[project @ 2003-06-19 10:42:24 by simonmar]

[ghc-hetmet.git] / ghc / includes / Block.h

diff --git a/ghc/includes/Block.h b/ghc/includes/Block.h
index d6bfdfe..867a73c 100644 (file)
--- a/ghc/includes/Block.h
+++ b/ghc/includes/Block.h
@@ -1,5 +1,5 @@
 /* -----------------------------------------------------------------------------
- * $Id: Block.h,v 1.8 2001/07/23 10:47:16 simonmar Exp $
+ * $Id: Block.h,v 1.13 2003/03/28 15:13:52 sof Exp $
  *
  * (c) The GHC Team, 1998-1999
  *
@@ -14,22 +14,29 @@
  * includes/Constants.h, all constants here are derived from these.
  */
 
-/* Block related constants (4k blocks) */
+/* Block related constants (BLOCK_SHIFT is defined in Constants.h) */
 
+#define BLOCK_SIZE   (1<<BLOCK_SHIFT)
 #define BLOCK_SIZE_W (BLOCK_SIZE/sizeof(W_))
 #define BLOCK_MASK   (BLOCK_SIZE-1)
 
 #define BLOCK_ROUND_UP(p)   ((void *) (((W_)(p)+BLOCK_SIZE-1) & ~BLOCK_MASK))
 #define BLOCK_ROUND_DOWN(p) ((void *) ((W_)(p) & ~BLOCK_MASK))
 
-/* Megablock related constants (1M megablocks) */
+/* Megablock related constants (MBLOCK_SHIFT is defined in Constants.h) */
 
+#define MBLOCK_SIZE    (1<<MBLOCK_SHIFT)
 #define MBLOCK_SIZE_W  (MBLOCK_SIZE/sizeof(W_))
 #define MBLOCK_MASK    (MBLOCK_SIZE-1)
 
 #define MBLOCK_ROUND_UP(p)   ((void *)(((W_)(p)+MBLOCK_SIZE-1) & ~MBLOCK_MASK))
 #define MBLOCK_ROUND_DOWN(p) ((void *)((W_)(p) & ~MBLOCK_MASK ))
 
+/* The largest size an object can be before we give it a block of its
+ * own and treat it as an immovable object during GC, expressed as a
+ * fraction of BLOCK_SIZE.
+ */
+#define LARGE_OBJECT_THRESHOLD ((nat)(BLOCK_SIZE * 8 / 10))
 
 /* -----------------------------------------------------------------------------
  * Block descriptor.  This structure *must* be the right length, so we
@@ -44,11 +51,14 @@ typedef struct _bdescr {
   StgPtr start;                        /* start addr of memory */
   StgPtr free;                 /* first free byte of memory */
   struct _bdescr *link;                /* used for chaining blocks together */
-  struct _bdescr *back;                /* used (occasionally) for doubly-linked lists*/
+  union { 
+      struct _bdescr *back;    /* used (occasionally) for doubly-linked lists*/
+      StgWord *bitmap;
+  } u;
   unsigned int gen_no;         /* generation */
   struct _step *step;          /* step */
   StgWord32 blocks;            /* no. of blocks (if grp head, 0 otherwise) */
-  StgWord32 evacuated;           /* block is in to-space */
+  StgWord32 flags;              /* block is in to-space */
 #if SIZEOF_VOID_P == 8
   StgWord32 _padding[2];
 #else
@@ -66,6 +76,9 @@ typedef struct _bdescr {
 #define BDESCR_SHIFT 5
 #endif
 
+#define BF_EVACUATED 1
+#define BF_LARGE     2
+
 /* Finding the block descriptor for a given block -------------------------- */
 
 static inline bdescr *Bdescr(StgPtr p)
@@ -81,7 +94,7 @@ static inline bdescr *Bdescr(StgPtr p)
 /* Offset of first real data block in a megablock */
 
 #define FIRST_BLOCK_OFF \
-   ((W_)BLOCK_ROUND_UP(MBLOCK_SIZE / BLOCK_SIZE * BDESCR_SIZE))
+   ((W_)BLOCK_ROUND_UP(BDESCR_SIZE * (MBLOCK_SIZE / BLOCK_SIZE)))
 
 /* First data block in a given megablock */