https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63661 --- Comment #11 from howarth at bromo dot med.uc.edu --- This issue isn't specific to Yosemite. I also see the failure at -O2 with gcc-4.9.1 on darwin13.4.0 using the cctools (as and ld) from Xcode 6.