c++ - Are multiple sequential array access optimised? -

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will c++ compilers automatically optimise following code calculate 3*i once, , increment result, or must programmer code this?

void writetoarray(int i, int a, int b, int c) {    array[3*i][1]=a;    array[3*i][2]=b;    array[3*i][3]=c; }

when enable optimization, compilers not precompute common index 3*i pointer array + (3*i)*sizeof (*array).


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