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| -rw-r--r-- | docs/GoldPlugin.html | 35 |
1 files changed, 24 insertions, 11 deletions
diff --git a/docs/GoldPlugin.html b/docs/GoldPlugin.html index 77a417f..66e099b 100644 --- a/docs/GoldPlugin.html +++ b/docs/GoldPlugin.html @@ -27,7 +27,7 @@ <p>Building with link time optimization requires cooperation from the system linker. LTO support on Linux systems requires that you use the <a href="http://sourceware.org/binutils">gold linker</a> which supports -LTO via plugins. This is the same system used by the upcoming +LTO via plugins. This is the same mechanism used by the <a href="http://gcc.gnu.org/wiki/LinkTimeOptimization">GCC LTO</a> project.</p> <p>The LLVM gold plugin implements the @@ -41,10 +41,15 @@ The same plugin can also be used by other tools such as <tt>ar</tt> and <div class="doc_section"><a name="build">How to build it</a></div> <!--=========================================================================--> <div class="doc_text"> - <p>You need to build gold with plugin support and build the LLVMgold -plugin.</p> + <p>You need to have gold with plugin support and build the LLVMgold +plugin. Check whether you have gold running <tt>/usr/bin/ld -v</tt>. It will +report “GNU gold” or else “GNU ld” if not. If you have +gold, check for plugin support by running <tt>/usr/bin/ld -plugin</tt>. If it +complains “missing argument” then you have plugin support. If not, +such as an “unknown option” error then you will either need to +build gold or install a version with plugin support.</p> <ul> - <li>Build gold with plugin support: + <li>To build gold with plugin support: <pre class="doc_code"> mkdir binutils cd binutils @@ -56,9 +61,11 @@ cd build ../src/configure --enable-gold --enable-plugins make all-gold </pre> - That should leave you with binutils/build/gold/ld-new which supports the -<tt>-plugin</tt> option. - + That should leave you with <tt>binutils/build/gold/ld-new</tt> which supports the <tt>-plugin</tt> option. It also built would have +<tt>binutils/build/binutils/ar</tt> and <tt>nm-new</tt> which support plugins +but don't have a visible -plugin option, instead relying on the gold plugin +being present in <tt>../lib/bfd-plugins</tt> relative to where the binaries are +placed. <li>Build the LLVMgold plugin: Configure LLVM with <tt>--with-binutils-include=/path/to/binutils/src/include</tt> and run <tt>make</tt>. @@ -72,7 +79,7 @@ make all-gold the plugin <tt>.so</tt> file. To find out what link command <tt>gcc</tt> would run in a given situation, run <tt>gcc -v <em>[...]</em></tt> and look for the line where it runs <tt>collect2</tt>. Replace that with - <tt>ld-new -plugin /path/to/LLVMgold.so</tt> to test it out. Once you're + <tt>ld-new -plugin /path/to/libLLVMgold.so</tt> to test it out. Once you're ready to switch to using gold, backup your existing <tt>/usr/bin/ld</tt> then replace it with <tt>ld-new</tt>.</p> <p>You can produce bitcode files from <tt>llvm-gcc</tt> using @@ -83,6 +90,11 @@ make all-gold passes the <tt>-plugin</tt> option to ld. It will not look for an alternate linker, which is why you need gold to be the installed system linker in your path.</p> + <p>If you want <tt>ar</tt> and <tt>nm</tt> to work seamlessly as well, install + <tt>libLLVMgold.so</tt> to <tt>/usr/lib/bfd-plugins</tt>. If you built your + own gold, be sure to install the <tt>ar</tt> and <tt>nm-new</tt> you built to + <tt>/usr/bin</tt>. + <p> </div> <!-- ======================================================================= --> @@ -141,8 +153,9 @@ $ llvm-gcc -use-gold-plugin a.a b.o -o main # <-- link with LLVMgold plugin <div class="doc_section"><a name="lto_autotools">Quickstart for using LTO with autotooled projects</a></div> <!--=========================================================================--> <div class="doc_text"> - <p><tt>gold</tt>, <tt>ar</tt> and <tt>nm</tt> all support plugins now, so everything should be - in place for an easy to use LTO build of autotooled projects:</p> + <p>Once your system <tt>ld</tt>, <tt>ar</tt> and <tt>nm</tt> all support LLVM + bitcode, everything is in place for an easy to use LTO build of autotooled + projects:</p> <ul> <li>Follow the instructions <a href="#build">on how to build libLLVMgold.so</a>.</li> <li>Install the newly built binutils to <tt>$PREFIX</tt></li> @@ -194,7 +207,7 @@ as much as gold could without the plugin.</p> src="http://www.w3.org/Icons/valid-html401-blue" alt="Valid HTML 4.01"></a> <a href="mailto:nicholas@metrix.on.ca">Nick Lewycky</a><br> <a href="http://llvm.org">The LLVM Compiler Infrastructure</a><br> - Last modified: $Date: 2009-01-01 23:10:51 -0800 (Thu, 01 Jan 2009) $ + Last modified: $Date: 2010-04-16 23:58:21 -0800 (Fri, 16 Apr 2010) $ </address> </body> </html> |