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On 7/8/11 4:09 PM, Andrew Ruef wrote:
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Hi list,
<div><br>
</div>
<div>I am trying to implement the technique outlined in the
following paper: <a moz-do-not-send="true"
href="http://www.cs.umd.edu/%7Emwh/papers/martin10ownership.html">http://www.cs.umd.edu/~mwh/papers/martin10ownership.html</a> in
LLVM. My approach so far involves the use of an IR level
transform (via runOnFunction) to identify memory loads and
stores. One thing I need to do (I am pretty sure I need to do it
at least) is automatically mark each stack frame as "owned" by
the current thread. </div>
<div><br>
</div>
<div>I'm not sure where the best place in the LLVM architecture to
do this is. As I currently understand it, the concept of a stack
frame appears pretty late in target code generation. I've hacked
in a hook for this in X86FrameLowering.cpp in the emitPrologue
and emitEpilogue methods. </div>
<div><br>
</div>
<div>Is there a cleaner way I can do this? Is there a way I can
subclass the X86 code generator to "hook" those two methods and
insert my instrumentation? Is there something I'm missing with
runOnMachineFunction? <br>
</div>
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<br>
I'm stepping beyond what I know a little bit, but have you looked at
writing a MachineFunctionPass? A student here at Illinois wrote a
MachineFunctionPass to insert additional epilogue code into
functions. Assuming that it's possible, putting your functionality
into a MachineFunctionPass should be cleaner than modifying the code
generator directly (MachineFunctionPass'es may even be load-able
into llc).<br>
<br>
Check out the doxygen docs for MachineFunctionPass
(<a class="moz-txt-link-freetext" href="http://llvm.org/doxygen/classllvm_1_1MachineFunctionPass.html">http://llvm.org/doxygen/classllvm_1_1MachineFunctionPass.html</a>),
MachineFunction
(<a class="moz-txt-link-freetext" href="http://llvm.org/doxygen/classllvm_1_1MachineFunction.html">http://llvm.org/doxygen/classllvm_1_1MachineFunction.html</a>), and
MachineFrameInfo
(<a class="moz-txt-link-freetext" href="http://llvm.org/doxygen/classllvm_1_1MachineFrameInfo.html">http://llvm.org/doxygen/classllvm_1_1MachineFrameInfo.html</a>).<br>
<br>
-- John T.<br>
<br>
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cite="mid:CAMaQ4+dpRAf-KaPv8Wz8HY3AjkCy6dwj1HZzY3GTV=BG5PkUTA@mail.gmail.com"
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<div>Thank you, <br>
<div><br>
</div>
<div>Andrew</div>
</div>
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