如果你问的是程序运行的时间，而不是一些运行时的帮助函数库，如printf，那么方法就是使用任何其他程序都可以用来测量其CPU使用率的相同系统调用。在Microsoft Win64上，这是GetProcessTime（）API，它接受以下64位参数，请记住首先推送最后一个参数，并将前4个参数传递到寄存器中。以下代码片段直接在此答案中编写，根本未进行测试

GetTimeSoFar PROC NEAR
    ; Stack is now aligned at multiple of 16
    sub rsp,32  ; Space for return vars and alignment
    push -1     ; 64 bit handle for the current process
    sub rsp,32  ; Space for 4 args
    lea r9,[rsp+40]  ; address of a 64 bit output var for creatTim
    lea r8,[rsp+48]  ; address of a 64 bit scratch var for exitTim
    lea rdx,[rsp+56] ; address of a 64 bit output var for kernTim
    lea rcx,[rsp+64] ; address of a 64 bit output var for userTim
    ; Stack is now aligned at multiple of 16 minus 8
    mov rax,[__imp_GetProcesTime]
    call rax ; Or use equivalent retpoline
    ; Stack is now aligned at multiple of 16 minus 8
    add rsp,40  ; Remove arg space and one pushed arg
    pop r9      ; r9 is now creation time in 100ns units since year 1600
    pop r8      ; r8 is now invalid data placeholder for exit time
    pop rdx     ; rdx is now time spent in NT kernel syscalls in 100ns units
    pop rcx     ; rcx in now program CPU user mode runtime in 100ns units.
    ; Stack is now aligned at multiple of 16
    ret         ; Or jump to retpoline for return
GetTimeSoFar ENDP

GetLastErrorWrap PROC NEAR
    sub rsp,40
    ; Stack is now aligned at multiple of 16 minus 8
    mov rax,[__imp_GetLastError]
    call rax ; Or use equivalent retpoline
    add rsp,40
    ; Stack is now aligned at multiple of 16
    mov ecx,eax
    shr ecx,16
    cmp cx,8007h
    jne notWin32AsHRESULT
    movsx eax,cx
notWin32AsHRESULT: 
    test eax,eax
    jne hasLastErr
    mov eax,1297 ; ERROR_UNIDENTIFIED_ERROR
hasLastErr:
    ; Stack is now aligned at multiple of 16
    ret         ; Or jump to retpoline for return
GetLastErrorWrap ENDP

    ; At top of main function
    sub rsp,localvarssize
    ; Stack is now aligned at multiple of 16
    push rdx ; Align stack
    ; Stack is now aligned at multiple of 16 minus 8
    call GetTimeSoFar
    pop rdx  ; Align stack
    ; Stack is now aligned at multiple of 16
    test rax,rax
    jz failCheckLastErr;
    mov [LocalVarWithValueBeforeRun], rcx

    ; TODO, TODO, Put calculations here

    push rdx ; Align stack
    ; Stack is now aligned at multiple of 16 minus 8
    call GetTimeSoFar
    pop rdx  ; Align stack
    ; Stack is now aligned at multiple of 16
    test rax,rax
    jz failCheckLastErr;
    sub rcx,[LocalVarWithValueBeforeRun]
    mov r8,10000000
    mov rax,rcx
    xor rdx,rdx
    div r8
    ; rdx is now seconds spent
    ; rax is now decimal seconds spent, printf as exactly 7 digits
    mov r8,rax
    lea rcx,StrTimePrintf ; "Runtime=%I64u.%07us\n"
    sub rsp,40
    ; Stack is now aligned at multiple of 16 minus 8
    call printf
    add rsp,40
    ; Stack is now aligned at multiple of 16
    ; Return success here
    xor rax,rax
    add rsp,localvarssize
    ; Stack is now aligned at multiple of 16
    ret ; Or jump to retpoline for return
failCheckLastErr:
    sub rsp,40   ; Scratch space for var area and alignment padding
    ; Stack is now aligned at multiple of 16 minus 8
    call GetLastErrorWrap
    mov [rsp + 32],eax  ; Save error code in alignment pad area
    mov r8d,eax
    mov edx,eax
    lea rcx,StrTimeMeasFailed ; "\nGetProcesTime() failed err=%d(0x%08X)\n"
    ; Stack is now aligned at multiple of 16 minus 8
    call printf
    ; Return error code as system exit code
    mov eax,[rsp + 32]
    add rsp,localvarssize + 40
    ; Stack is now aligned at multiple of 16
    ret ; Or jump to retpoline for return