9 ms·

LLVM 3.8 Release Notes

150 points by bla2 11y ago

millstone 11y ago
> There are numerous improvements to the PowerPC target in this release That's interesting, who are the current PPC users contributing to LLVM? Is this all from IBM?
- jlebar 11y ago
  Highly quick-and-dirty: $ git log origin/release_37..origin/release_38 --no-merges -i --grep \ 'ppc\|power pc' --pretty='%ae' | grep --only-matching '@.*' | sort | \ uniq -c | sort -rn 16 @anl.gov 11 @gmail.com 7 @linux.vnet.ibm.com 4 @iteratee.net 3 @ca.ibm.com 2 @hanshq.net 2 @de.ibm.com 2 @apple.com 1 @samsung.com 1 @linaro.org 1 @imgtec.com 1 @googlemail.com 1 @codeaurora.org You'd have to look at the individual addresses to disambiguate who @gmail.com and @googlemail.com are; at least 5 are from a Googler. @iteratee.net is also a Googler.
  - ambrop7 11y ago
    The @anl.gov is probably this: https://www.alcf.anl.gov/bgclang-compiler https://www.alcf.anl.gov/bgclang-compiler See: https://en.wikipedia.org/wiki/Blue_Gene#Blue_Gene.2FQ https://en.wikipedia.org/wiki/Blue_Gene#Blue_Gene.2FQ "The Blue Gene/Q Compute chip is an 18 core chip. The 64-bit PowerPC A2 processor cores are 4-way simultaneously multithreaded, and run at 1.6 GHz."
  - dumael 11y ago
    As I know, some of those contributors are just making systemic changes throughout LLVM, which would require touching the PowerPC backend. I'm not at all surprised at the @[a-z.]+.ibm.com contributors, the @anl.gov is the code maintainer and highly visible contributor. The Argonne National Laboratory run a PowerPC based supercomputer afaik.
- deleted 11y ago
  [deleted]
- kev009 11y ago
  It seems a bit low considering IBM is funneling $1 _B_illion into Linux on POWER projects. IBM has long ties to GCC, but LLVM has captured the code generation library market even where gcc is used as the system or application compiler so it's more relevant than ever for them to put some people on it.
  - ahazred8ta 11y ago
    IBM makes a lot of announcements with price tags. Their track record says most of that money is spent on developing business applications RUNNING on Linux. Some is spent on FLOSS code contributions, but not the whole $1B.
webkike 11y ago
LLVM is a wonderful project, but I dont really know much about this release. How is it significant? Side note, I wonder if this is related to why one of my professors - Dr. Adve - has been so busy lately...
- kps 11y ago
  http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html
asb 11y ago
See the LLVM release notes here: http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html and the Clang release notes here: http://llvm.org/releases/3.8.0/tools/clang/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/tools/clang/docs/ReleaseNotes... If you want to keep up with the latest LLVM developments, you might want to sign up for my LLVM Weekly newsletter http://llvmweekly.org/ http://llvmweekly.org/
- wyldfire 11y ago
  Thanks, Alex. The newsletter is handy. And belated congratulations BTW.
- dang 11y ago
  Ok, we changed the URL to the release notes from http://www.llvm.org/releases/download.html#3.8.0 http://www.llvm.org/releases/download.html#3.8.0.
  - bla2 11y ago
    The original link linked to both llvm and clang release notes.
_wmd 11y ago
Every time you link to a download page instead of something useful like a release announcement God kills a kitten
kozukumi 11y ago
I love LLVM/Clang but I wish there was a simple tar (or several) I could download and extract on Windows that gave me a full working environment. Finding information on what you need and where you need to put it sucks for someone who wants to just get up and running quickly.
- dancsi 11y ago
  You can download a nice installer from here: http://llvm.org/releases/download.html http://llvm.org/releases/download.html
  - kozukumi 11y ago
    Yes but that installer doesn't actually install a fully working environment, you need the standard library from MinGW or MSVC as well.
    - tavert 11y ago
      That's unlikely to change any time soon, at least from the LLVM side. They're not really in the business of providing OS API headers. At least there's a Windows SDK download now that is smaller than the whole Visual Studio IDE, and the MinGW-w64 project is working on making fully LLVM-based toolchains more usable over time.
      - kozukumi 11y ago
        It would be nice if they could at least keep the documentation up to date on which MinGW-W64 builds work and which don't etc. I just don't have the time to muck around with things when I can just grab a MinGW build and it "just works" out of the box. With how friendly Microsoft are getting with Clang I was hoping we might see a LLVM+MSVCHeaders build appear. I am sure it is possible considering the new MS. I know I am lazy in wanting a one-click solution but my build environment is very important to me. I don't want to have to hack it together using blog posts from 6 months ago that might or might not give me a stable setup. I don't think it is too much to ask for something like TDM's GCC installer.
wyldfire 11y ago
OpenMP FTW! Also, I'm using libFuzzer in my CPython fuzzer [1], and it's getting more awesome with each release. [1] https://bitbucket.org/ebadf/fuzzpy https://bitbucket.org/ebadf/fuzzpy
jimktrains2 11y ago
http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html "Slightly less than half of the AVR backend has been merged in at this point. It is still missing a number large parts which cause it to be unusable, but is well on the road to being completely merged and workable." It would be awesome to be able to use LLVM to cross-compile. Perhaps rust could be made to easily run on a µc at that point!
- wyldfire 11y ago
  There's a C/C++ frontend/variant of clang that's useful for cross-compiling: ellcc [1]. [1] http://ellcc.org/ http://ellcc.org/
- shepmaster 11y ago
  > Perhaps rust could be made to easily run on a µc at that point! That's being worked on: https://github.com/avr-rust/rust https://github.com/avr-rust/rust Note that it's mainly the same developer behind the LLVM support as well: https://github.com/avr-llvm/llvm https://github.com/avr-llvm/llvm
arca_vorago 11y ago
LLVM has done some great things, but I strongly dislike it's license. "Source code under the NCSA license can be incorporated into proprietary products without the reciprocity requirements that copyleft free software licenses raise." -LLVM Wikipedia For this reason, I will continue to use GCC wherever possible. Not completely on topic, but I just wanted to make the point so that people understand that some of us actually do make decisions not purely from pragmatic standpoints.
- Sanddancer 11y ago
  Clang's an important project if for one reason that is slowly starting to gain footage in GCC. Everything's callable outside of the compiler. You can have the compiler loop in your IDE, for example, and take advantage of its AST manipulation for better refactoring, its unidentified behavior sanitizer to immediately get a warning when you're heading into the tall grass, etc. GCC is stymied on this part by more conservative elements of their leadership that don't want to expose this behavior that is a growing necessity in code development.
  - GFK_of_xmaspast 11y ago
    Even if one insists on sticking with gcc on ideological grounds, one should be glad clang exists because it seems to have lit a fire under the maintainers.
    - jeffdavis 11y ago
      The ideological reason to use GCC is to prevent clang/llvm from succeeding, which will drive everyone toward a copyleft product (GCC), which will encourage reciprocity. Your observation is no consolation for someone who subscribes to that ideology. (Personally, I do not subscribe to that ideology.)
- Joky 11y ago
  "so that people understand that some of us actually do make decisions not purely from pragmatic standpoints." Well I guess you meant in fact: "so that people understand that some of us actually do make decisions purely on ideologic standpoints."
riscy 11y ago
The most interesting parts of this release to me are OpenMP support by default, and the shrink-wrapping in the code generator. Shrink-wrapping [1] moves the prologue/epilogue code that wraps functions in order to setup and tear down their stack frames into the parts of the function that actually need it: consider two control-flow paths, where one doesn't actually need stack space so we can avoid performing those unnecessary instructions. [1] http://perso.ensta-paristech.fr/~bmonsuez/Cours/B6-4/Articles/papers19.pdf http://perso.ensta-paristech.fr/~bmonsuez/Cours/B6-4/Article...
pdknsk 11y ago
Unfortunately the official DEB packages have not been updated in about two months – nightly packages they are not. http://llvm.org/apt/ http://llvm.org/apt/
apaprocki 11y ago
I'd have to track down where it is in relation to 3.8 release, but Xan López at Igalia has been fixing all the backend blockers to get LLVM on SPARC64/Solaris working properly for us. Can't let the POWER folks get all the RISC legacy love! :)
jeffdavis 11y ago
It seems like rust bundles it's own version of llvm. Are patches from the rust community making it in slowly? Or are there some fundamental differences? Does Swift do something similar, or does it work with stock llvm?
- kaeso 11y ago
  > It seems like rust bundles it's own version of llvm. Are patches from the rust community making it in slowly? Or are there some fundamental differences? https://github.com/rust-lang/llvm/commits/rust-llvm-2016-02-20 https://github.com/rust-lang/llvm/commits/rust-llvm-2016-02-... The delta is minimal, and mostly consists in bugfixes and optimizations. All changes are typically forwarded upstream. Since long time, rustc can be built without using the embedded LLVM, and several distributions (eg. Debian) do that.
- kibwen 11y ago
  It's strange to say it, given that Swift's principal designer is the original creator of LLVM and given that Apple drives the majority of LLVM development, but Swift does indeed ship its own custom version of LLVM: https://github.com/apple/swift-llvm https://github.com/apple/swift-llvm . I'm not sure if, like Rust, Swift also works on stock LLVM. This is actually quite common. Emscripten ships its own copy of LLVM as well. Rust and Emscripten might actually be combining their efforts into a single LLVM branch this year, in order to provide better WebAssembly support for Rust.
  - Sanddancer 11y ago
    I'm curious if you've seen any of the work in-tree that's going on for a native webassembly target in LLVM? It's still early and super rough, but it seems something you may want to peek at.

150 points by bla2 11y ago

> There are numerous improvements to the PowerPC target in this release That's interesting, who are the current PPC users contributing to LLVM? Is this all from IBM?

jlebar 11y ago
Highly quick-and-dirty: $ git log origin/release_37..origin/release_38 --no-merges -i --grep \ 'ppc\|power pc' --pretty='%ae' | grep --only-matching '@.*' | sort | \ uniq -c | sort -rn 16 @anl.gov 11 @gmail.com 7 @linux.vnet.ibm.com 4 @iteratee.net 3 @ca.ibm.com 2 @hanshq.net 2 @de.ibm.com 2 @apple.com 1 @samsung.com 1 @linaro.org 1 @imgtec.com 1 @googlemail.com 1 @codeaurora.org You'd have to look at the individual addresses to disambiguate who @gmail.com and @googlemail.com are; at least 5 are from a Googler. @iteratee.net is also a Googler.
- ambrop7 11y ago
  The @anl.gov is probably this: https://www.alcf.anl.gov/bgclang-compiler https://www.alcf.anl.gov/bgclang-compiler See: https://en.wikipedia.org/wiki/Blue_Gene#Blue_Gene.2FQ https://en.wikipedia.org/wiki/Blue_Gene#Blue_Gene.2FQ "The Blue Gene/Q Compute chip is an 18 core chip. The 64-bit PowerPC A2 processor cores are 4-way simultaneously multithreaded, and run at 1.6 GHz."
- dumael 11y ago
  As I know, some of those contributors are just making systemic changes throughout LLVM, which would require touching the PowerPC backend. I'm not at all surprised at the @[a-z.]+.ibm.com contributors, the @anl.gov is the code maintainer and highly visible contributor. The Argonne National Laboratory run a PowerPC based supercomputer afaik.
deleted 11y ago
[deleted]
kev009 11y ago
It seems a bit low considering IBM is funneling $1 _B_illion into Linux on POWER projects. IBM has long ties to GCC, but LLVM has captured the code generation library market even where gcc is used as the system or application compiler so it's more relevant than ever for them to put some people on it.
- ahazred8ta 11y ago
  IBM makes a lot of announcements with price tags. Their track record says most of that money is spent on developing business applications RUNNING on Linux. Some is spent on FLOSS code contributions, but not the whole $1B.

webkike 11y ago

LLVM is a wonderful project, but I dont really know much about this release. How is it significant? Side note, I wonder if this is related to why one of my professors - Dr. Adve - has been so busy lately...

kps 11y ago
http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html

asb 11y ago

See the LLVM release notes here: http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html and the Clang release notes here: http://llvm.org/releases/3.8.0/tools/clang/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/tools/clang/docs/ReleaseNotes... If you want to keep up with the latest LLVM developments, you might want to sign up for my LLVM Weekly newsletter http://llvmweekly.org/ http://llvmweekly.org/

wyldfire 11y ago
Thanks, Alex. The newsletter is handy. And belated congratulations BTW.
dang 11y ago
Ok, we changed the URL to the release notes from http://www.llvm.org/releases/download.html#3.8.0 http://www.llvm.org/releases/download.html#3.8.0.
- bla2 11y ago
  The original link linked to both llvm and clang release notes.

_wmd 11y ago

Every time you link to a download page instead of something useful like a release announcement God kills a kitten

kozukumi 11y ago

I love LLVM/Clang but I wish there was a simple tar (or several) I could download and extract on Windows that gave me a full working environment. Finding information on what you need and where you need to put it sucks for someone who wants to just get up and running quickly.

dancsi 11y ago
You can download a nice installer from here: http://llvm.org/releases/download.html http://llvm.org/releases/download.html
- kozukumi 11y ago
  Yes but that installer doesn't actually install a fully working environment, you need the standard library from MinGW or MSVC as well.
  - tavert 11y ago
    That's unlikely to change any time soon, at least from the LLVM side. They're not really in the business of providing OS API headers. At least there's a Windows SDK download now that is smaller than the whole Visual Studio IDE, and the MinGW-w64 project is working on making fully LLVM-based toolchains more usable over time.
    - kozukumi 11y ago
      It would be nice if they could at least keep the documentation up to date on which MinGW-W64 builds work and which don't etc. I just don't have the time to muck around with things when I can just grab a MinGW build and it "just works" out of the box. With how friendly Microsoft are getting with Clang I was hoping we might see a LLVM+MSVCHeaders build appear. I am sure it is possible considering the new MS. I know I am lazy in wanting a one-click solution but my build environment is very important to me. I don't want to have to hack it together using blog posts from 6 months ago that might or might not give me a stable setup. I don't think it is too much to ask for something like TDM's GCC installer.

wyldfire 11y ago

OpenMP FTW! Also, I'm using libFuzzer in my CPython fuzzer [1], and it's getting more awesome with each release. [1] https://bitbucket.org/ebadf/fuzzpy https://bitbucket.org/ebadf/fuzzpy

jimktrains2 11y ago

http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html http://llvm.org/releases/3.8.0/docs/ReleaseNotes.html "Slightly less than half of the AVR backend has been merged in at this point. It is still missing a number large parts which cause it to be unusable, but is well on the road to being completely merged and workable." It would be awesome to be able to use LLVM to cross-compile. Perhaps rust could be made to easily run on a µc at that point!

wyldfire 11y ago
There's a C/C++ frontend/variant of clang that's useful for cross-compiling: ellcc [1]. [1] http://ellcc.org/ http://ellcc.org/
shepmaster 11y ago
> Perhaps rust could be made to easily run on a µc at that point! That's being worked on: https://github.com/avr-rust/rust https://github.com/avr-rust/rust Note that it's mainly the same developer behind the LLVM support as well: https://github.com/avr-llvm/llvm https://github.com/avr-llvm/llvm

arca_vorago 11y ago

LLVM has done some great things, but I strongly dislike it's license. "Source code under the NCSA license can be incorporated into proprietary products without the reciprocity requirements that copyleft free software licenses raise." -LLVM Wikipedia For this reason, I will continue to use GCC wherever possible. Not completely on topic, but I just wanted to make the point so that people understand that some of us actually do make decisions not purely from pragmatic standpoints.

Sanddancer 11y ago
Clang's an important project if for one reason that is slowly starting to gain footage in GCC. Everything's callable outside of the compiler. You can have the compiler loop in your IDE, for example, and take advantage of its AST manipulation for better refactoring, its unidentified behavior sanitizer to immediately get a warning when you're heading into the tall grass, etc. GCC is stymied on this part by more conservative elements of their leadership that don't want to expose this behavior that is a growing necessity in code development.
- GFK_of_xmaspast 11y ago
  Even if one insists on sticking with gcc on ideological grounds, one should be glad clang exists because it seems to have lit a fire under the maintainers.
  - jeffdavis 11y ago
    The ideological reason to use GCC is to prevent clang/llvm from succeeding, which will drive everyone toward a copyleft product (GCC), which will encourage reciprocity. Your observation is no consolation for someone who subscribes to that ideology. (Personally, I do not subscribe to that ideology.)
Joky 11y ago
"so that people understand that some of us actually do make decisions not purely from pragmatic standpoints." Well I guess you meant in fact: "so that people understand that some of us actually do make decisions purely on ideologic standpoints."

riscy 11y ago

The most interesting parts of this release to me are OpenMP support by default, and the shrink-wrapping in the code generator. Shrink-wrapping [1] moves the prologue/epilogue code that wraps functions in order to setup and tear down their stack frames into the parts of the function that actually need it: consider two control-flow paths, where one doesn't actually need stack space so we can avoid performing those unnecessary instructions. [1] http://perso.ensta-paristech.fr/~bmonsuez/Cours/B6-4/Articles/papers19.pdf http://perso.ensta-paristech.fr/~bmonsuez/Cours/B6-4/Article...

pdknsk 11y ago

Unfortunately the official DEB packages have not been updated in about two months – nightly packages they are not. http://llvm.org/apt/ http://llvm.org/apt/

apaprocki 11y ago

I'd have to track down where it is in relation to 3.8 release, but Xan López at Igalia has been fixing all the backend blockers to get LLVM on SPARC64/Solaris working properly for us. Can't let the POWER folks get all the RISC legacy love! :)

jeffdavis 11y ago

It seems like rust bundles it's own version of llvm. Are patches from the rust community making it in slowly? Or are there some fundamental differences? Does Swift do something similar, or does it work with stock llvm?

kaeso 11y ago
> It seems like rust bundles it's own version of llvm. Are patches from the rust community making it in slowly? Or are there some fundamental differences? https://github.com/rust-lang/llvm/commits/rust-llvm-2016-02-20 https://github.com/rust-lang/llvm/commits/rust-llvm-2016-02-... The delta is minimal, and mostly consists in bugfixes and optimizations. All changes are typically forwarded upstream. Since long time, rustc can be built without using the embedded LLVM, and several distributions (eg. Debian) do that.
kibwen 11y ago
It's strange to say it, given that Swift's principal designer is the original creator of LLVM and given that Apple drives the majority of LLVM development, but Swift does indeed ship its own custom version of LLVM: https://github.com/apple/swift-llvm https://github.com/apple/swift-llvm . I'm not sure if, like Rust, Swift also works on stock LLVM. This is actually quite common. Emscripten ships its own copy of LLVM as well. Rust and Emscripten might actually be combining their efforts into a single LLVM branch this year, in order to provide better WebAssembly support for Rust.
- Sanddancer 11y ago
  I'm curious if you've seen any of the work in-tree that's going on for a native webassembly target in LLVM? It's still early and super rough, but it seems something you may want to peek at.