diff --git a/H/findclause.h b/H/findclause.h
index b8600b307..2b5eefa45 100644
--- a/H/findclause.h
+++ b/H/findclause.h
@@ -630,75 +630,75 @@
       cl = NEXTOP(cl,xi);
       break;
     case _p_atom_x:
+      if (cl->u.xl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_atom+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,xl);
+      break;
+    case _p_atomic_x:
       if (cl->u.xl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,xl);
-      break;
-    case _p_atomic_x:
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_atomic+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,xl);
+      break;
+    case _p_compound_x:
       if (cl->u.xl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,xl);
-      break;
-    case _p_compound_x:
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_compound+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,xl);
+      break;
+    case _p_db_ref_x:
       if (cl->u.xl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,xl);
-      break;
-    case _p_db_ref_x:
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = AbsAppl((CELL *)FunctorDBRef);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,xl);
+      break;
+    case _p_float_x:
       if (cl->u.xl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,xl);
-      break;
-    case _p_float_x:
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = AbsAppl((CELL *)FunctorDouble);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.xl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,xl);
       break;
     case _p_integer_x:
+      if (cl->u.xl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_integer+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.xl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,xl);
       break;
     case _p_nonvar_x:
@@ -709,39 +709,39 @@
       cl = NEXTOP(cl,xl);
       break;
     case _p_number_x:
+      if (cl->u.xl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_number+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,xl);
+      break;
+    case _p_primitive_x:
       if (cl->u.xl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,xl);
-      break;
-    case _p_primitive_x:
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_primitive+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.xl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,xl);
       break;
     case _p_var_x:
+      if (cl->u.xl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.xl.x)) {
 	clause->Tag = (_var+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.xl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,xl);
       break;
     case _get_x_val:
@@ -1011,75 +1011,75 @@
       cl = NEXTOP(cl,y);
       break;
     case _p_atom_y:
+      if (cl->u.yl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_atom+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,yl);
+      break;
+    case _p_atomic_y:
       if (cl->u.yl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,yl);
-      break;
-    case _p_atomic_y:
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_atomic+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,yl);
+      break;
+    case _p_compound_y:
       if (cl->u.yl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,yl);
-      break;
-    case _p_compound_y:
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_compound+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,yl);
+      break;
+    case _p_db_ref_y:
       if (cl->u.yl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,yl);
-      break;
-    case _p_db_ref_y:
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = AbsAppl((CELL *)FunctorDBRef);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,yl);
+      break;
+    case _p_float_y:
       if (cl->u.yl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,yl);
-      break;
-    case _p_float_y:
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = AbsAppl((CELL *)FunctorDouble);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.yl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,yl);
       break;
     case _p_integer_y:
+      if (cl->u.yl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_integer+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.yl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,yl);
       break;
     case _p_nonvar_y:
@@ -1090,39 +1090,39 @@
       cl = NEXTOP(cl,yl);
       break;
     case _p_number_y:
+      if (cl->u.yl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_number+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
+      cl = NEXTOP(cl,yl);
+      break;
+    case _p_primitive_y:
       if (cl->u.yl.F != FAILCODE) {
 	clause->Tag = (CELL)NULL;
 	return;
       }
-      cl = NEXTOP(cl,yl);
-      break;
-    case _p_primitive_y:
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_primitive+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.yl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,yl);
       break;
     case _p_var_y:
+      if (cl->u.yl.F != FAILCODE) {
+	clause->Tag = (CELL)NULL;
+	return;
+      }
       if (is_regcopy(myregs, nofregs, cl->u.yl.y)) {
 	clause->Tag = (_var+1)*sizeof(CELL);
 	clause->u.t_ptr = (CELL)NULL;
 	return;
       }
-      if (cl->u.yl.F != FAILCODE) {
-	clause->Tag = (CELL)NULL;
-	return;
-      }
       cl = NEXTOP(cl,yl);
       break;
     case _get_y_val:
diff --git a/misc/buildops b/misc/buildops
index db8bcd984..f2ef4069f 100644
--- a/misc/buildops
+++ b/misc/buildops
@@ -760,24 +760,27 @@ clean_statements(["unsigned"|Statements0], StatementsF) :- !,
 	clean_statements(Statements0, StatementsF).
 clean_statements(Statements, Statements).
 
-opinfo("p_number_x",[body,bind("x","(_number+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_number_y",[body,bind("y","(_number+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_atomic_x",[body,bind("x","(_atomic+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_atomic_y",[body,bind("y","(_atomic+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_primitive_x",[body,bind("x","(_primitive+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_primitive_y",[body,bind("y","(_primitive+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_compound_x",[body,bind("x","(_compound+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_compound_y",[body,bind("y","(_compound+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_atom_x",[body,bind("x","(_atom+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_atom_y",[body,bind("y","(_atom+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_integer_x",[body,bind("x","(_integer+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_integer_y",[body,bind("y","(_integer+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_float_x",[body,bind("x","AbsAppl((CELL *)FunctorDouble)",t_ptr=[]),ifthenelse]).
-opinfo("p_float_y",[body,bind("y","AbsAppl((CELL *)FunctorDouble)",t_ptr=[]),ifthenelse]).
-opinfo("p_db_ref_x",[body,bind("x","AbsAppl((CELL *)FunctorDBRef)",t_ptr=[]),ifthenelse]).
-opinfo("p_db_ref_y",[body,bind("y","AbsAppl((CELL *)FunctorDBRef)",t_ptr=[]),ifthenelse]).
-opinfo("p_var_x",[body,bind("x","(_var+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
-opinfo("p_var_y",[body,bind("y","(_var+1)*sizeof(CELL)",t_ptr=[]),ifthenelse]).
+%
+% Notice that order matters: for example ifthenelse should be tested before a bind
+%
+opinfo("p_number_x",[body,ifthenelse,bind("x","(_number+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_number_y",[body,ifthenelse,bind("y","(_number+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_atomic_x",[body,ifthenelse,bind("x","(_atomic+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_atomic_y",[body,ifthenelse,bind("y","(_atomic+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_primitive_x",[body,ifthenelse,bind("x","(_primitive+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_primitive_y",[body,ifthenelse,bind("y","(_primitive+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_compound_x",[body,ifthenelse,bind("x","(_compound+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_compound_y",[body,ifthenelse,bind("y","(_compound+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_atom_x",[body,ifthenelse,bind("x","(_atom+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_atom_y",[body,ifthenelse,bind("y","(_atom+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_integer_x",[body,ifthenelse,bind("x","(_integer+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_integer_y",[body,ifthenelse,bind("y","(_integer+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_float_x",[body,ifthenelse,bind("x","AbsAppl((CELL *)FunctorDouble)",t_ptr=[])]).
+opinfo("p_float_y",[body,ifthenelse,bind("y","AbsAppl((CELL *)FunctorDouble)",t_ptr=[])]).
+opinfo("p_db_ref_x",[body,ifthenelse,bind("x","AbsAppl((CELL *)FunctorDBRef)",t_ptr=[])]).
+opinfo("p_db_ref_y",[body,ifthenelse,bind("y","AbsAppl((CELL *)FunctorDBRef)",t_ptr=[])]).
+opinfo("p_var_x",[body,ifthenelse,bind("x","(_var+1)*sizeof(CELL)",t_ptr=[])]).
+opinfo("p_var_y",[body,ifthenelse,bind("y","(_var+1)*sizeof(CELL)",t_ptr=[])]).
 opinfo("p_nonvar_x",[body,ifthenelse]).
 opinfo("p_nonvar_y",[body,ifthenelse]).
 opinfo("save_b_x",[body,new("x")]).