/* ----------------------------------------------------------------------------
- * $Id: InfoTables.h,v 1.20 2001/03/02 16:12:18 simonmar Exp $
+ * $Id: InfoTables.h,v 1.35 2004/11/08 12:26:55 simonmar Exp $
*
- * (c) The GHC Team, 1998-1999
+ * (c) The GHC Team, 1998-2002
*
* Info Tables
*
Profiling info
-------------------------------------------------------------------------- */
-#ifdef PROFILING
-
typedef struct {
char *closure_type;
char *closure_desc;
} StgProfInfo;
-#else /* !PROFILING */
-
-typedef struct {
- /* empty */
-} StgProfInfo;
-
-#endif /* PROFILING */
-
/* -----------------------------------------------------------------------------
Parallelism info
-------------------------------------------------------------------------- */
StgInfoTable *rbh_infoptr; /* infoptr to the RBH */
} StgParInfo;
-#else /* !PAR */
-
-typedef struct {
- /* empty */
-} StgParInfo;
-
-#endif /* PAR */
+#endif /* 0 */
/*
Copied from ghc-0.29; ToDo: check this code -- HWL
#endif
/* -----------------------------------------------------------------------------
+ Ticky info
+
+ There is no ticky-specific stuff in an info table at this time.
+ -------------------------------------------------------------------------- */
+
+/* -----------------------------------------------------------------------------
Debugging info
-------------------------------------------------------------------------- */
#else /* !DEBUG_CLOSURE */
-typedef struct {
- /* empty */
-} StgDebugInfo;
+// There is no DEBUG-specific stuff in an info table at this time.
#endif /* DEBUG_CLOSURE */
+/* -----------------------------------------------------------------------------
+ Closure flags
+ -------------------------------------------------------------------------- */
+
/* The type flags provide quick access to certain properties of a closure. */
#define _HNF (1<<0) /* head normal form? */
#define closure_HNF(c) ( closureFlags(c) & _HNF)
#define closure_BITMAP(c) ( closureFlags(c) & _BTM)
+#define closure_NON_SPARK(c) ( (closureFlags(c) & _NS))
#define closure_SHOULD_SPARK(c) (!(closureFlags(c) & _NS))
#define closure_STATIC(c) ( closureFlags(c) & _STA)
#define closure_THUNK(c) ( closureFlags(c) & _THU)
#define ip_IND(ip) ( ipFlags(ip) & _IND)
/* -----------------------------------------------------------------------------
- Info Tables
+ Bitmaps
+
+ These are used to describe the pointerhood of a sequence of words
+ (usually on the stack) to the garbage collector. The two primary
+ uses are for stack frames, and functions (where we need to describe
+ the layout of a PAP to the GC).
+
+ In these bitmaps: 0 == ptr, 1 == non-ptr.
-------------------------------------------------------------------------- */
-/* A large bitmap. Small 32-bit ones live in the info table, but sometimes
- * 32 bits isn't enough and we have to generate a larger one. (sizes
- * differ for 64-bit machines.
- */
+//
+// Small bitmaps: for a small bitmap, we store the size and bitmap in
+// the same word, using the following macros. If the bitmap doesn't
+// fit in a single word, we use a pointer to an StgLargeBitmap below.
+//
+#define MK_SMALL_BITMAP(size,bits) (((bits)<<BITMAP_BITS_SHIFT) | (size))
+#define BITMAP_SIZE(bitmap) ((bitmap) & BITMAP_SIZE_MASK)
+#define BITMAP_BITS(bitmap) ((bitmap) >> BITMAP_BITS_SHIFT)
+
+//
+// A large bitmap.
+//
typedef struct {
StgWord size;
- StgWord bitmap[0];
+ StgWord bitmap[FLEXIBLE_ARRAY];
} StgLargeBitmap;
-/*
- * Stuff describing the closure layout. Well, actually, it might
- * contain the selector index for a THUNK_SELECTOR. If we're on a
- * 64-bit architecture then we can enlarge some of these fields, since
- * the union contains a pointer field.
- */
+/* -----------------------------------------------------------------------------
+ SRTs (Static Reference Tables)
+
+ These tables are used to keep track of the static objects referred
+ to by the code for a closure or stack frame, so that we can follow
+ static data references from code and thus accurately
+ garbage-collect CAFs.
+ -------------------------------------------------------------------------- */
+
+// An SRT is just an array of closure pointers:
+typedef StgClosure* StgSRT[];
+
+// Each info table refers to some subset of the closure pointers in an
+// SRT. It does this using a pair of an StgSRT pointer and a
+// half-word bitmap. If the half-word bitmap isn't large enough, then
+// we fall back to a large SRT, including an unbounded bitmap. If the
+// half-word bitmap is set to all ones (0xffff), then the StgSRT
+// pointer instead points to an StgLargeSRT:
+typedef struct StgLargeSRT_ {
+ StgSRT *srt;
+ StgLargeBitmap l;
+} StgLargeSRT;
+
+/* ----------------------------------------------------------------------------
+ Info Tables
+ ------------------------------------------------------------------------- */
+//
+// Stuff describing the closure layout. Well, actually, it might
+// contain the selector index for a THUNK_SELECTOR. This union is one
+// word long.
+//
typedef union {
- struct {
-#if SIZEOF_VOID_P == 8
- StgWord32 ptrs; /* number of pointers */
- StgWord32 nptrs; /* number of non-pointers */
+ struct { // Heap closure payload layout:
+ StgHalfWord ptrs; // number of pointers
+ StgHalfWord nptrs; // number of non-pointers
+ } payload;
+
+ StgWord bitmap; // word-sized bit pattern describing
+ // a stack frame: see below
+
+#ifndef TABLES_NEXT_TO_CODE
+ StgLargeBitmap* large_bitmap; // pointer to large bitmap structure
#else
- StgWord16 ptrs; /* number of pointers */
- StgWord16 nptrs; /* number of non-pointers */
+ StgWord large_bitmap_offset; // offset from info table to large bitmap structure
#endif
- } payload;
+
+ StgWord selector_offset; // used in THUNK_SELECTORs
- StgWord bitmap; /* bit pattern, 1 = pointer, 0 = non-pointer */
- StgWord selector_offset; /* used in THUNK_SELECTORs */
- StgLargeBitmap* large_bitmap; /* pointer to large bitmap structure */
-
} StgClosureInfo;
-/*
- * Info tables. All info tables are the same type, to simplify code
- * generation. However, the mangler removes any unused SRT fields
- * from the asm to save space (convention: if srt_len is zero, or the
- * type is a CONSTR_ type, then the SRT field isn't present.
- */
-
-typedef StgClosure* StgSRT[];
+//
+// The "standard" part of an info table. Every info table has this bit.
+//
typedef struct _StgInfoTable {
- StgSRT *srt; /* pointer to the SRT table */
+
+#ifndef TABLES_NEXT_TO_CODE
+ StgFunPtr entry; // pointer to the entry code
+#endif
+
#if defined(PAR) || defined(GRAN)
struct _StgInfoTable *rbh_infoptr;
#endif
#ifdef PROFILING
StgProfInfo prof;
#endif
+#ifdef TICKY
+ // Ticky-specific stuff would go here.
+#endif
#ifdef DEBUG_CLOSURE
- StgDebugInfo debug;
+ // Debug-specific stuff would go here.
#endif
- StgClosureInfo layout; /* closure layout info (pointer-sized) */
-#if SIZEOF_VOID_P == 8
- StgWord32 type; /* } These 2 elements fit into 64 bits */
- StgWord32 srt_len; /* } */
+
+ StgClosureInfo layout; // closure layout info (one word)
+
+ StgHalfWord type; // closure type
+ StgHalfWord srt_bitmap; // number of entries in SRT (or constructor tag)
+
+#ifdef TABLES_NEXT_TO_CODE
+ StgCode code[FLEXIBLE_ARRAY];
+#endif
+} StgInfoTable;
+
+
+/* -----------------------------------------------------------------------------
+ Function info tables
+
+ This is the general form of function info tables. The compiler
+ will omit some of the fields in common cases:
+
+ - If fun_type is not ARG_GEN or ARG_GEN_BIG, then the slow_apply
+ and bitmap fields may be left out (they are at the end, so omitting
+ them doesn't affect the layout).
+
+ - If srt_bitmap (in the std info table part) is zero, then the srt
+ field may be omitted. This only applies if the slow_apply and
+ bitmap fields have also been omitted.
+ -------------------------------------------------------------------------- */
+
+typedef struct _StgFunInfoExtraRev {
+ StgWord slow_apply_offset; // apply to args on the stack
+ StgWord bitmap; // arg ptr/nonptr bitmap
+ StgWord srt_offset; // pointer to the SRT table
+ StgHalfWord fun_type; // function type
+ StgHalfWord arity; // function arity
+} StgFunInfoExtraRev;
+
+typedef struct _StgFunInfoExtraFwd {
+ StgHalfWord fun_type; // function type
+ StgHalfWord arity; // function arity
+ StgSRT *srt; // pointer to the SRT table
+ StgWord bitmap; // arg ptr/nonptr bitmap
+ StgFun *slow_apply; // apply to args on the stack
+} StgFunInfoExtraFwd;
+
+typedef struct {
+#if defined(TABLES_NEXT_TO_CODE)
+ StgFunInfoExtraRev f;
+ StgInfoTable i;
+#else
+ StgInfoTable i;
+ StgFunInfoExtraFwd f;
+#endif
+} StgFunInfoTable;
+
+/* -----------------------------------------------------------------------------
+ Return info tables
+ -------------------------------------------------------------------------- */
+
+// When info tables are laid out backwards, we can omit the SRT
+// pointer iff srt_bitmap is zero.
+
+typedef struct {
+#if defined(TABLES_NEXT_TO_CODE)
+ StgWord srt_offset; // offset to the SRT table
+ StgInfoTable i;
+#else
+ StgInfoTable i;
+ StgSRT *srt; // pointer to the SRT table
+ StgFunPtr vector[FLEXIBLE_ARRAY];
+#endif
+} StgRetInfoTable;
+
+/* -----------------------------------------------------------------------------
+ Thunk info tables
+ -------------------------------------------------------------------------- */
+
+// When info tables are laid out backwards, we can omit the SRT
+// pointer iff srt_bitmap is zero.
+
+typedef struct _StgThunkInfoTable {
+#if !defined(TABLES_NEXT_TO_CODE)
+ StgInfoTable i;
+#endif
+#if defined(TABLES_NEXT_TO_CODE)
+ StgWord srt_offset; // offset to the SRT table
#else
- StgWord type : 16; /* } These 2 elements fit into 32 bits */
- StgWord srt_len : 16; /* } */
+ StgSRT *srt; // pointer to the SRT table
#endif
+#if defined(TABLES_NEXT_TO_CODE)
+ StgInfoTable i;
+#endif
+} StgThunkInfoTable;
+
+
+/* -----------------------------------------------------------------------------
+ Accessor macros for fields that might be offsets (C version)
+ -------------------------------------------------------------------------- */
+
+// GET_SRT(info)
+// info must be a Stg[Ret|Thunk]InfoTable* (an info table that has a SRT)
#ifdef TABLES_NEXT_TO_CODE
- StgCode code[0];
+#define GET_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->srt_offset))
#else
- StgFunPtr entry;
- StgFunPtr vector[0];
+#define GET_SRT(info) ((info)->srt)
+#endif
+
+// GET_FUN_SRT(info)
+// info must be a StgFunInfoTable*
+#ifdef TABLES_NEXT_TO_CODE
+#define GET_FUN_SRT(info) ((StgSRT*) (((StgWord) ((info)+1)) + (info)->f.srt_offset))
+#else
+#define GET_FUN_SRT(info) ((info)->f.srt)
+#endif
+
+#ifdef TABLES_NEXT_TO_CODE
+#define GET_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
+ + (info)->layout.large_bitmap_offset))
+#else
+#define GET_LARGE_BITMAP(info) ((info)->layout.large_bitmap)
+#endif
+
+#ifdef TABLES_NEXT_TO_CODE
+#define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) (((StgWord) ((info)+1)) \
+ + (info)->f.bitmap))
+#else
+#define GET_FUN_LARGE_BITMAP(info) ((StgLargeBitmap*) ((info)->f.bitmap))
#endif
-} StgInfoTable;
-/* Info tables are read-only, therefore we uniformly declare them with
- * C's const attribute. This isn't just a nice thing to do: it's
- * necessary because the garbage collector has to distinguish between
- * closure pointers and info table pointers when traversing the
- * stack. We distinguish the two by checking whether the pointer is
- * into text-space or not.
- */
-
-#define INFO_TBL_CONST const
#endif /* INFOTABLES_H */
projects / ghc-hetmet.git / blobdiff