Opened 10 years ago

Closed 9 years ago

Last modified 45 years ago

#255 closed bug (Fixed)

SPECIALIZE pragma and polymorphic instances

Reported by: nobody Owned by: nobody
Priority: normal Milestone:
Component: Compiler Version: 6.2.1
Keywords: Cc:
Operating System: Architecture:
Type of failure: Difficulty:
Test Case: Blocked By:
Blocking: Related Tickets:

Description

Given a polymorphic specialization like

        f :: (Storable a, Eq a) => T a
        {-# SPECIALIZE f :: T (Ptr a) #-}

GHC does not produce the requested polymorphic
specialization, but if we use f at the ground types T
(Ptr Foo) and T (Ptr Bar), we get a specialization for
each, and these are essentially the same.

ross@soi.city.ac.uk

Change History (4)

comment:1 Changed 9 years ago by remit

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A few more links to messages about this:

SPJ explains (a.o. why he won't solve it before the POPL
deadline ;)
http://www.haskell.org/pipermail/glasgow-haskell-users/2004-June/006874.html

SPJ hints that the patch will appear soon, or perhaps even
already exists:
http://www.haskell.org/pipermail/glasgow-haskell-users/2005-May/008503.html

My own I-hadn't-seen-this-yet bugreport, explaining why it
is, ahum, Vitally Important(TM) to tackle this bug:
http://www.haskell.org/pipermail/glasgow-haskell-bugs/2005-March/004765.html

Simon Marlow implies this one (Priority 4) won't be solved
anytime soon.
http://haskell.org/pipermail/glasgow-haskell-users/2005-July/008738.html

Now, whether this counts as a "yell if you disagree [about
not solving priority < 5]." or as "if you know of a specific
perf problem, please submit it as a bug" I'll leave to the
ones who actually do the work :)

comment:2 Changed 9 years ago by simonpj

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Upping the priority. It's not trivial to do this, but it's still very 
much on my radar

comment:3 Changed 9 years ago by simonpj

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Another useful background link:

http://www.haskell.org//pipermail/libraries/2005-
May/003871.html

comment:4 Changed 9 years ago by simonpj

  • Status changed from assigned to closed
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Fixed, at last.

Simon
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