This lets us support indirect access to UBOs easily. The existing
constant special case disappears too, since the peephole optimizer can
inline the constant later. (note: this is too conservative since we can
go up to 16-bit immediates...)
Unfortunately, nir_opt_algebraic can't seem to optimize expressions like
"((a << 3) + 4) >> 2" to "(a << 1) + 1" which would be necessary for
reasonable perf out of this...
Fixes:
dEQP-GLES2.functional.shaders.indexing.uniform_array.float_dynamic_loop_read_fragment
Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14581>
b4108e1d01