From 6b4d578f5464b5e217311c2696958f4002b5b03c Mon Sep 17 00:00:00 2001 From: Andrew Trick Date: Fri, 18 Nov 2011 03:42:41 +0000 Subject: Fix a corner case in updating LoopInfo after fully unrolling an outer loop. The loop tree's inclusive block lists are painful and expensive to update. (I have no idea why they're inclusive). The design was supposed to handle this case but the implementation missed it and my unit tests weren't thorough enough. Fixes PR11335: loop unroll update. llvm-svn: 144970 --- llvm/lib/Analysis/LoopInfo.cpp | 20 +++++++++----------- 1 file changed, 9 insertions(+), 11 deletions(-) (limited to 'llvm/lib/Analysis/LoopInfo.cpp') diff --git a/llvm/lib/Analysis/LoopInfo.cpp b/llvm/lib/Analysis/LoopInfo.cpp index 85aaccaefc3..c7833bf7bb6 100644 --- a/llvm/lib/Analysis/LoopInfo.cpp +++ b/llvm/lib/Analysis/LoopInfo.cpp @@ -477,21 +477,19 @@ void UnloopUpdater::updateBlockParents() { /// removeBlocksFromAncestors - Remove unloop's blocks from all ancestors below /// their new parents. void UnloopUpdater::removeBlocksFromAncestors() { - // Remove unloop's blocks from all ancestors below their new parents. + // Remove all unloop's blocks (including those in nested subloops) from + // ancestors below the new parent loop. for (Loop::block_iterator BI = Unloop->block_begin(), BE = Unloop->block_end(); BI != BE; ++BI) { - Loop *NewParent = LI->getLoopFor(*BI); - // If this block is an immediate subloop, remove all blocks (including - // nested subloops) from ancestors below the new parent loop. - // Otherwise, if this block is in a nested subloop, skip it. - if (SubloopParents.count(NewParent)) - NewParent = SubloopParents[NewParent]; - else if (Unloop->contains(NewParent)) - continue; - + Loop *OuterParent = LI->getLoopFor(*BI); + if (Unloop->contains(OuterParent)) { + while (OuterParent->getParentLoop() != Unloop) + OuterParent = OuterParent->getParentLoop(); + OuterParent = SubloopParents[OuterParent]; + } // Remove blocks from former Ancestors except Unloop itself which will be // deleted. - for (Loop *OldParent = Unloop->getParentLoop(); OldParent != NewParent; + for (Loop *OldParent = Unloop->getParentLoop(); OldParent != OuterParent; OldParent = OldParent->getParentLoop()) { assert(OldParent && "new loop is not an ancestor of the original"); OldParent->removeBlockFromLoop(*BI); -- cgit v1.2.3