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<p>So many of you have struggled with the last midterm problem and
finding good compiler flags that work. Let's see if I can
simplify and clarify...<br>
</p>
<p>1. For your base run compile with -O0</p>
<p>2. Now pick three flags for your optimized run (not -O, -O1, -O2,
-O3, -Os, -Og, -Ofast). Then create a performance plot with two
curves -- one for your baseline and one for your optimized result
that was built using all of the flags you chose. Indicate on the
plot which flags you used.</p>
<p>As an example, on an old Xeon processor using the 11.2.0
compilers I got the following results...</p>
<p>No optimization...</p>
<p> 1000 554.267822 <br>
2000 559.134399 <br>
3000 561.197144 <br>
4000 559.307434 <br>
5000 561.014465 <br>
6000 561.945557 <br>
7000 563.093933 <br>
8000 562.336792 <br>
9000 561.579956 <br>
10000 561.907227 <br>
</p>
<p>With a selection of optimization/architecture compiler flags...</p>
<p> 1000 581.106140 <br>
2000 586.146118 <br>
3000 586.070557 <br>
4000 581.988281 <br>
5000 581.462219 <br>
6000 583.838684 <br>
7000 586.284851 <br>
8000 586.672729 <br>
9000 585.067749 <br>
10000 587.153320 <br>
</p>
<p><br>
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<div class="moz-signature">-- <br>
<b><em>Andrew J. Pounds, Ph.D.</em></b><br>
<em>Professor of Chemistry and Computer Science</em><br>
<em>Director of the Computational Science Program</em><br>
<em>Mercer University</em><br>
<em>1501 Mercer University Drive, Macon, GA 31207 </em><br>
<em>(478) 301-5627</em><br>
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