[sanitizer] speed up the bitvector-based deadlock detector by ~15% (iterate over the currently held locks using the array, not the bitvector. Bitvector is not the best data structure to iterate over)

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@205168 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 8 deletions

diff --git a/lib/sanitizer_common/sanitizer_bvgraph.h b/lib/sanitizer_common/sanitizer_bvgraph.h
index 9a547d3d4..df72f1c2d 100644
--- a/lib/sanitizer_common/sanitizer_bvgraph.h
+++ b/lib/sanitizer_common/sanitizer_bvgraph.h
@@ -61,18 +61,12 @@ class BVGraph {
   }
 
   // *EXPERIMENTAL*
-  // Returns true if all edges from=>to exist.
+  // Returns true if an edge from=>to exist.
   // This function does not use any global state except for 'this' itself,
   // and thus can be called from different threads w/o locking.
   // This would be racy.
   // FIXME: investigate how much we can prove about this race being "benign".
-  bool hasAllEdges(const BV &from, uptr to) {
-    for (typename BV::Iterator it(from); it.hasNext(); ) {
-      uptr idx = it.next();
-      if (!v[idx].getBit(to)) return false;
-    }
-    return true;
-  }
+  bool hasEdge(uptr from, uptr to) { return v[from].getBit(to); }
 
   // Returns true if the edge from=>to was removed.
   bool removeEdge(uptr from, uptr to) {