[GHC] #15696: Derived Ord instance for enumerations with more than 8 elements seems to be incorrect
GHC
ghc-devs at haskell.org
Fri Oct 5 16:22:32 UTC 2018
#15696: Derived Ord instance for enumerations with more than 8 elements seems to be
incorrect
-------------------------------------+-------------------------------------
Reporter: mrkkrp | Owner: (none)
Type: bug | Status: patch
Priority: highest | Milestone: 8.6.2
Component: Compiler | Version: 8.6.1
Resolution: | Keywords:
Operating System: Unknown/Multiple | Architecture:
Type of failure: Incorrect result | Unknown/Multiple
at runtime | Test Case:
Blocked By: | Blocking:
Related Tickets: | Differential Rev(s): Phab:D5196,
Wiki Page: | Phab:D5201
-------------------------------------+-------------------------------------
Comment (by osa1):
Well because this transformation
\z. case x of y -> let v = dataToTag# y in ...
==>
\z. case x of y -> let v = dataToTag# x in ...
is not a problem anymore. Although I now realize that floating `v` outsize
of
`\z` is still a problem, because that'd mean evaluating `x` more eagerly.
So I think first part of the note isn't relevant anymore, but second part
(floating out) is.
--
Ticket URL: <http://ghc.haskell.org/trac/ghc/ticket/15696#comment:54>
GHC <http://www.haskell.org/ghc/>
The Glasgow Haskell Compiler
More information about the ghc-tickets
mailing list