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Add phase FlowSensitiveReductionPhase. It is possible to remove GuardingPiNodes, CheckCastNodes, and FixedGuards during HighTier under certain conditions (control-flow sensitive conditions). The phase added in this commit (FlowSensitiveReductionPhase) does that, and in addition replaces usages with "downcasting" PiNodes when possible thus resulting in more precise object stamps (e.g., non-null). Finally, usages of floating, side-effects free, expressions are also simplified (as per control-flow sensitive conditions). The newly added phase runs only during HighTier and can be deactivated using Graal option FlowSensitiveReduction (it is active by default).
author Miguel Garcia <miguel.m.garcia@oracle.com>
date Fri, 25 Apr 2014 16:50:52 +0200
parents 7b23cb975cf2
children
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<html>
<head>
<title>
Replay
</title>
</head>
<body>

<h1>Compiler replay</h1>
<p>
The compiler replay is a function to repeat the compiling process from a crashed java process in compiled method<br>
This function only exists in debug version of VM
</p>
<h2>Usage</h2>
<pre>
First, use SA to attach to the core file, if succeeded, do
       hsdb&gt; dumpreplaydata &lt;address&gt; | -a | &lt;thread_id&gt; [&gt; replay.txt]
       create file replay.txt, address is address of Method, or nmethod(CodeBlob)
       hsdb&gt; buildreplayjars [all | boot | app]
       create files:
         all:
           app.jar, boot.jar
         boot:
           boot.jar
         app:
           app.jar
       exit SA now.
Second, use the obtained replay text file, replay.txt and jar files, app.jar and boot.jar, using debug version of java
       java -Xbootclasspath/p:boot.jar -cp app.jar -XX:ReplayDataFile=&lt;datafile&gt; -XX:+ReplayCompiles ....
       This will replay the compiling process.

       With ReplayCompiles, the replay will recompile all the methods in app.jar, and in boot.jar to emulate the process in java app.

notes:
       1) Most time, we don't need the boot.jar which is the classes loaded from JDK. It will be only modified when an agent(JVMDI) is running and modifies the classes.
       2) If encounter error as "&lt;flag&gt;" not found, that means the SA is using a VMStructs which is different from the one with corefile. In this case, SA has a utility tool vmstructsdump which is located at agent/src/os/&lt;os&gt;/proc/&lt;os_platform&gt;

       Use this tool to dump VM type library:
       vmstructsdump libjvm.so &gt; &lt;type_name&gt;.db

       set env SA_TYPEDB=&lt;type_name&gt;.db (refer different shell for set envs)