yiannist / otp

ErLLVM: Erlang/OTP with an LLVM backend for HiPE

Erlang/OTP

Erlang is a programming language used to build massively scalable soft real-time systems with requirements on high availability. Some of its uses are in telecom, banking, e-commerce, computer telephony and instant messaging. Erlang's runtime system has built-in support for concurrency, distribution and fault tolerance.

OTP is set of Erlang libraries and design principles providing middle-ware to develop these systems. It includes its own distributed database, applications to interface towards other languages, debugging and release handling tools.

More information can be found at [erlang.org] 1.

Building and Installing

Information on building and installing Erlang/OTP can be found in the [$ERL_TOP/HOWTO/INSTALL.md] 5 document.

Contributing to Erlang/OTP

Here are the [instructions for submitting patches] 2.

In short:

• We prefer to receive proposed updates via email on the [erlang-patches] 3 mailing list or through a pull request.

• Pull requests will be handled once everyday and there will be essential testing before we will take a decision on the outcome of the request. If the essential testings fails, the pull request will be closed and you will have to fix the problem and submit another pull request when this is done.

• We merge all proposed updates to the pu (proposed updates) branch, typically within one working day.

• At least once a day, the contents of the pu branch will be built on several platforms (Linux, Solaris, Mac OS X, Windows, and so on) and automatic test suites will be run. We will email you if any problems are found.

• If a proposed change builds and passes the tests, it will be reviewed by one or more members of the Erlang/OTP team at Ericsson. The reviewer may suggest improvements that are needed before the change can be accepted and merged.

• Once or twice a week, a status email called ["What's cooking in Erlang/OTP"] 4 will be sent to the [erlang-patches] 3 mailing list.

Copyright and License

%CopyrightBegin%

Copyright Ericsson AB 2010-2012. All Rights Reserved.

The contents of this file are subject to the Erlang Public License, Version 1.1, (the "License"); you may not use this file except in compliance with the License. You should have received a copy of the Erlang Public License along with this software. If not, it can be retrieved online at http://www.erlang.org/.

Software distributed under the License is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License for the specific language governing rights and limitations under the License.

%CopyrightEnd%

otp's Issues

Use load/store metadata to inform LLVM Type-Based Alias Analysis

Talking with David Terei convinced me that using Type-Based Alias Analysis (TBAA) in LLVM could enable various optimization transformations; the LLVM CodeGen does not apply them because it doesn't know that SP, HP and P (virtual machine registers) can never alias!

• For more information about TBAA see LLVM Language Reference.
• For more information about the implementation of TBAA in the LLVM backend of GHC see Haskell wiki.

Implement tagged var liveness analysis on RTL

Implement a liveness analysis on RTL variables (only tagged) in order to reduce LLVM stack usage. Each RTL tagged var is mapped explicitly to a stack slot (with 'alloca') because it should be tracked by the Garbage Collector (marked with 'gcroot'). A trivial liveness analysis algorithm might significantly improve the performance of ErLLVM (especially in the cases of small recursive functions).

Wrong llc argument is used when calling hipe:c()

I followed the steps on this page: http://erllvm.softlab.ntua.gr/documentation/installation/ , and successfully installed both custom LLVM and Erlang/OTP. But the test procedures doesn't work for me:

1> c(test).
{ok,test}
2> hipe:c(test,[to_llvm]).
** exception exit: {hipe_llvm_main,opt,
                                   "llc: Unknown command line argument '-enable-hipe-prologue'.  Try: 'llc -help'\nllc: Did you mean '-hipe-prologue'?\n"}
     in function  hipe:run_compiler_1/3 (hipe.erl, line 678)
     in call from hipe:run_compiler/4 (hipe.erl, line 640)
     in call from hipe:c/3 (hipe.erl, line 328)

The compiled LLVM llc only has a option '-hipe-prologue', but it seems that the last commit in otp repo changed the option to '-enable-hipe-prologue'. Any suggestions?