Re: [PATCH] ntdll: Implement _alldvrm() and _aulldvrm().

[Alexandre Julliard]

Zebediah Figura  writes:
> +static LONGLONG _alldvrm_wrapper(LARGE_INTEGER a, LARGE_INTEGER b, LARGE_INTEGER *rem)
> +{
> - /* _alldvrm() divides two LONGLONGs and returns the quotient in edx:eax and
> -
> * the remainder in ebx:ecx. */
> -
> - LONGLONG ret;
> -
> - __asm__ __volatile__ (
> -
>    "pushl %%ebx\n\t"
> -
>    "pushl %3\n\t"
> -
>    "pushl %4\n\t"
> -
>    "pushl %5\n\t"
> -
>    "pushl %6\n\t"
> -
>    "call *%7\n\t"
> -
>    "movl %%ebx, %1\n\t"
> -
>    "movl %%ecx, %2\n\t"
> -
>    "popl %%ebx\n\t"
> -
>    : "=A" (ret), "=r" (rem->HighPart), "=r" (rem->LowPart)
> -
>    : "ri" (b.HighPart), "ri" (b.LowPart), "ri" (a.HighPart), "ri" (a.LowPart), "m" (p_alldvrm)
> -
>    : "ebx", "ecx"
> - );

That sort of assembly with a million register constraints is fragile,
and will most likely break depending on optimization options.
> - /* _alldvrm(0x0123456701234567, 3) */
> - a.HighPart = a.LowPart = 0x01234567;
> - b.QuadPart = 3;
> - ret = _alldvrm_wrapper(a, b, &rem);
> - ok(ret == 0x61172255b66c77ULL, "got %x%08x\n", (DWORD)(ret >> 32), (DWORD)ret);

Please avoid long long constants.