Re: Efficient Bit Vector Manipulation.

["Jeffrey R. Carter" <spam.jrcarter.not@spam.not.acm.org>]

On 05/15/2015 05:07 AM, Vincent wrote:
> 
> I need to extract in a very efficient way, information from the bit sequence
> that represents a 32 bits Positive number, named I > 0.

Given your need to extract sequences of bits as integers, I'd say using an
Unsigned_* type from Interfaces would probably be best. This also has the
advantage of being endian independent.

Finding the most-significant 1 bit can be done with a binary search. Shifting
and masking out the B and E values is then fairly simple.

-- 
Jeff Carter
"C++ is like jamming a helicopter inside a Miata
and expecting some sort of improvement."
Drew Olbrich
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