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+++ b/hotspot/src/share/tools/IdealGraphVisualizer/README	Tue Jun 24 16:00:14 2008 -0700
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+The Ideal Graph Visualizer is a tool developed to help examine the
+intermediate representation of C2 which is commonly referred to as the
+"ideal graph".  It was developed in collaboration with the University
+of Linz in Austria and has been included as part of hotspot since that
+was the primary target of the tool.  The tool itself is fairly general
+with only a few modules that contain C2 specific elements.
+
+The tool is built on top of the NetBeans 6.0 rich client
+infrastructure and so requires NetBeans to build.  It currently
+requires Java 6 to run as it needs support for JavaScript for its
+filtering mechanism and assumes it's built into the platform.  It
+should build out of the box whit NetBeans 6 and Java 6 or later.  It's
+possible to run it on 1.5 by including Rhino on the classpath though
+that currently isn't working correctly.  Support for exporting graphs
+as SVG can be enabled by adding batik to the classpath which isn't
+included by default.
+
+It can be built on top of NetBeans 6.1 if you change the required
+modules to be platform8 instead of platform7.  The tool could run on
+JDK 1.5 with some reworking of the how the JavaScript support is
+enabled but currently it requires some tweaking of the setup.  This
+will be fixed in a later setup.
+
+The JVM support is controlled by the flag -XX:PrintIdealGraphLevel=#
+where # is:
+
+  0: no output, the default
+  1: dumps graph after parsing, before matching, and final code.
+     also dumps graph for failed compiles, if available
+  2: more detail, including after loop opts
+  3: even more detail
+  4: prints graph after parsing every bytecode (very slow)
+
+By default the JVM expects that it will connect to a visualizer on the
+local host on port 4444.  This can be configured using the options
+-XX:PrintIdealGraphAddress= and -XX:PrintIdealGraphPort=.
+PrintIdealGraphAddress can actually be a hostname.
+
+Alternatively the output can be sent to a file using
+-XX:PrintIdealGraphFile=filename.  Each compiler thread will get it's
+own file with unique names being generated by adding a number onto the
+provided file name.
+
+More information about the tool is available at
+http://wikis.sun.com/display/HotSpotInternals/IdealGraphVisualizer.