-----------------------------------------------------------------------
-- $Id: primops.txt.pp,v 1.37 2005/11/25 09:46:19 simonmar Exp $
--
--- Primitive Operations
+-- Primitive Operations and Types
--
-----------------------------------------------------------------------
{Operations on 31-bit characters.}
------------------------------------------------------------------------
+primtype Char#
primop CharGtOp "gtChar#" Compare Char# -> Char# -> Bool
primop CharGeOp "geChar#" Compare Char# -> Char# -> Bool
{Operations on native-size integers (30+ bits).}
------------------------------------------------------------------------
+primtype Int#
+
primop IntAddOp "+#" Dyadic
Int# -> Int# -> Int#
with commutable = True
If in doubt, return non-zero, but do make an effort to create the
correct answer for small args, since otherwise the performance of
- (*) :: Integer -> Integer -> Integer will be poor.
+ \texttt{(*) :: Integer -> Integer -> Integer} will be poor.
}
with commutable = True
{Operations on native-sized unsigned words (30+ bits).}
------------------------------------------------------------------------
+primtype Word#
+
primop WordAddOp "plusWord#" Dyadic Word# -> Word# -> Word#
with commutable = True
#if WORD_SIZE_IN_BITS < 32
------------------------------------------------------------------------
section "Int32#"
- {Operations on 32-bit integers (Int32\#). This type is only used
- if plain Int\# has less than 32 bits. In any case, the operations
+ {Operations on 32-bit integers ({\tt Int32\#}). This type is only used
+ if plain {\tt Int\#} has less than 32 bits. In any case, the operations
are not primops; they are implemented (if needed) as ccalls instead.}
------------------------------------------------------------------------
+primtype Int32#
+
primop Int32ToIntegerOp "int32ToInteger#" GenPrimOp
Int32# -> (# Int#, ByteArr# #)
with out_of_line = True
------------------------------------------------------------------------
section "Word32#"
{Operations on 32-bit unsigned words. This type is only used
- if plain Word\# has less than 32 bits. In any case, the operations
+ if plain {\tt Word\#} has less than 32 bits. In any case, the operations
are not primops; they are implemented (if needed) as ccalls instead.}
------------------------------------------------------------------------
+primtype Word32#
+
primop Word32ToIntegerOp "word32ToInteger#" GenPrimOp
Word32# -> (# Int#, ByteArr# #)
with out_of_line = True
------------------------------------------------------------------------
section "Int64#"
{Operations on 64-bit unsigned words. This type is only used
- if plain Int\# has less than 64 bits. In any case, the operations
+ if plain {\tt Int\#} has less than 64 bits. In any case, the operations
are not primops; they are implemented (if needed) as ccalls instead.}
------------------------------------------------------------------------
+primtype Int64#
+
primop Int64ToIntegerOp "int64ToInteger#" GenPrimOp
Int64# -> (# Int#, ByteArr# #)
with out_of_line = True
------------------------------------------------------------------------
section "Word64#"
{Operations on 64-bit unsigned words. This type is only used
- if plain Word\# has less than 64 bits. In any case, the operations
+ if plain {\tt Word\#} has less than 64 bits. In any case, the operations
are not primops; they are implemented (if needed) as ccalls instead.}
------------------------------------------------------------------------
+primtype Word64#
+
primop Word64ToIntegerOp "word64ToInteger#" GenPrimOp
Word64# -> (# Int#, ByteArr# #)
with out_of_line = True
section "Integer#"
{Operations on arbitrary-precision integers. These operations are
implemented via the GMP package. An integer is represented as a pair
-consisting of an Int\# representing the number of 'limbs' in use and
-the sign, and a ByteArr\# containing the 'limbs' themselves. Such pairs
+consisting of an {\tt Int\#} representing the number of 'limbs' in use and
+the sign, and a {\tt ByteArr\#} containing the 'limbs' themselves. Such pairs
are returned as unboxed pairs, but must be passed as separate
components.
primop IntegerIntGcdOp "gcdIntegerInt#" GenPrimOp
Int# -> ByteArr# -> Int# -> Int#
- {Greatest common divisor, where second argument is an ordinary Int\#.}
+ {Greatest common divisor, where second argument is an ordinary {\tt Int\#}.}
with out_of_line = True
primop IntegerDivExactOp "divExactInteger#" GenPrimOp
{Operations on double-precision (64 bit) floating-point numbers.}
------------------------------------------------------------------------
+primtype Double#
+
primop DoubleGtOp ">##" Compare Double# -> Double# -> Bool
primop DoubleGeOp ">=##" Compare Double# -> Double# -> Bool
primop DoubleDecodeOp "decodeDouble#" GenPrimOp
Double# -> (# Int#, Int#, ByteArr# #)
{Convert to arbitrary-precision integer.
- First Int\# in result is the exponent; second Int\# and ByteArr\# represent an Integer\#
- holding the mantissa.}
+ First {\tt Int\#} in result is the exponent; second {\tt Int\#} and {\tt ByteArr\#}
+ represent an {\tt Integer\#} holding the mantissa.}
with out_of_line = True
------------------------------------------------------------------------
{Operations on single-precision (32-bit) floating-point numbers.}
------------------------------------------------------------------------
+primtype Float#
+
primop FloatGtOp "gtFloat#" Compare Float# -> Float# -> Bool
primop FloatGeOp "geFloat#" Compare Float# -> Float# -> Bool
primop FloatDecodeOp "decodeFloat#" GenPrimOp
Float# -> (# Int#, Int#, ByteArr# #)
{Convert to arbitrary-precision integer.
- First Int\# in result is the exponent; second Int\# and ByteArr\# represent an Integer\#
- holding the mantissa.}
+ First {\tt Int\#} in result is the exponent; second {\tt Int\#} and {\tt ByteArr\#}
+ represent an {\tt Integer\#} holding the mantissa.}
with out_of_line = True
------------------------------------------------------------------------
section "Arrays"
- {Operations on Array\#.}
+ {Operations on {\tt Array\#}.}
------------------------------------------------------------------------
+primtype Array# a
+
+primtype MutArr# s a
+
primop NewArrayOp "newArray#" GenPrimOp
Int# -> a -> State# s -> (# State# s, MutArr# s a #)
{Create a new mutable array of specified size (in bytes),
------------------------------------------------------------------------
section "Byte Arrays"
- {Operations on ByteArray\#. A ByteArray\# is a just a region of
+ {Operations on {\tt ByteArray\#}. A {\tt ByteArray\#} is a just a region of
raw memory in the garbage-collected heap, which is not scanned
for pointers. It carries its own size (in bytes). There are
three sets of operations for accessing byte array contents:
------------------------------------------------------------------------
+primtype ByteArr#
+
+primtype MutByteArr# s
+
primop NewByteArrayOp_Char "newByteArray#" GenPrimOp
Int# -> State# s -> (# State# s, MutByteArr# s #)
{Create a new mutable byte array of specified size (in bytes), in
------------------------------------------------------------------------
section "Addr#"
- {Addr\# is an arbitrary machine address assumed to point outside
- the garbage-collected heap.
-
- NB: {\tt nullAddr\#::Addr\#} is not a primop, but is defined in MkId.lhs.
- It is the null address.}
------------------------------------------------------------------------
+primtype Addr#
+ { An arbitrary machine address assumed to point outside
+ the garbage-collected heap. }
+
+pseudoop "nullAddr#" Addr#
+ { The null address. }
+
primop AddrAddOp "plusAddr#" GenPrimOp Addr# -> Int# -> Addr#
primop AddrSubOp "minusAddr#" GenPrimOp Addr# -> Addr# -> Int#
- {Result is meaningless if two Addr\#s are so far apart that their
- difference doesn't fit in an Int\#.}
+ {Result is meaningless if two {\tt Addr\#}s are so far apart that their
+ difference doesn't fit in an {\tt Int\#}.}
primop AddrRemOp "remAddr#" GenPrimOp Addr# -> Int# -> Int#
- {Return the remainder when the Addr\# arg, treated like an Int\#,
- is divided by the Int\# arg.}
+ {Return the remainder when the {\tt Addr\#} arg, treated like an {\tt Int\#},
+ is divided by the {\tt Int\#} arg.}
#if (WORD_SIZE_IN_BITS == 32 || WORD_SIZE_IN_BITS == 64)
primop Addr2IntOp "addr2Int#" GenPrimOp Addr# -> Int#
{Coerce directly from address to int. Strongly deprecated.}
------------------------------------------------------------------------
section "Mutable variables"
- {Operations on MutVar\#s, which behave like single-element mutable arrays.}
+ {Operations on MutVar\#s.}
------------------------------------------------------------------------
+primtype MutVar# s a
+ {A {\tt MutVar\#} behaves like a single-element mutable array.}
+
primop NewMutVarOp "newMutVar#" GenPrimOp
a -> State# s -> (# State# s, MutVar# s a #)
- {Create MutVar\# with specified initial value in specified state thread.}
+ {Create {\tt MutVar\#} with specified initial value in specified state thread.}
with
usage = { mangle NewMutVarOp [mkM, mkP] mkM }
out_of_line = True
primop ReadMutVarOp "readMutVar#" GenPrimOp
MutVar# s a -> State# s -> (# State# s, a #)
- {Read contents of MutVar\#. Result is not yet evaluated.}
+ {Read contents of {\tt MutVar\#}. Result is not yet evaluated.}
with
usage = { mangle ReadMutVarOp [mkM, mkP] mkM }
primop WriteMutVarOp "writeMutVar#" GenPrimOp
MutVar# s a -> a -> State# s -> State# s
- {Write contents of MutVar\#.}
+ {Write contents of {\tt MutVar\#}.}
with
usage = { mangle WriteMutVarOp [mkM, mkM, mkP] mkR }
has_side_effects = True
section "STM-accessible Mutable Variables"
------------------------------------------------------------------------
+primtype TVar# s a
+
primop AtomicallyOp "atomically#" GenPrimOp
(State# RealWorld -> (# State# RealWorld, a #) )
-> State# RealWorld -> (# State# RealWorld, a #)
primop NewTVarOp "newTVar#" GenPrimOp
a
-> State# s -> (# State# s, TVar# s a #)
- {Create a new Tar\# holding a specified initial value.}
+ {Create a new {\tt TVar\#} holding a specified initial value.}
with
out_of_line = True
primop ReadTVarOp "readTVar#" GenPrimOp
TVar# s a
-> State# s -> (# State# s, a #)
- {Read contents of TVar\#. Result is not yet evaluated.}
+ {Read contents of {\tt TVar\#}. Result is not yet evaluated.}
with
out_of_line = True
TVar# s a
-> a
-> State# s -> State# s
- {Write contents of TVar\#.}
+ {Write contents of {\tt TVar\#}.}
with
out_of_line = True
has_side_effects = True
------------------------------------------------------------------------
section "Synchronized Mutable Variables"
- {Operations on MVar\#s, which are shared mutable variables
- ({\it not} the same as MutVar\#s!). (Note: in a non-concurrent implementation,
- (MVar\# a) can be represented by (MutVar\# (Maybe a)).)}
+ {Operations on {\tt MVar\#}s. }
------------------------------------------------------------------------
+primtype MVar# s a
+ { A shared mutable variable ({\it not} the same as a {\tt MutVar\#}!).
+ (Note: in a non-concurrent implementation, {\tt (MVar\# a)} can be
+ represented by {\tt (MutVar\# (Maybe a))}.) }
primop NewMVarOp "newMVar#" GenPrimOp
State# s -> (# State# s, MVar# s a #)
- {Create new mvar; initially empty.}
+ {Create new {\tt MVar\#}; initially empty.}
with
usage = { mangle NewMVarOp [mkP] mkR }
out_of_line = True
primop TakeMVarOp "takeMVar#" GenPrimOp
MVar# s a -> State# s -> (# State# s, a #)
- {If mvar is empty, block until it becomes full.
+ {If {\tt MVar\#} is empty, block until it becomes full.
Then remove and return its contents, and set it empty.}
with
usage = { mangle TakeMVarOp [mkM, mkP] mkM }
primop TryTakeMVarOp "tryTakeMVar#" GenPrimOp
MVar# s a -> State# s -> (# State# s, Int#, a #)
- {If mvar is empty, immediately return with integer 0 and value undefined.
- Otherwise, return with integer 1 and contents of mvar, and set mvar empty.}
+ {If {\tt MVar\#} is empty, immediately return with integer 0 and value undefined.
+ Otherwise, return with integer 1 and contents of {\tt MVar\#}, and set {\tt MVar\#} empty.}
with
usage = { mangle TryTakeMVarOp [mkM, mkP] mkM }
has_side_effects = True
primop PutMVarOp "putMVar#" GenPrimOp
MVar# s a -> a -> State# s -> State# s
- {If mvar is full, block until it becomes empty.
+ {If {\tt MVar\#} is full, block until it becomes empty.
Then store value arg as its new contents.}
with
usage = { mangle PutMVarOp [mkM, mkM, mkP] mkR }
primop TryPutMVarOp "tryPutMVar#" GenPrimOp
MVar# s a -> a -> State# s -> (# State# s, Int# #)
- {If mvar is full, immediately return with integer 0.
- Otherwise, store value arg as mvar's new contents, and return with integer 1.}
+ {If {\tt MVar\#} is full, immediately return with integer 0.
+ Otherwise, store value arg as {\tt MVar\#}'s new contents, and return with integer 1.}
with
usage = { mangle TryPutMVarOp [mkM, mkM, mkP] mkR }
has_side_effects = True
primop IsEmptyMVarOp "isEmptyMVar#" GenPrimOp
MVar# s a -> State# s -> (# State# s, Int# #)
- {Return 1 if mvar is empty; 0 otherwise.}
+ {Return 1 if {\tt MVar\#} is empty; 0 otherwise.}
with
usage = { mangle IsEmptyMVarOp [mkP, mkP] mkM }
out_of_line = True
------------------------------------------------------------------------
section "Concurrency primitives"
- {(In a non-concurrent implementation, ThreadId\# can be as singleton
- type, whose (unique) value is returned by myThreadId\#. The
- other operations can be omitted.)}
------------------------------------------------------------------------
+primtype State# s
+ { {\tt State\#} is the primitive, unlifted type of states. It has
+ one type parameter, thus {\tt State\# RealWorld}, or {\tt State\# s},
+ where s is a type variable. The only purpose of the type parameter
+ is to keep different state threads separate. It is represented by
+ nothing at all. }
+
+primtype RealWorld
+ { {\tt RealWorld} is deeply magical. It is {\it primitive}, but it is not
+ {\it unlifted} (hence {\tt ptrArg}). We never manipulate values of type
+ {\tt RealWorld}; it's only used in the type system, to parameterise {\tt State\#}. }
+
+primtype ThreadId#
+ {(In a non-concurrent implementation, this can be a singleton
+ type, whose (unique) value is returned by {\tt myThreadId\#}. The
+ other operations can be omitted.)}
+
primop ForkOp "fork#" GenPrimOp
a -> State# RealWorld -> (# State# RealWorld, ThreadId# #)
with
with
out_of_line = True
+primop NoDuplicateOp "noDuplicate#" GenPrimOp
+ State# RealWorld -> State# RealWorld
+ with
+ out_of_line = True
+
------------------------------------------------------------------------
section "Weak pointers"
------------------------------------------------------------------------
+primtype Weak# b
+
-- note that tyvar "o" denotes openAlphaTyVar
primop MkWeakOp "mkWeak#" GenPrimOp
section "Stable pointers and names"
------------------------------------------------------------------------
+primtype StablePtr# a
+
+primtype StableName# a
+
primop MakeStablePtrOp "makeStablePtr#" GenPrimOp
a -> State# RealWorld -> (# State# RealWorld, StablePtr# a #)
with
{Support for the bytecode interpreter and linker.}
------------------------------------------------------------------------
+primtype BCO#
+ {Primitive bytecode type.}
primop AddrToHValueOp "addrToHValue#" GenPrimOp
Addr# -> (# a #)
- {Convert an Addr\# to a followable type.}
+ {Convert an {\tt Addr\#} to a followable type.}
primop MkApUpd0_Op "mkApUpd0#" GenPrimOp
BCO# -> (# a #)
out_of_line = True
primop NewBCOOp "newBCO#" GenPrimOp
- ByteArr# -> ByteArr# -> Array# a -> ByteArr# -> Int# -> ByteArr# -> State# s -> (# State# s, BCO# #)
+ ByteArr# -> ByteArr# -> Array# a -> Int# -> ByteArr# -> State# s -> (# State# s, BCO# #)
with
has_side_effects = True
out_of_line = True
-primop InfoPtrOp "infoPtr#" GenPrimOp
- a -> Addr#
+primop UnpackClosureOp "unpackClosure#" GenPrimOp
+ a -> (# Addr#, Array# b, ByteArr# #)
with
out_of_line = True
-primop ClosurePayloadOp "closurePayload#" GenPrimOp
- a -> (# Array# b, ByteArr# #)
- with
- out_of_line = True
------------------------------------------------------------------------
-section "Coercion"
- {{\tt unsafeCoerce\# :: a -> b} is not a primop, but is defined in MkId.lhs.}
-
+section "Etc"
+ {Miscellaneous built-ins}
------------------------------------------------------------------------
+pseudoop "seq"
+ a -> b -> b
+ { Evaluates its first argument to head normal form, and then returns its second
+ argument as the result. }
+
+pseudoop "inline"
+ a -> a
+ { The call {\tt (inline f)} arranges that f is inlined, regardless of its size.
+ More precisely, the call {\tt (inline f)} rewrites to the right-hand side of
+ {\tt f}'s definition. This allows the programmer to control inlining from a
+ particular call site rather than the definition site of the function (c.f.
+ {\tt INLINE} pragmas in User's Guide, Section 7.10.3, "INLINE and NOINLINE
+ pragmas").
+
+ This inlining occurs regardless of the argument to the call or the size of
+ {\tt f}'s definition; it is unconditional. The main caveat is that {\tt f}'s
+ definition must be visible to the compiler. That is, {\tt f} must be
+ {\tt let}-bound in the current scope. If no inlining takes place, the
+ {\tt inline} function expands to the identity function in Phase zero; so its
+ use imposes no overhead.
+
+ If the function is defined in another module, GHC only exposes its inlining
+ in the interface file if the function is sufficiently small that it might be
+ inlined by the automatic mechanism. There is currently no way to tell GHC to
+ expose arbitrarily-large functions in the interface file. (This shortcoming
+ is something that could be fixed, with some kind of pragma.) }
+
+pseudoop "lazy"
+ a -> a
+ { The {\tt lazy} function restrains strictness analysis a little. The call
+ {\tt (lazy e)} means the same as {\tt e}, but {\tt lazy} has a magical
+ property so far as strictness analysis is concerned: it is lazy in its first
+ argument, even though its semantics is strict. After strictness analysis has
+ run, calls to {\tt lazy} are inlined to be the identity function.
+
+ This behaviour is occasionally useful when controlling evaluation order.
+ Notably, {\tt lazy} is used in the library definition of {\tt Control.Parallel.par}:
+
+ {\tt par :: a -> b -> b}
+
+ {\tt par x y = case (par\# x) of \_ -> lazy y}
+
+ If {\tt lazy} were not lazy, {\tt par} would look strict in {\tt y} which
+ would defeat the whole purpose of {\tt par}.
+
+ Like {\tt seq}, the argument of {\tt lazy} can have an unboxed type. }
+
+primtype Any a
+ { The type constructor {\tt Any} is type to which you can unsafely coerce any
+ lifted type, and back.
+
+ * It is lifted, and hence represented by a pointer
+
+ * It does not claim to be a {\it data} type, and that's important for
+ the code generator, because the code gen may {\it enter} a data value
+ but never enters a function value.
+
+ It's also used to instantiate un-constrained type variables after type
+ checking. For example
+
+ {\tt length Any []}
+
+ Annoyingly, we sometimes need {\tt Any}s of other kinds, such as {\tt (* -> *)} etc.
+ This is a bit like tuples. We define a couple of useful ones here,
+ and make others up on the fly. If any of these others end up being exported
+ into interface files, we'll get a crash; at least until we add interface-file
+ syntax to support them. }
+
+pseudoop "unsafeCoerce#"
+ a -> b
+ { The function {\tt unsafeCoerce\#} allows you to side-step the typechecker entirely. That
+ is, it allows you to coerce any type into any other type. If you use this function,
+ you had better get it right, otherwise segmentation faults await. It is generally
+ used when you want to write a program that you know is well-typed, but where Haskell's
+ type system is not expressive enough to prove that it is well typed.
+
+ The argument to {\tt unsafeCoerce\#} can have unboxed types, although extremely bad
+ things will happen if you coerce a boxed type to an unboxed type. }
+
------------------------------------------------------------------------
--- ---
projects / ghc-hetmet.git / blobdiff