nir: add lod_bias_min_agx tex src

this lets nir_opt_preamble Just Do The Right thing, so model in NIR

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Acked-by: Konstantin Seurer <konstantin.seurer@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33386>

src/compiler/nir/nir.c

@@ -3338,6 +3338,7 @@ nir_tex_instr_src_type(const nir_tex_instr *instr, unsigned src)
    case nir_tex_src_sampler_deref_intrinsic:
    case nir_tex_src_texture_deref_intrinsic:
    case nir_tex_src_ms_mcs_intel:
+   case nir_tex_src_lod_bias_min_agx:
    case nir_tex_src_texture_deref:
    case nir_tex_src_sampler_deref:
    case nir_tex_src_texture_offset:

src/compiler/nir/nir.h

@@ -2233,6 +2233,14 @@ typedef enum nir_tex_src_type {
     */
    nir_tex_src_min_lod,
 
+   /** LOD bias + min LOD packed together into 32-bits. This is the common case
+    * for texturing on Honeykrisp with DX12, where both LOD bias and min LOD are
+    * emulated and passed in a single hardware source together. So it's
+    * important to optimize so e.g. nir_opt_preamble can make good decisions
+    * that avoid extra moves.
+    */
+   nir_tex_src_lod_bias_min_agx,
+
    /** MSAA sample index */
    nir_tex_src_ms_index,
 

src/compiler/nir/nir_print.c

@@ -1835,6 +1835,9 @@ print_tex_instr(nir_tex_instr *instr, print_state *state)
       case nir_tex_src_ms_mcs_intel:
          fprintf(fp, "(ms_mcs_intel)");
          break;
+      case nir_tex_src_lod_bias_min_agx:
+         fprintf(fp, "(lod_bias_min_agx)");
+         break;
       case nir_tex_src_ddx:
          fprintf(fp, "(ddx)");
          break;