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Ryosuke Niwa
known as rniwa.
known as rniwa.


I don't know why people have such a hard time understanding that I'm not interested in engaging in discussions or debates at all. The only reason I use SNS is because there are things I want to say but don't necessarily want to broadcast them to the entire world. In most cases, I'm not interested in justifying or supporting my positions or hearing opposing opinions.
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One of the most important things I learned at the Google S.F. office might be how to enjoy cheese & bread.
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Q: What do you get in the alert below?

<!DOCTYPE html>
<option name="length">
<option name="namedItem">
var select = document.querySelector('select');
select.options.namedItem = 4;
alert(select.options.length + ', ' + select.options.namedItem);
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I've ported the R's implementation of the Shapiro-Wilk (normality) test to JavaScript for you.
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I don't want to be too egoistic but I want to share my life story for anyone behind in their education:
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It was a fun one night project :) I think I coded the entire thing in roughly two hours.


I've added run-perf-tests the ability to aggregate results locally with
--output-json-path option.
This new feature is very useful when you want to compare performance test

Say we have two WebKit checkouts:

1. At revision X with a patch that may have regressed Dromaeo/dom-traverse.html
2. At revision X without the patch

Then execute run-perf-tests with the said option as follows in both
run-perf-tests --output-json-path=~/perf-test-results.json

Just like that, ~/perf-test-results.html is generated with beautiful flot
graphs summarizing the results.
Sample results page:
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Have you been annoyed by having to manually copy & paste performance test results from Terminal? I say no more!

I'm adding run-perf-tests the ability to generate results.html with beautiful flot graphs in:

It can even aggregate results from multiple runs of run-perf-tests. So if you've ran run-perf-tests multiple times with the same JSON file path (specified by --output-json-path), results.html will contain the results from all previous runs in each graph.

Furthermore, you can aggregate results from different WebKit checkouts because the output JSON file is solely determined by --output-json-path option. For example, if you have two checkouts of WebKit with and without a patch, you can execute run-webkit-perf --output-json-path=/Users/rniwa/output.json on both checkouts and compare the results.

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REGRESSION(r122873): 15% regression on Dromaeo/dom-attr

Last week, I wrote a function that runs a statement for each value of enum. To ensure this function is updated when a new value is added to the enum, I wrote a simple "for" loop over the values of enum that calls ALWAYS_INLINE function with a giant switch statement on the enum values.

I was thinking that compilers are smart enough to detect that the loop is of a fixed length, unroll the loop, and then use constant propagation to see that switch statement reduces to a single statement. It turned out that gcc doesn't, and my patch caused a 15% performance regression on some Dromaeo test (dom-attr).

My fix? Use template meta programming to unroll the loop and inline the heck out of the function.
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