On Wednesday, 7 September 2016 at 14:46:46 UTC, Sai wrote:
I suspected the same, most of the CPUs support fast floating
point operations anyway (with FPUs), shouldn't take a lot more
time than doing integer arithmetic. Unless we are targeting
8bit avr or something similar.
No. Floating point in binaries are represented as
v = m * 2 ^ e
Now:
v0 / v1 = (m0 * 2 ^ e0) / (m1 * 2 ^ e1)
v0 / v1 = (m0 / m1) * 2 ^ (e0 - e1)
ie to do a 32 bits float division, you need to do a 24 bits
integer division, while when doing a 32bits integer division you
need to do a 32bits integer division (!)
The same apply to floating point multiply that are usually faster
than integer multiply. In fact, on some machines, multiplying
floats is faster than adding them.
