/* -----------------------------------------------------------------------------
- * $Id: MBlock.h,v 1.15 2002/10/21 11:38:54 simonmar Exp $
+ * $Id: MBlock.h,v 1.18 2003/08/29 16:00:29 simonmar Exp $
*
* (c) The GHC Team, 1998-1999
*
constant comparison).
-------------------------------------------------------------------------- */
-#if SIZEOF_VOID_P == 4
-
-// This is the table. Each byte is non-zero if the appropriate MBlock
-// in the address space contains heap.
extern StgWord8 mblock_map[];
-#define HEAP_ALLOCED(p) \
- ((int)(mblock_map[((StgWord)(p) & ~MBLOCK_MASK) >> MBLOCK_SHIFT]))
-
-#else // SIZEOF_VOID_P != 4
+#if SIZEOF_VOID_P == 4
+/* On a 32-bit machine a 4KB table is always sufficient */
+# define MBLOCK_MAP_SIZE 4096
+# define MBLOCK_MAP_ENTRY(p) ((StgWord)(p) >> MBLOCK_SHIFT)
+# define HEAP_ALLOCED(p) mblock_map[MBLOCK_MAP_ENTRY(p)]
+# define MARK_HEAP_ALLOCED(p) (mblock_map[MBLOCK_MAP_ENTRY(p)] = 1)
+
+#elif defined(ia64_TARGET_ARCH)
+/* Instead of trying to cover the whole 64-bit address space (which would
+ * require a better data structure), we assume that mmap allocates mappings
+ * from the bottom of region 1, and track some portion of address space from
+ * there upwards (currently 4GB). */
+# define MBLOCK_MAP_SIZE 4096
+# define MBLOCK_MAP_ENTRY(p) (((StgWord)(p) - (1UL << 61)) >> MBLOCK_SHIFT)
+# define HEAP_ALLOCED(p) ((MBLOCK_MAP_ENTRY(p) < MBLOCK_MAP_SIZE) \
+ && mblock_map[MBLOCK_MAP_ENTRY(p)])
+# 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)
-// on a 64-bit machine, we need to extend the above scheme to use a
-// 2-level mapping. (ToDo)
-#ifdef TEXT_BEFORE_HEAP
-# define HEAP_ALLOCED(x) ((StgPtr)(x) >= (StgPtr)(HEAP_BASE))
#else
-#error HEAP_ALLOCED not defined
+# error HEAP_ALLOCED not defined
#endif
-#endif // SIZEOF_VOID_P != 4
-
#endif // __MBLOCK_H__