Re: renamed GMP symbols in GHC

* Simon Marlow: > One potential problem is that some Linux distributions really don't > like it if you bundle modified versions of external libraries. > However, I just don't see a way around this: GMP is inherently broken > because it has global state, so if you want two use it from two > clients

Re: REQ: add a non-closing version of handleToFd

* Simon Marlow: > There's another danger. A Handle has an associated finalizer that > closes the file descriptor when the Handle is no longer needed by the > program, so you can't make a handleToFd_noClose because the Handle > might be closed anyway. Could you keep a reference to the Handle asso

Re: Records in Haskell

* Simon Peyton-Jones: > Provoked the (very constructive) Yesod blog post on "Limitations of > Haskell", and the follow up discussion, I've started a wiki page to > collect whatever ideas we have about the name spacing issue for > record fields. > > http://hackage.haskell.org/trac/g

Re: RFC: migrating to git

* Simon Marlow: > Thanks for this. I distilled your example into a shell script that > uses git, and demonstrates that git gets the merge wrong: > > http://hpaste.org/42953/git_mismerge > > Still, git could get this merge right, it just doesn't (I know there > are more complex cases that would

Re: Parallel build broken

* Ian Lynagh: > On Thu, Sep 30, 2010 at 08:13:01PM +0200, Florian Weimer wrote: >> <http://hackage.haskell.org/trac/ghc/wiki/Building/Hacking> says that >> parallel builds are supported, but this doesn't seem to be true >> anymore. > > It's still tru

Parallel build broken

says that parallel builds are supported, but this doesn't seem to be true anymore. This is a bit unfortunate because in theory, builds should parallelize quite well. ___ Glasgow-haskell-users ma

Re: -O vs. -O2

* Bulat Ziganshin: > cloning gcc policy may be a good choice. -O2 is the best optimization > that "guaranteed" to make program faster and -O3 is for speculative > optimization (those that may be breaked by unusual code or made > program slower). not sure about -O1, -O1 is supposed to yield somewh

Re: integer-simple by default

* Greg Fitzgerald: >> You can dynamically link libgmp on windows. That might be easier: > > Do you know if the dynamic link escape hatch has ever held up in > court? GMP is LGPL, so if you use an official build or a private build from unmodified sources, all you need to do is to ship the sources

Trying to build from the darcs repository

How much memory does GHC need to build on amd64 GNU/Linux? I'm trying to build from the darcs repository, and this command "inplace/bin/ghc-stage1" -H32m -O -package-name terminfo-0.3.1.1 -hide-all-packages -i ilibraries/terminfo/. --ilibraries/terminfo/dist-install/build -ilibraries/termin

Status of exception handling

What's the status of exception handling? A couple of years ago, I think it wasn't clear how to do that in the Haskell context. Are there any GHC extensions which provide means to retry on temporary errors, without passing too much status around? I've seen on the Wiki that backtraces are still an

Re: Floating point problems

* > On Wed, 2006-08-30 at 14:58 -0400, David Roundy wrote: >> It's >> sad, but we're stuck with it, as I'm not aware of any compiler that is >> capable of generating IEEE arithmetic. > > Gcc man page: > > -ffast-math You quoted the wrong paragraph. Here's the right one: `-ffloat-store' Do n

Re: Floating point problems

* David Roundy: > definition of the variable and the comparison, this check may be > failed. The reason is that intermediate results are commonly stored "commonly" = "on legacy i386 platforms" > at higher than double precision, leading to non-IEEE arithmetic. AFAIK, GCC's behavior is not in it

Re: Replacement for GMP: Update

* Peter Tanski: > Quite right; my mistake: under the OpenSSL license a developer cannot > mention features of the software in advertising materials, so the > license grant of the GPL-OpenSSL program to the developer is void. > The reason I mentioned "users" only was that in the particular > proble

Re: Replacement for GMP: Update

* Peter Tanski: > On the other hand, the OpenSSL FAQ at faq.html#LEGAL2> mentions that some "GPL" programs do not allow > binary combination (static linking) or interoperation (dynamic > linking) with OpenSSL. Honestly I have not seen any "GPL" licenses > like t

Re: jhc vs ghc and the surprising result involving ghcgeneratedassembly.

* Lennart Augustsson: > Simon Marlow wrote: >>>Is it correct that you use indirect gotos across functions? Such >>>gotos aren't supported by GCC and work only by accident. >> Yes, but cross-function gotos are always to the beginning of a >> function. > > Is that enough to ensure that the constant

Re: jhc vs ghc and the surprising result involving ghc generated assembly.

>> It seems that the goto-based version leads to different static branch >> prediction results, which happen to be favorable. > > It has nothing to do with branch prediction. I know > it is determined ENTIRELY by stack use. In both cases, The C compiler emits code which doesn't use the stack. __

Re: jhc vs ghc and the surprising result involving ghc generatedassembly.

>> Is it correct that you use indirect gotos across functions? Such >> gotos aren't supported by GCC and work only by accident. > > Even direct gotos aren't universally supported. Some info > in Fergus Henderson's paper may be of interest > > http://felix.sourceforge.net/papers/mercury_to_c.ps Th

Re: jhc vs ghc and the surprising result involving ghcgeneratedassembly.

* Simon Marlow: >> However, beginning with GCC 3.4, you can use: >> >> extern void bar(); >> >> void foo() >> { >> void (*p)(void) = bar; >> p(); >> } > > Interesting.. though I'm not sure I'm comfortable with relying on gcc's > tail call optimisation to do the right thing. Aren't there sid

Re: jhc vs ghc and the surprising result involving ghc generatedassembly.

* Simon Marlow: >>> gcc started generating this rubbish around version 3.4, if I recall >>> correctly. I've tried disabling various optimisations, but can't >>> seem to convince gcc not to generate the extra jump. You don't get >>> this from the native code generator, BTW. >> >> But the compari

Re: jhc vs ghc and the surprising result involving ghc generated assembly.

* > On Tue, 2005-11-01 at 17:30 +0100, Florian Weimer wrote: > >> > use C control constructs rather than gotos. >> >> With GCC version 4, this will have no effect because the gimplifier >> converts everything to goto-style anyway. > > Felix generates C

Re: jhc vs ghc and the surprising result involving ghc generatedassembly.

* Simon Marlow: > gcc started generating this rubbish around version 3.4, if I recall > correctly. I've tried disabling various optimisations, but can't seem > to convince gcc not to generate the extra jump. You don't get this from > the native code generator, BTW. But the comparison is present

Re: jhc vs ghc and the surprising result involving ghc generated assembly.

* John Meacham: > loop: > > if () goto loop; > > is not equivalent to a do-while loop, loop invarients cannot be hoisted out of > the above for instance (except in some cases... it is all quite tricky and we > want gcc to have as much freedom as possible). do-while loops are converted to this for