NTT can't convert local 64 variables of type vec3 or vec4, therefore,
they need to be split into vec2 + double or vec2 + vec2.
At the same time deal splitting the phi nodes.
The pass goes into the global namespace because it is also useful
for r600.
v2: only lower function_temps (Emma) and handle array of arrays (Jason)
v3: - remove bool parameter in function to merge
vec3 and vec4
- simplify load/store_deref_(array|var)
- use a pointer hash table
- simplify PHI splitting (all Emma)
Signed-off-by: Gert Wollny <gert.wollny@collabora.com>
Reviewed-by: Emma Anholt <emma@anholt.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15945>
Gert Wollny