Hlaaftana, thanks for confirming. I was really tired yesterday and though I was doing something wrong.
cdome, your message makes not too much sense for me currently. Indeed I tried using unlikely() for this test, which made no difference, as expected, as automatic branch prediction should work fine here. Indeed I wonder if Nim supports branchless cmov instructions at all currently, maybe not because of so much goto use? At least I have not seen a cmov in Nims assembler listings yet. My feeling is, that mul is indeed slow in this special loop -- will inspect assembly listing when I have some more time.
