diff options
Diffstat (limited to 'lib/Transforms')
| -rw-r--r-- | lib/Transforms/Utils/LoopSimplify.cpp | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp index e40f1457ae..c5adfd2553 100644 --- a/lib/Transforms/Utils/LoopSimplify.cpp +++ b/lib/Transforms/Utils/LoopSimplify.cpp @@ -192,6 +192,22 @@ void Preheaders::InsertPreheaderForLoop(Loop *L) { // We know that we have loop information to update... update it now. if (Loop *Parent = L->getParentLoop()) Parent->addBasicBlockToLoop(NewBB, getAnalysis<LoopInfo>()); + + // If the header for the loop used to be an exit node for another loop, then + // we need to update this to know that the loop-preheader is now the exit + // node. Note that the only loop that could have our header as an exit node + // is a sibling loop, ie, one with the same parent loop. + const std::vector<Loop*> *ParentSubLoops; + if (Loop *Parent = L->getParentLoop()) + ParentSubLoops = &Parent->getSubLoops(); + else // Must check top-level loops... + ParentSubLoops = &getAnalysis<LoopInfo>().getTopLevelLoops(); + + // Loop over all sibling loops, performing the substitution... + for (unsigned i = 0, e = ParentSubLoops->size(); i != e; ++i) + if ((*ParentSubLoops)[i]->hasExitBlock(Header)) + (*ParentSubLoops)[i]->changeExitBlock(Header, NewBB); + DominatorSet &DS = getAnalysis<DominatorSet>(); // Update dominator info { |