A better algorithm for ctz #550
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x*2^k equivalent to x<<k . Construct a number 0x0xFB5CA62, it have a features: when it left shift 0, left shift 1... left shift 31, it‘s most 5 significant bit just take all numbers from 0 to 31.
it makes ctz(0)=0
Avoided branches in lfs_npw2()
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Hmmm, the next step would be to run the CI benchmarks to see if this is worth taking in, but it seems CI doesn't want to run on this PR for some reason... debugging... |
geky
added
needs investigation
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x*2^k equivalent to x<<k . Construct a number 0x07C4ACDD, it have a features: when it left shift 0, left shift 1... left shift 31, it‘s most 5 significant bits just take all numbers from 0 to 31.