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<div class="moz-cite-prefix">On 2/18/16 1:17 PM, Laura personen
wrote:<br>
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<div>Thank you for your swift reply.<br>
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I also need some reference about instruction sequence in
llvm. I mean, do the order of instructions remain the same
as they appear in a .ll file? or do they change by
different optimizations (e.g. <a moz-do-not-send="true"
class=""
href="http://llvm.org/docs/CodeGenerator.html#ssa-based-machine-code-optimizations">SSA-based
Machine Code Optimizations</a>, <a
moz-do-not-send="true" class=""
href="http://llvm.org/docs/CodeGenerator.html#late-machine-code-optimizations">Late
Machine Code Optimizations</a>, etc.)? <br>
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I believe there are optimizations that can change the order of
instructions at the LLVM IR level. You can find a list of LLVM
optimizations at <a class="moz-txt-link-freetext" href="http://llvm.org/docs/Passes.html">http://llvm.org/docs/Passes.html</a>.<br>
<br>
When generating native code, the Instruction Scheduler will reorder
the native code instructions as well.<br>
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If they change, which algorithms are used for reordering
instructions? I appreciate a reference that explains them
or just gives the name of the algorithms that are used.<br>
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You can look at the list of passes, but to get more detail, you will
probably need to examine the source code.<br>
<br>
Regards,<br>
<br>
John Criswell<br>
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BR<br>
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Laura<br>
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<div class="gmail_extra"><br>
<div class="gmail_quote">On Thu, Feb 18, 2016 at 6:45 PM, John
Criswell <span dir="ltr"><<a moz-do-not-send="true"
href="mailto:jtcriswel@gmail.com" target="_blank">jtcriswel@gmail.com</a>></span>
wrote:<br>
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<div>On 2/18/16 12:03 PM, Laura personen via llvm-dev
wrote:<br>
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<div>Hi,<br>
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Is there any way to detect which virtual
registers are assigned to physical registers and
which ones are assigned to memory slots?<br>
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</span> At the LLVM IR level, no. However, it might be
possible for a MachineFunctionPass to determine this or to
modify the register allocator to record this information
somewhere for query by a MachineFunctionPass later.<br>
<br>
Regards,<br>
<br>
John Criswell<br>
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BR<br>
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Laura<br>
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<pre cols="72">--
John Criswell
Assistant Professor
Department of Computer Science, University of Rochester
<a moz-do-not-send="true" href="http://www.cs.rochester.edu/u/criswell" target="_blank">http://www.cs.rochester.edu/u/criswell</a></pre>
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<pre class="moz-signature" cols="72">--
John Criswell
Assistant Professor
Department of Computer Science, University of Rochester
<a class="moz-txt-link-freetext" href="http://www.cs.rochester.edu/u/criswell">http://www.cs.rochester.edu/u/criswell</a></pre>
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