GHC Haskell switches to an LLVM backend

http://www.haskell.org/pipermail/cvs-ghc/2010-February/052606.html

by dons • 16 years ago

87 19 16 years ago

haskell.org

frou_dh• 16 years ago

Is this a big deal? (not a rhetorical question!)

dons4• 16 years ago

Here's a short summary of the benefits: http://www.reddit.com/r/haskell/comments/b3tby/the_new_llvm_...

kwantam• 16 years ago

Yes; at present, adding code generation for new architectures is kind of a nightmare (google "haskell Evil Mangler"). LLVM will make this much simpler (or, at least, foist it on the LLVM guys :) )

hga4• 16 years ago

What about GC? When I last looked at LLVM (the current stable release, in fact), it looks like it didn't have a very good story there. Plenty planned out, but little implemented and less solidly.

bts2• 16 years ago

Although this is really cool stuff and it looks like it's going to get merged in, the title is a little misleading here. GHC hasn't switched to an LLVM backend -- they're currently reviewing this patch and possibly merging in this support for LLVM output (not necessarily switching over to it entirely).

dons4• 16 years ago

The title is accurate, as simultaneously, the GCC backend is being dropped. [1]

1. http://www.haskell.org/pipermail/glasgow-haskell-users/2010-...

bts2• 16 years ago

But that link only says that via-C is being dropped which, as I understand it, is not currently the default backend -- NGC is[1]. This means that (1) via-C is being dropped; (2) NCG (native code generator) has been, and is still the default; and (3) this LLVM backend support is currently being considered to be merged in.

[1] http://hackage.haskell.org/trac/ghc/wiki/Commentary/Compiler...

loup-vaillant• 16 years ago

What happened to C--?

dons4• 16 years ago

GHC uses a modified form of C-- internally, which is fed to LLVM, GCC or the native codegen.

The C-- standalone compilers never reached the maturity of e.g. LLVM, to justify the port.

hga4• 16 years ago

Yeah, as far as I can tell C-- is lying the street slowly bleeding. The group at Harvard has run out of money for the compiler they were working on, and as soon as the principle investigator can catch his breath (he had to assume the duties of a TA) he'll finish packaging it into something that others can easily work with (e.g. a Git repository as I recall).

As it is, it's supposed to be pretty hard to build, depending on a lot of old and/or exotic tools.

GHC forked off of this effort sometime before the current C-- standard.

robryan• 16 years ago

Without going in depth this looks like very impressive honors thesis work compared with some of the other work I have seen.

adaszko• 16 years ago

Especially given that the author writes that he had "no haskell knowledge at first."

GHC Haskell switches to an LLVM backend

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