Re: [Haskell-cafe] How to improve speed? (MersenneTwister is several times slower than C version)

On 11/2/06, Lennart Augustsson wrote:

A big problem with the Mersenne Twister is the shifts. As has been noted elsewhere, ghc doesn't do such a great job on those.

Actually, the shifts are only evaluated once (hurrah for lazy evaluation) and with -funfolding-use-threshold=16 they're all compiled to unchecked primitives (GHC.Prim.uncheckedShiftRL#). -- Cheers, Lemmih