+++ /dev/null
-%
-% (c) The GRASP/AQUA Project, Glasgow University, 1992-1994
-%
-%************************************************************************
-%* *
-\section{How data is handled, especially floats and doubles}
-%* *
-%************************************************************************
-
-\begin{code}
-#ifndef STGTYPES_H
-#define STGTYPES_H
-\end{code}
-
-Some variables (eg the A stack, the stack pointers, floating point
-registers) can only contain data of a particular (machine type).
-
-%partain:\begin{center}
-\begin{tabular}{|l|l|}
-\hline
-What we call it & The C type which represents it \\ \hline
- & \\
-StgInt & long \\
-StgFloat & float \\
-StgDouble & double \\
-StgChar & unsigned char \\\hline
-StgStablePtr & long \\
-StgForeignObj & (long *) \\
-\end{tabular}
-%partain:\end{center}
-
-Others, notably the heap itself and the B stack, can contain various
-kinds of data; pointers, floats, doubles, chars and so on. These
-structures are given C type @StgWord@, meaning ``I don't know''.
-
-%partain:\begin{center}
-\begin{tabular}{|l|l|}
-\hline
-StgWord & long \\\hline
-\end{tabular}
-%partain:\end{center}
-
-% @StgWord@s only live in {\em memory locations}; there are no registers
-% of type @StgWord@.
-
-When we load/store things in the heap, or on the B stack, we therefore
-have to coerce data in and out of the @StgWord@ type. For @StgInt@
-and @StgChar@ that's no problem; we just use a C cast.
-
-Now here's the rub: we can't cast a @StgFloat@ to @StgWord@ because C
-performs numeric conversions if you do! Worse, we obviously can't
-cast a @StgDouble@ to @StgWord@, because it's the wrong size. The
-solution we adopt is to provide functions/macros with the following
-prototypes
-
-\begin{pseudocode}
- StgFloat PK_FLT( StgWord * )
- void ASSIGN_FLT( StgWord [], StgFloat )
-
- StgDouble PK_DBL( StgWord * )
- void ASSIGN_DBL( StgWord [], StgDouble )
-\end{pseudocode}
-
-The @PK@ functions create a suitable float/double given a pointer to
-some @StgWord@ memory locations; the @ASSIGN@ functions do the
-reverse. Notice that it is a private matter between @PK_DBL@ and
-@ASSIGN_DBL@ how the words are acutally used to store the double (the
-high word could go in the upper or lower memory location).
-
-We implement these operations as inlined C functions; much
-better than macros because they need a local variable which
-macros don't give you. There is probably more than one way
-to implement them; we have cheated the type system using a
-union type.
-
-\begin{code}
-typedef unsigned long StgWord; /* used for heap- and Bstk- words,
- which can be of various types */
-
-/* macro to round a number-of-bytes up to a sufficient number of words: */
-#define BYTES_TO_STGWORDS(no_bytes) (((no_bytes)+sizeof(W_)-1)/sizeof(W_))
-
-typedef unsigned long *StgPtr; /* StgPtr is a ptr to a heap object
- or into the B stack */
-typedef StgPtr *StgPtrPtr; /* used for A stack pointer */
-typedef long StgInt;
-
-#if HAVE_LONG_LONG
-/* These types are only used to allow the passing of
- 64-bit ints from Haskell to ccalls and to ease
- the implementation of the Int64 and Word64 libraries.
-*/
-typedef unsigned long long int StgWord64;
-typedef long long int StgInt64;
-typedef StgInt64 LI_;
-typedef StgWord64 LW_;
-#endif
-
-typedef unsigned char StgChar;
-typedef void *StgAddr;
-
-#if alpha_TARGET_ARCH
-typedef double StgFloat;
-typedef double StgDouble;
-#else
-typedef float StgFloat;
-typedef double StgDouble;
-#endif
-
-/* seven shorthand forms:
- StgChar, StgWord, StgPtr, StgPtrPtr, StgInt, StgAddr, const StgPtr */
-
-typedef StgChar C_;
-typedef StgWord W_;
-typedef StgPtr P_;
-typedef P_ *PP_;
-typedef StgInt I_;
-typedef void *A_;
-typedef const unsigned long *D_;
-
-/* Typedefs for the various sized ints
- (ToDo: better.)
-*/
-
-typedef unsigned char StgWord8;
-typedef signed char StgInt8;
-typedef unsigned short StgWord16;
-typedef short StgInt16;
-typedef unsigned int StgWord32;
-typedef signed int StgInt32;
-
-
-typedef StgPtr StgArray;
-typedef StgChar *StgByteArray;
-typedef StgByteArray B_;
-
-typedef I_ StgStablePtr; /* Index into Stable Pointer Table */
-typedef P_ StgForeignObj; /* (Probably) Pointer to object in C Heap */
-/* On any architecture, StgForeignObj should be big enough to hold
- the largest possible pointer. */
-
-/* These are used to pass the do_full_collection flag to RealPerformGC
- and collectHeap. (Is there a standard name for them?)
- [ADR]
-
- Why longs? --JSM
- No good reason (bad reason: same as StgInt) -- ADR
- An abomination! Death to StgBool! --JSM
-*/
-#define StgFalse 0
-#define StgTrue 1
-typedef long StgBool;
-
-typedef long StgTag;
-
-typedef StgWord StgInfoEntry;
-typedef StgWord *StgInfoPtr;
-
-\end{code}
-
-Types for the generated C functions
- take no arguments
- return a pointer to the next function to be called
- use: Ptr to Fun that returns a Ptr to Fun which returns Ptr to void
-
-\begin{code}
-typedef void *(*(*StgFunPtr)(STG_NO_ARGS))(STG_NO_ARGS);
-
-typedef StgFunPtr (StgFun)(STG_NO_ARGS);
-typedef StgFunPtr sfp; /* shorthand, for less typing while debugging */
-
-typedef StgFunPtr (*StgFunPtrFunPtr)(STG_NO_ARGS);
-
-typedef StgFunPtr F_;
-typedef StgFunPtrFunPtr *FP_;
-
-typedef D_ StgRetAddr; /* for now ... */
-#if 0
-typedef union {
- StgFunPtr d; /* direct return */
- D_ v; /* vectored return */
-} StgRetAddr;
-#endif
-
-/* new union type, to eventually replace StgWord */
-typedef union word {
- B_ b; /* pointer to byte array */
- W_ c; /* (unsigned) character; *not* StgChar type */
- D_ d; /* read-only data pointer */
- StgFloat f; /* single-precision float */
- StgFunPtr fp; /* function (code) pointer */
- I_ i; /* integer */
- P_ p; /* basic pointer */
- StgRetAddr r; /* return address or vector */
- W_ w; /* arbitrary word (needed?) */
- void *v; /* ??? (AddrKind) */
-} StgUnion;
-
-
-/*
- If a BitWord is anything other than an StgWord, you may have some problems.
- In particular, be sure that the dynamic allocation of a BitWord array from the
- heap is done properly.
- */
-typedef StgWord BitWord; /* Bit marking words */
-
-/* Stuff for hashing */
-typedef StgWord hash_t;
-
-#define UNHASHED (~0L)
-
-/* ullong (64|128-bit) type: only include if needed (not ANSI) */
-#if defined(__GNUC__)
-typedef unsigned long long ullong; /* need prototypes */
-#define LL(x) CAT2(x,LL)
-#else
-typedef unsigned long ullong;
-#define LL(x) CAT2(x,L)
-#endif
-\end{code}
-
-Stuff for packed shorts; used in @StgMacros.h@.
-
-\begin{code}
-typedef struct __uw
- { unsigned short s1;
- unsigned short s2;
- } unpacked_word;
-
-typedef union __ps
- { unsigned int u;
- unpacked_word wu;
- } packed_shorts;
-\end{code}
-
-Stuff for floats/doubles; used in @StgMacros.h@.
-ToDo: looks pretty 64-bit unfriendly to me! [WDP]
-
-\begin{code}
-typedef struct __ud
- { StgWord dhi;
- StgWord dlo;
- } unpacked_double;
-
-typedef union __dt
- { StgDouble d;
- unpacked_double du;
- } double_thing;
-
-typedef StgWord unpacked_float;
-
-typedef union __ft
- { StgFloat f;
- unpacked_float fu;
- } float_thing;
-
-#if HAVE_LONG_LONG
-typedef union __it
- { StgInt64 i;
- unpacked_double iu;
- } int64_thing;
-
-typedef union __wt
- { StgWord64 w;
- unpacked_double wu;
- } word64_thing;
-#endif
-
-\end{code}
-
-Also include the RTS types for the runtime system modules.
-
-\begin{code}
-
-#include "RtsTypes.h"
-
-#endif /* ! STGTYPES_H */
-\end{code}
projects / ghc-hetmet.git / blobdiff