foo:
.LFB6:
        movabsq $10000000000, %rdx
        xorl    %ecx, %ecx
        .p2align 4,,7
.L2:
        movl    $1, %eax
        subl    %ecx, %eax
        subq    $1, %rdx
        movl    %eax, %ecx
        jne     .L2
        rep ; ret