[DRAGONERO]

I’d expect most vendors do, at least in their closed source drivers. You could also check in the mesa project if this is implemented but it’s definitely possible to do

[ryao]

Shader compilers tend to be very latency sensitive, so “it takes too long to run” would be a valid reason why it is not done if it is not done.

[DRAGONERO]

Shader compilers mostly use LLVM even though runtime is a constraint, if the pattern is common enough it’s definitely easy to match (it’s just two intrinsics after all) meaning you can do it for cheap in instcombine which you’re going to be running anyway