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Which compiles to faster code: ‘ans = n * 3’ or ‘ans = n+(n*2)’?
Assuming that n is either an int or a long, and it is is running on a modern Win32 Intel box.
Would this be different if there was some dereferencing involved, that is, which of these would be faster?
long a; long *pn; long ans; ... *pn = some_number; ans = *pn * 3;
Or
ans = *pn+(*pn*2);
Or, is it something one need not worry about as optimizing compilers are likely to account for this in any case?
IMO such micro-optimization is not necessary unless you work with some exotic compiler. I would put readability on the first place.