#516: Enable Vectorisation in McLachlan ------------------------------------+--------------------------------------- Reporter: barry.wardell | Owner: Type: enhancement | Status: new Priority: major | Milestone: Component: EinsteinToolkit thorn | Version: Resolution: | Keywords: ------------------------------------+---------------------------------------
Comment (by eschnett):
How do you know that SSE 4a was not used? This is autodetected in vectors-8-SSE2.h. It may be that this autodetection is faulty, of course, if e.g. the Intel and GNU compilers use different conventions here.
Most of the vector instructions that we are using are defined in SSE 2. SSE 4.1 defines an instruction that allows a more efficient IfThen implementation, SSE 4a provides a more efficient implementation of a streaming partial store. Since you probably don't use streaming stores (Ian found them slower), it should make no difference whether SSE 4a is present or not.