------- Comment #1 from hjl dot tools at gmail dot com 2008-09-04 16:02 ------- "-O2 -march=core2 -fno-ira -fno-regmove" generates
movq x(%rip), %mm0 paddd y(%rip), %mm0 movq %mm0, -8(%rsp) movq -8(%rsp), %rax It seems that regmove isn't effective for IRA. -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=37364