/// DeleteDeadBlock - Delete the specified block, which must have no
/// predecessors.
void DeleteDeadBlock(BasicBlock *BB);
-
-
+
+
/// FoldSingleEntryPHINodes - We know that BB has one predecessor. If there are
/// any single-entry PHI nodes in it, fold them away. This handles the case
/// when all entries to the PHI nodes in a block are guaranteed equal, such as
/// The output is added to Result, as pairs of <from,to> edge info.
void FindFunctionBackedges(const Function &F,
SmallVectorImpl<std::pair<const BasicBlock*,const BasicBlock*> > &Result);
-
+
/// GetSuccessorNumber - Search for the specified successor of basic block BB
/// and return its position in the terminator instruction's list of
/// was split, null otherwise.
///
/// If MergeIdenticalEdges is true (not the default), *all* edges from TI to the
-/// specified successor will be merged into the same critical edge block.
-/// This is most commonly interesting with switch instructions, which may
+/// specified successor will be merged into the same critical edge block.
+/// This is most commonly interesting with switch instructions, which may
/// have many edges to any one destination. This ensures that all edges to that
-/// dest go to one block instead of each going to a different block, but isn't
+/// dest go to one block instead of each going to a different block, but isn't
/// the standard definition of a "critical edge".
///
/// It is invalid to call this function on a critical edge that starts at an
}
}
-/// SplitEdge - Split the edge connecting specified block. Pass P must
-/// not be NULL.
+/// SplitEdge - Split the edge connecting specified block. Pass P must
+/// not be NULL.
BasicBlock *SplitEdge(BasicBlock *From, BasicBlock *To, Pass *P);
/// SplitBlock - Split the specified block at the specified instruction - every
/// the loop info is updated.
///
BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P);
-
+
/// 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
/// 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 SplitLandingPadPredecessors(BasicBlock *OrigBB,ArrayRef<BasicBlock*> Preds,
const char *Suffix, const char *Suffix2,
Pass *P, SmallVectorImpl<BasicBlock*> &NewBBs);
ReturnInst *FoldReturnIntoUncondBranch(ReturnInst *RI, BasicBlock *BB,
BasicBlock *Pred);
-/// GetFirstDebugLocInBasicBlock - Return first valid DebugLoc entry in a
+/// GetFirstDebugLocInBasicBlock - Return first valid DebugLoc entry in a
/// given basic block.
DebugLoc GetFirstDebugLocInBasicBlock(const BasicBlock *BB);
++I; // Skip one edge due to the incoming arc from TI.
if (!AllowIdenticalEdges)
return I != E;
-
+
// If AllowIdenticalEdges is true, then we allow this edge to be considered
// non-critical iff all preds come from TI's block.
while (I != E) {
/// This returns the new block if the edge was split, null otherwise.
///
/// If MergeIdenticalEdges is true (not the default), *all* edges from TI to the
-/// specified successor will be merged into the same critical edge block.
-/// This is most commonly interesting with switch instructions, which may
+/// specified successor will be merged into the same critical edge block.
+/// This is most commonly interesting with switch instructions, which may
/// have many edges to any one destination. This ensures that all edges to that
-/// dest go to one block instead of each going to a different block, but isn't
+/// dest go to one block instead of each going to a different block, but isn't
/// the standard definition of a "critical edge".
///
/// It is invalid to call this function on a critical edge that starts at an
BasicBlock *llvm::SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum,
Pass *P, bool MergeIdenticalEdges) {
if (!isCriticalEdge(TI, SuccNum, MergeIdenticalEdges)) return 0;
-
+
assert(!isa<IndirectBrInst>(TI) &&
"Cannot split critical edge from IndirectBrInst");
-
+
BasicBlock *TIBB = TI->getParent();
BasicBlock *DestBB = TI->getSuccessor(SuccNum);
Function &F = *TIBB->getParent();
Function::iterator FBBI = TIBB;
F.getBasicBlockList().insert(++FBBI, NewBB);
-
+
// If there are any PHI nodes in DestBB, we need to update them so that they
// merge incoming values from NewBB instead of from TIBB.
{
// happens because the BB list of PHI nodes are usually in the same
// order.
if (PN->getIncomingBlock(BBIdx) != TIBB)
- BBIdx = PN->getBasicBlockIndex(TIBB);
+ BBIdx = PN->getBasicBlockIndex(TIBB);
PN->setIncomingBlock(BBIdx, NewBB);
}
}
-
+
// If there are any other edges from TIBB to DestBB, update those to go
// through the split block, making those edges non-critical as well (and
// reducing the number of phi entries in the DestBB if relevant).
if (MergeIdenticalEdges) {
for (unsigned i = SuccNum+1, e = TI->getNumSuccessors(); i != e; ++i) {
if (TI->getSuccessor(i) != DestBB) continue;
-
+
// Remove an entry for TIBB from DestBB phi nodes.
DestBB->removePredecessor(TIBB);
-
+
// We found another edge to DestBB, go to NewBB instead.
TI->setSuccessor(i, NewBB);
}
}
-
-
+
+
// If we don't have a pass object, we can't update anything...
if (P == 0) return NewBB;
-
+
DominatorTree *DT = P->getAnalysisIfAvailable<DominatorTree>();
LoopInfo *LI = P->getAnalysisIfAvailable<LoopInfo>();
ProfileInfo *PI = P->getAnalysisIfAvailable<ProfileInfo>();
-
+
// If we have nothing to update, just return.
if (DT == 0 && LI == 0 && PI == 0)
return NewBB;
}
bool NewBBDominatesDestBB = true;
-
+
// Should we update DominatorTree information?
if (DT) {
DomTreeNode *TINode = DT->getNode(TIBB);
if (TINode) { // Don't break unreachable code!
DomTreeNode *NewBBNode = DT->addNewBlock(NewBB, TIBB);
DomTreeNode *DestBBNode = 0;
-
+
// If NewBBDominatesDestBB hasn't been computed yet, do so with DT.
if (!OtherPreds.empty()) {
DestBBNode = DT->getNode(DestBB);
}
OtherPreds.clear();
}
-
+
// If NewBBDominatesDestBB, then NewBB dominates DestBB, otherwise it
// doesn't dominate anything.
if (NewBBDominatesDestBB) {
projects / oota-llvm.git / commitdiff