diff --git a/packages/prism/src/c/core/bpx.c b/packages/prism/src/c/core/bpx.c
index eaa5bcf5c..e0eea2f00 100644
--- a/packages/prism/src/c/core/bpx.c
+++ b/packages/prism/src/c/core/bpx.c
@@ -127,10 +127,12 @@ bool bpx_is_identical(TERM t1, TERM t2)
 
 TERM bpx_get_call_arg(BPLONG i, BPLONG arity)
 {
-    if (i < 1 || i > arity) {
-        bpx_raise("index out of range");
-    }
-    return ARG(i, arity);
+  CACHE_REGS
+
+  if (i < 1 || i > arity) {
+    bpx_raise("index out of range");
+  }
+  return ARG(i, arity);
 }
 
 BPLONG bpx_get_integer(TERM t)
@@ -245,6 +247,7 @@ TERM bpx_get_cdr(TERM t)
 
 TERM bpx_build_var(void)
 {
+  CACHE_REGS
     TERM term;
 
     REQUIRE_HEAP(1);
@@ -260,6 +263,7 @@ TERM bpx_build_integer(BPLONG n)
 
 TERM bpx_build_float(double x)
 {
+  CACHE_REGS
     REQUIRE_HEAP(4);
     return encodefloat1(x);
 }
@@ -274,6 +278,7 @@ TERM bpx_build_atom(const char *name)
 
 TERM bpx_build_list(void)
 {
+  CACHE_REGS
     TERM term;
 
     REQUIRE_HEAP(2);
@@ -290,6 +295,7 @@ TERM bpx_build_nil(void)
 
 TERM bpx_build_structure(const char *name, BPLONG arity)
 {
+  CACHE_REGS
     SYM_REC_PTR sym;
     TERM term;
 
@@ -314,6 +320,7 @@ bool bpx_unify(TERM t1, TERM t2)
 
 TERM bpx_string_2_term(const char *s)
 {
+  CACHE_REGS
     TERM term, vars;
     int  result;
 
diff --git a/packages/prism/src/c/core/bpx.h b/packages/prism/src/c/core/bpx.h
index 451841425..f15f36704 100644
--- a/packages/prism/src/c/core/bpx.h
+++ b/packages/prism/src/c/core/bpx.h
@@ -80,6 +80,27 @@ long int XTAG(TERM t)
   }
 }
 
+extern inline TERM ADDTAG(void * t,int tag);
+extern inline int is_UNIFIABLE(TERM t1, TERM t2);
+extern inline int is_IDENTICAL(TERM t1, TERM t2);
+extern inline char *bp_term_2_string(TERM t);
+extern inline int bp_string_2_term(const char *s, TERM to, TERM tv);
+extern inline SYM_REC_PTR insert(const char *name, int size, int arity);
+extern inline int compare(TERM t1, TERM t2);
+extern inline void write_term(TERM t);
+extern inline void numberVarTermOpt(TERM t);
+extern inline TERM unnumberVarTerm(TERM t, BPLONG_PTR pt1, BPLONG_PTR pt2);
+extern inline int unifyNumberedTerms(TERM t1, TERM t2);
+
+int bpx_call_term(TERM t);
+int bpx_call_string(const char *s);
+int bpx_call_string(const char *s);
+int bpx_mount_query_string(const char *s);
+int bpx_next_solution(void);
+void bpx_write(TERM t);
+int bpx_printf(const char *fmt, ...);
+
+
 extern inline TERM ADDTAG(void * t,int tag) {
   if (tag == ATM) 
     return MkAtomTerm((Atom)t);
@@ -210,13 +231,13 @@ list_length(BPLONG t1, BPLONG t2)
 
 #define PRE_NUMBER_VAR(X) 
 
-static inline void
+extern inline void
 numberVarTermOpt(TERM t)
 {
   YAP_NumberVars(t, 0);
 }
 
-static inline TERM
+extern inline TERM
 unnumberVarTerm(TERM t, BPLONG_PTR pt1, BPLONG_PTR pt2)
 {
   return YAP_UnNumberVars(t);
diff --git a/packages/prism/src/c/core/idtable.c b/packages/prism/src/c/core/idtable.c
index ed1bac53f..f9cb9acdd 100644
--- a/packages/prism/src/c/core/idtable.c
+++ b/packages/prism/src/c/core/idtable.c
@@ -170,6 +170,7 @@ int id_table_count(const ID_TABLE *this)
 
 TERM unnumber_var_term(TERM term)
 {
+  CACHE_REGS
     BPLONG mvn = -1;
     return unnumberVarTerm(term, local_top, &mvn);
 }
diff --git a/packages/prism/src/c/core/idtable_preds.c b/packages/prism/src/c/core/idtable_preds.c
index 8f0c1e802..9d364d2f5 100644
--- a/packages/prism/src/c/core/idtable_preds.c
+++ b/packages/prism/src/c/core/idtable_preds.c
@@ -15,6 +15,38 @@ char * bp_term_2_string(TERM);
 /* unify.c */
 int    unify(TERM, TERM);
 
+int prism_goal_id_register(TERM term);
+int prism_sw_id_register(TERM term);
+int prism_sw_ins_id_register(TERM term);
+int prism_goal_id_get(TERM term);
+int prism_sw_id_get(TERM term);
+int prism_sw_ins_id_get(TERM term);
+int prism_goal_count(void);
+int prism_sw_count(void);
+int prism_sw_ins_count(void);
+TERM prism_goal_term(IDNUM i);
+TERM prism_sw_term(IDNUM i);
+TERM prism_sw_ins_term(IDNUM i);
+char * prism_goal_string(IDNUM i);
+char * prism_sw_string(IDNUM i);
+char * prism_sw_ins_string(IDNUM i);
+char * copy_prism_goal_string(IDNUM i);
+char * copy_prism_sw_string(IDNUM i);
+char * copy_prism_sw_ins_string(IDNUM i);
+int pc_prism_id_table_init_0(void);
+int pc_prism_goal_id_register_2(void);
+int pc_prism_sw_id_register_2(void);
+int pc_prism_sw_ins_id_register_2(void);
+int pc_prism_goal_id_get_2(void);
+int pc_prism_sw_id_get_2(void);
+int pc_prism_sw_ins_id_get_2(void);
+int pc_prism_goal_count_1(void);
+int pc_prism_sw_count_1(void);
+int pc_prism_sw_ins_count_1(void);
+int pc_prism_goal_term_2(void);
+int pc_prism_sw_term_2(void);
+int pc_prism_sw_ins_term_2(void);
+
 /*--------------------------------------------------------------------*/
 
 int prism_goal_id_register(TERM term)
@@ -125,6 +157,7 @@ int pc_prism_id_table_init_0(void)
 
 int pc_prism_goal_id_register_2(void)
 {
+  CACHE_REGS
     TERM term;
     IDNUM id;
 
@@ -137,6 +170,7 @@ int pc_prism_goal_id_register_2(void)
 
 int pc_prism_sw_id_register_2(void)
 {
+  CACHE_REGS
     TERM term;
     IDNUM id;
 
@@ -149,6 +183,7 @@ int pc_prism_sw_id_register_2(void)
 
 int pc_prism_sw_ins_id_register_2(void)
 {
+  CACHE_REGS
     TERM term;
     IDNUM id;
 
@@ -161,6 +196,7 @@ int pc_prism_sw_ins_id_register_2(void)
 
 int pc_prism_goal_id_get_2(void)
 {
+  CACHE_REGS
     TERM term;
     IDNUM id;
 
@@ -175,6 +211,7 @@ int pc_prism_goal_id_get_2(void)
 
 int pc_prism_sw_id_get_2(void)
 {
+  CACHE_REGS
     TERM term;
     IDNUM id;
 
@@ -188,6 +225,7 @@ int pc_prism_sw_id_get_2(void)
 
 int pc_prism_sw_ins_id_get_2(void)
 {
+  CACHE_REGS
     TERM term;
     IDNUM id;
 
@@ -201,21 +239,25 @@ int pc_prism_sw_ins_id_get_2(void)
 
 int pc_prism_goal_count_1(void)
 {
+  CACHE_REGS
     return unify(MAKEINT(prism_goal_count()), ARG(1,1));
 }
 
 int pc_prism_sw_count_1(void)
 {
+  CACHE_REGS
     return unify(MAKEINT(prism_sw_count()), ARG(1,1));
 }
 
 int pc_prism_sw_ins_count_1(void)
 {
+  CACHE_REGS
     return unify(MAKEINT(prism_sw_ins_count()), ARG(1,1));
 }
 
 int pc_prism_goal_term_2(void)
 {
+  CACHE_REGS
     TERM id, term;
 
     id = ARG(1,2);
@@ -227,6 +269,7 @@ int pc_prism_goal_term_2(void)
 
 int pc_prism_sw_term_2(void)
 {
+  CACHE_REGS
     TERM id, term;
 
     id = ARG(1,2);
@@ -239,6 +282,7 @@ int pc_prism_sw_term_2(void)
 
 int pc_prism_sw_ins_term_2(void)
 {
+  CACHE_REGS
     TERM id, term;
 
     id = ARG(1,2);
diff --git a/packages/prism/src/c/core/random.c b/packages/prism/src/c/core/random.c
index 97c30f232..43cca4e81 100644
--- a/packages/prism/src/c/core/random.c
+++ b/packages/prism/src/c/core/random.c
@@ -247,18 +247,21 @@ double random_gaussian(void)
 
 int pc_random_auto_seed_1(void)
 {
+  CACHE_REGS
     BPLONG seed = (BPLONG)(time(NULL));
     return bpx_unify(ARG(1,1), bpx_build_integer(seed));
 }
 
 int pc_random_init_by_seed_1(void)
 {
+  CACHE_REGS
     init_genrand((unsigned long)(bpx_get_integer(ARG(1,1))));
     return BP_TRUE;
 }
 
 int pc_random_init_by_list_1(void)
 {
+  CACHE_REGS
     unsigned long *seed;
     TERM t, u;
 
@@ -278,16 +281,19 @@ int pc_random_init_by_list_1(void)
 
 int pc_random_float_1(void)
 {
+  CACHE_REGS
     return bpx_unify(ARG(1,1), bpx_build_float(random_float()));
 }
 
 int pc_random_gaussian_1(void)
 {
+  CACHE_REGS
     return bpx_unify(ARG(1,1), bpx_build_float(random_gaussian(0.0,1.0)));
 }
 
 int pc_random_int_2(void)
 {
+  CACHE_REGS
     int n_max = bpx_get_integer(ARG(1,2));
     int n_out = random_int(n_max);
     return bpx_unify(ARG(2,2), bpx_build_integer((BPLONG)(n_out)));
@@ -295,6 +301,7 @@ int pc_random_int_2(void)
 
 int pc_random_int_3(void)
 {
+  CACHE_REGS
     int n_min = bpx_get_integer(ARG(1,3));
     int n_max = bpx_get_integer(ARG(2,3));
     int n_out = random_int(n_max - n_min + 1) + n_min;
@@ -305,6 +312,7 @@ int pc_random_int_3(void)
 
 int pc_random_get_state_1(void)
 {
+  CACHE_REGS
     int  i, j;
     TERM t, u;
     unsigned long temp;
@@ -333,6 +341,7 @@ int pc_random_get_state_1(void)
 
 int pc_random_set_state_1(void)
 {
+  CACHE_REGS
     int  i, j;
     TERM term;
     unsigned long temp;
diff --git a/packages/prism/src/c/core/termpool.c b/packages/prism/src/c/core/termpool.c
index 565ef17ed..45a803193 100644
--- a/packages/prism/src/c/core/termpool.c
+++ b/packages/prism/src/c/core/termpool.c
@@ -62,6 +62,7 @@ static ptrdiff_t trail_pos0 = 0;
 
 static void number_vars(TERM term)
 {
+  CACHE_REGS
     assert(trail_pos0 == 0);
 
     trail_pos0 = trail_up_addr - trail_top;
@@ -75,6 +76,7 @@ static void number_vars(TERM term)
 
 static void revert_vars(void)
 {
+  CACHE_REGS
     BPLONG_PTR trail_top0;
 
     assert(trail_pos0 != 0);
@@ -90,6 +92,7 @@ static void revert_vars(void)
  */
 static BPULONG prism_hash_value(TERM term)
 {
+  CACHE_REGS
     TERM    t, *rest;
     BPLONG  i, n;
     SYM_REC_PTR sym;
diff --git a/packages/prism/src/c/up/graph.c b/packages/prism/src/c/up/graph.c
index 385e25cc4..c64d048ee 100644
--- a/packages/prism/src/c/up/graph.c
+++ b/packages/prism/src/c/up/graph.c
@@ -770,6 +770,7 @@ int pc_get_snode_expectation_2(void)
 
 int pc_import_occ_switches_3(void)
 {
+  CACHE_REGS
     TERM p_sw_list,p_sw_list0,p_sw_list1;
     TERM p_sw_ins_list0,p_sw_ins_list1,sw,sw_ins;
     TERM p_num_sw, p_num_sw_ins;