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author | Paul Eggert <eggert@cs.ucla.edu> | 2017-08-29 14:52:57 -0700 |
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committer | Paul Eggert <eggert@cs.ucla.edu> | 2017-08-29 14:58:49 -0700 |
commit | 9b4b2e9fc8dfd37ad8f44940a16330c477f896ea (patch) | |
tree | 5bef08feb71816f3de5805465d966514ca13ff4b /INSTALL | |
parent | e13bdfee1742a7cc1eff5dc3bfbe2d71ea3532ef (diff) | |
download | emacs-9b4b2e9fc8dfd37ad8f44940a16330c477f896ea.tar.gz |
Be more conservative in link time optimization doc
While testing --enable-link-time-optimization with GCC 7.1.1
I ran into a serious GCC code-generation bug which makes me
think that --enable-link-time-optimization should be
discouraged for typical installs (Bug#28213). See:
https://bugzilla.redhat.com/show_bug.cgi?id=1486455
Diffstat (limited to 'INSTALL')
-rw-r--r-- | INSTALL | 18 |
1 files changed, 7 insertions, 11 deletions
@@ -339,17 +339,13 @@ Use --disable-silent-rules to cause 'make' to give more details about the commands it executes. This can be helpful when debugging a build that goes awry. 'make V=1' also enables the extra chatter. -Use --enable-link-time-optimization to enable link-time optimizer. If -you're using GNU compiler, this feature is supported since version 4.5.0. -If 'configure' can determine number of online CPUS on your system, final -link-time optimization and code generation is executed in parallel using -one job per each available online CPU. - -This option is also supported for clang. You should have GNU binutils -with 'gold' linker and plugin support, and clang with LLVMgold.so plugin. -Read http://llvm.org/docs/GoldPlugin.html for details. Also note that -this feature is still experimental, so prepare to build binutils and -clang from the corresponding source code repositories. +Use --enable-link-time-optimization to enable link-time optimization. +With GCC, you need GCC 4.5.0 and later, and 'configure' arranges for +linking to be parallelized if possible. With Clang, you need GNU +binutils with the gold linker and plugin support, along with the LLVM +gold plugin <http://llvm.org/docs/GoldPlugin.html>. Link time +optimization is not the default as it tends to cause crashes and to +make Emacs slower. The '--prefix=PREFIXDIR' option specifies where the installation process should put emacs and its data files. This defaults to '/usr/local'. |