March 2015 - ghc-devs

Hoopl advice: How to extend the graph?
by Joachim Breitner 06 Mar '15

06 Mar '15

Dear devs, I haven’t worked with our Cmm representation before, so I have a beginner question: What function I should reach for when I want to look at each block (or each Last node) in an CmmGraph, possibly modifying it and possibly adding auxillary nodes on the way? It seems that one could use dataflowPassFwd for it, but * I could not find any use of it, and * I do not need to run an analysis along, I just want to rewrite the blocks, so I am not sure if this is the right thing. Any pointers? Thanks, Joachim -- Joachim “nomeata” Breitner mail(a)joachim-breitner.de • http://www.joachim-breitner.de/ Jabber: nomeata(a)joachim-breitner.de • GPG-Key: 0xF0FBF51F Debian Developer: nomeata(a)debian.org

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Re: freebsd-amd64-head (FreeBSD/amd64 HEAD (Gabor Pali)), build 556, Success
by Karel Gardas 05 Mar '15

05 Mar '15

Hi, due to recent switch to full testsuite run, our buildbots now provides a lot of output due to much more failing testcases. The case with FreeBSD buildbots even got so far, that server can't handle amount of data and leaks some binary trash to the log. I would really be curious if this is a leak of runtime memory and so it shows serious bug somewhere in GHC rts or what is it exactly... If you are curious investigate output attached to the last night freebsd buildots status emails. Thanks, Karel PS: I'm assuming the builder infrastructure as run by Gabor on his server is still written in Haskell and compiled by GHC... On 03/ 4/15 04:49 AM, Builder wrote: > freebsd-amd64-head (FreeBSD/amd64 HEAD (Gabor Pali)), build 556 > > Build succeeded > Details: http://haskell.inf.elte.hu/builders/freebsd-amd64-head/556.html > > git clone | Success > create mk/build.mk | Success > get subrepos | Success > repo versions | Success > touching clean-check files | Success > setting version date | Success > booting | Success > configuring | Success > creating check-remove-before | Success > compiling | Success > creating check-remove-after | Success > compiling testremove | Success > simulating clean | Success > checking clean | Success > making bindist | Success > making srcdist | Success > uploading bindist | Success > uploading srcdist | Success > uploading tarball source | Success > testing bindist | Success > testing | Success > testsuite summary | Success > > Build succeeded > Details: http://haskell.inf.elte.hu/builders/freebsd-amd64-head/556.html > > > > > _______________________________________________ > ghc-builds mailing list > ghc-builds(a)haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-builds

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Fwd: PSA: building HEAD with Nix/NixOS
by member MP2E 04 Mar '15

04 Mar '15

Looks great, thank you! One question however, in one of the lines you have this command: 'nix-build '<nixpkgs>' -A haskell-ng.compiler.ghcHEAD --run-env -I /home/user' Is nix-build supposed to be nix-shell? Usage afterwards seems to indicate that it is, but I'm not 100% sure. On Tue, Mar 3, 2015 at 3:32 AM, Nikita Karetnikov <nikita(a)karetnikov.org> wrote: > I've just added instructions showing how easy it is to build GHC HEAD > and its dependencies with Nix/NixOS: > > > https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Linux#NixNixOS > > I hope someone finds them useful. > > _______________________________________________ > ghc-devs mailing list > ghc-devs(a)haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs > >

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LLVM failures
by Simon Peyton Jones 04 Mar '15

04 Mar '15

These two LLVM tests are still failing consistently for me (on Linux). I think Austin said this should not happen, and he would fix, but I can't find the thread. Anyway, what should I do? Simon <no location info>: You are using an old version of LLVM that isn't supported anymore! We will try though... /usr/bin/opt: /tmp/ghc60014_1/ghc60014_2.ll:7:6: error: expected type !0 = !{!"top", i8* null} Unexpected failures: llvm/should_compile T5681 [exit code non-0] (optllvm) llvm/should_compile T7571 [exit code non-0] (optllvm)

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Windows build broken
by Simon Peyton Jones 04 Mar '15

04 Mar '15

AAARGH! Windows build is broken again. Please can someone fix? In file included from rts\RtsMain.c:12:0: rts\PosixSource.h:31:0: error: "__USE_MINGW_ANSI_STDIO" redefined c:\code\head\inplace\mingw\bin\../lib/gcc/mingw32/4.5.2/../../../../include/_mingw.h:280:0: note: this is the location of the previous definition rts/ghc.mk:243: recipe for target 'rts/dist/build/RtsMain.o' failed make[1]: *** [rts/dist/build/RtsMain.o] Error 1

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GHC Weekly News - 2015/03/03
by Austin Seipp 03 Mar '15

03 Mar '15

(This post is available online at https://ghc.haskell.org/trac/ghc/blog/weekly20150303) Hi *, It's that time again! Today GHC HQ met on a Tuesday to avoid some scheduling conflicts, and that means it's time to send some news to people. Just a quick reminder from last week: we're hoping to make our third GHC 7.10.1 release candidate on '''Friday, March 13th''', with the final release on '''Friday, March 27th'''. Today, GHC HQ met up and mostly discussed the current status of GHC 7.10 and its bugs, which you can find on the Status page: https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.10.1 But we've also had a little more list activity this week than we did before: - Simon PJ showed up to tell everyone he'd be a bit busy due to upcoming ICFP deadlines! However, since it's passed as of last Friday, it looks like the coming weeks will be more normal. https://mail.haskell.org/pipermail/ghc-devs/2015-February/008420.html - Michael Snoyman started a thread about a serious bug that has eluded attention during the 7.10 RC period: `cabal haddock --hoogle` does not work! https://mail.haskell.org/pipermail/ghc-devs/2015-February/008412.html - Jan Bracker is working on using the new type-checking plugins infrastructure, and had a question about the usage of what the typechecker calls `EvTerms`. Adam swooped in to respond. https://mail.haskell.org/pipermail/ghc-devs/2015-February/008414.html - Ben Gamari has been working on #9661, but while trying to do so hit a very painful set of conditions due to the import dependency graph of the compiler, making his fix much more difficult. Simon responds with his thoughts. https://mail.haskell.org/pipermail/ghc-devs/2015-March/008432.html - After returning from an ICFP-writing-induced hiatus, Simon alerted us to a new paper of his describing his new, GADT-aware pattern matching checker. As usual, he'd love comments! The implementation will hopefully land in HEAD soon. https://mail.haskell.org/pipermail/ghc-devs/2015-March/008437.html - Nikita Karetnikov was kind enough to alert the list that he's gotten a nice, Nix/NixOS based solution to building GHC, which he's documented on the wiki. https://mail.haskell.org/pipermail/ghc-devs/2015-March/008445.html Some noteworthy commits that went into `ghc.git` in the past week include: - Commit aead01902e1c41e85b758dbafd15e60d08956374 - the `-fwarn-unused-binds` warning was split into 3 warnings, fixing #17 (one of our oldest open tickets). - Commit 5be8ed4da1963ed2d45a65fb61d761c977707cce - restores `integer-gmp` compatibility with GMP 4.x. This will be part of GHC 7.10. - Commit 31d4f2e9c89e22a91f98b4a4aa0f80af6b07b60f - `make test` in the top-level directory now works as expected. - Commit 5200bdeb26c5ec98739b14b10fc8907296bceeb9 - Replace Windows SEH handlers with VEH handlers, working uniformly across x86 and x86_64. Closed tickets the past week include: #9586, #10122, #10026, #8896, #10090, #10123, #10128, #10025, #10024, #10125, #9994, #9962, #10103, #10112, #10122, #9901, #10130, #10129, #9044, #8342, #8780, #10003, #17, #2530, #8274, and #10107. -- Regards, Austin Seipp, Haskell Consultant Well-Typed LLP, http://www.well-typed.com/

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Re: Hoopl and Arrows
by John Lato 03 Mar '15

03 Mar '15

Thomas, I'd be very careful mixing effectful arrows with the CCA framework. Effectful arrows are not necessarily commutative, so the CCA transformations may be invalid. I did something very similar a couple years ago, by creating an arrow instance that generated TH expressions. IME the ghc optimizer handled it extremely well, and no extra optimizations were necessary. John L. On 14:43, Mon, Mar 2, 2015 Justin Bailey <jgbailey(a)gmail.com> wrote: > Thomas, > > I did some stuff with Hoopl a few years ago as part of my Master's > thesis ("Using Dataflow Optimization Techniques with a Monadic > Intermediate Language"). In Chapter 3 ("The Hoopl Library"), I wrote > up an overview of Hoopl and work through a new example (new at the > time, at least). > > You can download my thesis from http://mil.codeslower.com. The example > code from that chapter is available at > https://github.com/m4dc4p/mil/blob/master/thesis/DeadCodeC.lhs. No > guarantees that it still compiles, but I'm glad to try and help needed > :) > > > On Mon, Mar 2, 2015 at 1:34 PM, Simon Peyton Jones > <simonpj(a)microsoft.com> wrote: > > Thomas > > > > > > > > Hoopl works on control flow graphs, whereas Core is lambda calculus. I > > really don’t think Hoopl is going to be any good for optimising Core. > > > > > > > > Ask the ghc-devs mailing list too. Someone there has been writing about > > arrows recently (take a look at the archive). > > > > > > > > Simon > > > > > > > > From: Thomas Bereknyei [mailto:tomberek@gmail.com] > > Sent: 02 March 2015 17:07 > > To: nr(a)cs.tufts.edu; Simon Peyton Jones > > Subject: Hoopl and Arrows > > > > > > > > I've been interested in Arrows and their optimization recently. I've run > > into problems during basic tooling so I built a quasiquoter for proc > > notation (still working on rec and let statements, but the rest of it > works) > > that converts from haskell-src-exts into a desugarred TH format. My > original > > goal was to implement "Casual Commutative Arrows" [1] but to make it > more > > user friendly and to include arrows with effects. I came across Hoopl > and at > > first glance I would think it can help with Arrow optimization, > especially > > with the tuple shuffling from desuggared proc-do notation. In spite of > the > > slogan of "Hoopl: Dataflow Optimization made Simple" and the git repo's > > testing folder, I'm not 100% clear on Hoopl usage. I would be interested > in > > anything that can get me started or even a thought or two whether it > would > > be worth looking into for Arrows. > > > > Simon, regarding [2], my quasiquoter can be rewritten to take `bind`, > > `bind_`, `fixA`, and `ifThenElseA` from scope rather than being built in. > > Would that help with #7828? I am not very familiar with GHC internals at > > the moment, and I am confused about the complexity of dsArrows.hs in > > contrast with my own parser. It seems I have a good start on it in the > > Parser module at [3], WARNING: untested and rough draft code, though > > suggestions and pointers are welcome. I was thinking of sending some of > my > > code to haskell-src-meta because they can't yet translate their version > of > > Exp into TH's ExpQ. > > > > -Tom > > > > > > [1] (https://hackage.haskell.org/package/CCA) > > [2] (https://ghc.haskell.org/trac/ghc/ticket/7828#comment:54) > > [3] (https://www.fpcomplete.com/user/tomberek/rulestesting) > > > > > > _______________________________________________ > > ghc-devs mailing list > > ghc-devs(a)haskell.org > > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs > > > _______________________________________________ > ghc-devs mailing list > ghc-devs(a)haskell.org > http://mail.haskell.org/cgi-bin/mailman/listinfo/ghc-devs >

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PSA: building HEAD with Nix/NixOS
by Nikita Karetnikov 03 Mar '15

03 Mar '15

I've just added instructions showing how easy it is to build GHC HEAD and its dependencies with Nix/NixOS: https://ghc.haskell.org/trac/ghc/wiki/Building/Preparation/Linux#NixNixOS I hope someone finds them useful.

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Heads up: top level `make test` now runs the full testsuite
by Thomas Miedema 03 Mar '15

03 Mar '15

Typing `make test` in the ghc root directory now runs the full testsuite, just like it already did in the `testsuite/tests` directory. If you want to run the fast testsuite, use the new targets `make fasttest` or `make fast`. The `validate` script still runs the same tests as before (depending on the argument, `--slow`, `--fast` or normal). References: https://ghc.haskell.org/trac/ghc/wiki/Building/StandardTargets#Topleveltarg… https://ghc.haskell.org/trac/ghc/wiki/Building/RunningTests -Thomas Miedema

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RE: Hoopl and Arrows
by Simon Peyton Jones 02 Mar '15

02 Mar '15

Thomas Hoopl works on control flow graphs, whereas Core is lambda calculus. I really don’t think Hoopl is going to be any good for optimising Core. Ask the ghc-devs mailing list too. Someone there has been writing about arrows recently (take a look at the archive). Simon From: Thomas Bereknyei [mailto:tomberek@gmail.com] Sent: 02 March 2015 17:07 To: nr(a)cs.tufts.edu; Simon Peyton Jones Subject: Hoopl and Arrows I've been interested in Arrows and their optimization recently. I've run into problems during basic tooling so I built a quasiquoter for proc notation (still working on rec and let statements, but the rest of it works) that converts from haskell-src-exts into a desugarred TH format. My original goal was to implement "Casual Commutative Arrows" [1] but to make it more user friendly and to include arrows with effects. I came across Hoopl and at first glance I would think it can help with Arrow optimization, especially with the tuple shuffling from desuggared proc-do notation. In spite of the slogan of "Hoopl: Dataflow Optimization made Simple" and the git repo's testing folder, I'm not 100% clear on Hoopl usage. I would be interested in anything that can get me started or even a thought or two whether it would be worth looking into for Arrows. Simon, regarding [2], my quasiquoter can be rewritten to take `bind`, `bind_`, `fixA`, and `ifThenElseA` from scope rather than being built in. Would that help with #7828? I am not very familiar with GHC internals at the moment, and I am confused about the complexity of dsArrows.hs in contrast with my own parser. It seems I have a good start on it in the Parser module at [3], WARNING: untested and rough draft code, though suggestions and pointers are welcome. I was thinking of sending some of my code to haskell-src-meta because they can't yet translate their version of Exp into TH's ExpQ. -Tom [1] (https://hackage.haskell.org/package/CCA) [2] (https://ghc.haskell.org/trac/ghc/ticket/7828#comment:54) [3] (https://www.fpcomplete.com/user/tomberek/rulestesting)

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