nir/lower_io_to_scalar: Look at derefs for modes

This is instead of looking all the way back to the variable which may
not exist for all derefs.  This makes this code properly ignore casts
with modes other than the mode[s] we care about (where casts aren't
allowed).

Reviewed-by: Timothy Arceri <tarceri@itsqueeze.com>

diff --git a/src/compiler/nir/nir_lower_io_to_scalar.c b/src/compiler/nir/nir_lower_io_to_scalar.c
index 929761fa888394dda92ce96a4d2eec0ac7232f37..d58805294b5fa908426f5c0905fff083cd3889e7 100644 (file)
--- a/src/compiler/nir/nir_lower_io_to_scalar.c
+++ b/src/compiler/nir/nir_lower_io_to_scalar.c
@@ -308,9 +308,12 @@ nir_lower_io_to_scalar_early(nir_shader *shader, nir_variable_mode mask)
                    intr->intrinsic != nir_intrinsic_interp_deref_at_offset)
                   continue;
 
-               nir_variable *var =
-                  nir_deref_instr_get_variable(nir_src_as_deref(intr->src[0]));
-               nir_variable_mode mode = var->data.mode;
+               nir_deref_instr *deref = nir_src_as_deref(intr->src[0]);
+               nir_variable_mode mode = deref->mode;
+               if (!(mode & mask))
+                  continue;
+
+               nir_variable *var = nir_deref_instr_get_variable(deref);
 
                /* TODO: add patch support */
                if (var->data.patch)