The Old New Thing

Integer signum in SSE

December 29, 2014 Dec 29, 2014 12/29/14

Raymond Chen

The signum function is defined as follows: There are a couple of ways of calculating this in SSE integers. One way is to convert the C idiom The SSE translation of this is mostly straightforward. The quirk is that the SSE comparison functions return −1 to indicate , whereas C uses +1 to represent . But this is easy to take into ...