diff --git a/hphp/runtime/vm/translator/hopt/codegen.h b/hphp/runtime/vm/translator/hopt/codegen.h
index 0521c043e..bade0ea5d 100644
--- a/hphp/runtime/vm/translator/hopt/codegen.h
+++ b/hphp/runtime/vm/translator/hopt/codegen.h
@@ -21,7 +21,8 @@
 #include "runtime/vm/translator/hopt/ir.h"
 #include "runtime/vm/translator/hopt/irfactory.h"
 #include "runtime/vm/translator/targetcache.h"
-#include <runtime/vm/translator/translator-x64.h>
+#include "runtime/vm/translator/translator-x64.h"
+#include "runtime/vm/translator/hopt/state_vector.h"
 
 namespace HPHP {
 namespace VM {
diff --git a/hphp/runtime/vm/translator/hopt/dce.cpp b/hphp/runtime/vm/translator/hopt/dce.cpp
index c79e4fce4..325fa141c 100644
--- a/hphp/runtime/vm/translator/hopt/dce.cpp
+++ b/hphp/runtime/vm/translator/hopt/dce.cpp
@@ -14,12 +14,14 @@
    +----------------------------------------------------------------------+
 */
 
+#include <boost/range/adaptors.hpp>
+
 #include "util/trace.h"
 #include "runtime/vm/translator/hopt/ir.h"
 #include "runtime/vm/translator/hopt/opt.h"
 #include "runtime/vm/translator/hopt/irfactory.h"
 #include "runtime/vm/translator/hopt/simplifier.h"
-#include <boost/range/adaptors.hpp>
+#include "runtime/vm/translator/hopt/state_vector.h"
 
 namespace HPHP {
 namespace VM {
diff --git a/hphp/runtime/vm/translator/hopt/irfactory.h b/hphp/runtime/vm/translator/hopt/irfactory.h
index 02d36d18a..f09d3cac6 100644
--- a/hphp/runtime/vm/translator/hopt/irfactory.h
+++ b/hphp/runtime/vm/translator/hopt/irfactory.h
@@ -264,72 +264,6 @@ private:
   Arena m_arena;
 };
 
-/*
- * Utility to keep a vector of state about each key, indexed by
- * factoryId(key), where key can be an IRInstruction, Block, or SSATmp.
- */
-template<class Key, class Info>
-struct StateVector {
-  typedef std::vector<Info> InfoVector;
-  typedef typename InfoVector::iterator iterator;
-  typedef typename InfoVector::reference reference;
-  typedef typename InfoVector::const_reference const_reference;
-
-  static unsigned factoryId(const IRInstruction* inst) {
-    return inst->getIId();
-  }
-  static unsigned factoryId(const Block* block) { return block->getId(); }
-  static unsigned factoryId(const SSATmp* tmp) { return tmp->getId(); }
-  static unsigned count(const IRFactory* factory, IRInstruction*) {
-    return factory->numInsts();
-  }
-  static unsigned count(const IRFactory* factory, SSATmp*) {
-    return factory->numTmps();
-  }
-  static unsigned count(const IRFactory* factory, Block*) {
-    return factory->numBlocks();
-  }
-  StateVector(const IRFactory* factory, Info init)
-    : m_factory(factory)
-    , m_info(count(factory, (Key*)nullptr), init)
-    , m_init(init) {
-  }
-  reference operator[](const Key& k) { return (*this)[&k]; }
-  reference operator[](const Key* k) {
-    auto id = factoryId(k);
-    if (id >= m_info.size()) grow();
-    assert(id < m_info.size());
-    return m_info[id];
-  }
-  const_reference operator[](const Key& k) const { return (*this)[&k]; }
-  const_reference operator[](const Key* k) const {
-    assert(factoryId(k) < m_info.size());
-    return m_info[factoryId(k)];
-  }
-  void reset() {
-    for (size_t i = 0, n = m_info.size(); i < n; ++i) {
-      m_info[i] = m_init;
-    }
-    grow();
-  }
-
-  iterator begin() { return m_info.begin(); }
-  iterator end() { return m_info.end(); }
-
-private:
-  void grow() {
-    for (size_t i = m_info.size(), n = count(m_factory, (Key*)nullptr);
-         i < n; ++i) {
-      m_info.push_back(m_init);
-    }
-  }
-
-private:
-  const IRFactory* m_factory;
-  InfoVector m_info;
-  Info m_init;
-};
-
 //////////////////////////////////////////////////////////////////////
 
 }}}
diff --git a/hphp/runtime/vm/translator/hopt/linearscan.cpp b/hphp/runtime/vm/translator/hopt/linearscan.cpp
index d52a9a565..9d21ed8c3 100644
--- a/hphp/runtime/vm/translator/hopt/linearscan.cpp
+++ b/hphp/runtime/vm/translator/hopt/linearscan.cpp
@@ -608,6 +608,7 @@ void LinearScan::insertAllocFreeSpillAux(Trace* trace,
 void LinearScan::collectInfo(BlockList::iterator it, Trace* trace) {
   m_natives.clear();
   m_jmps.reset();
+
   for (auto* block : m_blocks) {
     for (auto& inst : *block) {
       for (auto& dst : inst.getDsts()) {
diff --git a/hphp/runtime/vm/translator/hopt/linearscan.h b/hphp/runtime/vm/translator/hopt/linearscan.h
index a537aa46a..aa75321da 100644
--- a/hphp/runtime/vm/translator/hopt/linearscan.h
+++ b/hphp/runtime/vm/translator/hopt/linearscan.h
@@ -24,6 +24,7 @@
 #include "runtime/vm/translator/hopt/ir.h"
 #include "runtime/vm/translator/hopt/tracebuilder.h"
 #include "runtime/vm/translator/hopt/codegen.h"
+#include "runtime/vm/translator/hopt/state_vector.h"
 
 namespace HPHP { namespace VM { namespace JIT {
 
diff --git a/hphp/runtime/vm/translator/hopt/state_vector.h b/hphp/runtime/vm/translator/hopt/state_vector.h
new file mode 100644
index 000000000..8a653be1d
--- /dev/null
+++ b/hphp/runtime/vm/translator/hopt/state_vector.h
@@ -0,0 +1,108 @@
+/*
+   +----------------------------------------------------------------------+
+   | HipHop for PHP                                                       |
+   +----------------------------------------------------------------------+
+   | Copyright (c) 2010- Facebook, Inc. (http://www.facebook.com)         |
+   +----------------------------------------------------------------------+
+   | This source file is subject to version 3.01 of the PHP license,      |
+   | that is bundled with this package in the file LICENSE, and is        |
+   | available through the world-wide-web at the following url:           |
+   | http://www.php.net/license/3_01.txt                                  |
+   | If you did not receive a copy of the PHP license and are unable to   |
+   | obtain it through the world-wide-web, please send a note to          |
+   | license@php.net so we can mail you a copy immediately.               |
+   +----------------------------------------------------------------------+
+*/
+
+#ifndef incl_HPHP_JIT_STATE_VECTOR_H_
+#define incl_HPHP_JIT_STATE_VECTOR_H_
+
+#include "runtime/base/memory/memory_manager.h"
+
+#include "runtime/vm/translator/hopt/irfactory.h"
+
+namespace HPHP { namespace VM { namespace JIT {
+
+//////////////////////////////////////////////////////////////////////
+
+/*
+ * Utility to keep a vector of state about each key, indexed by
+ * factoryId(key), where key can be an IRInstruction, Block, or SSATmp.
+ *
+ * Takes an `init' element, which everything is defaulted to.  Calls
+ * to reset() restore all entries to this state.
+ */
+template<class Key, class Info>
+struct StateVector {
+  typedef smart::vector<Info> InfoVector;
+  typedef typename InfoVector::iterator iterator;
+  typedef typename InfoVector::const_iterator const_iterator;
+  typedef typename InfoVector::reference reference;
+  typedef typename InfoVector::const_reference const_reference;
+
+  StateVector(const IRFactory* factory, Info init)
+    : m_factory(factory)
+    , m_info(count(factory, (Key*)nullptr), init)
+    , m_init(init) {
+  }
+
+  void reset() {
+    m_info.assign(m_info.size(), m_init);
+    grow();
+  }
+
+  reference operator[](const Key& k) { return (*this)[&k]; }
+  reference operator[](const Key* k) {
+    auto id = factoryId(k);
+    if (id >= m_info.size()) grow();
+    assert(id < m_info.size());
+    return m_info[id];
+  }
+
+  const_reference operator[](const Key& k) const { return (*this)[&k]; }
+  const_reference operator[](const Key* k) const {
+    assert(factoryId(k) < m_info.size());
+    return m_info[factoryId(k)];
+  }
+
+  iterator begin()              { return m_info.begin(); }
+  iterator end()                { return m_info.end(); }
+  const_iterator begin()  const { return m_info.begin(); }
+  const_iterator end()    const { return m_info.end(); }
+  const_iterator cbegin() const { return m_info.cbegin(); }
+  const_iterator cend()   const { return m_info.cend(); }
+
+private:
+  static unsigned factoryId(const IRInstruction* inst) {
+    return inst->getIId();
+  }
+  static unsigned factoryId(const Block* block) { return block->getId(); }
+  static unsigned factoryId(const SSATmp* tmp) { return tmp->getId(); }
+
+  static unsigned count(const IRFactory* factory, IRInstruction*) {
+    return factory->numInsts();
+  }
+  static unsigned count(const IRFactory* factory, SSATmp*) {
+    return factory->numTmps();
+  }
+  static unsigned count(const IRFactory* factory, Block*) {
+    return factory->numBlocks();
+  }
+
+private:
+  void grow() {
+    m_info.resize(count(m_factory, static_cast<Key*>(nullptr)),
+                  m_init);
+  }
+
+private:
+  const IRFactory* m_factory;
+  InfoVector m_info;
+  Info m_init;
+};
+
+//////////////////////////////////////////////////////////////////////
+
+}}}
+
+#endif
diff --git a/hphp/runtime/vm/translator/hopt/tracebuilder.h b/hphp/runtime/vm/translator/hopt/tracebuilder.h
index be7fc9a71..2cf2f5a45 100644
--- a/hphp/runtime/vm/translator/hopt/tracebuilder.h
+++ b/hphp/runtime/vm/translator/hopt/tracebuilder.h
@@ -23,6 +23,7 @@
 #include "runtime/vm/translator/hopt/irfactory.h"
 #include "runtime/vm/translator/hopt/cse.h"
 #include "runtime/vm/translator/hopt/simplifier.h"
+#include "runtime/vm/translator/hopt/state_vector.h"
 
 #include "folly/ScopeGuard.h"