<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_NEW " title="NEW - [GLSL] "Multiplication by zero" optimization for floating point expression should be skipped" href="https://bugs.freedesktop.org/show_bug.cgi?id=107089#c1">Comment # 1</a> on <a class="bz_bug_link bz_status_NEW " title="NEW - [GLSL] "Multiplication by zero" optimization for floating point expression should be skipped" href="https://bugs.freedesktop.org/show_bug.cgi?id=107089">bug 107089</a> from <a class="email" href="mailto:imirkin@alum.mit.edu" title="Ilia Mirkin <imirkin@alum.mit.edu>"> Ilia Mirkin</a> <pre>GLSL's approach to NaN is pretty weak. <a href="https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shader_precision.txt">https://www.khronos.org/registry/OpenGL/extensions/ARB/ARB_shader_precision.txt</a> """ The following rules apply to both single and double precision operations: Dividing by 0 results in the appropriately signed IEEE Inf. Any denormalized value input into a shader or potentially generated by an operation in a shader can be flushed to 0. In general, correct signedness of 0 is not required. The rounding mode cannot be set and is undefined. Support for signaling NaNs is not required and exceptions are never raised. Operations and built-in functions that operate on a NaN are not required to return a NaN as the result. """ So NaN * 0 -> 0 appears to be a valid transformation. I haven't gone back and checked what's in the core specs, but I doubt it's any different.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> <li>You are the assignee for the bug.</li> </ul> </body> </html>