-- text between curly brackets. This is a kludge to enable
-- processors of this file to easily get hold of simple info
-- (eg, out_of_line), whilst avoiding parsing complex expressions
--- needed for strictness and usage info.
+-- needed for strictness info.
defaults
has_side_effects = False
needs_wrapper = False
can_fail = False
strictness = { \ arity -> mkStrictSig (mkTopDmdType (replicate arity lazyDmd) TopRes) }
- usage = { nomangle other }
-- Currently, documentation is produced using latex, so contents of
-- description fields should be legal latex. Descriptions can contain
in the specified state thread,
with each element containing the specified initial value.}
with
- usage = { mangle NewArrayOp [mkP, mkM, mkP] mkM }
out_of_line = True
primop SameMutableArrayOp "sameMutableArray#" GenPrimOp
MutArr# s a -> MutArr# s a -> Bool
- with
- usage = { mangle SameMutableArrayOp [mkP, mkP] mkM }
primop ReadArrayOp "readArray#" GenPrimOp
MutArr# s a -> Int# -> State# s -> (# State# s, a #)
{Read from specified index of mutable array. Result is not yet evaluated.}
- with
- usage = { mangle ReadArrayOp [mkM, mkP, mkP] mkM }
primop WriteArrayOp "writeArray#" GenPrimOp
MutArr# s a -> Int# -> a -> State# s -> State# s
{Write to specified index of mutable array.}
with
- usage = { mangle WriteArrayOp [mkM, mkP, mkM, mkP] mkR }
has_side_effects = True
primop IndexArrayOp "indexArray#" GenPrimOp
Array# a -> Int# -> (# a #)
{Read from specified index of immutable array. Result is packaged into
an unboxed singleton; the result itself is not yet evaluated.}
- with
- usage = { mangle IndexArrayOp [mkM, mkP] mkM }
primop UnsafeFreezeArrayOp "unsafeFreezeArray#" GenPrimOp
MutArr# s a -> State# s -> (# State# s, Array# a #)
{Make a mutable array immutable, without copying.}
with
- usage = { mangle UnsafeFreezeArrayOp [mkM, mkP] mkM }
has_side_effects = True
primop UnsafeThawArrayOp "unsafeThawArray#" GenPrimOp
Array# a -> State# s -> (# State# s, MutArr# s a #)
{Make an immutable array mutable, without copying.}
with
- usage = { mangle UnsafeThawArrayOp [mkM, mkP] mkM }
out_of_line = True
------------------------------------------------------------------------
a -> State# s -> (# State# s, MutVar# s a #)
{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 {\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 {\tt MutVar\#}.}
with
- usage = { mangle WriteMutVarOp [mkM, mkM, mkP] mkR }
has_side_effects = True
primop SameMutVarOp "sameMutVar#" GenPrimOp
MutVar# s a -> MutVar# s a -> Bool
- with
- usage = { mangle SameMutVarOp [mkP, mkP] mkM }
-- not really the right type, but we don't know about pairs here. The
-- correct type is
primop AtomicModifyMutVarOp "atomicModifyMutVar#" GenPrimOp
MutVar# s a -> (a -> b) -> State# s -> (# State# s, c #)
with
- usage = { mangle AtomicModifyMutVarOp [mkP, mkM, mkP] mkM }
has_side_effects = True
out_of_line = True
-- Catch is actually strict in its first argument
-- but we don't want to tell the strictness
-- analyser about that!
- usage = { mangle CatchOp [mkM, mkM . (inFun CatchOp mkM mkM), mkP] mkM }
- -- [mkO, mkO . (inFun mkM mkO)] mkO
-- might use caught action multiply
out_of_line = True
with
strictness = { \ arity -> mkStrictSig (mkTopDmdType [lazyDmd] BotRes) }
-- NB: result is bottom
- usage = { mangle RaiseOp [mkM] mkM }
out_of_line = True
-- raiseIO# needs to be a primop, because exceptions in the IO monad
State# s -> (# State# s, MVar# s a #)
{Create new {\tt MVar\#}; initially empty.}
with
- usage = { mangle NewMVarOp [mkP] mkR }
out_of_line = True
primop TakeMVarOp "takeMVar#" GenPrimOp
{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 }
has_side_effects = True
out_of_line = True
{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
out_of_line = True
{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 }
has_side_effects = True
out_of_line = True
{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
out_of_line = True
primop SameMVarOp "sameMVar#" GenPrimOp
MVar# s a -> MVar# s a -> Bool
- with
- usage = { mangle SameMVarOp [mkP, mkP] mkM }
primop IsEmptyMVarOp "isEmptyMVar#" GenPrimOp
MVar# s a -> State# s -> (# State# s, Int# #)
{Return 1 if {\tt MVar\#} is empty; 0 otherwise.}
with
- usage = { mangle IsEmptyMVarOp [mkP, mkP] mkM }
out_of_line = True
------------------------------------------------------------------------
primop ForkOp "fork#" GenPrimOp
a -> State# RealWorld -> (# State# RealWorld, ThreadId# #)
with
- usage = { mangle ForkOp [mkO, mkP] mkR }
has_side_effects = True
out_of_line = True
primop ForkOnOp "forkOn#" GenPrimOp
Int# -> a -> State# RealWorld -> (# State# RealWorld, ThreadId# #)
with
- usage = { mangle ForkOnOp [mkO, mkP] mkR }
has_side_effects = True
out_of_line = True
primop KillThreadOp "killThread#" GenPrimOp
ThreadId# -> a -> State# RealWorld -> State# RealWorld
with
- usage = { mangle KillThreadOp [mkP, mkM, mkP] mkR }
has_side_effects = True
out_of_line = True
primop MkWeakOp "mkWeak#" GenPrimOp
o -> b -> c -> State# RealWorld -> (# State# RealWorld, Weak# b #)
with
- usage = { mangle MkWeakOp [mkZ, mkM, mkM, mkP] mkM }
has_side_effects = True
out_of_line = True
primop DeRefWeakOp "deRefWeak#" GenPrimOp
Weak# a -> State# RealWorld -> (# State# RealWorld, Int#, a #)
with
- usage = { mangle DeRefWeakOp [mkM, mkP] mkM }
has_side_effects = True
out_of_line = True
Weak# a -> State# RealWorld -> (# State# RealWorld, Int#,
(State# RealWorld -> (# State# RealWorld, () #)) #)
with
- usage = { mangle FinalizeWeakOp [mkM, mkP]
- (mkR . (inUB FinalizeWeakOp
- [id,id,inFun FinalizeWeakOp mkR mkM])) }
has_side_effects = True
out_of_line = True
primop MakeStablePtrOp "makeStablePtr#" GenPrimOp
a -> State# RealWorld -> (# State# RealWorld, StablePtr# a #)
with
- usage = { mangle MakeStablePtrOp [mkM, mkP] mkM }
has_side_effects = True
out_of_line = True
primop DeRefStablePtrOp "deRefStablePtr#" GenPrimOp
StablePtr# a -> State# RealWorld -> (# State# RealWorld, a #)
with
- usage = { mangle DeRefStablePtrOp [mkM, mkP] mkM }
needs_wrapper = True
has_side_effects = True
out_of_line = True
primop EqStablePtrOp "eqStablePtr#" GenPrimOp
StablePtr# a -> StablePtr# a -> Int#
with
- usage = { mangle EqStablePtrOp [mkP, mkP] mkR }
has_side_effects = True
primop MakeStableNameOp "makeStableName#" GenPrimOp
a -> State# RealWorld -> (# State# RealWorld, StableName# a #)
with
- usage = { mangle MakeStableNameOp [mkZ, mkP] mkR }
needs_wrapper = True
has_side_effects = True
out_of_line = True
primop EqStableNameOp "eqStableName#" GenPrimOp
StableName# a -> StableName# a -> Int#
- with
- usage = { mangle EqStableNameOp [mkP, mkP] mkR }
primop StableNameToIntOp "stableNameToInt#" GenPrimOp
StableName# a -> Int#
- with
- usage = { mangle StableNameToIntOp [mkP] mkR }
------------------------------------------------------------------------
section "Unsafe pointer equality"
primop ReallyUnsafePtrEqualityOp "reallyUnsafePtrEquality#" GenPrimOp
a -> a -> Int#
- with
- usage = { mangle ReallyUnsafePtrEqualityOp [mkZ, mkZ] mkR }
------------------------------------------------------------------------
section "Parallelism"
primop ParOp "par#" GenPrimOp
a -> Int#
with
- usage = { mangle ParOp [mkO] mkR }
-- Note that Par is lazy to avoid that the sparked thing
-- gets evaluted strictly, which it should *not* be
has_side_effects = True
primop ParGlobalOp "parGlobal#" GenPrimOp
a -> Int# -> Int# -> Int# -> Int# -> b -> Int#
with
- usage = { mangle ParGlobalOp [mkO, mkP, mkP, mkP, mkP, mkM] mkM }
has_side_effects = True
primop ParLocalOp "parLocal#" GenPrimOp
a -> Int# -> Int# -> Int# -> Int# -> b -> Int#
with
- usage = { mangle ParLocalOp [mkO, mkP, mkP, mkP, mkP, mkM] mkM }
has_side_effects = True
primop ParAtOp "parAt#" GenPrimOp
b -> a -> Int# -> Int# -> Int# -> Int# -> c -> Int#
with
- usage = { mangle ParAtOp [mkO, mkZ, mkP, mkP, mkP, mkP, mkM] mkM }
has_side_effects = True
primop ParAtAbsOp "parAtAbs#" GenPrimOp
a -> Int# -> Int# -> Int# -> Int# -> Int# -> b -> Int#
with
- usage = { mangle ParAtAbsOp [mkO, mkP, mkP, mkP, mkP, mkM] mkM }
has_side_effects = True
primop ParAtRelOp "parAtRel#" GenPrimOp
a -> Int# -> Int# -> Int# -> Int# -> Int# -> b -> Int#
with
- usage = { mangle ParAtRelOp [mkO, mkP, mkP, mkP, mkP, mkM] mkM }
has_side_effects = True
primop ParAtForNowOp "parAtForNow#" GenPrimOp
b -> a -> Int# -> Int# -> Int# -> Int# -> c -> Int#
with
- usage = { mangle ParAtForNowOp [mkO, mkZ, mkP, mkP, mkP, mkP, mkM] mkM }
has_side_effects = True
-- copyable# and noFollow# are yet to be implemented (for GpH)
--primop CopyableOp "copyable#" GenPrimOp
-- a -> Int#
-- with
--- usage = { mangle CopyableOp [mkZ] mkR }
-- has_side_effects = True
--
--primop NoFollowOp "noFollow#" GenPrimOp
-- a -> Int#
-- with
--- usage = { mangle NoFollowOp [mkZ] mkR }
-- has_side_effects = True
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. }
+ The following uses of {\tt unsafeCoerce\#} are supposed to work (i.e. not lead to
+ spurious compile-time or run-time crashes):
+
+ * Casting any lifted type to {\tt Any}
+
+ * Casting {\tt Any} back to the real type
+
+ * Casting an unboxed type to another unboxed type of the same size
+
+ * Casting between two types that have the same runtime representation. One case is when
+ the two types differ only in "phantom" type parameters, for example
+ {\tt Ptr Int} to {\tt Ptr Float}, or {\tt [Int]} to {\tt [Float]} when the list is
+ known to be empty. Also, a {\tt newtype} of a type {\tt T} has the same representation
+ at runtime as {\tt T}.
+
+ Other uses of {\tt unsafeCoerce\#} are undefined.
+ }
+-- NB. It is tempting to think that casting a value to a type that it doesn't have is safe
+-- as long as you don't "do anything" with the value in its cast form, such as seq on it. This
+-- isn't the case: the compiler can insert seqs itself, and if these happen at the wrong type,
+-- Bad Things Might Happen. See bug #1616: in this case we cast a function of type (a,b) -> (a,b)
+-- to () -> () and back again. The strictness analyser saw that the function was strict, but
+-- the wrapper had type () -> (), and hence the wrapper de-constructed the (), the worker re-constructed
+-- a new (), with the result that the code ended up with "case () of (a,b) -> ...".
------------------------------------------------------------------------
--- ---