<li>tes - dump shader assembly for tessellation evaluation shaders</li>
<li>tex - emit messages about textures.</li>
<li>urb - emit messages about URB setup</li>
- <li>vec4 - force vec4 mode in vertex shader</li>
<li>vert - emit messages about vertex assembly</li>
<li>vs - dump shader assembly for vertex shaders</li>
</ul>
+<li>INTEL_SCALAR_VS (or TCS, TES, GS) - force scalar/vec4 mode for a shader stage (Gen8-9 only)</li>
<li>INTEL_PRECISE_TRIG - if set to 1, true or yes, then the driver prefers
accuracy over performance in trig functions.</li>
</ul>