It is a compiler intrinsic named after the SQRTPS instruction it's intended to generate. The "PS" refers to the vectorization type and stands for packed single.

It is a compiler intrinsic named after the SQRTPS instruction it's intended to generate. The "PS" refers to the vectorization type and stands for packed single. That being said, the naming of Intel's vector intrinsics _is_ pretty bad, such as the pi64 vs. epi64 difference. ARM's vector intrinsic naming, despite looking like having come from a cat sitting on the home row keys, is more consistent and has less gotchas.