[mike64_t]

Yes, the Nvidia SASS ISAs are not documented and emitting them is non trivial due to Nvidia GPUs not handling pipeline hazards in Hardware and requires the compiler to correctly schedule instructions to avoid race conditions. The only available code that does this can be found in MESA, but even they say "//this is bs and we know it" in a comment above their instruction latencies, which you also can't easily figure out.

Replacing ptxas is highly non trivial. I will attempt to do so, but it increasingly looks like ptxas is here to stay. I started working on a nvcc + cuda SDK replacement which already works surprisingly well for a day of work.

However, ptxas is in my sight. But I know this is something that to my knowledge nobody that wasn't fed Nvidia documentation under license has ever successfully accomplished.