nir: Add ability to count emitted GS primitives.

Add an option to nir_lower_gs_intrinsics which tells it to track
the number of emitted primitives, not just vertices. Additionally,
also make it per-stream.

Also rename the set_vertex_count intrinsic to
set_vertex_and_primitive_count.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Jason Ekstrand <jason@jlekstrand.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6964>

src/intel/compiler/brw_fs_nir.cpp

@@ -3149,7 +3149,7 @@ fs_visitor::nir_emit_gs_intrinsic(const fs_builder &bld,
       emit_gs_end_primitive(instr->src[0]);
       break;
 
-   case nir_intrinsic_set_vertex_count:
+   case nir_intrinsic_set_vertex_and_primitive_count:
       bld.MOV(this->final_gs_vertex_count, get_nir_src(instr->src[0]));
       break;
 

src/intel/compiler/brw_nir.c

@@ -692,7 +692,7 @@ brw_preprocess_nir(const struct brw_compiler *compiler, nir_shader *nir,
    }
 
    if (nir->info.stage == MESA_SHADER_GEOMETRY)
-      OPT(nir_lower_gs_intrinsics, false);
+      OPT(nir_lower_gs_intrinsics, 0);
 
    /* See also brw_nir_trig_workarounds.py */
    if (compiler->precise_trig &&

src/intel/compiler/brw_vec4_gs_nir.cpp

@@ -78,7 +78,7 @@ vec4_gs_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
       gs_end_primitive();
       break;
 
-   case nir_intrinsic_set_vertex_count:
+   case nir_intrinsic_set_vertex_and_primitive_count:
       this->vertex_count =
          retype(get_nir_src(instr->src[0], 1), BRW_REGISTER_TYPE_UD);
       break;