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This is an automatically generated e-mail. To reply, visit:
<a href="http://git.reviewboard.kde.org/r/102723/">http://git.reviewboard.kde.org/r/102723/</a>
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<p style="margin-top: 0;">On September 28th, 2011, 8:59 a.m., <b>Josef Weidendorfer</b> wrote:</p>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">I would expect that the ->constEnd() method completely gets inlined with compiler optimization turned on. So are you sure your change
improves anything for a release build? Anything performance related always needs to be backed by numbers from a release build. Numbers from a debug build are useless.</pre>
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<pre style="white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">I'll check again, but I think I compile with -O2 -g (RELEASE_DEBUG).In any case, it is a minor improvement compared to the use of QBitArray.count, and the removal of a for loop (I'm checking it this has been this way since the beginning, or if fixing it makes other things faster) as Rolf has pointed.</pre>
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<p>- Jaime Torres</p>
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<p>On September 27th, 2011, 8:42 p.m., Jaime Torres Amate wrote:</p>
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<div>Review request for kdelibs.</div>
<div>By Jaime Torres Amate.</div>
<p style="color: grey;"><i>Updated Sept. 27, 2011, 8:42 p.m.</i></p>
<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Description </h1>
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<pre style="margin: 0; padding: 0; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; white-space: -o-pre-wrap; word-wrap: break-word;">Using this way to build a for loop: for (const_iterator it=list.constBegin, end=list.constEnd ; it != end; ++it)
and replacing the count of bits with the QBitArray method for doing that.
callgrind says:
before: 2984 calls to constBegin, 0,00%. 2960531 calls to constEnd, 2.33%
after: 2921 calls to constBegin, 0,00%. 2921 calls to constEnd, 0.00%
before: calcDiversity, 55.83% (debug enabled)
after: calcDiversity, 14,46% (debug enabled)
buildsycoca is still not faster than light, but it is only a four lines patch.</pre>
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<h1 style="color: #575012; font-size: 10pt; margin-top: 1.5em;">Diffs</b> </h1>
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<li>kdecore/sycoca/ksycocadict.cpp <span style="color: grey">(17ed9ac)</span></li>
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<p><a href="http://git.reviewboard.kde.org/r/102723/diff/" style="margin-left: 3em;">View Diff</a></p>
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