page loading is very slow in IE when a less file is big

[ntopia]

I've used less.js(Client-side usage) 1.7.5 until yesterday.
Today, I upgraded less.js version to 2.3.1.
After that, the page loading time is terribly increased in IE. (before: 1 second / after: 20 seconds )

I think it happened because of less file's size and complex structure, so I can't make the reduced test case. Sorry.

IE version is 11 and OS is Windows 8.1.
Our less file size is 441kb, 18000 lines.
It happened with all of versions in 2.x tree, but not happened with 1.7.5.

I ran IE11's profiler and here is the result. I hope that it will help you.

Thanks.

[lukeapage]

can you send me the less file? I've been trying with bootstrap but I don't see anything too bad - with the latest less and bootstrap its around 1s.
Alternatively work out if one of the regular expressions is taking longer than any of the others by adding timings based on the regexp.

[ntopia]

I found your advice about 'chuckInput' option in #2339 (comment), so I set that option to true.
It makes the page amazingly faster than before.
Thank you so much.

[lukeapage]

Any chance you could share the less? Its hard to find or create long files with this behaviour. I think i may have fixed it on master, but good to check. Alt. I can send you a built less js file to try without chunk input set any more...