Missed constant folding oportunities
A work colleague of mine found that some expressions were not being constant folded as expected.
module Test where import Data.Int number :: Int64 number = 2 ^ 10 - 3
ghc -O2 -keep-s-file -c test.hs
should result in an assembler file containing the constant
1021 but doesn't. However, if I change the above expression to:
number = 1024 -3
then the output assembler files does contain the value
I did a bit of a search and found some constant folding code in the
hoopl library, but that doesn't seem to be what GHC actually uses.