intel/compiler: Export TCS passthrough creation

Move create_passthrough_tcs() from i965 so can be used in other
contexts.

Acked-by: Jason Ekstrand <[email protected]>

2 files changed, 86 insertions, 0 deletions

diff --git a/src/intel/compiler/brw_nir.c b/src/intel/compiler/brw_nir.c
index b38c3ba383d..f61baee230a 100644
--- a/src/intel/compiler/brw_nir.c
+++ b/src/intel/compiler/brw_nir.c
@@ -958,3 +958,84 @@ brw_glsl_base_type_for_nir_type(nir_alu_type type)
       unreachable("bad type");
    }
 }
+
+nir_shader *
+brw_nir_create_passthrough_tcs(void *mem_ctx, const struct brw_compiler *compiler,
+                               const nir_shader_compiler_options *options,
+                               const struct brw_tcs_prog_key *key)
+{
+   nir_builder b;
+   nir_builder_init_simple_shader(&b, mem_ctx, MESA_SHADER_TESS_CTRL,
+                                  options);
+   nir_shader *nir = b.shader;
+   nir_variable *var;
+   nir_intrinsic_instr *load;
+   nir_intrinsic_instr *store;
+   nir_ssa_def *zero = nir_imm_int(&b, 0);
+   nir_ssa_def *invoc_id =
+      nir_load_system_value(&b, nir_intrinsic_load_invocation_id, 0);
+
+   nir->info.inputs_read = key->outputs_written &
+      ~(VARYING_BIT_TESS_LEVEL_INNER | VARYING_BIT_TESS_LEVEL_OUTER);
+   nir->info.outputs_written = key->outputs_written;
+   nir->info.tess.tcs_vertices_out = key->input_vertices;
+   nir->info.name = ralloc_strdup(nir, "passthrough");
+   nir->num_uniforms = 8 * sizeof(uint32_t);
+
+   var = nir_variable_create(nir, nir_var_uniform, glsl_vec4_type(), "hdr_0");
+   var->data.location = 0;
+   var = nir_variable_create(nir, nir_var_uniform, glsl_vec4_type(), "hdr_1");
+   var->data.location = 1;
+
+   /* Write the patch URB header. */
+   for (int i = 0; i <= 1; i++) {
+      load = nir_intrinsic_instr_create(nir, nir_intrinsic_load_uniform);
+      load->num_components = 4;
+      load->src[0] = nir_src_for_ssa(zero);
+      nir_ssa_dest_init(&load->instr, &load->dest, 4, 32, NULL);
+      nir_intrinsic_set_base(load, i * 4 * sizeof(uint32_t));
+      nir_builder_instr_insert(&b, &load->instr);
+
+      store = nir_intrinsic_instr_create(nir, nir_intrinsic_store_output);
+      store->num_components = 4;
+      store->src[0] = nir_src_for_ssa(&load->dest.ssa);
+      store->src[1] = nir_src_for_ssa(zero);
+      nir_intrinsic_set_base(store, VARYING_SLOT_TESS_LEVEL_INNER - i);
+      nir_intrinsic_set_write_mask(store, WRITEMASK_XYZW);
+      nir_builder_instr_insert(&b, &store->instr);
+   }
+
+   /* Copy inputs to outputs. */
+   uint64_t varyings = nir->info.inputs_read;
+
+   while (varyings != 0) {
+      const int varying = ffsll(varyings) - 1;
+
+      load = nir_intrinsic_instr_create(nir,
+                                        nir_intrinsic_load_per_vertex_input);
+      load->num_components = 4;
+      load->src[0] = nir_src_for_ssa(invoc_id);
+      load->src[1] = nir_src_for_ssa(zero);
+      nir_ssa_dest_init(&load->instr, &load->dest, 4, 32, NULL);
+      nir_intrinsic_set_base(load, varying);
+      nir_builder_instr_insert(&b, &load->instr);
+
+      store = nir_intrinsic_instr_create(nir,
+                                         nir_intrinsic_store_per_vertex_output);
+      store->num_components = 4;
+      store->src[0] = nir_src_for_ssa(&load->dest.ssa);
+      store->src[1] = nir_src_for_ssa(invoc_id);
+      store->src[2] = nir_src_for_ssa(zero);
+      nir_intrinsic_set_base(store, varying);
+      nir_intrinsic_set_write_mask(store, WRITEMASK_XYZW);
+      nir_builder_instr_insert(&b, &store->instr);
+
+      varyings &= ~BITFIELD64_BIT(varying);
+   }
+
+   nir_validate_shader(nir);
+
+   nir = brw_preprocess_nir(compiler, nir);
+
+   return nir;
+}
diff --git a/src/intel/compiler/brw_nir.h b/src/intel/compiler/brw_nir.h
index 06f0e8690e4..2ff8c72b94f 100644
--- a/src/intel/compiler/brw_nir.h
+++ b/src/intel/compiler/brw_nir.h
@@ -164,6 +164,11 @@ nir_shader *brw_nir_optimize(nir_shader *nir,
                              bool is_scalar,
                              bool allow_copies);
 
+nir_shader *brw_nir_create_passthrough_tcs(void *mem_ctx,
+                                           const struct brw_compiler *compiler,
+                                           const nir_shader_compiler_options *options,
+                                           const struct brw_tcs_prog_key *key);
+
 #define BRW_NIR_FRAG_OUTPUT_INDEX_SHIFT 0
 #define BRW_NIR_FRAG_OUTPUT_INDEX_MASK INTEL_MASK(0, 0)
 #define BRW_NIR_FRAG_OUTPUT_LOCATION_SHIFT 1