diff --git a/ghc/includes/MachDeps.h b/ghc/includes/MachDeps.h
index eb8b6d7088d671d2e86bacd3767de11a260ec0d4..48c54e8ac1cf8e085824e61ff31941308f93ff70 100644
--- a/ghc/includes/MachDeps.h
+++ b/ghc/includes/MachDeps.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: MachDeps.h,v 1.3 1999/02/05 16:02:23 simonm Exp $
+ * $Id: MachDeps.h,v 1.4 2000/01/25 14:39:14 panne Exp $
  *
  * (c) The GRASP/AQUA Project, Glasgow University, 1998
  * (c) The GHC Team, 1998-1999
@@ -29,4 +29,38 @@
 #define DOUBLE_SIZE_IN_BYTES	SIZEOF_DOUBLE
 #endif
 
+#define SIZEOF_INT8             SIZEOF_CHAR
+#define ALIGNMENT_INT8          ALIGNMENT_CHAR
+#define SIZEOF_WORD8            SIZEOF_UNSIGNED_CHAR
+#define ALIGNMENT_WORD8         ALIGNMENT_UNSIGNED_CHAR
+
+#define SIZEOF_INT16            SIZEOF_SHORT
+#define ALIGNMENT_INT16         ALIGNMENT_SHORT
+#define SIZEOF_WORD16           SIZEOF_UNSIGNED_SHORT
+#define ALIGNMENT_WORD16        ALIGNMENT_UNSIGNED_SHORT
+
+#if SIZEOF_UNSIGNED_INT == 4
+#define SIZEOF_INT32            ALIGNMENT_INT
+#define ALIGNMENT_INT32         SIZEOF_INT
+#define SIZEOF_WORD32           ALIGNMENT_UNSIGNED_INT
+#define ALIGNMENT_WORD32        SIZEOF_UNSIGNED_INT
+#else
+#error GHC untested on this architecture: sizeof(unsigned int) != 4
+#endif
+
+#if HAVE_LONG_LONG && SIZEOF_VOID_P < 8
+/* assume long long is 64 bits */
+#define SIZEOF_INT64            SIZEOF_LONG_LONG
+#define ALIGNMENT_INT64         ALIGNMENT_LONG_LONG
+#define SIZEOF_WORD64           SIZEOF_UNSIGNED_LONG_LONG
+#define ALIGNMENT_WORD64        ALIGNMENT_UNSIGNED_LONG_LONG
+#elif SIZEOF_LONG == 8
+#define SIZEOF_INT64            SIZEOF_LONG
+#define ALIGNMENT_INT64         ALIGNMENT_LONG
+#define SIZEOF_WORD64           SIZEOF_UNSIGNED_LONG
+#define ALIGNMENT_WORD64        ALIGNMENT_UNSIGNED_LONG
+#else
+#error GHC untested on this architecture: sizeof(void *) < 8 and no long longs.
+#endif
+
 #endif