--- /dev/null
+/* ----------------------------------------------------------------------------
+ *
+ * (c) The GHC Team, 1998-2002
+ *
+ * Constants
+ *
+ * NOTE: this information is used by both the compiler and the RTS.
+ * Some of it is tweakable, and some of it must be kept up to date
+ * with various other parts of the system.
+ *
+ * Constants which are derived automatically from other definitions in
+ * the system (eg. structure sizes) are generated into the file
+ * DerivedConstants.h by a C program (mkDerivedConstantsHdr).
+ *
+ * -------------------------------------------------------------------------- */
+
+#ifndef RTS_CONSTANTS_H
+#define RTS_CONSTANTS_H
+
+/* -----------------------------------------------------------------------------
+ Minimum closure sizes
+
+ This is the minimum number of words in the payload of a
+ heap-allocated closure, so that the closure has enough room to be
+ overwritten with a forwarding pointer during garbage collection.
+ -------------------------------------------------------------------------- */
+
+#define MIN_PAYLOAD_SIZE 1
+
+/* -----------------------------------------------------------------------------
+ Constants to do with specialised closure types.
+ -------------------------------------------------------------------------- */
+
+/* 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
+
+/* Vector-apply thunks. These thunks just push their free variables
+ * on the stack and enter the first one. They're a bit like PAPs, but
+ * don't have a dynamic size. We've pre-compiled a few to save
+ * space.
+ */
+
+#define MAX_SPEC_AP_SIZE 7
+
+/* Specialised FUN/THUNK/CONSTR closure types */
+
+#define MAX_SPEC_THUNK_SIZE 2
+#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.
+
+ Note that in MachRegs.h we define how many of these registers are
+ *real* machine registers, and not just offsets in the Register Table.
+ -------------------------------------------------------------------------- */
+
+#define MAX_VANILLA_REG 8
+#define MAX_FLOAT_REG 4
+#define MAX_DOUBLE_REG 2
+#define MAX_LONG_REG 1
+
+/* -----------------------------------------------------------------------------
+ Semi-Tagging constants
+
+ Old Comments about this stuff:
+
+ Tags for indirection nodes and ``other'' (probably unevaluated) nodes;
+ normal-form values of algebraic data types will have tags 0, 1, ...
+
+ @INFO_IND_TAG@ is different from @INFO_OTHER_TAG@ just so we can count
+ how often we bang into indirection nodes; that's all. (WDP 95/11)
+
+ ToDo: find out if we need any of this.
+ -------------------------------------------------------------------------- */
+
+#define INFO_OTHER_TAG (-1)
+#define INFO_IND_TAG (-2)
+#define INFO_FIRST_TAG 0
+
+/* -----------------------------------------------------------------------------
+ How much C stack to reserve for local temporaries when in the STG
+ world. Used in StgCRun.c.
+ -------------------------------------------------------------------------- */
+
+#define RESERVED_C_STACK_BYTES (2048 * SIZEOF_LONG)
+
+/* -----------------------------------------------------------------------------
+ How much Haskell stack space to reserve for the saving of registers
+ etc. in the case of a stack/heap overflow.
+
+ 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 - 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 21
+
+/* -----------------------------------------------------------------------------
+ The limit on the size of the stack check performed when we enter an
+ AP_STACK, in words. See raiseAsync() and bug #1466.
+ -------------------------------------------------------------------------- */
+
+#define AP_STACK_SPLIM 1024
+
+/* -----------------------------------------------------------------------------
+ Storage manager constants
+ -------------------------------------------------------------------------- */
+
+/* The size of a block (2^BLOCK_SHIFT bytes) */
+#define BLOCK_SHIFT 12
+
+/* The size of a megablock (2^MBLOCK_SHIFT bytes) */
+#define MBLOCK_SHIFT 20
+
+/* -----------------------------------------------------------------------------
+ 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.
+ */
+#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
+
+/* -----------------------------------------------------------------------------
+ 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
+ * NB. keep these in sync with GHC/Conc.lhs: threadStatus
+ */
+#define NotBlocked 0
+#define BlockedOnMVar 1
+#define BlockedOnBlackHole 2
+#define BlockedOnException 3
+#define BlockedOnRead 4
+#define BlockedOnWrite 5
+#define BlockedOnDelay 6
+#define BlockedOnSTM 7
+
+/* Win32 only: */
+#define BlockedOnDoProc 8
+
+/* Only relevant for PAR: */
+ /* blocked on a remote closure represented by a Global Address: */
+#define BlockedOnGA 9
+ /* same as above but without sending a Fetch message */
+#define BlockedOnGA_NoSend 10
+/* Only relevant for THREADED_RTS: */
+#define BlockedOnCCall 11
+#define BlockedOnCCall_NoUnblockExc 12
+ /* 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
+
+/*
+ * Flags for the tso->flags field.
+ *
+ * The TSO_DIRTY flag indicates that this TSO's stack should be
+ * scanned during garbage collection. The link field of a TSO is
+ * always scanned, so we don't have to dirty a TSO just for linking
+ * it on a different list.
+ *
+ * TSO_DIRTY is set by
+ * - schedule(), just before running a thread,
+ * - raiseAsync(), because it modifies a thread's stack
+ * - resumeThread(), just before running the thread again
+ * and unset by the garbage collector (only).
+ */
+#define TSO_DIRTY 1
+
+/*
+ * TSO_LOCKED is set when a TSO is locked to a particular Capability.
+ */
+#define TSO_LOCKED 2
+
+/*
+ * TSO_BLOCKEX: the TSO is blocking exceptions
+ *
+ * TSO_INTERRUPTIBLE: the TSO can be interrupted if it blocks
+ * interruptibly (eg. with BlockedOnMVar).
+ *
+ * TSO_STOPPED_ON_BREAKPOINT: the thread is currently stopped in a breakpoint
+ */
+#define TSO_BLOCKEX 4
+#define TSO_INTERRUPTIBLE 8
+#define TSO_STOPPED_ON_BREAKPOINT 16
+
+/*
+ * TSO_LINK_DIRTY is set when a TSO's link field is modified
+ */
+#define TSO_LINK_DIRTY 32
+
+#define TSO_MARKED 64
+
+/* -----------------------------------------------------------------------------
+ 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 /* RTS_CONSTANTS_H */
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