diff --git a/src/force.cpp b/src/force.cpp
index 2691cb3fd8..ed27df1215 100644
--- a/src/force.cpp
+++ b/src/force.cpp
@@ -80,7 +80,11 @@ Force::Force(LAMMPS *lmp) : Pointers(lmp)
   strcpy(kspace_style,str);
 
   pair_restart = NULL;
+  create_factories();
+}
 
+void _noopt Force::create_factories()
+{
   // fill pair map with pair styles listed in style_pair.h
 
   pair_map = new PairCreatorMap();
diff --git a/src/force.h b/src/force.h
index 2b4298d049..227b9427c0 100644
--- a/src/force.h
+++ b/src/force.h
@@ -143,6 +143,7 @@ class Force : protected Pointers {
   bigint memory_usage();
 
  private:
+  void create_factories();
   template <typename T> static Pair *pair_creator(LAMMPS *);
   template <typename T> static Bond *bond_creator(LAMMPS *);
   template <typename T> static Angle *angle_creator(LAMMPS *);
diff --git a/src/lammps.cpp b/src/lammps.cpp
index 780327c0d9..f8d04c9323 100644
--- a/src/lammps.cpp
+++ b/src/lammps.cpp
@@ -53,12 +53,6 @@
 #include "memory.h"
 #include "error.h"
 
-#if defined(__GNUC__) && !defined(__clang__) && !defined(__INTEL_COMPILER)
-#if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 4))
-#pragma GCC optimize ("no-var-tracking-assignments")
-#endif
-#endif
-
 #include "lmpinstalledpkgs.h"
 #include "lmpgitversion.h"
 
@@ -902,7 +896,7 @@ void LAMMPS::destroy()
    initialize lists of styles in packages
 ------------------------------------------------------------------------- */
 
-void LAMMPS::init_pkg_lists()
+void _noopt LAMMPS::init_pkg_lists()
 {
   pkg_lists = new package_styles_lists;
 #define PACKAGE "UNKNOWN"
@@ -1002,7 +996,7 @@ void LAMMPS::init_pkg_lists()
 #include "packages_region.h"
 #undef RegionStyle
 #undef REGION_CLASS
-} 
+}
 
 bool LAMMPS::is_installed_pkg(const char *pkg) 
 {
@@ -1045,7 +1039,7 @@ const char *LAMMPS::match_style(const char *style, const char *name)
    help message for command line options and styles present in executable
 ------------------------------------------------------------------------- */
 
-void LAMMPS::help()
+void _noopt LAMMPS::help()
 {
   FILE *fp = screen;
   const char *pager = NULL;
diff --git a/src/lmptype.h b/src/lmptype.h
index 4743a38837..20d29880ed 100644
--- a/src/lmptype.h
+++ b/src/lmptype.h
@@ -179,6 +179,9 @@ typedef int bigint;
 #ifdef _noalias
 #undef _noalias
 #endif
+#ifdef _noopt
+#undef _noopt
+#endif
 
 // define stack variable alignment
 
@@ -200,6 +203,23 @@ typedef int bigint;
 #define _noalias
 #endif
 
+// declaration to turn off optimization for specific functions
+// and avoid compiler warnings about variable tracking
+
+#if defined(__clang__)
+#  define _noopt __attribute__((optnone))
+#elif defined(__INTEL_COMPILER)
+#  define _noopt
+#elif defined(__GNUC__)
+#  if (__GNUC__ > 4) || ((__GNUC__ == 4) && (__GNUC_MINOR__ >= 4))
+#    define _noopt __attribute__((optimize("O0","no-var-tracking-assignments")))
+#  else
+#    define _noopt __attribute__((optimize("O0")))
+#  endif
+#else
+#  define _noopt
+#endif
+
 // settings to enable LAMMPS to build under Windows
 
 #ifdef _WIN32
diff --git a/src/modify.cpp b/src/modify.cpp
index 69cdb424b2..3f034bf034 100644
--- a/src/modify.cpp
+++ b/src/modify.cpp
@@ -81,6 +81,11 @@ Modify::Modify(LAMMPS *lmp) : Pointers(lmp)
   ncompute = maxcompute = 0;
   compute = NULL;
 
+  create_factories();
+}
+
+void _noopt Modify::create_factories()
+{
   // fill map with fixes listed in style_fix.h
 
   fix_map = new FixCreatorMap();
diff --git a/src/modify.h b/src/modify.h
index 537ff81543..5ff81855fe 100644
--- a/src/modify.h
+++ b/src/modify.h
@@ -172,6 +172,7 @@ class Modify : protected Pointers {
   FixCreatorMap *fix_map;
 
  protected:
+  void create_factories();
   template <typename T> static Compute *compute_creator(LAMMPS *, int, char **);
   template <typename T> static Fix *fix_creator(LAMMPS *, int, char **);
 };