fix an overly conservative caching issue that caused memdep to
cache a pointer as being unavailable due to phi trans in the
wrong place. This would cause later queries to fail even when
they didn't involve phi trans.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@91787 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index a0c7706..743420b 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -894,36 +894,12 @@
PredPtrVal);
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);
-
- if (It != Cache->begin() && (It-1)->getBB() == Pred)
- --It;
-
- if (It == Cache->end() || It->getBB() != Pred) {
- Cache->insert(It, Entry);
- // Add it to the reverse map.
- ReverseNonLocalPtrDeps[Pred->getTerminator()].insert(CacheKey);
- } else if (!It->getResult().isDirty()) {
- // noop
- } else if (It->getResult().getInst() == Pred->getTerminator()) {
- // Same instruction, clear the dirty marker.
- It->setResult(Entry.getResult(), PredPtrVal);
- } else if (It->getResult().getInst() == 0) {
- // Dirty, with no instruction, just add this.
- It->setResult(Entry.getResult(), PredPtrVal);
- ReverseNonLocalPtrDeps[Pred->getTerminator()].insert(CacheKey);
- } else {
- // Otherwise, dirty with a different instruction.
- RemoveFromReverseMap(ReverseNonLocalPtrDeps,
- It->getResult().getInst(), CacheKey);
- It->setResult(Entry.getResult(),PredPtrVal);
- ReverseNonLocalPtrDeps[Pred->getTerminator()].insert(CacheKey);
- }
- Cache = 0;
+ // Since we had a phi translation failure, the cache for CacheKey won't
+ // include all of the entries that we need to immediately satisfy future
+ // queries. Mark this in NonLocalPointerDeps by setting the
+ // BBSkipFirstBlockPair pointer to null. This requires reuse of the
+ // cached value to do more work but not miss the phi trans failure.
+ NonLocalPointerDeps[CacheKey].first = BBSkipFirstBlockPair();
continue;
}
@@ -961,10 +937,10 @@
NumSortedEntries = Cache->size();
}
- // Since we did phi translation, the "Cache" set won't contain all of the
+ // Since we failed phi translation, the "Cache" set won't contain all of the
// results for the query. This is ok (we can still use it to accelerate
// specific block queries) but we can't do the fastpath "return all
- // results from the set" Clear out the indicator for this.
+ // results from the set". Clear out the indicator for this.
CacheInfo->first = BBSkipFirstBlockPair();
// If *nothing* works, mark the pointer as being clobbered by the first