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On 2/28/11 4:43 PM, Devang Patel wrote:
<blockquote
cite="mid:DC195044-5B1A-4564-AB55-B1DE3497EFCC@apple.com"
type="cite"><br>
<div>
<div>On Feb 28, 2011, at 2:35 PM, Naznin Fauzia wrote:</div>
<br class="Apple-interchange-newline">
<blockquote type="cite">Hi all,<br>
<br>
How Can I get the Loops around an Instruction?<br>
<br>
I know I can get the basic block of an instruction using
inst.getParent() which returns a BasicBlock*. Now I want to
use the getLoopFor(BasicBlock) method of the class LoopInfo.<br>
But I dont know how to get the LoopInfo.<br>
<br>
BasicBlock* bb = inst.getParent();<br>
<br>
(... what should I add here?)<br>
<br>
Loop* innerloop = LI -> getLoopFor(bb):<br>
<br>
</blockquote>
<br>
</div>
<div>Two steps:</div>
<div>1) In your pass's getAnalysisUsage(), request LoopInfo.</div>
<div><br>
</div>
<div>
<div><span class="Apple-tab-span" style="white-space: pre;"><font
class="Apple-style-span" face="Courier"> </font></span><font
class="Apple-style-span" face="Courier">virtual void
getAnalysisUsage(AnalysisUsage &AU) const {</font></div>
<div><span class="Apple-tab-span" style="white-space: pre;"><font
class="Apple-style-span" face="Courier"> </font></span><font
class="Apple-style-span" face="Courier"> AU.addRequired<LoopInfo>();</font></div>
<div><span class="Apple-tab-span" style="white-space: pre;"><font
class="Apple-style-span" face="Courier"> </font></span><font
class="Apple-style-span" face="Courier">}</font></div>
<div><br>
</div>
<div>2) In your runOnLoop() method get the analysis.</div>
<div><br>
</div>
<div><span class="Apple-tab-span" style="white-space: pre;"><font
class="Apple-style-span" face="Courier"> </font></span><font
class="Apple-style-span" face="Courier">LoopPass *</font><span
class="Apple-tab-span" style="white-space: pre;"><font
class="Apple-style-span" face="Courier">LI =
&getAnalysis<LoopInfo>();</font></span></div>
<div><span class="Apple-style-span" style="white-space: pre;"><br>
</span></div>
<div><span class="Apple-style-span" style="white-space: pre;">Now,
you can do LI->getLoopFor(...)</span></div>
</div>
</blockquote>
<br>
To add to what Devang has said, you may find the doxygen docs on
LoopInfo helpful:<br>
<br>
<a class="moz-txt-link-freetext" href="http://llvm.org/doxygen/classllvm_1_1LoopInfo.html">http://llvm.org/doxygen/classllvm_1_1LoopInfo.html</a><br>
<br>
-- John T.<br>
<br>
<br>
<blockquote
cite="mid:DC195044-5B1A-4564-AB55-B1DE3497EFCC@apple.com"
type="cite">
<div>
<div><span class="Apple-style-span" style="white-space: pre;"><br>
</span></div>
<div><span class="Apple-style-span" style="white-space: pre;">-</span></div>
<div><span class="Apple-style-span" style="white-space: pre;">Devang</span></div>
<div><br>
</div>
</div>
<br>
</blockquote>
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