From 6155ce3427c9a4107f9d4ebd65026407a5304c85 Mon Sep 17 00:00:00 2001 From: Chris Lattner Date: Sun, 29 Nov 2009 21:09:36 +0000 Subject: [PATCH] Fix a really nasty caching bug I introduced in memdep. An entry was being added to the Result vector, but not being put in the cache. This means that if the cache was reused wholesale for a later query that it would be missing this entry and we'd do an incorrect load elimination. Unfortunately, it's not really possible to write a useful testcase for this, but this unbreaks 255.vortex. llvm-svn: 90093 --- lib/Analysis/MemoryDependenceAnalysis.cpp | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp index b5069ecbc92..49dfeb5d3ff 100644 --- a/lib/Analysis/MemoryDependenceAnalysis.cpp +++ b/lib/Analysis/MemoryDependenceAnalysis.cpp @@ -1156,8 +1156,18 @@ getNonLocalPointerDepFromBB(Value *Pointer, uint64_t PointeeSize, // that predecessor. We can still do PRE of the load, which would insert // a computation of the pointer in this predecessor. if (PredPtr == 0) { - Result.push_back(NonLocalDepEntry(Pred, - MemDepResult::getClobber(Pred->getTerminator()))); + // Add the entry to the Result list. + NonLocalDepEntry Entry(Pred, + MemDepResult::getClobber(Pred->getTerminator())); + Result.push_back(Entry); + + // Add it to the cache for this CacheKey so that subsequent queries get + // this result. + Cache = &NonLocalPointerDeps[CacheKey].second; + MemoryDependenceAnalysis::NonLocalDepInfo::iterator It = + std::upper_bound(Cache->begin(), Cache->end(), Entry); + Cache->insert(It, Entry); + Cache = 0; continue; }