Comparing the performance of gcc and other compilers

[Yang Zhang <yanghatespam@xxxxxxxxx>]

I recently came across:

http://biolpc22.york.ac.uk/wx/wxhatch/wxMSW_Compiler_choice.html

via:

http://www.digitalmars.com/d/archives/24911.html

Are there any more recent but similar such benchmarks comparing gcc 
(g++) against other compilers on various dimensions, for x86/x86_64, on 
real applications like this wx library?

Is there an understanding as to the principal causes behind the apparent 
lower performances on gcc's part in this benchmark?
--
Yang Zhang
http://www.mit.edu/~y_z/