In nested control flow this is nessecary to not demote/terminate invocations
that are part of the global but not part of the local mask.
At the top level, the masks are the same and no additional invocations
can be accidentally disabled.
Foz-DB Navi21:
Totals from 2095 (2.64% of 79395) affected shaders:
Instrs: 1058326 -> 1056839 (-0.14%)
CodeSize: 5632480 -> 5626616 (-0.10%)
Latency: 12082761 -> 12080520 (-0.02%); split: -0.02%, +0.00%
InvThroughput: 2246677 -> 2246636 (-0.00%); split: -0.00%, +0.00%
Copies: 114446 -> 114433 (-0.01%)
SALU: 230585 -> 229098 (-0.64%)
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32755>
Georg Lehmann
33a73203b0