i965: Drop mark_surface_used mechanism.

The original idea was that the backend compiler could eliminate
surfaces, so we would have it mark which ones are actually used,
then shrink the binding table accordingly.  Unfortunately, it's a
pretty blunt mechanism - it can only prune things from the end,
not the middle - since we decide the layout before we even start
the backend compiler, and only limit the size.  It also basically
gives up if it sees indirect array access.

Besides, we do the vast majority of our surface elimination in NIR
anyway, not the backend - and I don't see that trend changing any
time soon.  Vulkan abandoned this plan a long time ago, and I don't
use it in Iris, but it's still been kicking around in i965.

I hacked shader-db to print the binding table size in bytes, and
observed no changes with this patch.  So, this code appears to do
nothing useful.

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

1 files changed, 0 insertions, 29 deletions

diff --git a/src/intel/compiler/brw_vec4_nir.cpp b/src/intel/compiler/brw_vec4_nir.cpp
index f8d4dfb4682..98632b5af08 100644
--- a/src/intel/compiler/brw_vec4_nir.cpp
+++ b/src/intel/compiler/brw_vec4_nir.cpp
@@ -387,16 +387,11 @@ vec4_visitor::get_nir_ssbo_intrinsic_index(nir_intrinsic_instr *instr)
       unsigned index = prog_data->base.binding_table.ssbo_start +
                        nir_src_as_uint(instr->src[src]);
       surf_index = brw_imm_ud(index);
-      brw_mark_surface_used(&prog_data->base, index);
    } else {
       surf_index = src_reg(this, glsl_type::uint_type);
       emit(ADD(dst_reg(surf_index), get_nir_src(instr->src[src], 1),
                brw_imm_ud(prog_data->base.binding_table.ssbo_start)));
       surf_index = emit_uniformize(surf_index);
-
-      brw_mark_surface_used(&prog_data->base,
-                            prog_data->base.binding_table.ssbo_start +
-                            nir->info.num_ssbos - 1);
    }
 
    return surf_index;
@@ -492,8 +487,6 @@ vec4_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
       emit(MOV(dst_reg(MRF, param_base, glsl_type::int_type, writemask), lod));
 
       emit(inst);
-
-      brw_mark_surface_used(&prog_data->base, index);
       break;
    }
 
@@ -700,7 +693,6 @@ vec4_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
          const unsigned index = prog_data->base.binding_table.ubo_start +
                                 nir_src_as_uint(instr->src[0]);
          surf_index = brw_imm_ud(index);
-         brw_mark_surface_used(&prog_data->base, index);
       } else {
          /* The block index is not a constant. Evaluate the index expression
           * per-channel and add the base UBO index; we have to select a value
@@ -711,13 +703,6 @@ vec4_visitor::nir_emit_intrinsic(nir_intrinsic_instr *instr)
                                                    instr->num_components),
                   brw_imm_ud(prog_data->base.binding_table.ubo_start)));
          surf_index = emit_uniformize(surf_index);
-
-         /* Assume this may touch any UBO. It would be nice to provide
-          * a tighter bound, but the array information is already lowered away.
-          */
-         brw_mark_surface_used(&prog_data->base,
-                               prog_data->base.binding_table.ubo_start +
-                               nir->info.num_ubos - 1);
       }
 
       src_reg offset_reg;
@@ -2031,20 +2016,6 @@ vec4_visitor::nir_emit_texture(nir_tex_instr *instr)
       }
 
       case nir_tex_src_texture_offset: {
-         /* The highest texture which may be used by this operation is
-          * the last element of the array. Mark it here, because the generator
-          * doesn't have enough information to determine the bound.
-          */
-         uint32_t array_size = instr->texture_array_size;
-         uint32_t max_used = texture + array_size - 1;
-         if (instr->op == nir_texop_tg4) {
-            max_used += prog_data->base.binding_table.gather_texture_start;
-         } else {
-            max_used += prog_data->base.binding_table.texture_start;
-         }
-
-         brw_mark_surface_used(&prog_data->base, max_used);
-
          /* Emit code to evaluate the actual indexing expression */
          src_reg src = get_nir_src(instr->src[i].src, 1);
          src_reg temp(this, glsl_type::uint_type);