/* ----------------------------------------------------------------------------
- * $Id: Constants.h,v 1.18 2001/10/03 13:57:42 simonmar Exp $
+ * $Id: Constants.h,v 1.26 2004/08/13 13:09:13 simonmar Exp $
*
- * (c) The GHC Team, 1998-1999
+ * (c) The GHC Team, 1998-2002
*
* Constants
*
/* -----------------------------------------------------------------------------
Minimum closure sizes
- Here We define the minimum size for updatable closures. This must be at
+ Here we define the minimum size for updatable closures. This must be at
least 2, to allow for cons cells and linked indirections. All updates
will be performed on closures of this size. For non-updatable closures
the minimum size is 1 to allow for a forwarding pointer.
Constants to do with specialised closure types.
-------------------------------------------------------------------------- */
-/* We have some pre-compiled selector thunks defined in
- * StgSelectors.hc in the runtime system. This constant defines the
- * highest selectee index that we can replace with a reference to the
- * pre-compiled code.
+/* We have some pre-compiled selector thunks defined in rts/StgStdThunks.hc.
+ * This constant defines the highest selectee index that we can replace with a
+ * reference to the pre-compiled code.
*/
#define MAX_SPEC_SELECTEE_SIZE 15
* space.
*/
-#define MAX_SPEC_AP_SIZE 8
+#define MAX_SPEC_AP_SIZE 7
/* Specialised FUN/THUNK/CONSTR closure types */
#define MAX_SPEC_FUN_SIZE 2
#define MAX_SPEC_CONSTR_SIZE 2
+/* Range of built-in table of static small int-like and char-like closures.
+ *
+ * NB. This corresponds with the number of actual INTLIKE/CHARLIKE
+ * closures defined in rts/StgMiscClosures.cmm.
+ */
+#define MAX_INTLIKE 16
+#define MIN_INTLIKE (-16)
+
+#define MAX_CHARLIKE 255
+#define MIN_CHARLIKE 0
+
/* -----------------------------------------------------------------------------
STG Registers.
#define MAX_VANILLA_REG 8
#define MAX_FLOAT_REG 4
#define MAX_DOUBLE_REG 2
-/* register is only used for returning (unboxed) 64-bit vals */
#define MAX_LONG_REG 1
-/*---- Maximum number of constructors in a data type for direct-returns. */
+/* -----------------------------------------------------------------------------
+ * Maximum number of constructors in a data type for direct-returns.
+ *
+ * NB. There are various places that assume the value of this
+ * constant, such as the polymorphic return frames for updates
+ * (stg_upd_frame_info) and catch frames (stg_catch_frame_info).
+ * -------------------------------------------------------------------------- */
#define MAX_VECTORED_RTN 8
-/*---- Range of built-in table of static small int-like and char-like closures. */
-
-#define MAX_INTLIKE 16
-#define MIN_INTLIKE (-16)
-
-#define MAX_CHARLIKE 255
-#define MIN_CHARLIKE 0
-
-/* You can change these constants (I hope) but be sure to modify
- rts/StgMiscClosures.hs accordingly. */
-
-/*---- Minimum number of words left in heap after GC to carry on */
-
-#define HEAP_HWM_WORDS 1024
-
/* -----------------------------------------------------------------------------
Semi-Tagging constants
/* -----------------------------------------------------------------------------
How much C stack to reserve for local temporaries when in the STG
- world. Used in StgRun.S and StgCRun.c.
+ world. Used in StgCRun.c.
-------------------------------------------------------------------------- */
#define RESERVED_C_STACK_BYTES (2048 * SIZEOF_LONG)
This must be large enough to accomodate the largest stack frame
pushed in one of the heap check fragments in HeapStackCheck.hc
- (ie. currently the generic heap checks - 19 words).
+ (ie. currently the generic heap checks - 3 words for StgRetDyn,
+ 18 words for the saved registers, see StgMacros.h).
+
+ In the event of an unboxed tuple or let-no-escape stack/heap check
+ failure, there will be other words on the stack which are covered
+ by the RET_DYN frame. These will have been accounted for by stack
+ checks however, so we don't need to allow for them here.
-------------------------------------------------------------------------- */
-#define RESERVED_STACK_WORDS 19
+#define RESERVED_STACK_WORDS 21
/* -----------------------------------------------------------------------------
Storage manager constants
/* The size of a megablock (2^MBLOCK_SHIFT bytes) */
#define MBLOCK_SHIFT 20
-/* 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.
+/* -----------------------------------------------------------------------------
+ Bitmap/size fields (used in info tables)
+ -------------------------------------------------------------------------- */
+
+/* In a 32-bit bitmap field, we use 5 bits for the size, and 27 bits
+ * for the bitmap. If the bitmap requires more than 27 bits, then we
+ * store it in a separate array, and leave a pointer in the bitmap
+ * field. On a 64-bit machine, the sizes are extended accordingly.
*/
-#define LARGE_OBJECT_THRESHOLD ((nat)(BLOCK_SIZE * 8 / 10))
+#if SIZEOF_VOID_P == 4
+#define BITMAP_SIZE_MASK 0x1f
+#define BITMAP_BITS_SHIFT 5
+#elif SIZEOF_VOID_P == 8
+#define BITMAP_SIZE_MASK 0x3f
+#define BITMAP_BITS_SHIFT 6
+#else
+#error unknown SIZEOF_VOID_P
+#endif
-#endif /* CONSTANTS_H */
+/* -----------------------------------------------------------------------------
+ Lag/Drag/Void constants
+ -------------------------------------------------------------------------- */
+
+/*
+ An LDV word is divided into 3 parts: state bits (LDV_STATE_MASK), creation
+ time bits (LDV_CREATE_MASK), and last use time bits (LDV_LAST_MASK).
+ */
+#if SIZEOF_VOID_P == 8
+#define LDV_SHIFT 30
+#define LDV_STATE_MASK 0x1000000000000000
+#define LDV_CREATE_MASK 0x0FFFFFFFC0000000
+#define LDV_LAST_MASK 0x000000003FFFFFFF
+#define LDV_STATE_CREATE 0x0000000000000000
+#define LDV_STATE_USE 0x1000000000000000
+#else
+#define LDV_SHIFT 15
+#define LDV_STATE_MASK 0x40000000
+#define LDV_CREATE_MASK 0x3FFF8000
+#define LDV_LAST_MASK 0x00007FFF
+#define LDV_STATE_CREATE 0x00000000
+#define LDV_STATE_USE 0x40000000
+#endif // SIZEOF_VOID_P
+
+/* -----------------------------------------------------------------------------
+ TSO related constants
+ -------------------------------------------------------------------------- */
+
+/*
+ * Constants for the what_next field of a TSO, which indicates how it
+ * is to be run.
+ */
+#define ThreadRunGHC 1 /* return to address on top of stack */
+#define ThreadInterpret 2 /* interpret this thread */
+#define ThreadKilled 3 /* thread has died, don't run it */
+#define ThreadRelocated 4 /* thread has moved, link points to new locn */
+#define ThreadComplete 5 /* thread has finished */
+
+/*
+ * Constants for the why_blocked field of a TSO
+ */
+#define NotBlocked 0
+#define BlockedOnMVar 1
+#define BlockedOnBlackHole 2
+#define BlockedOnException 3
+#define BlockedOnRead 4
+#define BlockedOnWrite 5
+#define BlockedOnDelay 6
+
+/* Win32 only: */
+#define BlockedOnDoProc 7
+
+/* Only relevant for PAR: */
+ /* blocked on a remote closure represented by a Global Address: */
+#define BlockedOnGA 8
+ /* same as above but without sending a Fetch message */
+#define BlockedOnGA_NoSend 9
+/* Only relevant for RTS_SUPPORTS_THREADS: */
+#define BlockedOnCCall 10
+#define BlockedOnCCall_NoUnblockExc 11
+ /* same as above but don't unblock async exceptions in resumeThread() */
+
+/*
+ * These constants are returned to the scheduler by a thread that has
+ * stopped for one reason or another. See typedef StgThreadReturnCode
+ * in TSO.h.
+ */
+#define HeapOverflow 1 /* might also be StackOverflow */
+#define StackOverflow 2
+#define ThreadYielding 3
+#define ThreadBlocked 4
+#define ThreadFinished 5
+
+/* -----------------------------------------------------------------------------
+ RET_DYN stack frames
+ -------------------------------------------------------------------------- */
+/* VERY MAGIC CONSTANTS!
+ * must agree with code in HeapStackCheck.c, stg_gen_chk, and
+ * RESERVED_STACK_WORDS in Constants.h.
+ */
+#define RET_DYN_BITMAP_SIZE 8
+#define RET_DYN_NONPTR_REGS_SIZE 10
+
+/* Sanity check that RESERVED_STACK_WORDS is reasonable. We can't
+ * just derive RESERVED_STACK_WORDS because it's used in Haskell code
+ * too.
+ */
+#if RESERVED_STACK_WORDS != (3 + RET_DYN_BITMAP_SIZE + RET_DYN_NONPTR_REGS_SIZE)
+#error RESERVED_STACK_WORDS may be wrong!
+#endif
+
+#endif /* CONSTANTS_H */
projects / ghc-hetmet.git / blobdiff