------- Comment #6 from rguenth at gcc dot gnu dot org 2008-08-01 13:21 ------- with -march=core2 it uses
movd %xmm0, %rax movq %rax, %xmm0 with -march=opteron (and -march=generic) it uses movhps .LC0(%rip), %xmm0 ISTR there is some penalty for using movq on opteron? -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36992