[Haskell-cafe] Sub-optimal

[Max Bolingbroke]

On 14 February 2011 21:00, Andrew Coppin <andrewcoppin at btinternet.com> wrote:
>>> Is this a known bug? (GHC 6.10.x)
>>
>> It's known to happen when optimising shares what shouldn't be shared. Try
>> compiling with -O2 -fno-cse (if that doesn't help, it doesn't necessarily
>> mean it's not unwanted sharing, though).
>> And, please, let us see some code to identify the problem.
>
> I tried -O2 -fno-cse. No difference.
>
> I also tried -O2 -fno-full-laziness. BIG DIFFERENCE.

See also the very old GHC ticket at
http://hackage.haskell.org/trac/ghc/ticket/917

Max