/// is dead. Also recursively delete any operands that become dead as
/// a result. This includes tracing the def-use list from the PHI to see if
/// it is ultimately unused or if it reaches an unused cycle.
-bool llvm::DeleteDeadPHIs(BasicBlock *BB) {
+bool llvm::DeleteDeadPHIs(BasicBlock *BB, const TargetLibraryInfo *TLI) {
// Recursively deleting a PHI may cause multiple PHIs to be deleted
// or RAUW'd undef, so use an array of WeakVH for the PHIs to delete.
SmallVector<WeakVH, 8> PHIs;
bool Changed = false;
for (unsigned i = 0, e = PHIs.size(); i != e; ++i)
if (PHINode *PN = dyn_cast_or_null<PHINode>(PHIs[i].operator Value*()))
- Changed |= RecursivelyDeleteDeadPHINode(PN);
+ Changed |= RecursivelyDeleteDeadPHINode(PN, TLI);
return Changed;
}
// Delete the unconditional branch from the predecessor...
PredBB->getInstList().pop_back();
- // Move all definitions in the successor to the predecessor...
- PredBB->getInstList().splice(PredBB->end(), BB->getInstList());
-
// Make all PHI nodes that referred to BB now refer to Pred as their
// source...
BB->replaceAllUsesWith(PredBB);
+ // Move all definitions in the successor to the predecessor...
+ PredBB->getInstList().splice(PredBB->end(), BB->getInstList());
+
// Inherit predecessors name if it exists.
if (!PredBB->hasName())
PredBB->takeName(BB);
if (Term->getSuccessor(i) == Succ)
return i;
}
- return 0;
}
/// SplitEdge - Split the edge connecting specified block. Pass P must
///
BasicBlock *llvm::SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P) {
BasicBlock::iterator SplitIt = SplitPt;
- while (isa<PHINode>(SplitIt))
+ while (isa<PHINode>(SplitIt) || isa<LandingPadInst>(SplitIt))
++SplitIt;
BasicBlock *New = Old->splitBasicBlock(SplitIt, Old->getName()+".split");
if (DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>()) {
// Old dominates New. New node dominates all other nodes dominated by Old.
- DomTreeNode *OldNode = DT->getNode(Old);
- std::vector<DomTreeNode *> Children;
- for (DomTreeNode::iterator I = OldNode->begin(), E = OldNode->end();
- I != E; ++I)
- Children.push_back(*I);
+ if (DomTreeNode *OldNode = DT->getNode(Old)) {
+ std::vector<DomTreeNode *> Children;
+ for (DomTreeNode::iterator I = OldNode->begin(), E = OldNode->end();
+ I != E; ++I)
+ Children.push_back(*I);
DomTreeNode *NewNode = DT->addNewBlock(New,Old);
for (std::vector<DomTreeNode *>::iterator I = Children.begin(),
E = Children.end(); I != E; ++I)
DT->changeImmediateDominator(*I, NewNode);
+ }
}
return New;
}
+/// UpdateAnalysisInformation - Update DominatorTree, LoopInfo, and LCCSA
+/// analysis information.
+static void UpdateAnalysisInformation(BasicBlock *OldBB, BasicBlock *NewBB,
+ ArrayRef<BasicBlock *> Preds,
+ Pass *P, bool &HasLoopExit) {
+ if (!P) return;
-/// SplitBlockPredecessors - This method transforms BB by introducing a new
-/// basic block into the function, and moving some of the predecessors of BB to
-/// be predecessors of the new block. The new predecessors are indicated by the
-/// Preds array, which has NumPreds elements in it. The new block is given a
-/// suffix of 'Suffix'.
-///
-/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
-/// LoopInfo, and LCCSA but no other analyses. In particular, it does not
-/// preserve LoopSimplify (because it's complicated to handle the case where one
-/// of the edges being split is an exit of a loop with other exits).
-///
-BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
- BasicBlock *const *Preds,
- unsigned NumPreds, const char *Suffix,
- Pass *P) {
- // Create new basic block, insert right before the original block.
- BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), BB->getName()+Suffix,
- BB->getParent(), BB);
-
- // The new block unconditionally branches to the old block.
- BranchInst *BI = BranchInst::Create(BB, NewBB);
-
- LoopInfo *LI = P ? P->getAnalysisIfAvailable<LoopInfo>() : 0;
- Loop *L = LI ? LI->getLoopFor(BB) : 0;
- bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
+ LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>();
+ Loop *L = LI ? LI->getLoopFor(OldBB) : 0;
- // Move the edges from Preds to point to NewBB instead of BB.
- // While here, if we need to preserve loop analyses, collect
- // some information about how this split will affect loops.
- bool HasLoopExit = false;
+ // If we need to preserve loop analyses, collect some information about how
+ // this split will affect loops.
bool IsLoopEntry = !!L;
bool SplitMakesNewLoopHeader = false;
- for (unsigned i = 0; i != NumPreds; ++i) {
- // This is slightly more strict than necessary; the minimum requirement
- // is that there be no more than one indirectbr branching to BB. And
- // all BlockAddress uses would need to be updated.
- assert(!isa<IndirectBrInst>(Preds[i]->getTerminator()) &&
- "Cannot split an edge from an IndirectBrInst");
-
- Preds[i]->getTerminator()->replaceUsesOfWith(BB, NewBB);
-
- if (LI) {
- // If we need to preserve LCSSA, determine if any of
- // the preds is a loop exit.
+ if (LI) {
+ bool PreserveLCSSA = P->mustPreserveAnalysisID(LCSSAID);
+ for (ArrayRef<BasicBlock*>::iterator
+ i = Preds.begin(), e = Preds.end(); i != e; ++i) {
+ BasicBlock *Pred = *i;
+
+ // If we need to preserve LCSSA, determine if any of the preds is a loop
+ // exit.
if (PreserveLCSSA)
- if (Loop *PL = LI->getLoopFor(Preds[i]))
- if (!PL->contains(BB))
+ if (Loop *PL = LI->getLoopFor(Pred))
+ if (!PL->contains(OldBB))
HasLoopExit = true;
- // If we need to preserve LoopInfo, note whether any of the
- // preds crosses an interesting loop boundary.
- if (L) {
- if (L->contains(Preds[i]))
- IsLoopEntry = false;
- else
- SplitMakesNewLoopHeader = true;
- }
+
+ // If we need to preserve LoopInfo, note whether any of the preds crosses
+ // an interesting loop boundary.
+ if (!L) continue;
+ if (L->contains(Pred))
+ IsLoopEntry = false;
+ else
+ SplitMakesNewLoopHeader = true;
}
}
// Update dominator tree if available.
- DominatorTree *DT = P ? P->getAnalysisIfAvailable<DominatorTree>() : 0;
+ DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>();
if (DT)
DT->splitBlock(NewBB);
- // Insert a new PHI node into NewBB for every PHI node in BB and that new PHI
- // node becomes an incoming value for BB's phi node. However, if the Preds
- // list is empty, we need to insert dummy entries into the PHI nodes in BB to
- // account for the newly created predecessor.
- if (NumPreds == 0) {
- // Insert dummy values as the incoming value.
- for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ++I)
- cast<PHINode>(I)->addIncoming(UndefValue::get(I->getType()), NewBB);
- return NewBB;
+ if (!L) return;
+
+ if (IsLoopEntry) {
+ // Add the new block to the nearest enclosing loop (and not an adjacent
+ // loop). To find this, examine each of the predecessors and determine which
+ // loops enclose them, and select the most-nested loop which contains the
+ // loop containing the block being split.
+ Loop *InnermostPredLoop = 0;
+ for (ArrayRef<BasicBlock*>::iterator
+ i = Preds.begin(), e = Preds.end(); i != e; ++i) {
+ BasicBlock *Pred = *i;
+ if (Loop *PredLoop = LI->getLoopFor(Pred)) {
+ // Seek a loop which actually contains the block being split (to avoid
+ // adjacent loops).
+ while (PredLoop && !PredLoop->contains(OldBB))
+ PredLoop = PredLoop->getParentLoop();
+
+ // Select the most-nested of these loops which contains the block.
+ if (PredLoop && PredLoop->contains(OldBB) &&
+ (!InnermostPredLoop ||
+ InnermostPredLoop->getLoopDepth() < PredLoop->getLoopDepth()))
+ InnermostPredLoop = PredLoop;
+ }
+ }
+
+ if (InnermostPredLoop)
+ InnermostPredLoop->addBasicBlockToLoop(NewBB, LI->getBase());
+ } else {
+ L->addBasicBlockToLoop(NewBB, LI->getBase());
+ if (SplitMakesNewLoopHeader)
+ L->moveToHeader(NewBB);
}
+}
+/// UpdatePHINodes - Update the PHI nodes in OrigBB to include the values coming
+/// from NewBB. This also updates AliasAnalysis, if available.
+static void UpdatePHINodes(BasicBlock *OrigBB, BasicBlock *NewBB,
+ ArrayRef<BasicBlock*> Preds, BranchInst *BI,
+ Pass *P, bool HasLoopExit) {
+ // Otherwise, create a new PHI node in NewBB for each PHI node in OrigBB.
AliasAnalysis *AA = P ? P->getAnalysisIfAvailable<AliasAnalysis>() : 0;
-
- if (L) {
- if (IsLoopEntry) {
- // Add the new block to the nearest enclosing loop (and not an
- // adjacent loop). To find this, examine each of the predecessors and
- // determine which loops enclose them, and select the most-nested loop
- // which contains the loop containing the block being split.
- Loop *InnermostPredLoop = 0;
- for (unsigned i = 0; i != NumPreds; ++i)
- if (Loop *PredLoop = LI->getLoopFor(Preds[i])) {
- // Seek a loop which actually contains the block being split (to
- // avoid adjacent loops).
- while (PredLoop && !PredLoop->contains(BB))
- PredLoop = PredLoop->getParentLoop();
- // Select the most-nested of these loops which contains the block.
- if (PredLoop &&
- PredLoop->contains(BB) &&
- (!InnermostPredLoop ||
- InnermostPredLoop->getLoopDepth() < PredLoop->getLoopDepth()))
- InnermostPredLoop = PredLoop;
- }
- if (InnermostPredLoop)
- InnermostPredLoop->addBasicBlockToLoop(NewBB, LI->getBase());
- } else {
- L->addBasicBlockToLoop(NewBB, LI->getBase());
- if (SplitMakesNewLoopHeader)
- L->moveToHeader(NewBB);
- }
- }
-
- // Otherwise, create a new PHI node in NewBB for each PHI node in BB.
- for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ) {
+ for (BasicBlock::iterator I = OrigBB->begin(); isa<PHINode>(I); ) {
PHINode *PN = cast<PHINode>(I++);
-
+
// Check to see if all of the values coming in are the same. If so, we
// don't need to create a new PHI node, unless it's needed for LCSSA.
Value *InVal = 0;
if (!HasLoopExit) {
InVal = PN->getIncomingValueForBlock(Preds[0]);
- for (unsigned i = 1; i != NumPreds; ++i)
+ for (unsigned i = 1, e = Preds.size(); i != e; ++i)
if (InVal != PN->getIncomingValueForBlock(Preds[i])) {
InVal = 0;
break;
// If all incoming values for the new PHI would be the same, just don't
// make a new PHI. Instead, just remove the incoming values from the old
// PHI.
- for (unsigned i = 0; i != NumPreds; ++i)
+ for (unsigned i = 0, e = Preds.size(); i != e; ++i)
PN->removeIncomingValue(Preds[i], false);
} else {
// If the values coming into the block are not the same, we need a PHI.
// Create the new PHI node, insert it into NewBB at the end of the block
PHINode *NewPHI =
- PHINode::Create(PN->getType(), NumPreds, PN->getName()+".ph", BI);
+ PHINode::Create(PN->getType(), Preds.size(), PN->getName() + ".ph", BI);
if (AA) AA->copyValue(PN, NewPHI);
// Move all of the PHI values for 'Preds' to the new PHI.
- for (unsigned i = 0; i != NumPreds; ++i) {
+ for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
Value *V = PN->removeIncomingValue(Preds[i], false);
NewPHI->addIncoming(V, Preds[i]);
}
+
InVal = NewPHI;
}
-
+
// Add an incoming value to the PHI node in the loop for the preheader
// edge.
PN->addIncoming(InVal, NewBB);
}
+}
+
+/// SplitBlockPredecessors - This method transforms BB by introducing a new
+/// basic block into the function, and moving some of the predecessors of BB to
+/// be predecessors of the new block. The new predecessors are indicated by the
+/// Preds array, which has NumPreds elements in it. The new block is given a
+/// suffix of 'Suffix'.
+///
+/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
+/// LoopInfo, and LCCSA but no other analyses. In particular, it does not
+/// preserve LoopSimplify (because it's complicated to handle the case where one
+/// of the edges being split is an exit of a loop with other exits).
+///
+BasicBlock *llvm::SplitBlockPredecessors(BasicBlock *BB,
+ ArrayRef<BasicBlock*> Preds,
+ const char *Suffix, Pass *P) {
+ // Create new basic block, insert right before the original block.
+ BasicBlock *NewBB = BasicBlock::Create(BB->getContext(), BB->getName()+Suffix,
+ BB->getParent(), BB);
+
+ // The new block unconditionally branches to the old block.
+ BranchInst *BI = BranchInst::Create(BB, NewBB);
+ // Move the edges from Preds to point to NewBB instead of BB.
+ for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
+ // This is slightly more strict than necessary; the minimum requirement
+ // is that there be no more than one indirectbr branching to BB. And
+ // all BlockAddress uses would need to be updated.
+ assert(!isa<IndirectBrInst>(Preds[i]->getTerminator()) &&
+ "Cannot split an edge from an IndirectBrInst");
+ Preds[i]->getTerminator()->replaceUsesOfWith(BB, NewBB);
+ }
+
+ // Insert a new PHI node into NewBB for every PHI node in BB and that new PHI
+ // node becomes an incoming value for BB's phi node. However, if the Preds
+ // list is empty, we need to insert dummy entries into the PHI nodes in BB to
+ // account for the newly created predecessor.
+ if (Preds.size() == 0) {
+ // Insert dummy values as the incoming value.
+ for (BasicBlock::iterator I = BB->begin(); isa<PHINode>(I); ++I)
+ cast<PHINode>(I)->addIncoming(UndefValue::get(I->getType()), NewBB);
+ return NewBB;
+ }
+
+ // Update DominatorTree, LoopInfo, and LCCSA analysis information.
+ bool HasLoopExit = false;
+ UpdateAnalysisInformation(BB, NewBB, Preds, P, HasLoopExit);
+
+ // Update the PHI nodes in BB with the values coming from NewBB.
+ UpdatePHINodes(BB, NewBB, Preds, BI, P, HasLoopExit);
return NewBB;
}
+/// SplitLandingPadPredecessors - This method transforms the landing pad,
+/// OrigBB, by introducing two new basic blocks into the function. One of those
+/// new basic blocks gets the predecessors listed in Preds. The other basic
+/// block gets the remaining predecessors of OrigBB. The landingpad instruction
+/// OrigBB is clone into both of the new basic blocks. The new blocks are given
+/// the suffixes 'Suffix1' and 'Suffix2', and are returned in the NewBBs vector.
+///
+/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree,
+/// DominanceFrontier, LoopInfo, and LCCSA but no other analyses. In particular,
+/// it does not preserve LoopSimplify (because it's complicated to handle the
+/// case where one of the edges being split is an exit of a loop with other
+/// exits).
+///
+void llvm::SplitLandingPadPredecessors(BasicBlock *OrigBB,
+ ArrayRef<BasicBlock*> Preds,
+ const char *Suffix1, const char *Suffix2,
+ Pass *P,
+ SmallVectorImpl<BasicBlock*> &NewBBs) {
+ assert(OrigBB->isLandingPad() && "Trying to split a non-landing pad!");
+
+ // Create a new basic block for OrigBB's predecessors listed in Preds. Insert
+ // it right before the original block.
+ BasicBlock *NewBB1 = BasicBlock::Create(OrigBB->getContext(),
+ OrigBB->getName() + Suffix1,
+ OrigBB->getParent(), OrigBB);
+ NewBBs.push_back(NewBB1);
+
+ // The new block unconditionally branches to the old block.
+ BranchInst *BI1 = BranchInst::Create(OrigBB, NewBB1);
+
+ // Move the edges from Preds to point to NewBB1 instead of OrigBB.
+ for (unsigned i = 0, e = Preds.size(); i != e; ++i) {
+ // This is slightly more strict than necessary; the minimum requirement
+ // is that there be no more than one indirectbr branching to BB. And
+ // all BlockAddress uses would need to be updated.
+ assert(!isa<IndirectBrInst>(Preds[i]->getTerminator()) &&
+ "Cannot split an edge from an IndirectBrInst");
+ Preds[i]->getTerminator()->replaceUsesOfWith(OrigBB, NewBB1);
+ }
+
+ // Update DominatorTree, LoopInfo, and LCCSA analysis information.
+ bool HasLoopExit = false;
+ UpdateAnalysisInformation(OrigBB, NewBB1, Preds, P, HasLoopExit);
+
+ // Update the PHI nodes in OrigBB with the values coming from NewBB1.
+ UpdatePHINodes(OrigBB, NewBB1, Preds, BI1, P, HasLoopExit);
+
+ // Move the remaining edges from OrigBB to point to NewBB2.
+ SmallVector<BasicBlock*, 8> NewBB2Preds;
+ for (pred_iterator i = pred_begin(OrigBB), e = pred_end(OrigBB);
+ i != e; ) {
+ BasicBlock *Pred = *i++;
+ if (Pred == NewBB1) continue;
+ assert(!isa<IndirectBrInst>(Pred->getTerminator()) &&
+ "Cannot split an edge from an IndirectBrInst");
+ NewBB2Preds.push_back(Pred);
+ e = pred_end(OrigBB);
+ }
+
+ BasicBlock *NewBB2 = 0;
+ if (!NewBB2Preds.empty()) {
+ // Create another basic block for the rest of OrigBB's predecessors.
+ NewBB2 = BasicBlock::Create(OrigBB->getContext(),
+ OrigBB->getName() + Suffix2,
+ OrigBB->getParent(), OrigBB);
+ NewBBs.push_back(NewBB2);
+
+ // The new block unconditionally branches to the old block.
+ BranchInst *BI2 = BranchInst::Create(OrigBB, NewBB2);
+
+ // Move the remaining edges from OrigBB to point to NewBB2.
+ for (SmallVectorImpl<BasicBlock*>::iterator
+ i = NewBB2Preds.begin(), e = NewBB2Preds.end(); i != e; ++i)
+ (*i)->getTerminator()->replaceUsesOfWith(OrigBB, NewBB2);
+
+ // Update DominatorTree, LoopInfo, and LCCSA analysis information.
+ HasLoopExit = false;
+ UpdateAnalysisInformation(OrigBB, NewBB2, NewBB2Preds, P, HasLoopExit);
+
+ // Update the PHI nodes in OrigBB with the values coming from NewBB2.
+ UpdatePHINodes(OrigBB, NewBB2, NewBB2Preds, BI2, P, HasLoopExit);
+ }
+
+ LandingPadInst *LPad = OrigBB->getLandingPadInst();
+ Instruction *Clone1 = LPad->clone();
+ Clone1->setName(Twine("lpad") + Suffix1);
+ NewBB1->getInstList().insert(NewBB1->getFirstInsertionPt(), Clone1);
+
+ if (NewBB2) {
+ Instruction *Clone2 = LPad->clone();
+ Clone2->setName(Twine("lpad") + Suffix2);
+ NewBB2->getInstList().insert(NewBB2->getFirstInsertionPt(), Clone2);
+
+ // Create a PHI node for the two cloned landingpad instructions.
+ PHINode *PN = PHINode::Create(LPad->getType(), 2, "lpad.phi", LPad);
+ PN->addIncoming(Clone1, NewBB1);
+ PN->addIncoming(Clone2, NewBB2);
+ LPad->replaceAllUsesWith(PN);
+ LPad->eraseFromParent();
+ } else {
+ // There is no second clone. Just replace the landing pad with the first
+ // clone.
+ LPad->replaceAllUsesWith(Clone1);
+ LPad->eraseFromParent();
+ }
+}
+
/// FindFunctionBackedges - Analyze the specified function to find all of the
/// loop backedges in the function and return them. This is a relatively cheap
/// (compared to computing dominators and loop info) analysis.
// If the return instruction returns a value, and if the value was a
// PHI node in "BB", propagate the right value into the return.
for (User::op_iterator i = NewRet->op_begin(), e = NewRet->op_end();
- i != e; ++i)
- if (PHINode *PN = dyn_cast<PHINode>(*i))
- if (PN->getParent() == BB)
- *i = PN->getIncomingValueForBlock(Pred);
+ i != e; ++i) {
+ Value *V = *i;
+ Instruction *NewBC = 0;
+ if (BitCastInst *BCI = dyn_cast<BitCastInst>(V)) {
+ // Return value might be bitcasted. Clone and insert it before the
+ // return instruction.
+ V = BCI->getOperand(0);
+ NewBC = BCI->clone();
+ Pred->getInstList().insert(NewRet, NewBC);
+ *i = NewBC;
+ }
+ if (PHINode *PN = dyn_cast<PHINode>(V)) {
+ if (PN->getParent() == BB) {
+ if (NewBC)
+ NewBC->setOperand(0, PN->getIncomingValueForBlock(Pred));
+ else
+ *i = PN->getIncomingValueForBlock(Pred);
+ }
+ }
+ }
// Update any PHI nodes in the returning block to realize that we no
// longer branch to them.
return cast<ReturnInst>(NewRet);
}
-/// GetFirstDebugLocInBasicBlock - Return first valid DebugLoc entry in a
-/// given basic block.
-DebugLoc llvm::GetFirstDebugLocInBasicBlock(const BasicBlock *BB) {
- if (const Instruction *I = BB->getFirstNonPHI())
- return I->getDebugLoc();
- // Scanning entire block may be too expensive, if the first instruction
- // does not have valid location info.
- return DebugLoc();
-}
projects / oota-llvm.git / blobdiff