Re: Make Eq type class single method
Sven Panne <[email protected]> Wed, 20 Oct 2021 18:52:19 +0200
| Newsgroups | gmane.comp.lang.haskell.libraries |
|---|---|
| Message-ID | <CANBN=mt=uvd0C7xRYHf5LiSCCj+r_5LZHvSM63+iRm_R85q=2Q@mail.gmail.com> |
Am Mi., 20. Okt. 2021 um 17:17 Uhr schrieb Viktor Dukhovni < [email protected]>: > For primitive types CPUs often have both '==' and '/=' instructions, > and so a direct call to `(/=)` may be more efficient than calling > `(not .) . (==)`. [...] For every native code generator which is worth its salt, this shouldn't make a difference at all. Swapping the "polarity" of a condition is an extremely common transformation, which can be used for many reasons. And even if you don't have anything sophisticated, a simple peephole optimizer can get rid of the negation operation. And even if all that doesn't help: Perhaps the negation + condition are fused together in the microcode operations, depending on your CPU. _______________________________________________ Libraries mailing list [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries