diff options
Diffstat (limited to 'llvm/lib')
| -rw-r--r-- | llvm/lib/Transforms/Utils/MemorySSA.cpp | 16 |
1 files changed, 11 insertions, 5 deletions
diff --git a/llvm/lib/Transforms/Utils/MemorySSA.cpp b/llvm/lib/Transforms/Utils/MemorySSA.cpp index b71c1945a0e..1ce8970c78e 100644 --- a/llvm/lib/Transforms/Utils/MemorySSA.cpp +++ b/llvm/lib/Transforms/Utils/MemorySSA.cpp @@ -763,11 +763,11 @@ struct CachingMemorySSAWalker::UpwardsMemoryQuery { const Instruction *Inst; // Set of visited Instructions for this query. DenseSet<MemoryAccessPair> Visited; - // Set of visited call accesses for this query. This is separated out because - // you can always cache and lookup the result of call queries (IE when IsCall - // == true) for every call in the chain. The calls have no AA location + // Vector of visited call accesses for this query. This is separated out + // because you can always cache and lookup the result of call queries (IE when + // IsCall == true) for every call in the chain. The calls have no AA location // associated with them with them, and thus, no context dependence. - SmallPtrSet<const MemoryAccess *, 32> VisitedCalls; + SmallVector<const MemoryAccess *, 32> VisitedCalls; // The MemoryAccess we actually got called with, used to test local domination const MemoryAccess *OriginalAccess; // The Datalayout for the module we started in @@ -862,7 +862,7 @@ bool CachingMemorySSAWalker::instructionClobbersQuery( // If this is a call, mark it for caching if (ImmutableCallSite(DefMemoryInst)) - Q.VisitedCalls.insert(MD); + Q.VisitedCalls.push_back(MD); ModRefInfo I = AA->getModRefInfo(DefMemoryInst, ImmutableCallSite(Q.Inst)); return I != MRI_NoModRef; } @@ -918,6 +918,8 @@ MemoryAccessPair CachingMemorySSAWalker::UpwardsDFSWalk( break; } + std::size_t InitialVisitedCallSize = Q.VisitedCalls.size(); + // Recurse on PHI nodes, since we need to change locations. // TODO: Allow graphtraits on pairs, which would turn this whole function // into a normal single depth first walk. @@ -947,6 +949,10 @@ MemoryAccessPair CachingMemorySSAWalker::UpwardsDFSWalk( if (!ModifyingAccess) { assert(FirstDef && "Found a Phi with no upward defs?"); ModifyingAccess = FirstDef; + } else { + // If we can't optimize this Phi, then we can't safely cache any of the + // calls we visited when trying to optimize it. Wipe them out now. + Q.VisitedCalls.resize(InitialVisitedCallSize); } break; } |
