Last I heard IE was closed source ... I'd love to know how he got his hands on the IE code base to make that measurement... All his posturing about - design decisions being a business need of google make me wonder whether this was a M$ sponsored article...
They say 'estimated'. A way to do that is to look at the disassembly of IE code, assuming an on average constant number of assembly instructions per C statement. I don't think that is a bad assumption, but it does ignore potential differences between compilers.
Also, IE source likely is available through Microsoft's Shared Source Initiative (http://www.microsoft.com/en-us/sharedsource/default.aspx). After all, Microsoft has vehemently argumented that IE is inseparable from the OS. I think it would require some lenient interpretation of that license to use it for this purpose, though.
Well you could instrument the source code and measure the number of calls, and compare that to the rough number of non-call ops per function. Not a perfect metric but it's something. His claims do seem far fetched though.
