/* -----------------------------------------------------------------------------
- * $Id: MBlock.h,v 1.17 2003/07/30 10:38:42 simonmar Exp $
+ * $Id: MBlock.h,v 1.18 2003/08/29 16:00:29 simonmar Exp $
*
* (c) The GHC Team, 1998-1999
*
# define MARK_HEAP_ALLOCED(p) ((MBLOCK_MAP_ENTRY(p) < MBLOCK_MAP_SIZE) \
&& (mblock_map[MBLOCK_MAP_ENTRY(p)] = 1))
+#elif defined(x86_64_TARGET_ARCH)
+/* XXX: This is a HACK, and will not work in general! We just use the
+ * lower 32 bits of the address, and do the same as for the 32-bit
+ * version. As long as the OS gives us memory in a roughly linear
+ * fashion, it won't go wrong until we've allocated 4G. */
+# define MBLOCK_MAP_SIZE 4096
+# define MBLOCK_MAP_ENTRY(p) (((StgWord)(p) & 0xffffffff) >> MBLOCK_SHIFT)
+# define HEAP_ALLOCED(p) (mblock_map[MBLOCK_MAP_ENTRY(p)])
+# define MARK_HEAP_ALLOCED(p) (mblock_map[MBLOCK_MAP_ENTRY(p)] = 1)
+
+
#else
# error HEAP_ALLOCED not defined
#endif