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<div class="moz-cite-prefix">On 6/22/12 2:04 PM, Justin Holewinski
wrote:<br>
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<div class="gmail_quote">On Fri, Jun 22, 2012 at 2:46 PM,
amruth.rd <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:amruth.rd@knights.ucf.edu" target="_blank">amruth.rd@knights.ucf.edu</a>></span>
wrote:<br>
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<br>
Does LLVM allow mapping a virtual register to a specific
memory location? If not, how do we extract information on
where the virtual registers are mapped to?<br>
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<div>In general, you do not know where a virtual register is
mapped, and the mapping is dependent on the back-end. It
could be allocated or spilled onto the stack, or it may live
entirely within a physical register (e.g. no address).</div>
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<br>
To elaborate on what Justin said, at the LLVM IR level, you don't
know where a virtual register will live after code generation (or
even if it will live in the same "place;" the code generator is free
to allocate it to a register for part of its life and a stack spill
slot for another part of its life).<br>
<br>
You may be able to get this information if you write a
MachineFunction pass or some other code that is run by LLVM after
code generation and register allocation (because you can see the
generated code). However, I don't know enough about MachineFunction
passes to be sure that it's possible; that's just where I'd look if
I were you.<br>
<br>
-- John T.<br>
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<br>
Thanks,<br>
Amruth<br>
<br>
<br>
<br>
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-- <br>
<br>
<div>Thanks,</div>
<div><br>
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<div>Justin Holewinski</div>
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