diff options
Diffstat (limited to 'llvm/tools')
| -rw-r--r-- | llvm/tools/llvmc2/doc/LLVMC-Reference.rst | 38 |
1 files changed, 26 insertions, 12 deletions
diff --git a/llvm/tools/llvmc2/doc/LLVMC-Reference.rst b/llvm/tools/llvmc2/doc/LLVMC-Reference.rst index 2d782572987..a389ea69685 100644 --- a/llvm/tools/llvmc2/doc/LLVMC-Reference.rst +++ b/llvm/tools/llvmc2/doc/LLVMC-Reference.rst @@ -121,7 +121,7 @@ generic:: $ mv Simple.td MyPlugin.td -Note that the plugin source directory should be placed under +Note that the plugin source directory must be placed under ``$LLVMC_DIR/plugins`` to make use of the existing build infrastructure. To build a version of the LLVMC executable called ``mydriver`` with your plugin compiled in, use the following command:: @@ -129,13 +129,6 @@ infrastructure. To build a version of the LLVMC executable called $ cd $LLVMC_DIR $ make BUILTIN_PLUGINS=MyPlugin DRIVER_NAME=mydriver -When linking plugins dynamically, you'll usually want a 'bare-bones' -version of LLVMC that has no built-in plugins. It can be compiled with -the following command:: - - $ cd $LLVMC_DIR - $ make BUILTIN_PLUGINS="" - To build your plugin as a dynamic library, just ``cd`` to its source directory and run ``make``. The resulting file will be called ``LLVMC$(LLVMC_PLUGIN).$(DLL_EXTENSION)`` (in our case, @@ -146,7 +139,28 @@ directory and run ``make``. The resulting file will be called $ make $ llvmc2 -load $LLVM_DIR/Release/lib/LLVMCSimple.so -In the future LLVMC will be able to load TableGen files directly. +Sometimes, you will want a 'bare-bones' version of LLVMC that has no +built-in plugins. It can be compiled with the following command:: + + $ cd $LLVMC_DIR + $ make BUILTIN_PLUGINS="" + +How plugins are loaded +====================== + +It is possible for LLVMC plugins to depend on each other. For example, +one can create edges between nodes defined in some other plugin. To +make this work, however, that plugin should be loaded first. To +achieve this, the concept of plugin priority was introduced. By +default, every plugin has priority zero; to specify the priority +explicitly, put the following line in your ``.td`` file:: + + def Priority : PluginPriority<$PRIORITY_VALUE>; + # Where PRIORITY_VALUE is some integer > 0 + +Plugins are loaded in order of their (increasing) priority, starting +with 0. Therefore, the plugin with the highest priority value will be +loaded last. Customizing LLVMC: the compilation graph @@ -194,9 +208,9 @@ The definition of the compilation graph (see file As you can see, the edges can be either default or optional, where optional edges are differentiated by an additional ``case`` expression used to calculate the weight of this edge. Notice also that we refer -to tools via their names (as strings). This allows us to add edges to -an existing compilation graph without having to include all tool -definitions that it uses. +to tools via their names (as strings). This makes it possible to add +edges to an existing compilation graph in plugins without having to +know about all tool definitions used in the graph. The default edges are assigned a weight of 1, and optional edges get a weight of 0 + 2*N where N is the number of tests that evaluated to |
