Fix a bug in non-local memdep that was causing an infinite loop on 175.vpr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40495 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryDependenceAnalysis.cpp b/lib/Analysis/MemoryDependenceAnalysis.cpp
index ae26c26..e260b27 100644
--- a/lib/Analysis/MemoryDependenceAnalysis.cpp
+++ b/lib/Analysis/MemoryDependenceAnalysis.cpp
@@ -103,7 +103,8 @@
bool MemoryDependenceAnalysis::nonLocalHelper(Instruction* query,
BasicBlock* block,
- DenseMap<BasicBlock*, Value*>& resp) {
+ DenseMap<BasicBlock*, Value*>& resp,
+ SmallPtrSet<BasicBlock*, 4>& visited) {
if (resp.count(block))
return resp[block] != None;
@@ -113,10 +114,15 @@
return true;
}
+ visited.insert(block);
+
bool inserted = false;
for (pred_iterator PI = pred_begin(block), PE = pred_end(block);
PI != PE; ++PI)
- inserted |= nonLocalHelper(query, *PI, resp);
+ if (!visited.count(*PI))
+ inserted |= nonLocalHelper(query, *PI, resp, visited);
+
+ visited.erase(block);
if (!inserted)
resp.insert(std::make_pair(block, None));
@@ -133,11 +139,14 @@
}
bool inserted = false;
+ SmallPtrSet<BasicBlock*, 4> visited;
+ visited.insert(query->getParent());
BasicBlock* parent = query->getParent();
for (pred_iterator PI = pred_begin(parent), PE = pred_end(parent);
PI != PE; ++PI) {
- inserted |= nonLocalHelper(query, *PI, resp);
+ if (!visited.count(*PI))
+ inserted |= nonLocalHelper(query, *PI, resp, visited);
}
if (!inserted)