Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic ---+ Reporter: simonpj | Owner: Type: bug | Status: closed Priority: normal| Milestone: 7.6.2 Component: Compiler |Version: 7.6.1 Resolution: fixed | Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: deSugar/should_compile/T5252, T5252Take2 | Blockedby: Blocking:|Related: ---+ Changes (by pcapriotti): * status: merge = closed * resolution: = fixed Comment: Merged as 8b4fee353aa6bfcd08d7ea5ab8b8cc2b526e26f3. -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:8 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic ---+ Reporter: simonpj | Owner: Type: bug | Status: merge Priority: normal| Milestone: 7.6.2 Component: Compiler |Version: 7.6.1 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: deSugar/should_compile/T5252, T5252Take2 | Blockedby: Blocking:|Related: ---+ Changes (by igloo): * milestone: = 7.6.2 -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:7 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic
---+
Reporter: simonpj | Owner:
Type: bug | Status: merge
Priority: normal| Milestone:
Component: Compiler |Version: 7.6.1
Resolution:| Keywords:
Os: Unknown/Multiple | Architecture:
Unknown/Multiple
Failure: None/Unknown | Difficulty:
Unknown
Testcase: deSugar/should_compile/T5252, T5252Take2 | Blockedby:
Blocking:|Related:
---+
Changes (by simonpj):
* status: new = merge
* testcase: deSugar/should_compile/T5252 =
deSugar/should_compile/T5252, T5252Take2
Comment:
Needs this patch too:
{{{
commit ba8fd081ba9b222dd5f93604d7deeaca372e4511
Author: Simon Peyton Jones simo...@microsoft.com
Date: Mon Sep 17 18:22:10 2012 +0100
Make the call to chooseBoxingStrategy lazy again
I made it strict, as an incidental consequence of this patch:
commit 5bae803a18b17bdb158a7780e6b6ac3c520e5b39
Author: Simon Peyton Jones simo...@microsoft.com
Date: Sat Sep 15 23:09:25 2012 +0100
Fix UNPACK with -fomit-interface-pragmas.
But it's very important that chooseBoxingStrategy is lazy, else
(in bigger programs with lots of recursion in types) GHC can
loop. This showed up in Data.Sequence; and I think it was making
haddock loop as well.
Anyway this patch makes it lazy again.
compiler/typecheck/TcTyClsDecls.lhs | 34
+-
1 file changed, 17 insertions(+), 17 deletions(-)
}}}
Regression test added.
Merge to 7.6 branch.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:6
GHC http://www.haskell.org/ghc/
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Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic
---+
Reporter: simonpj | Owner:
Type: bug | Status: new
Priority: normal| Milestone:
Component: Compiler |Version: 7.6.1
Resolution:| Keywords:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: None/Unknown | Difficulty: Unknown
Testcase: deSugar/should_compile/T5252 | Blockedby:
Blocking:|Related:
---+
Comment(by simonpj@…):
commit 5bae803a18b17bdb158a7780e6b6ac3c520e5b39
{{{
Author: Simon Peyton Jones simo...@microsoft.com
Date: Sat Sep 15 23:09:25 2012 +0100
Fix UNPACK with -fomit-interface-pragmas.
We were missing a case, so that you could expose a constructor
with UNPACKed fields, but the field tpye was trimmed, and hence
can't be expanded.
Fixes Trac #5252 (revived)
compiler/typecheck/TcTyClsDecls.lhs | 29 -
1 files changed, 16 insertions(+), 13 deletions(-)
}}}
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:5
GHC http://www.haskell.org/ghc/
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Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic
---+
Reporter: simonpj | Owner:
Type: bug | Status: new
Priority: normal| Milestone:
Component: Compiler |Version: 7.6.1
Resolution:| Keywords:
Os: Unknown/Multiple | Architecture: Unknown/Multiple
Failure: None/Unknown | Difficulty: Unknown
Testcase: deSugar/should_compile/T5252 | Blockedby:
Blocking:|Related:
---+
Changes (by simonpj):
* cc: qdunkan@… (added)
* difficulty: = Unknown
* status: closed = new
* resolution: fixed =
* version: 7.0.3 = 7.6.1
Comment:
Evan Laforge writes (to ghc-users): I have something that looks similar to
#5252, namely, given these two modules:
{{{
% cat Midi.hs
{-# OPTIONS_GHC -funbox-strict-fields #-}
module Midi (
WriteMessage(..)
, WriteDevice
-- TODO due ghc bug: http://hackage.haskell.org/trac/ghc/ticket/5252
-- , WriteDevice(WriteDevice)
) where
import qualified Data.ByteString as ByteString
data WriteMessage = WriteMessage !WriteDevice
newtype WriteDevice = WriteDevice ByteString.ByteString
% cat CoreMidi.hs
module CoreMidi where
import qualified Midi
write_message :: Midi.WriteMessage - IO Bool
write_message (Midi.WriteMessage _) = return True
}}}
If I compile thus I get a compiler crash with GHC 7.6.1
{{{
% ghc -c Midi.hs
% ghc -c CoreMidi.hs
ghc: panic! (the 'impossible' happened)
(GHC version 7.6.1 for x86_64-apple-darwin):
reboxProduct: not a product main:Midi.WriteDevice{tc r2M}
}}}
Oddly, if I put `{-# UNPACK #-}` on the strict `WriteDevice` and remove
`-funbox-strict-fields`, I don't get a crash anymore. Also, it has to
be `ByteString` inside, I guess it has to do with the optimization
`ByteString` applies.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:3
GHC http://www.haskell.org/ghc/
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Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic ---+ Reporter: simonpj | Owner: Type: bug | Status: new Priority: normal| Milestone: Component: Compiler |Version: 7.6.1 Resolution:| Keywords: Os: Unknown/Multiple | Architecture: Unknown/Multiple Failure: None/Unknown | Difficulty: Unknown Testcase: deSugar/should_compile/T5252 | Blockedby: Blocking:|Related: ---+ Comment(by simonpj): Quite right. My fix for #5252 had a bug. Patch coming. Simon -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
Re: [GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic ---+ Reporter: simonpj | Owner: Type: bug | Status: closed Priority: normal| Milestone: Component: Compiler |Version: 7.0.3 Resolution: fixed | Keywords: Testcase: deSugar/should_compile/T5252 | Blockedby: Difficulty:| Os: Unknown/Multiple Blocking:| Architecture: Unknown/Multiple Failure: None/Unknown | ---+ Changes (by simonpj): * testcase: = deSugar/should_compile/T5252 -- Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252#comment:2 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler ___ Glasgow-haskell-bugs mailing list Glasgow-haskell-bugs@haskell.org http://www.haskell.org/mailman/listinfo/glasgow-haskell-bugs
[GHC] #5252: UNPACK without optimisation leads to panic
#5252: UNPACK without optimisation leads to panic
-+--
Reporter: simonpj |Owner:
Type: bug | Status: new
Priority: normal|Milestone:
Component: Compiler | Version: 7.0.3
Keywords:| Testcase:
Blockedby:| Difficulty:
Os: Unknown/Multiple | Blocking:
Architecture: Unknown/Multiple | Failure: None/Unknown
-+--
Here's a two-module progam
{{{
module Foo where
import Bar
blah :: S - T
blah (MkS x _) = x
module Bar( S(..), T ) where
data T = MkT Int Int
data S = MkS {-# UNPACK #-}!T Int
}}}
Now with ghc 7.0.3 we get
{{{
bash-3.1$ ghc -c Bar.hs
bash-3.1$ ghc -c Foo.hs
ghc.exe: panic! (the 'impossible' happened)
(GHC version 7.0.3 for i386-unknown-mingw32):
reboxProduct: not a product main:Foo1.T{tc r2}
}}}
The problem is that
* We are compiling with -O so GHC tries to put as little as possible into
the interface file `Bar.hi`. And it does not put in T's constructors
{{{
data S
RecFlag NonRecursive
Generics: no
= MkS :: Foo1.T - GHC.Types.Int - S
HasWrapper
Stricts: {-# UNPACK #-} ! _
43edb8535d0555fb50e9f93a9c3203bf
data T
RecFlag NonRecursive
Generics: no
{- abstract -}
}}}
* However the pattern match in `Foo` requires that GHC can see the full
representation for T, becuase it UNPACK's the argument.
* A workaround is to export `MkT` from `Bar`.
The solution I am implementing is to ignore UNPACK pragmas when
`OmitInterfacePragmas` is on. This flag is the one that causes trimming
of the exposed constructors.
--
Ticket URL: http://hackage.haskell.org/trac/ghc/ticket/5252
GHC http://www.haskell.org/ghc/
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