[6.8.1 regression] 6.8.2 panics in nameModule with -O2
The attached file makes GHC 6.8.2 panic:
$ ghc-6.8.2 -fforce-recomp -O2 -c PPrCF.hs
ghc-6.8.2: panic! (the 'impossible' happened)
(GHC version 6.8.2 for i386-apple-darwin):
nameModule $wprCFTree{v sdg}
Please report this as a GHC bug: http://www.haskell.org/ghc/reportabugIt only happens with -O2:
$ ghc-6.8.2 -fforce-recomp -O1 -c PPrCF.hs And only with 6.8.2:
$ ghc-6.8.1 -fforce-recomp -O2 -c PPrCF.hs
$ ghc-6.6.1 -fforce-recomp -O2 -c PPrCF.hs-dcore-lint gives no additional information.
Adding a NOINLINE pragma for prCFTree makes the panic go away.
This problem and the NOINLINE work-around was found by Jean-Philippe Bernardy in GF.
Trac metadata
| Trac field | Value |
|---|---|
| Version | 6.8.2 |
| Type | Bug |
| TypeOfFailure | OtherFailure |
| Priority | normal |
| Resolution | Unresolved |
| Component | Compiler |
| Test case | |
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