Harald Alvestrand wrote: > Ted Faber wrote: > >> On Mon, Jun 12, 2006 at 02:11:19PM +0200, Iljitsch van Beijnum wrote: >> >> >>> The problem with text is that you have to walk through memory and >>> compare characters. A LOT. >>> >> >> That's not where your code spends its time. >> >> Run gprof(1). The majority of time your code spends is spent doing the >> 2 integer divides per text to integer conversion and in strtoimax >> (called by fscanf). >> Multiplying or dividing is the worst thing you can do on a CPU in >> general. > Note that CPUs are different; some multiply faster than others, compared > to the rest of the HW. > > And if you really need to, you can optimize... a multiplication by 10, > for instance, can be done by two left shifts and an addition (a*10 = a > <<3 + a<<1); You might not end up with the same set of condition codes at the end, though... Joe
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