+#include <sys/types.h>
+
+#if defined(LISP_FEATURE_SB_THREAD)
+#include <pthread.h>
+typedef pthread_t os_thread_t;
+#else
+typedef pid_t os_thread_t;
+#endif
+
+/* FIXME: we do things this way because of the alpha32 port. once
+ alpha64 has arrived, all this nastiness can go away */
+#if 64 == N_WORD_BITS
+#define LOW_WORD(c) ((pointer_sized_uint_t)c)
+typedef unsigned long lispobj;
+#else
+#define LOW_WORD(c) ((long)(c) & 0xFFFFFFFFL)
+/* fake it on alpha32 */
+typedef unsigned int lispobj;
+#endif