74a40cc4b6
We use a non-uniform lowering loop in the backend which we can do better in NIR because we can also use divergence analysis there. This change also limits VGRF usage to a single VGRF to hold the sample ID in the backend. Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com> Reviewed-by: Emma Anholt <emma@anholt.net> Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24716>