[GHC] #10527: Panic Simplifier ticks exhausted with type families
GHC
ghc-devs at haskell.org
Thu Jun 25 16:56:20 UTC 2015
#10527: Panic Simplifier ticks exhausted with type families
-------------------------------------+-------------------------------------
Reporter: sopvop | Owner: bgamari
Type: bug | Status: new
Priority: highest | Milestone: 7.10.2
Component: Compiler | Version: 7.10.1-rc1
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
Type of failure: None/Unknown | Unknown/Multiple
Blocked By: | Test Case:
Related Tickets: | Blocking:
| Differential Revisions:
-------------------------------------+-------------------------------------
Comment (by bgamari):
rVery early in simplifier run I noticed this difference.
In 7.10.1,
{{{#!hs
Inlining done: Data.Functor.Identity.$fFoldableIdentity2
Inlined fn: \ (@ a4)
(ds [Occ=Once] :: Data.Functor.Identity.Identity a4) ->
ds
Cont: ApplyToTy (Bug.Rec ss)
ApplyToVal nodup ((g x)
`cast` (Sym
(Nth:0
(<Data.Functor.Identity.Identity (Bug.Rec ss)>_R
->
Data.Functor.Identity.NTCo:Identity[0]
<Bug.Rec ss>_R))
:: Data.Functor.Identity.Identity
(Bug.Rec ss)
~R#
Data.Functor.Identity.Identity (Bug.Rec ss)))
CastIt Nth:1
(<Data.Functor.Identity.Identity (Bug.Rec ss)>_R
-> Data.Functor.Identity.NTCo:Identity[0] <Bug.Rec
ss>_R)
Stop[BoringCtxt] Bug.Rec ss
}}}
In 7.10.2,
{{{#!hs
Inlining done: Data.Functor.Identity.$fFoldableIdentity2
Inlined fn: \ (@ a4)
(ds [Occ=Once] :: Data.Functor.Identity.Identity a4) ->
ds
Cont: ApplyToTy (Bug.Rec ss)
ApplyToVal simpl ((g x)
`cast` (Sym
(Nth:0
(<Data.Functor.Identity.Identity (Bug.Rec ss)>_R
->
Data.Functor.Identity.NTCo:Identity[0]
<Bug.Rec ss>_R))
:: Data.Functor.Identity.Identity
(Bug.Rec ss)
~R#
Data.Functor.Identity.Identity (Bug.Rec ss)))
CastIt Nth:1
(<Data.Functor.Identity.Identity (Bug.Rec ss)>_R
-> Data.Functor.Identity.NTCo:Identity[0] <Bug.Rec
ss>_R)
Stop[BoringCtxt] Bug.Rec ss
}}}
Notice the second "frame" of the context: `ApplyToVal nodup ((g x) ...)`
(7.10.1) in contrast to `ApplyToVal simpl ((g x) ...)` (7.10.2). I'm not
yet sure whether this is significant.
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/10527#comment:7>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
More information about the ghc-tickets
mailing list