What is faster Div or SSE2 divss ?
And how write asm code work like Div ?
And asm code faster than Div (asm comand)

The timings of division instructions (integer, single, double) depend on the divisor. Why don't you run some tests on you own computer?

tthsqe
ok !
PS: А так хотелось поговорить,пообщяться.

A) What is faster Div or SSE2 divss ?

They use the same execution units.

B) And how write asm code work like Div ?

a. Binary: Shift and subtract until zero.
b. Approximate and check/modify. (Newton's method)

C) And asm code faster than Div (asm comand)

Only possible for constant cases. At runtime it might be useful to calculate 1/x and multiply. Often algorithms can be setup in that fashion - to eliminate or reduce division use.

Easiest method:

Obviously, these also apply to remainder or modulus.

Your questions cannot be answered because DIV/IDIV work on integers, but DIVSS/DIVPS work on floating point numbers. They are generally equally fast, integer one taking 20-27 clocks while floating point taking 10-14 clock to execute (these are the latencies for Sandy Bridge CPU). While comparing DIVSS to FDIV you lose precision. FDIV takes 10-24 clocks. So you see they are competing in the same class, measured in "tens of clocks".

There are some tricks (with integer arithmetric):
http://www.azillionmonkeys.com/qed/adiv.html
For example I often find myself using (x*0x55555556) shr 32 instead of x/3
because in simple cases it works and is a lot faster. You can easily extend this
to division by 6, 12 etc by shifting. Useful in 24-bi / 32-bit RGB / RGBA conversions.