ae486b263c
f2b5b0a3b48f9241971c14238040048f8b630811 build: add linker optimization flags to guix (fanquake) b8b050a8d642e38c81d1e451750c2c8db92fee5e build: add linker optimization flags to gitian descriptors (fanquake) Pull request description: This PR adds `-Wl,O2` to our gitian and guix LDFLAGS. This makes the linker perform certain optimisations (and is different from LTO). Any -O argument will enable optimizations in GNU ld. We can use -O2 here, as this matches our compile flags. Note that this would also enable additional optimizations if using the lld or gold linkers, when compared to -O0. A nice writeup + diagrams of some of these optimizations is available here: http://lwn.net/Articles/192624/. #### master ```bash # bitcoind Histogram for `.gnu.hash' bucket list length (total of 3 buckets) Length Number % of total Coverage 0 1 ( 33.3%) 0.0% 1 0 ( 0.0%) 0.0% 2 1 ( 33.3%) 40.0% 3 1 ( 33.3%) 100.0% ``` ```bash # bitcoin-qt Histogram for `.gnu.hash' bucket list length (total of 3 buckets) Length Number % of total Coverage 0 0 ( 0.0%) 0.0% 1 1 ( 33.3%) 10.0% 2 0 ( 0.0%) 10.0% 3 0 ( 0.0%) 10.0% 4 1 ( 33.3%) 50.0% 5 1 ( 33.3%) 100.0% ``` #### this PR: ```bash # bitcoind Histogram for `.gnu.hash' bucket list length (total of 8 buckets) Length Number % of total Coverage 0 3 ( 37.5%) 0.0% 1 5 ( 62.5%) 100.0% ``` ```bash # bitcoin-qt Histogram for `.gnu.hash' bucket list length (total of 19 buckets) Length Number % of total Coverage 0 9 ( 47.4%) 0.0% 1 10 ( 52.6%) 100.0% ``` #### GNU ld -O > If level is a numeric values greater than zero ld optimizes the output. This might take significantly longer and therefore probably should only be enabled for the final binary. At the moment this option only affects ELF shared library generation. Future releases of the linker may make more use of this option. Also currently there is no difference in the linker’s behaviour for different non-zero values of this option. Again this may change with future releases. #### lld -O > Optimize output file size ACKs for top commit: dongcarl: ACK f2b5b0a3b48f9241971c14238040048f8b630811 laanwj: ACK f2b5b0a3b48f9241971c14238040048f8b630811 Tree-SHA512: e53f3a4338317dbec65d3a93b57b5a6204aabdf9ac82d99447847a3c8627facc53c58c2cf947376f13edd979fc8129a80f18d9ebeccd191a576c83f1dad5c513
Bitcoin Core integration/staging tree
What is Bitcoin?
Bitcoin is an experimental digital currency that enables instant payments to anyone, anywhere in the world. Bitcoin uses peer-to-peer technology to operate with no central authority: managing transactions and issuing money are carried out collectively by the network. Bitcoin Core is the name of open source software which enables the use of this currency.
For more information, as well as an immediately usable, binary version of the Bitcoin Core software, see https://bitcoincore.org/en/download/, or read the original whitepaper.
License
Bitcoin Core is released under the terms of the MIT license. See COPYING for more information or see https://opensource.org/licenses/MIT.
Development Process
The master branch is regularly built and tested, but is not guaranteed to be
completely stable. Tags are created
regularly to indicate new official, stable release versions of Bitcoin Core.
The contribution workflow is described in CONTRIBUTING.md and useful hints for developers can be found in doc/developer-notes.md.
Testing
Testing and code review is the bottleneck for development; we get more pull requests than we can review and test on short notice. Please be patient and help out by testing other people's pull requests, and remember this is a security-critical project where any mistake might cost people lots of money.
Automated Testing
Developers are strongly encouraged to write unit tests for new code, and to
submit new unit tests for old code. Unit tests can be compiled and run
(assuming they weren't disabled in configure) with: make check. Further details on running
and extending unit tests can be found in /src/test/README.md.
There are also regression and integration tests, written
in Python, that are run automatically on the build server.
These tests can be run (if the test dependencies are installed) with: test/functional/test_runner.py
The Travis CI system makes sure that every pull request is built for Windows, Linux, and macOS, and that unit/sanity tests are run automatically.
Manual Quality Assurance (QA) Testing
Changes should be tested by somebody other than the developer who wrote the code. This is especially important for large or high-risk changes. It is useful to add a test plan to the pull request description if testing the changes is not straightforward.
Translations
Changes to translations as well as new translations can be submitted to Bitcoin Core's Transifex page.
Translations are periodically pulled from Transifex and merged into the git repository. See the translation process for details on how this works.
Important: We do not accept translation changes as GitHub pull requests because the next pull from Transifex would automatically overwrite them again.
Translators should also subscribe to the mailing list.