Category Archives: bit shift

“Unusual uses of SSE2” posted to github

In this month’s frenzy of putting source code out there in a usable form, I’ve posted source to github for the SSE2 implementations of string search, BNDM search, sorting [16] doubles, and bit-matrix transpose; plus some convenience tools for SSE2. … Continue reading

Posted in bit, bit matrix transpose, bit shift, ffs, SSE2, string search, Uncategorized | 2 Comments

SSE2 bit matrix transpose special case … 8 x 256 … for Marek

It turns out that Marek’s Idea of the Day: Bitsliced SipHash used my SSE2 bit-matrix transpose¬†routine, but it wasn’t fast enough. This is normally the case for SSE2: the more specific the problem, the better the code can be. I … Continue reading

Posted in algorithm, bit, bit shift, SSE2 | Tagged , , | Leave a comment

The “C” preprocessor: not as cryptic as you’d think

The C preprocessor is a modest macro-expansion language (check out “m4” if you want to see an immodest one).¬† Basic symbols and function-macros are convenient for giving meaningful names to constants and tiny function calls, with the rewarding feeling that … Continue reading

Posted in bit shift, preprocessor | Tagged , , , , , , | 6 Comments

SSE2 bit shift

For some reason, there are a ridiculously many google hits on this blog, for the string “SSE2 bit shift”. I didn’t post verbatim code for this, just cpp hints on addressing the silly const-arg-ness of counts for SSE2 shift operators. … Continue reading

Posted in bit, bit shift, SSE2, Uncategorized | Leave a comment

What is SSE !@#$% good for? #2: Bit vector operations

You’ll notice that my definition of “good for” does not include video codec operations or other very specialized computations. You will probably never write a video codec in your life (well, perhaps you will — you know whom I mean). … Continue reading

Posted in algorithm, bit, bit shift, Uncategorized | 6 Comments