docs: document INTEL_PRECISE_TRIG envvar

v2: use more generic description (Jordan)

Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>

diff --git a/docs/envvars.html b/docs/envvars.html
index 9eee8db2ebe2a53c8c57b80cadfdf4b9ab675f82..276cea3cf34d7916087cd37e02ea8d03ea41ef90 100644 (file)
--- a/docs/envvars.html
+++ b/docs/envvars.html
@@ -187,6 +187,8 @@ See the <a href="xlibdriver.html">Xlib software driver page</a> for details.
    <li>do32 - generate compute shader SIMD32 programs even if workgroup size doesn't exceed the SIMD16 limit</li>
    <li>norbc - disable single sampled render buffer compression</li>
 </ul>
+<li>INTEL_PRECISE_TRIG - if set to 1, true or yes, then the driver prefers
+   accuracy over performance in trig functions.</li>
 </ul>