The Old New Thing

Setting, clearing, and testing a single bit in an SSE register

December 22, 2014 Dec 22, 2014 12/22/14

Raymond Chen

Today I'm going to set, clear, and test a single bit in an SSE register. Why? On Mondays I don't have to explain why. First, we use the trick from last time that lets us generate constants where all set bits are contiguous, and apply it to the case where we want only one bit. We start by setting all bits in . We then shift both 64...