asm {
_DIV_U64_BY_U64::
        PUSH    RBP
        MOV     RBP,RSP
        XOR     RDX,RDX
        MOV     RCX,64
        MOV     RAX,SF_ARG1[RBP]
        MOV     RBX,SF_ARG2[RBP]
@@1:    SHL1    RAX
        RCL1    RDX
        CMP     RBX,RDX
        JA      @@2
        INC     RAX
        SUB     RDX,RBX
@@2:    LOOP    @@1
        POP     RBP
        RET1    16
}

_extern _DIV_U64_BY_U64 I64 DivU64ByU64(I64 dividend,I64 divisor);

"123456/10=%d\n",DivU64ByU64(123456,10);