http://gcc.gnu.org/bugzilla/show_bug.cgi?id=60969
--- Comment #10 from Uroš Bizjak <ubizjak at gmail dot com> --- (In reply to H.J. Lu from comment #5) > to load a SFmode value into mm0 for later use. MMX register should never be allocated for moves, unless absolutely necessary to satisfy insn constraints. This was fine-tuned for reload by using "*" and "!" in MMX alternatives (please see "*movsf_internal" pattern) and for some reason LRA works in a different way.