I think thats done on a per backend basis (though theres been a lot of changes since i last looked at some of the relevent pieces). (i'm actually based in Cambridge MA for the next 1-2 years if you wanna brain storm IRL sometime)
On x86, GHC can translate 8-bit and 16-bit operations directly
into the 8-bit and 16-bit machine instructions that the hardware
supports. But there are other platforms on which the smallest
unit of arithmetic may be 32 or even 64 bits. Is there a central
module in GHC that can take care of rewriting 8-bit and 16-bit operations
into 32-bit or 64-bit operations? Or is each back end on its own
for this?
(One of my students did some nice work on implementing this transformation
with a minimal set of sign-extension and zero-extension operations:
https://www.cs.tufts.edu/~nr/pubs/widen.pdf.)
Norman
_______________________________________________
ghc-devs mailing list
ghc-devs@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs