperand(0)))
ExtendedArg = dyn_cast<Argument>(SExt->getOperand(0));
if (ExtendedArg)
- DbgVal = Builder.insertDbgValueIntrinsic(ExtendedArg, 0, DIVar, SI);
+ Builder.insertDbgValueIntrinsic(ExtendedArg, 0, DIVar, DIExpr,
+ DDI->getDebugLoc(), SI);
else
- DbgVal = Builder.insertDbgValueIntrinsic(SI->getOperand(0), 0, DIVar, SI);
-
- // Propagate any debug metadata from the store onto the dbg.value.
- DebugLoc SIDL = SI->getDebugLoc();
- if (!SIDL.isUnknown())
- DbgVal->setDebugLoc(SIDL);
- // Otherwise propagate debug metadata from dbg.declare.
- else
- DbgVal->setDebugLoc(DDI->getDebugLoc());
+ Builder.insertDbgValueIntrinsic(SI->getOperand(0), 0, DIVar, DIExpr,
+ DDI->getDebugLoc(), SI);
return true;
}
/// that has an associated llvm.dbg.decl intrinsic.
bool llvm::ConvertDebugDeclareToDebugValue(DbgDeclareInst *DDI,
LoadInst *LI, DIBuilder &Builder) {
- DIVariable DIVar(DDI->getVariable());
- assert((!DIVar || DIVar.isVariable()) &&
- "Variable in DbgDeclareInst should be either null or a DIVariable.");
- if (!DIVar)
- return false;
+ auto *DIVar = DDI->getVariable();
+ auto *DIExpr = DDI->getExpression();
+ assert(DIVar && "Missing variable");
if (LdStHasDebugValue(DIVar, LI))
return true;
- Instruction *DbgVal =
- Builder.insertDbgValueIntrinsic(LI->getOperand(0), 0,
- DIVar, LI);
-
- // Propagate any debug metadata from the store onto the dbg.value.
- DebugLoc LIDL = LI->getDebugLoc();
- if (!LIDL.isUnknown())
- DbgVal->setDebugLoc(LIDL);
- // Otherwise propagate debug metadata from dbg.declare.
- else
- DbgVal->setDebugLoc(DDI->getDebugLoc());
+ Builder.insertDbgValueIntrinsic(LI->getOperand(0), 0, DIVar, DIExpr,
+ DDI->getDebugLoc(), LI);
return true;
}
+/// Determine whether this alloca is either a VLA or an array.
+static bool isArray(AllocaInst *AI) {
+ return AI->isArrayAllocation() ||
+ AI->getType()->getElementType()->isArrayTy();
+}
+
/// LowerDbgDeclare - Lowers llvm.dbg.declare intrinsics into appropriate set
/// of llvm.dbg.value intrinsics.
bool llvm::LowerDbgDeclare(Function &F) {
- DIBuilder DIB(*F.getParent());
+ DIBuilder DIB(*F.getParent(), /*AllowUnresolved*/ false);
SmallVector<DbgDeclareInst *, 4> Dbgs;
for (auto &FI : F)
- for (BasicBlock::iterator BI : FI)
- if (auto DDI = dyn_cast<DbgDeclareInst>(BI))
+ for (Instruction &BI : FI)
+ if (auto DDI = dyn_cast<DbgDeclareInst>(&BI))
Dbgs.push_back(DDI);
if (Dbgs.empty())
AllocaInst *AI = dyn_cast_or_null<AllocaInst>(DDI->getAddress());
// If this is an alloca for a scalar variable, insert a dbg.value
// at each load and store to the alloca and erase the dbg.declare.
- if (AI && !AI->isArrayAllocation()) {
-
- // We only remove the dbg.declare intrinsic if all uses are
- // converted to dbg.value intrinsics.
- bool RemoveDDI = true;
+ // The dbg.values allow tracking a variable even if it is not
+ // stored on the stack, while the dbg.declare can only describe
+ // the stack slot (and at a lexical-scope granularity). Later
+ // passes will attempt to elide the stack slot.
+ if (AI && !isArray(AI)) {
for (User *U : AI->users())
if (StoreInst *SI = dyn_cast<StoreInst>(U))
ConvertDebugDeclareToDebugValue(DDI, SI, DIB);
else if (LoadInst *LI = dyn_cast<LoadInst>(U))
ConvertDebugDeclareToDebugValue(DDI, LI, DIB);
- else
- RemoveDDI = false;
- if (RemoveDDI)
- DDI->eraseFromParent();
+ else if (CallInst *CI = dyn_cast<CallInst>(U)) {
+ // This is a call by-value or some other instruction that
+ // takes a pointer to the variable. Insert a *value*
+ // intrinsic that describes the alloca.
+ DIB.insertDbgValueIntrinsic(AI, 0, DDI->getVariable(),
+ DDI->getExpression(), DDI->getDebugLoc(),
+ CI);
+ }
+ DDI->eraseFromParent();
}
}
return true;
/// FindAllocaDbgDeclare - Finds the llvm.dbg.declare intrinsic describing the
/// alloca 'V', if any.
DbgDeclareInst *llvm::FindAllocaDbgDeclare(Value *V) {
- if (MDNode *DebugNode = MDNode::getIfExists(V->getContext(), V))
- for (User *U : DebugNode->users())
- if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U))
- return DDI;
+ if (auto *L = LocalAsMetadata::getIfExists(V))
+ if (auto *MDV = MetadataAsValue::getIfExists(V->getContext(), L))
+ for (User *U : MDV->users())
+ if (DbgDeclareInst *DDI = dyn_cast<DbgDeclareInst>(U))
+ return DDI;
- return 0;
+ return nullptr;
}
-bool llvm::replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
- DIBuilder &Builder) {
- DbgDeclareInst *DDI = FindAllocaDbgDeclare(AI);
+bool llvm::replaceDbgDeclare(Value *Address, Value *NewAddress,
+ Instruction *InsertBefore, DIBuilder &Builder,
+ bool Deref, int Offset) {
+ DbgDeclareInst *DDI = FindAllocaDbgDeclare(Address);
if (!DDI)
return false;
- DIVariable DIVar(DDI->getVariable());
- assert((!DIVar || DIVar.isVariable()) &&
- "Variable in DbgDeclareInst should be either null or a DIVariable.");
- if (!DIVar)
- return false;
-
- // Create a copy of the original DIDescriptor for user variable, appending
- // "deref" operation to a list of address elements, as new llvm.dbg.declare
- // will take a value storing address of the memory for variable, not
- // alloca itself.
- Type *Int64Ty = Type::getInt64Ty(AI->getContext());
- SmallVector<Value*, 4> NewDIVarAddress;
- if (DIVar.hasComplexAddress()) {
- for (unsigned i = 0, n = DIVar.getNumAddrElements(); i < n; ++i) {
- NewDIVarAddress.push_back(
- ConstantInt::get(Int64Ty, DIVar.getAddrElement(i)));
+ DebugLoc Loc = DDI->getDebugLoc();
+ auto *DIVar = DDI->getVariable();
+ auto *DIExpr = DDI->getExpression();
+ assert(DIVar && "Missing variable");
+
+ if (Deref || Offset) {
+ // Create a copy of the original DIDescriptor for user variable, prepending
+ // "deref" operation to a list of address elements, as new llvm.dbg.declare
+ // will take a value storing address of the memory for variable, not
+ // alloca itself.
+ SmallVector<uint64_t, 4> NewDIExpr;
+ if (Deref)
+ NewDIExpr.push_back(dwarf::DW_OP_deref);
+ if (Offset > 0) {
+ NewDIExpr.push_back(dwarf::DW_OP_plus);
+ NewDIExpr.push_back(Offset);
+ } else if (Offset < 0) {
+ NewDIExpr.push_back(dwarf::DW_OP_minus);
+ NewDIExpr.push_back(-Offset);
}
+ if (DIExpr)
+ NewDIExpr.append(DIExpr->elements_begin(), DIExpr->elements_end());
+ DIExpr = Builder.createExpression(NewDIExpr);
}
- NewDIVarAddress.push_back(ConstantInt::get(Int64Ty, DIBuilder::OpDeref));
- DIVariable NewDIVar = Builder.createComplexVariable(
- DIVar.getTag(), DIVar.getContext(), DIVar.getName(),
- DIVar.getFile(), DIVar.getLineNumber(), DIVar.getType(),
- NewDIVarAddress, DIVar.getArgNumber());
-
- // Insert llvm.dbg.declare in the same basic block as the original alloca,
- // and remove old llvm.dbg.declare.
- BasicBlock *BB = AI->getParent();
- Builder.insertDeclare(NewAllocaAddress, NewDIVar, BB);
+
+ // Insert llvm.dbg.declare immediately after the original alloca, and remove
+ // old llvm.dbg.declare.
+ Builder.insertDeclare(NewAddress, DIVar, DIExpr, Loc, InsertBefore);
DDI->eraseFromParent();
return true;
}
+bool llvm::replaceDbgDeclareForAlloca(AllocaInst *AI, Value *NewAllocaAddress,
+ DIBuilder &Builder, bool Deref, int Offset) {
+ return replaceDbgDeclare(AI, NewAllocaAddress, AI->getNextNode(), Builder,
+ Deref, Offset);
+}
+
/// changeToUnreachable - Insert an unreachable instruction before the specified
/// instruction, making it and the rest of the code in the block dead.
static void changeToUnreachable(Instruction *I, bool UseLLVMTrap) {
new UnreachableInst(I->getContext(), I);
// All instructions after this are dead.
- BasicBlock::iterator BBI = I, BBE = BB->end();
+ BasicBlock::iterator BBI = I->getIterator(), BBE = BB->end();
while (BBI != BBE) {
if (!BBI->use_empty())
BBI->replaceAllUsesWith(UndefValue::get(BBI->getType()));
/// changeToCall - Convert the specified invoke into a normal call.
static void changeToCall(InvokeInst *II) {
- SmallVector<Value*, 8> Args(II->op_begin(), II->op_end() - 3);
- CallInst *NewCall = CallInst::Create(II->getCalledValue(), Args, "", II);
+ SmallVector<Value*, 8> Args(II->arg_begin(), II->arg_end());
+ SmallVector<OperandBundleDef, 1> OpBundles;
+ II->getOperandBundlesAsDefs(OpBundles);
+ CallInst *NewCall = CallInst::Create(II->getCalledValue(), Args, OpBundles,
+ "", II);
NewCall->takeName(II);
NewCall->setCallingConv(II->getCallingConv());
NewCall->setAttributes(II->getAttributes());
II->eraseFromParent();
}
-static bool markAliveBlocks(BasicBlock *BB,
- SmallPtrSet<BasicBlock*, 128> &Reachable) {
+static bool markAliveBlocks(Function &F,
+ SmallPtrSetImpl<BasicBlock*> &Reachable) {
SmallVector<BasicBlock*, 128> Worklist;
+ BasicBlock *BB = &F.front();
Worklist.push_back(BB);
Reachable.insert(BB);
bool Changed = false;
// instructions into LLVM unreachable insts. The instruction combining pass
// canonicalizes unreachable insts into stores to null or undef.
for (BasicBlock::iterator BBI = BB->begin(), E = BB->end(); BBI != E;++BBI){
+ // Assumptions that are known to be false are equivalent to unreachable.
+ // Also, if the condition is undefined, then we make the choice most
+ // beneficial to the optimizer, and choose that to also be unreachable.
+ if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(BBI))
+ if (II->getIntrinsicID() == Intrinsic::assume) {
+ bool MakeUnreachable = false;
+ if (isa<UndefValue>(II->getArgOperand(0)))
+ MakeUnreachable = true;
+ else if (ConstantInt *Cond =
+ dyn_cast<ConstantInt>(II->getArgOperand(0)))
+ MakeUnreachable = Cond->isZero();
+
+ if (MakeUnreachable) {
+ // Don't insert a call to llvm.trap right before the unreachable.
+ changeToUnreachable(&*BBI, false);
+ Changed = true;
+ break;
+ }
+ }
+
if (CallInst *CI = dyn_cast<CallInst>(BBI)) {
if (CI->doesNotReturn()) {
// If we found a call to a no-return function, insert an unreachable
++BBI;
if (!isa<UnreachableInst>(BBI)) {
// Don't insert a call to llvm.trap right before the unreachable.
- changeToUnreachable(BBI, false);
+ changeToUnreachable(&*BBI, false);
Changed = true;
}
break;
if (isa<ConstantPointerNull>(Callee) || isa<UndefValue>(Callee)) {
changeToUnreachable(II, true);
Changed = true;
- } else if (II->doesNotThrow()) {
+ } else if (II->doesNotThrow() && canSimplifyInvokeNoUnwind(&F)) {
if (II->use_empty() && II->onlyReadsMemory()) {
// jump to the normal destination branch.
BranchInst::Create(II->getNormalDest(), II);
Changed |= ConstantFoldTerminator(BB, true);
for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
- if (Reachable.insert(*SI))
+ if (Reachable.insert(*SI).second)
Worklist.push_back(*SI);
} while (!Worklist.empty());
return Changed;
}
+void llvm::removeUnwindEdge(BasicBlock *BB) {
+ TerminatorInst *TI = BB->getTerminator();
+
+ if (auto *II = dyn_cast<InvokeInst>(TI)) {
+ changeToCall(II);
+ return;
+ }
+
+ TerminatorInst *NewTI;
+ BasicBlock *UnwindDest;
+
+ if (auto *CRI = dyn_cast<CleanupReturnInst>(TI)) {
+ NewTI = CleanupReturnInst::Create(CRI->getCleanupPad(), nullptr, CRI);
+ UnwindDest = CRI->getUnwindDest();
+ } else if (auto *CEP = dyn_cast<CleanupEndPadInst>(TI)) {
+ NewTI = CleanupEndPadInst::Create(CEP->getCleanupPad(), nullptr, CEP);
+ UnwindDest = CEP->getUnwindDest();
+ } else if (auto *CEP = dyn_cast<CatchEndPadInst>(TI)) {
+ NewTI = CatchEndPadInst::Create(CEP->getContext(), nullptr, CEP);
+ UnwindDest = CEP->getUnwindDest();
+ } else if (auto *TPI = dyn_cast<TerminatePadInst>(TI)) {
+ SmallVector<Value *, 3> TerminatePadArgs;
+ for (Value *Operand : TPI->arg_operands())
+ TerminatePadArgs.push_back(Operand);
+ NewTI = TerminatePadInst::Create(TPI->getContext(), nullptr,
+ TerminatePadArgs, TPI);
+ UnwindDest = TPI->getUnwindDest();
+ } else {
+ llvm_unreachable("Could not find unwind successor");
+ }
+
+ NewTI->takeName(TI);
+ NewTI->setDebugLoc(TI->getDebugLoc());
+ UnwindDest->removePredecessor(BB);
+ TI->eraseFromParent();
+}
+
/// removeUnreachableBlocksFromFn - Remove blocks that are not reachable, even
/// if they are in a dead cycle. Return true if a change was made, false
/// otherwise.
bool llvm::removeUnreachableBlocks(Function &F) {
SmallPtrSet<BasicBlock*, 128> Reachable;
- bool Changed = markAliveBlocks(F.begin(), Reachable);
+ bool Changed = markAliveBlocks(F, Reachable);
// If there are unreachable blocks in the CFG...
if (Reachable.size() == F.size())
// Loop over all of the basic blocks that are not reachable, dropping all of
// their internal references...
for (Function::iterator BB = ++F.begin(), E = F.end(); BB != E; ++BB) {
- if (Reachable.count(BB))
+ if (Reachable.count(&*BB))
continue;
- for (succ_iterator SI = succ_begin(BB), SE = succ_end(BB); SI != SE; ++SI)
+ for (succ_iterator SI = succ_begin(&*BB), SE = succ_end(&*BB); SI != SE;
+ ++SI)
if (Reachable.count(*SI))
- (*SI)->removePredecessor(BB);
+ (*SI)->removePredecessor(&*BB);
BB->dropAllReferences();
}
for (Function::iterator I = ++F.begin(); I != F.end();)
- if (!Reachable.count(I))
+ if (!Reachable.count(&*I))
I = F.getBasicBlockList().erase(I);
else
++I;
return true;
}
+
+void llvm::combineMetadata(Instruction *K, const Instruction *J,
+ ArrayRef<unsigned> KnownIDs) {
+ SmallVector<std::pair<unsigned, MDNode *>, 4> Metadata;
+ K->dropUnknownNonDebugMetadata(KnownIDs);
+ K->getAllMetadataOtherThanDebugLoc(Metadata);
+ for (unsigned i = 0, n = Metadata.size(); i < n; ++i) {
+ unsigned Kind = Metadata[i].first;
+ MDNode *JMD = J->getMetadata(Kind);
+ MDNode *KMD = Metadata[i].second;
+
+ switch (Kind) {
+ default:
+ K->setMetadata(Kind, nullptr); // Remove unknown metadata
+ break;
+ case LLVMContext::MD_dbg:
+ llvm_unreachable("getAllMetadataOtherThanDebugLoc returned a MD_dbg");
+ case LLVMContext::MD_tbaa:
+ K->setMetadata(Kind, MDNode::getMostGenericTBAA(JMD, KMD));
+ break;
+ case LLVMContext::MD_alias_scope:
+ K->setMetadata(Kind, MDNode::getMostGenericAliasScope(JMD, KMD));
+ break;
+ case LLVMContext::MD_noalias:
+ K->setMetadata(Kind, MDNode::intersect(JMD, KMD));
+ break;
+ case LLVMContext::MD_range:
+ K->setMetadata(Kind, MDNode::getMostGenericRange(JMD, KMD));
+ break;
+ case LLVMContext::MD_fpmath:
+ K->setMetadata(Kind, MDNode::getMostGenericFPMath(JMD, KMD));
+ break;
+ case LLVMContext::MD_invariant_load:
+ // Only set the !invariant.load if it is present in both instructions.
+ K->setMetadata(Kind, JMD);
+ break;
+ case LLVMContext::MD_nonnull:
+ // Only set the !nonnull if it is present in both instructions.
+ K->setMetadata(Kind, JMD);
+ break;
+ case LLVMContext::MD_invariant_group:
+ // Preserve !invariant.group in K.
+ break;
+ case LLVMContext::MD_align:
+ K->setMetadata(Kind,
+ MDNode::getMostGenericAlignmentOrDereferenceable(JMD, KMD));
+ break;
+ case LLVMContext::MD_dereferenceable:
+ case LLVMContext::MD_dereferenceable_or_null:
+ K->setMetadata(Kind,
+ MDNode::getMostGenericAlignmentOrDereferenceable(JMD, KMD));
+ break;
+ }
+ }
+ // Set !invariant.group from J if J has it. If both instructions have it
+ // then we will just pick it from J - even when they are different.
+ // Also make sure that K is load or store - f.e. combining bitcast with load
+ // could produce bitcast with invariant.group metadata, which is invalid.
+ // FIXME: we should try to preserve both invariant.group md if they are
+ // different, but right now instruction can only have one invariant.group.
+ if (auto *JMD = J->getMetadata(LLVMContext::MD_invariant_group))
+ if (isa<LoadInst>(K) || isa<StoreInst>(K))
+ K->setMetadata(LLVMContext::MD_invariant_group, JMD);
+}
+
+unsigned llvm::replaceDominatedUsesWith(Value *From, Value *To,
+ DominatorTree &DT,
+ const BasicBlockEdge &Root) {
+ assert(From->getType() == To->getType());
+
+ unsigned Count = 0;
+ for (Value::use_iterator UI = From->use_begin(), UE = From->use_end();
+ UI != UE; ) {
+ Use &U = *UI++;
+ if (DT.dominates(Root, U)) {
+ U.set(To);
+ DEBUG(dbgs() << "Replace dominated use of '"
+ << From->getName() << "' as "
+ << *To << " in " << *U << "\n");
+ ++Count;
+ }
+ }
+ return Count;
+}
+
+unsigned llvm::replaceDominatedUsesWith(Value *From, Value *To,
+ DominatorTree &DT,
+ const BasicBlock *BB) {
+ assert(From->getType() == To->getType());
+
+ unsigned Count = 0;
+ for (Value::use_iterator UI = From->use_begin(), UE = From->use_end();
+ UI != UE;) {
+ Use &U = *UI++;
+ auto *I = cast<Instruction>(U.getUser());
+ if (DT.dominates(BB, I->getParent())) {
+ U.set(To);
+ DEBUG(dbgs() << "Replace dominated use of '" << From->getName() << "' as "
+ << *To << " in " << *U << "\n");
+ ++Count;
+ }
+ }
+ return Count;
+}
+
+bool llvm::callsGCLeafFunction(ImmutableCallSite CS) {
+ if (isa<IntrinsicInst>(CS.getInstruction()))
+ // Most LLVM intrinsics are things which can never take a safepoint.
+ // As a result, we don't need to have the stack parsable at the
+ // callsite. This is a highly useful optimization since intrinsic
+ // calls are fairly prevalent, particularly in debug builds.
+ return true;
+
+ // Check if the function is specifically marked as a gc leaf function.
+ //
+ // TODO: we should be checking the attributes on the call site as well.
+ if (const Function *F = CS.getCalledFunction())
+ return F->hasFnAttribute("gc-leaf-function");
+
+ return false;
+}
projects / oota-llvm.git / blobdiff