agx: report uses_txf

so driver can optimize usc binding.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/29179>

src/asahi/compiler/agx_compile.c

@@ -1063,6 +1063,8 @@ agx_emit_image_load(agx_builder *b, agx_index dst, nir_intrinsic_instr *intr)
       b, tmp, coords, lod, bindless, texture, agx_immediate(0), agx_null(),
       agx_tex_dim(dim, is_array), lod_mode, 0, false);
    I->mask = agx_expand_tex_to(b, &intr->def, tmp, true);
+
+   b->shader->out->uses_txf = true;
    return NULL;
 }
 
@@ -2098,8 +2100,10 @@ agx_emit_tex(agx_builder *b, nir_tex_instr *instr)
       !agx_is_null(packed_offset), !agx_is_null(compare),
       instr->op == nir_texop_lod, agx_gather_for_nir(instr));
 
-   if (instr->op == nir_texop_txf || instr->op == nir_texop_txf_ms)
+   if (instr->op == nir_texop_txf || instr->op == nir_texop_txf_ms) {
       I->op = AGX_OPCODE_TEXTURE_LOAD;
+      b->shader->out->uses_txf = true;
+   }
 
    /* Destination masking doesn't seem to work properly for gathers (because
     * it's mostly pointless), but it does show up in the lowering of

src/asahi/compiler/agx_compile.h

@@ -112,6 +112,9 @@ struct agx_shader_info {
    /* Reads base vertex/instance */
    bool uses_base_param;
 
+   /* Uses txf and hence needs a txf sampler mapped */
+   bool uses_txf;
+
    /* Number of 16-bit registers used by the main shader and preamble
     * respectively.
     */

src/asahi/lib/agx_linker.c

@@ -110,6 +110,7 @@ agx_fast_link(void *memctx, struct agx_device *dev, bool fragment,
       writes_sample_mask |= part->info.writes_sample_mask;
       disable_tri_merging |= part->info.disable_tri_merging;
       linked->uses_base_param |= part->info.uses_base_param;
+      linked->uses_txf |= part->info.uses_txf;
       tag_write_disable &= part->info.tag_write_disable;
    }
 

src/asahi/lib/agx_linker.h

@@ -21,6 +21,11 @@ struct agx_linked_shader {
     */
    bool uses_base_param;
 
+   /* Set if the linked shader uses txf. The epilog may even if the main shader
+    * does not, in the case of spilled render targets.
+    */
+   bool uses_txf;
+
    /* Coefficient register bindings */
    struct agx_varyings_fs cf;