No, I’m talking about Spectre. The example given in the paper was
if (x < array1_size) y = array2[array1[x] * 256];
If array1[x] evaluates to NaR then you won’t get different parts of array2 in cache depending on what values were in memory where you ran off the end of array1. But of course there are lots of Spectre-like attacks that might be possible and who knows if the Mill is resistant to all of them.