From 5c89b5240c90eb8171f999e5f06f815502d0321c Mon Sep 17 00:00:00 2001 From: Dan Gohman Date: Tue, 8 Sep 2009 15:45:00 +0000 Subject: Re-apply r80926, with fixes: keep the domtree informed of new blocks that get created during loop unswitching, and fix SplitBlockPredecessors' LCSSA updating code to create new PHIs instead of trying to just move existing ones. Also, optimize Loop::verifyLoop, since it gets called a lot. Use searches on a sorted list of blocks instead of calling the "contains" function, as is done in other places in the Loop class, since "contains" does a linear search. Also, don't call verifyLoop from LoopSimplify or LCSSA, as the PassManager is already calling verifyLoop as part of LoopInfo's verifyAnalysis. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81221 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/Transforms/Utils/BasicBlockUtils.h | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) (limited to 'include/llvm/Transforms/Utils') diff --git a/include/llvm/Transforms/Utils/BasicBlockUtils.h b/include/llvm/Transforms/Utils/BasicBlockUtils.h index 95ffa46..e766d72 100644 --- a/include/llvm/Transforms/Utils/BasicBlockUtils.h +++ b/include/llvm/Transforms/Utils/BasicBlockUtils.h @@ -126,10 +126,10 @@ bool isCriticalEdge(const TerminatorInst *TI, unsigned SuccNum, /// dest go to one block instead of each going to a different block, but isn't /// the standard definition of a "critical edge". /// -bool SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, Pass *P = 0, - bool MergeIdenticalEdges = false); +BasicBlock *SplitCriticalEdge(TerminatorInst *TI, unsigned SuccNum, + Pass *P = 0, bool MergeIdenticalEdges = false); -inline bool SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) { +inline BasicBlock *SplitCriticalEdge(BasicBlock *BB, succ_iterator SI, Pass *P = 0) { return SplitCriticalEdge(BB->getTerminator(), SI.getSuccessorIndex(), P); } @@ -143,7 +143,7 @@ inline bool SplitCriticalEdge(BasicBlock *Succ, pred_iterator PI, Pass *P = 0) { TerminatorInst *TI = (*PI)->getTerminator(); for (unsigned i = 0, e = TI->getNumSuccessors(); i != e; ++i) if (TI->getSuccessor(i) == Succ) - MadeChange |= SplitCriticalEdge(TI, i, P); + MadeChange |= !!SplitCriticalEdge(TI, i, P); return MadeChange; } @@ -151,8 +151,9 @@ inline bool SplitCriticalEdge(BasicBlock *Succ, pred_iterator PI, Pass *P = 0) { /// and return true, otherwise return false. This method requires that there be /// an edge between the two blocks. If P is specified, it updates the analyses /// described above. -inline bool SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, Pass *P = 0, - bool MergeIdenticalEdges = false) { +inline BasicBlock *SplitCriticalEdge(BasicBlock *Src, BasicBlock *Dst, + Pass *P = 0, + bool MergeIdenticalEdges = false) { TerminatorInst *TI = Src->getTerminator(); unsigned i = 0; while (1) { @@ -180,8 +181,12 @@ BasicBlock *SplitBlock(BasicBlock *Old, Instruction *SplitPt, Pass *P); /// Preds array, which has NumPreds elements in it. The new block is given a /// suffix of 'Suffix'. This function returns the new block. /// -/// This currently updates the LLVM IR, AliasAnalysis, DominatorTree and -/// DominanceFrontier, but no other analyses. +/// 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). +/// BasicBlock *SplitBlockPredecessors(BasicBlock *BB, BasicBlock *const *Preds, unsigned NumPreds, const char *Suffix, Pass *P = 0); -- cgit v1.1