The bounds checking is actually less safe than just pushing the data.
If the bounds checking actually ever kicks in and it's not on the last
UBO push range, then the shrinking will cause all subsequent ranges to
be pushed to the wrong place in the GRF. One of the behaviors we
definitely don't want is for OOB UBO access to result in completely
unrelated UBOs returning garbage values. It's safer to just push the
UBOs as-requested. If we're really concerned about robustness, we can
emit shader code to do bounds checking which should be stupid cheap (a
CMP followed by SEL).
Cc: mesa-stable@lists.freedesktop.org
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Jason Ekstrand
4b392ced2d