Created attachment 8555704 [details] index.html User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.9; rv:35.0) Gecko/20100101 Firefox/35.0 Build ID: 20150122214805 Steps to reproduce: 1. Open the attached file. 2. Look at console. Actual results: The 'slow' function executes ten times slower than the 'fast' function: slow: 0.88ms fast: 0.07ms slow: 0.68ms fast: 0.06ms Note that at no time do the generated functions (wrapFunc) ever get called. This is just as test of how quickly they can be parsed. This is a minimal test case derived from Google's Blockly where one (using 'arguments') function parses 200 times slower than another function (not using 'arguments'). Firefox only. Expected results: Both functions should run at the same speed. Here's Chrome: slow: 0.010ms fast: 0.011ms slow: 0.022ms fast: 0.018ms
Hi, I have tested this on Mac OS X 10.10 with Firefox Nightly 46.0a1 and I can't reproduce the issue, the "slow" function is 2 times slower than the "fast" function. Do you still have this problem? Please download the Firefox Nightly from here: https://nightly.mozilla.org/ and retest the problem.
On Windows 10 for me: 35.0.1: slow: 0.08ms attachment.cgi:14 fast: 0.02ms attachment.cgi:22 slow: 0.02ms attachment.cgi:14 fast: 0.02ms attachment.cgi:22 44.0b4: slow: 1.24ms attachment.cgi:14 fast: 0.48ms attachment.cgi:22 slow: 0.66ms attachment.cgi:14 fast: 0.41ms attachment.cgi:22
Product: Firefox → Core
Given all the parsing changes that have happened since this was filed, I somewhat doubt this is still relevant. Profiling to see if this still exists is definitely in order -- but as I'm going on a long vacation now, I can't be the one to deal with it. :-\
As the original submitter, I can no longer replicate this issue. Closing.
Status: UNCONFIRMED → RESOLVED
Last Resolved: 10 months ago
Resolution: --- → WORKSFORME
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