Hi,

I also think we should do this but it has a lot of ramifications: contant folding in Core, codegen, TH, etc.

Also it will break codes that use primitive types directly, so maybe it's worth a ghc proposal.

Sylvain

Hi all,

I'm working on making it possible to pack constructor fields [1],

example:

```

data Foo = Foo {-# UNPACK #-} !Float {-# UNPACK #-} !Int32

```

should only require 4 bytes for unpacked `Float` and 4 bytes for

unpacked `Int32`, which on 64-bit arch would take just 1 word (instead

of 2 it currently does).

The diff to support packing of fields is in review [2], but to really

take advantage of it I think we need to introduce new primitive types:

- Int{8,16,32}#

- Word{8,16,32}#

along with some corresponding primops and with some other follow-up

changes like extending `PrimRep`.

Then we could use them in definitions of `Int{8,16,32}` and

`Word{8,16,32}` (they're currently just wrapping `Int#` and `Word#`).

Does that sound ok with everyone? (just making sure that this makes

sense before I invest more time into this :)

Thanks,

Michal

[1] https://ghc.haskell.org/trac/ghc/ticket/13825

[2] https://phabricator.haskell.org/D3809

_______________________________________________
ghc-devs mailing list
ghc-devs@haskell.org
http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs