HYPRE_COMM_SIMPLE made default on Blue only.

configure.in

@@ -188,18 +188,6 @@ AC_ARG_WITH(MPI, [\
   casc_using_mpi=yes
 )
 
-AC_ARG_WITH(COMM_SIMPLE, [\
-  --without-MPI           do not use MPI],
-  if test "$withval" = "no"
-  then
-    CFLAGS="$CFLAGS"
-  else
-    CFLAGS="$CFLAGS -DHYPRE_COMM_SIMPLE"
-  fi,
-    CFLAGS="$CFLAGS -DHYPRE_COMM_SIMPLE"
-)
-
-
 
 AC_ARG_WITH(dmalloc, [\
   --with-dmalloc          use dmalloc package],
@@ -454,6 +442,18 @@ then
 
    rs6000)
 
+   AC_ARG_WITH(COMM_SIMPLE, [\
+   --without-COMM_SIMPLE           use MPI derived data types],
+   if test "$withval" = "no"
+   then
+     CFLAGS="$CFLAGS"
+   else
+     CFLAGS="$CFLAGS -DHYPRE_COMM_SIMPLE"
+   fi,
+     CFLAGS="$CFLAGS -DHYPRE_COMM_SIMPLE"
+)
+
+
      if test "$casc_user_chose_compilers" = "no"
      then
        if test "$casc_using_mpi" = "no"