Re: fast bit rotation
- Posted by "Derek Parnell" <ddparnell at bigpond.com> Jan 01, 2004
- 444 views
----- Original Message ----- From: "jiri babor" <jbabor at paradise.net.nz> To: <EUforum at topica.com> Subject: Re: fast bit rotation > > > Thanks, guys, for your tremendous response. Tommy's machine code looks most > promising. Currently I am looking at 24 bit integers, later I might even be > forced beyond the Euphoria's 31-bit limit. So, sorry, look up tables and > similar 8-bit solutions are interesting, but not of much practical use. Doesn't the INTEGER type only support 30-bit integers? I make the range for INTEGER types to be from (-power(2,30)) to (power(2,30) - 1). It seems that Euphoria uses 30-bits to hold the value, one bit to hold the sign and the 32nd bit to hold the flag to tell if its an integer or something else? Just guessing. > And thank you, Robert, for your explanation. I still think any > self-respecting language should have fast shifts and rotations built into > it. Why is this Jiri? I would have thought that they are only a few programming problems where bit shifting/rotating is of much use. Low-level device interfacing, cryptography, image/audio manipulating, low-RAM environments (8-bit embedded systems), ... What are you working on that needs it? -- Derek