From 6eb7964b7d3b734c73ecfb1cac457c02769a80ff Mon Sep 17 00:00:00 2001 From: Frederic Riss Date: Tue, 11 Nov 2014 21:21:08 +0000 Subject: [PATCH] Totally forget deallocated SDNodes in SDDbgInfo. What would happen before that commit is that the SDDbgValues associated with a deallocated SDNode would be marked Invalidated, but SDDbgInfo would keep a map entry keyed by the SDNode pointer pointing to this list of invalidated SDDbgNodes. As the memory gets reused, the list might get wrongly associated with another new SDNode. As the SDDbgValues are cloned when they are transfered, this can lead to an exponential number of SDDbgValues being produced during DAGCombine like in http://llvm.org/bugs/show_bug.cgi?id=20893 Note that the previous behavior wasn't really buggy as the invalidation made sure that the SDDbgValues won't be used. This commit can be considered a memory optimization and as such is really hard to validate in a unit-test. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@221709 91177308-0d34-0410-b5e6-96231b3b80d8 --- include/llvm/CodeGen/SelectionDAG.h | 4 ++++ lib/CodeGen/SelectionDAG/SelectionDAG.cpp | 16 ++++++++++++---- 2 files changed, 16 insertions(+), 4 deletions(-) diff --git a/include/llvm/CodeGen/SelectionDAG.h b/include/llvm/CodeGen/SelectionDAG.h index ade7e566942..fbdaf0d7fd2 100644 --- a/include/llvm/CodeGen/SelectionDAG.h +++ b/include/llvm/CodeGen/SelectionDAG.h @@ -128,6 +128,10 @@ public: DbgValMap[Node].push_back(V); } + /// \brief Invalidate all DbgValues attached to the node and remove + /// it from the Node-to-DbgValues map. + void erase(const SDNode *Node); + void clear() { DbgValMap.clear(); DbgValues.clear(); diff --git a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp index 7fb7aba00c4..4a83a3f00b5 100644 --- a/lib/CodeGen/SelectionDAG/SelectionDAG.cpp +++ b/lib/CodeGen/SelectionDAG/SelectionDAG.cpp @@ -687,6 +687,15 @@ void SelectionDAG::DeleteNodeNotInCSEMaps(SDNode *N) { DeallocateNode(N); } +void SDDbgInfo::erase(const SDNode *Node) { + DbgValMapType::iterator I = DbgValMap.find(Node); + if (I == DbgValMap.end()) + return; + for (auto &Val: I->second) + Val->setIsInvalidated(); + DbgValMap.erase(I); +} + void SelectionDAG::DeallocateNode(SDNode *N) { if (N->OperandsNeedDelete) delete[] N->OperandList; @@ -697,10 +706,9 @@ void SelectionDAG::DeallocateNode(SDNode *N) { NodeAllocator.Deallocate(AllNodes.remove(N)); - // If any of the SDDbgValue nodes refer to this SDNode, invalidate them. - ArrayRef DbgVals = DbgInfo->getSDDbgValues(N); - for (unsigned i = 0, e = DbgVals.size(); i != e; ++i) - DbgVals[i]->setIsInvalidated(); + // If any of the SDDbgValue nodes refer to this SDNode, invalidate + // them and forget about that node. + DbgInfo->erase(N); } #ifndef NDEBUG -- 2.11.0