diff --git a/C/alloc.c b/C/alloc.c
index 243d45be1..755364aa1 100644
--- a/C/alloc.c
+++ b/C/alloc.c
@@ -49,8 +49,8 @@ static char SccsId[] = "%W% %G%";
 #include <stdio.h>
 
 #if __simplescalar__
-#ifdef USE_MMAP
-#undef USE_MMAP
+#ifdef USE_SYSTEM_MMAP
+#undef USE_SYSTEM_MMAP
 #endif
 #ifdef USE_SBRK
 #undef USE_SBRK
@@ -900,7 +900,7 @@ Yap_FreeWorkSpace(void)
   return TRUE;
 }
 
-#elif USE_MMAP
+#elif USE_SYSTEM_MMAP
 
 #if HAVE_UNISTD_H
 #include <unistd.h>
@@ -1194,7 +1194,7 @@ Yap_FreeWorkSpace(void)
   return 1;
 }
 
-#elif USE_SHM
+#elif USE_SYSTEM_SHM
 
 #if HAVE_SYS_SHM_H
 #include <sys/shm.h>
@@ -1591,7 +1591,7 @@ void Yap_add_memory_hole(ADDR Start, ADDR End)
 int
 Yap_ExtendWorkSpace(Int s)
 {
-#if USE_MMAP
+#if USE_SYSTEM_MMAP
   return ExtendWorkSpace(s, MAP_FIXED);
 #elif defined(_WIN32)
   return ExtendWorkSpace(s, MAP_FIXED);
@@ -1603,7 +1603,7 @@ Yap_ExtendWorkSpace(Int s)
 UInt
 Yap_ExtendWorkSpaceThroughHole(UInt s)
 {
-#if USE_MMAP || defined(_WIN32) || defined(__CYGWIN__)
+#if USE_SYSTEM_MMAP || defined(_WIN32) || defined(__CYGWIN__)
   MALLOC_T WorkSpaceTop0 = WorkSpaceTop;
 #if SIZEOF_INT_P==4
   while (WorkSpaceTop < (MALLOC_T)0xc0000000L) {
@@ -1650,7 +1650,7 @@ Yap_ExtendWorkSpaceThroughHole(UInt s)
 void
 Yap_AllocHole(UInt actual_request, UInt total_size)
 {
-#if (USE_MMAP || defined(_WIN32) || defined(__CYGWIN__)) && !USE_DL_MALLOC
+#if (USE_SYSTEM_MMAP || defined(_WIN32) || defined(__CYGWIN__)) && !USE_DL_MALLOC
   /* where we were when the hole was created,
    also where is the hole store */
   ADDR WorkSpaceTop0 = WorkSpaceTop-total_size;
diff --git a/H/alloc.h b/H/alloc.h
index e7f41be86..88c405e73 100644
--- a/H/alloc.h
+++ b/H/alloc.h
@@ -100,12 +100,12 @@ void   Yap_InitHeap(void *);
 UInt   Yap_ExtendWorkSpaceThroughHole(UInt);
 void   Yap_AllocHole(UInt, UInt);
 
-#if USE_MMAP && ! defined(__CYGWIN__)
+#if USE_SYSTEM_MMAP && ! defined(__CYGWIN__)
 
 #include <sys/types.h>
 #include <sys/mman.h>
 
-#elif USE_SHM
+#elif USE_SYSTEM_SHM
 
 
 
diff --git a/configure b/configure
index a72d4e887..ebe951427 100755
--- a/configure
+++ b/configure
@@ -4546,7 +4546,7 @@ $as_echo "#define MinStackSpace (1024*SIZEOF_INT_P)" >>confdefs.h
 
 $as_echo "#define MinTrailSpace (256*SIZEOF_INT_P)" >>confdefs.h
 
-if test "$orparallelism" = yes
+if test "$orparallelism" != no
 then
 
 cat >>confdefs.h <<_ACEOF
@@ -7422,7 +7422,12 @@ else
   YAPLIB_CFLAGS="$CFLAGS"
 fi
 
-YAP_EXTRAS="$YAP_EXTRAS -DCOROUTINING=1 -DRATIONAL_TREES=1 -DTABLING=1"
+YAP_EXTRAS="$YAP_EXTRAS -DCOROUTINING=1 -DRATIONAL_TREES=1"
+
+if test "$orparallelism"  = no
+  then
+  YAP_EXTRAS="$YAP_EXTRAS -DTABLING=1"
+fi
 
 if test "$debugyap" = "yes"
   then
@@ -9378,19 +9383,17 @@ $as_echo "#define USE_SYSTEM_SHM 1" >>confdefs.h
       fi
     ;;
 #    a-cow)
-    **)
-      if test "$use_malloc" = "no"
-      then
+  esac
+  if test "$use_malloc" = "no"
+  then
 
 $as_echo "#define USE_DL_MALLOC 1" >>confdefs.h
 
-      else
+  else
 
 $as_echo "#define USE_SYSTEM_MALLOC 1" >>confdefs.h
 
-      fi
-    ;;
-  esac
+  fi
 fi
 
 $as_echo "#define GC_NO_TAGS 1" >>confdefs.h
@@ -12166,7 +12169,7 @@ else
 JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 cat << \EOF > $JAVA_TEST
-/* #line 12169 "configure" */
+/* #line 12172 "configure" */
 public class Test {
 }
 EOF
@@ -12342,7 +12345,7 @@ EOF
 if uudecode$EXEEXT Test.uue; then
         ac_cv_prog_uudecode_base64=yes
 else
-        echo "configure: 12345: uudecode had trouble decoding base 64 file 'Test.uue'" >&5
+        echo "configure: 12348: uudecode had trouble decoding base 64 file 'Test.uue'" >&5
         echo "configure: failed file was:" >&5
         cat Test.uue >&5
         ac_cv_prog_uudecode_base64=no
@@ -12473,7 +12476,7 @@ else
 JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 cat << \EOF > $JAVA_TEST
-/* #line 12476 "configure" */
+/* #line 12479 "configure" */
 public class Test {
 }
 EOF
@@ -12508,7 +12511,7 @@ JAVA_TEST=Test.java
 CLASS_TEST=Test.class
 TEST=Test
 cat << \EOF > $JAVA_TEST
-/* [#]line 12511 "configure" */
+/* [#]line 12514 "configure" */
 public class Test {
 public static void main (String args[]) {
         System.exit (0);
@@ -12893,6 +12896,9 @@ while test $found = no; do
         fi
 done
 
+{ $as_echo "$as_me:${as_lineno-$LINENO}: result: _JTOPDIR=\"$_JTOPDIR\"" >&5
+$as_echo "_JTOPDIR=\"$_JTOPDIR\"" >&6; }
+
 # get the likely subdirectories for system specific java includes
 case "$host_os" in
 bsdi*)          _JNI_INC_SUBDIRS="bsdos";;
diff --git a/configure.in b/configure.in
index 1975eb179..82f532739 100755
--- a/configure.in
+++ b/configure.in
@@ -308,7 +308,7 @@ AC_ARG_WITH(max-threads,
   AC_DEFINE(MinHeapSpace, (2048*SIZEOF_INT_P), [at least 2M Cells for Heap])
   AC_DEFINE(MinStackSpace,(1024*SIZEOF_INT_P), [at least 1M Cells for Stack]) 
   AC_DEFINE(MinTrailSpace,(256*SIZEOF_INT_P), [at least 1/2M Cells for Trail])
-if test "$orparallelism" = yes
+if test "$orparallelism" != no
 then
   AC_DEFINE_UNQUOTED(MAX_WORKERS,$yap_cv_max_workers,[maximum amount of or-parallelism])
   if test "$orparallelism" = copy -o "$orparallelism" = yes
@@ -1108,7 +1108,12 @@ else
   YAPLIB_CFLAGS="$CFLAGS"
 fi
 
-YAP_EXTRAS="$YAP_EXTRAS -DCOROUTINING=1 -DRATIONAL_TREES=1 -DTABLING=1"
+YAP_EXTRAS="$YAP_EXTRAS -DCOROUTINING=1 -DRATIONAL_TREES=1"
+
+if test "$orparallelism"  = no
+  then
+  YAP_EXTRAS="$YAP_EXTRAS -DTABLING=1"
+fi
 
 if test "$debugyap" = "yes"
   then
@@ -1686,15 +1691,13 @@ else
       fi
     ;;
 #    a-cow)
-    **)
-      if test "$use_malloc" = "no"
-      then
-        AC_DEFINE(USE_DL_MALLOC,1,[use Doug Lea's malloc for all allocation])
-      else
-        AC_DEFINE(USE_SYSTEM_MALLOC,1,[use OS malloc for all allocation])
-      fi
-    ;;
   esac
+  if test "$use_malloc" = "no"
+  then
+    AC_DEFINE(USE_DL_MALLOC,1,[use Doug Lea's malloc for all allocation])
+  else
+    AC_DEFINE(USE_SYSTEM_MALLOC,1,[use OS malloc for all allocation])
+  fi
 fi
 AC_DEFINE(GC_NO_TAGS,1,[use Barts idea of allocating extra memory])