SIMD test optimization?

[SoniEx2]

A lot of the SIMD tests run the same floats through all of the lanes, instead of just assuming lanewise operations to be implemented in a lanewise way. Is there any particular reason to do it this way? You could probably cut down the size of the tests by a factor of 2 or 4 if you just assumed all the lanes behave the same.

[rossberg]

Isn't more detailed testing and more coverage always better?

[SoniEx2]

it would certainly be able to catch hardware bugs that only manifest with certain lanes.

but it also takes 4x longer?

[dtig]

Is speed a constraint for running tests? For operations that don't map to a single hardware instruction, or for engines that scalarize, testing all lanes could still be helpful in catching implementation bugs.