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<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US">I can confirm that testing that condition is indeed useless<o:p></o:p></span></p>
<p class="MsoNormal"><span lang="EN-US" style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
<p class="MsoNormal"><span style="font-size:11.0pt;mso-fareast-language:EN-US"><o:p> </o:p></span></p>
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<b><span style="font-size:12.0pt;color:black">From: </span></b><span style="font-size:12.0pt;color:black">core-libs-dev <core-libs-dev-retn@openjdk.org> on behalf of Andrey Turbanov <turbanoff@gmail.com><br>
<b>Date: </b>Friday, 2022-November-25 at 14:18<br>
<b>To: </b>core-libs-dev <core-libs-dev@openjdk.java.net><br>
<b>Subject: </b>Redundant condition in java.math.MutableBigInteger#divideMagnitude<o:p></o:p></span></p>
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<p class="MsoNormal" style="margin-left:36.0pt"><span style="font-size:11.0pt">Hello.<br>
I noticed that IntelliJ IDEA show warning in the method<br>
java.math.MutableBigInteger#divideMagnitude<br>
here - <a href="https://github.com/openjdk/jdk/blob/4f65570204e2d38415e7761bd81660b081eae882/src/java.base/share/classes/java/math/MutableBigInteger.java#L1536">
https://github.com/openjdk/jdk/blob/4f65570204e2d38415e7761bd81660b081eae882/src/java.base/share/classes/java/math/MutableBigInteger.java#L1536</a><br>
It seems that condition is always 'true'<br>
<br>
if (rem.intLen == nlen) {<br>
<br>
'rem' and 'nlen' variables are not changed anyhow after this<br>
assignment a few lines above:<br>
<br>
int nlen = rem.intLen;<br>
<br>
To make sure that it's really true, I've modified source to include else branch:<br>
<br>
} else {<br>
throw new AssertionError("Condition 'rem.intLen == nlen' wasn't met.");<br>
}<br>
<br>
And all tests from "jdk/java/math" passed.<br>
<br>
<br>
Can we clean up the code to remove this condition? Code is already<br>
complex enough and each condition makes its reading harder.<br>
It was added as part of performance improvements in<br>
<a href="https://bugs.openjdk.org/browse/JDK-7082971">https://bugs.openjdk.org/browse/JDK-7082971</a><br>
<br>
<br>
Andrey Turbanov<o:p></o:p></span></p>
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