Phoronix: Mozilla Spots Massive Performance Regression In GCC

Mozilla developers on the GCC mailing list have been expressing what they describe as a "massive performance regression" and "what might be the biggest compiler-upgrade-related performance difference we've seen at Mozilla." The Mozilla developers have upgraded from GCC 4.3 to GCC 4.5, which was released in April, and now they are experiencing massive slowdowns...

http://www.phoronix.com/vr.php?view=ODM2NQ