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Re^2: vec overflow?

by Anonymous Monk
on Jun 25, 2013 at 01:07 UTC ( #1040504=note: print w/ replies, xml ) Need Help??


in reply to Re: vec overflow?
in thread vec overflow?

Thanks very much. Good to know.


Comment on Re^2: vec overflow?
Re^3: vec overflow?
by BrowserUk (Pope) on Jun 25, 2013 at 01:34 UTC

    Another workaround that is useful if your algorithm benefits from having a single contiguous bitvector -- for example if you want to count the set bits quickly using my $popcount = unpack '%32b*', $bitvector; -- is to nest calls to vec. Eg:

    vec( vec( $bitvector, $n >> 5, 64 ), $n & 0x1f, 1 ) = 1;

    Theoretically, as neither offset breaches the 2**31-1 barrier, this can allow you to address bitvectors up to 16GB/137 billion bits, though I don't have enough memory to try it.


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