diff --git a/bolt/runtime/common.h b/bolt/runtime/common.h
--- a/bolt/runtime/common.h
+++ b/bolt/runtime/common.h
@@ -475,7 +475,7 @@
 public:
   bool acquire() {
     bool Result = true;
-    asm volatile("lock; xchg %0, %1" : "+m"(InUse), "=r"(Result) : : "cc");
+    asm volatile("lock; xchg %0, %1" : "+m"(InUse), "+r"(Result) : : "cc");
     return !Result;
   }
   void release() { InUse = false; }
diff --git a/bolt/runtime/instr.cpp b/bolt/runtime/instr.cpp
--- a/bolt/runtime/instr.cpp
+++ b/bolt/runtime/instr.cpp
@@ -289,6 +289,7 @@
   /// Traverses all elements in the table
   template <typename... Args>
   void forEachElement(void (*Callback)(MapEntry &, Args...), Args... args) {
+    Lock L(M);
     if (!TableRoot)
       return;
     return forEachElement(Callback, InitialSize, TableRoot, args...);
@@ -378,7 +379,6 @@
 
 template <typename T, uint32_t X, uint32_t Y>
 void SimpleHashTable<T, X, Y>::resetCounters() {
-  Lock L(M);
   forEachElement(resetIndCallCounter);
 }