ac/nir: Add ac_nir_load_arg helper for shader arguments.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Daniel Schürmann <daniel@schuermann.dev>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/13155>

src/amd/common/ac_nir.c

@@ -22,6 +22,18 @@
  */
 
 #include "ac_nir.h"
+#include "nir_builder.h"
+
+nir_ssa_def *
+ac_nir_load_arg(nir_builder *b, const struct ac_shader_args *ac_args, struct ac_arg arg)
+{
+   unsigned num_components = ac_args->args[arg.arg_index].size;
+
+   if (ac_args->args[arg.arg_index].file == AC_ARG_SGPR)
+      return nir_load_scalar_arg_amd(b, num_components, .base = arg.arg_index);
+   else
+      return nir_load_vector_arg_amd(b, num_components, .base = arg.arg_index);
+}
 
 bool
 ac_nir_lower_indirect_derefs(nir_shader *shader,

src/amd/common/ac_nir.h

@@ -52,6 +52,9 @@ enum
 struct nir_builder;
 typedef struct nir_builder nir_builder;
 
+nir_ssa_def *
+ac_nir_load_arg(nir_builder *b, const struct ac_shader_args *ac_args, struct ac_arg arg);
+
 bool ac_nir_optimize_outputs(nir_shader *nir, bool sprite_tex_disallowed,
                              int8_t slot_remap[NUM_TOTAL_VARYING_SLOTS],
                              uint8_t param_export_index[NUM_TOTAL_VARYING_SLOTS]);