Which loop is faster?


for (I = 0; I < N; I++)
  for (J = 0; J < M; J++)
    update(Xs[I][J]);
or

for (I = 0; I < N; I++)
  for (J = 0; J < M; J++)
    update(Xs[J][I]);
???

>>6
Not that it matters when it is a separate statement, such as above, the compiler (assuming you use one) should be able to optimize it. But at least for IA32/IA64, int var = ++i; is fewer instructions than int var = i++;

Deal with it, kid