&gt; but if GPUOpen is to have any substance at all it&#x27;s obvious that they&#x27;re going to actually do some of that.<p>I don&#x27;t think they&#x27;ll do it.  I think they&#x27;re going to shoot for SPIR-V being close enough that SPIR-V compilers generate code good enough that the internal compilers can gen good ISA code.<p>&gt; They&#x27;re not overhauling the ISA every year.<p>They aren&#x27;t, but the changes rev to rev are more significant than you&#x27;d expect.  On top of that, the big bumps are significant, such as Fermi to Kepler or Northern Islands to Southern Islands (or whatever).  These are not backwards compatible with each other, unlike Intel x86 ISA.<p>Bonus edit: Also...I&#x27;d speculate that some IHVs would rather not expose their IL-to-ISA compiler.  Not because of &#x27;secret sauce&#x27;.  But because they aren&#x27;t that good, and would rather have the OSS community start fresh and do a better job.