ticket for adding ARM backend to NCG?

[Simon Peyton-Jones]

| I've been tinkering with ARM NCG idea for quite some time now, but
| honestly I've been always in doubts if it's the best way for GHC at all.
| I've thought that the plan was to kind of move out of NCG to LLVM based
| backends and I've though that although this plan may be kind of stuck
| now, it's still on the table.

I have not been following the ARM and LLVM threads very closely, but here's my take:

* LLVM is (I hope) very much on the table. LLVM itself is a well-resourced project,
  and we can expect it to continue to exist.  We should piggy-back on all the 
  hard work that is going into it.

* But using LLVM has some disadvantages.
  a) it imposes a dependency on LLVM
  b) it makes compilation slower
  c) we play some efficiency tricks (notably "tables next to code") that 
     LLVM can't play (yet).  I think.

So GHC currently aims to have a built-in NCG for popular platforms, and to rely on LLVM for more esoteric platforms and also for superior optimisation.

Is this still a sensible policy?  

Maybe you can articulate your doubts on the ARM NCG?

Simon

| -----Original Message-----
| From: ghc-devs [mailto:ghc-devs-bounces at haskell.org] On Behalf Of Karel
| Gardas
| Sent: 03 January 2014 11:24
| To: Jens Petersen
| Cc: ghc-devs at haskell.org
| Subject: Re: ticket for adding ARM backend to NCG?
| 
| 
| Guys,
| 
| I've been tinkering with ARM NCG idea for quite some time now, but
| honestly I've been always in doubts if it's the best way for GHC at all.
| I've thought that the plan was to kind of move out of NCG to LLVM based
| backends and I've though that although this plan may be kind of stuck
| now, it's still on the table.
| 
| Yes, I know that GHC is volunteering effort so if someone comes and asks
| for an ARM NCG implementation merge it'll be probably done in some time,
| but I'm not sure if it's what's the most welcome at the end.
| 
| Just some of my doubts about it...
| 
| I would really appreciate some authoritative word about the topic from
| more involved GHC developers... I mean especially about NCG future...
| 
| Thanks!
| Karel
| 
| On 01/ 3/14 09:35 AM, Jens Petersen wrote:
| > On 3 January 2014 03:10, Corey O'Connor <coreyoconnor at gmail.com
| > <mailto:coreyoconnor at gmail.com>> wrote:
| >
| >     My interest is just to get involved somehow in the NCG. Starting a
| >     new backend seemed reasonable only because I couldn't break
| >     something that didn't exist. ;-)
| >
| >
| > Well a big +1 from me for armv7 NCG.
| >
| >
| > _______________________________________________
| > ghc-devs mailing list
| > ghc-devs at haskell.org
| > http://www.haskell.org/mailman/listinfo/ghc-devs
| 
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