Correct me if I'm wrong here, but it's preserving the effect of (==)
forcing its arguments. This makes the optimization less surprising, in
my opinion.
Is there a benefit to not doing this?
On Sat, May 20, 2017 at 11:56 AM, Joachim Breitner
Hi,
I just observed that GHC optimizes
fun (n::Int) = n == 0 + n
to essentially
fun (n::Int) = n `seq` True
I am wondering under what circumstances we would be happy to transform this further to
fun _ = True
Clearly, we do not want to drop `seq`s in general. But is there some commonly accepted rule about which strictness we generally allow the compiler to get rid of, if it turns out that the compiler can do without? Or are all such transformations out of bounds for GHC?
Greetings, Joachim
-- Joachim Breitner mail@joachim-breitner.de http://www.joachim-breitner.de/
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