http://gcc.gnu.org/bugzilla/show_bug.cgi?id=55941
--- Comment #6 from Uros Bizjak <ubizjak at gmail dot com> 2013-02-15 08:55:05 UTC --- With a fix, testcase compiles to (-O2): f: addsd %xmm0, %xmm2 movapd %xmm2, %xmm0 ret gcc-4.7 generates: f: addsd %xmm2, %xmm0 ret I have opened PR56339 for this problem.