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, 32 deletions

diff --git a/src/intel/compiler/brw_fs_nir.cpp b/src/intel/compiler/brw_fs_nir.cpp
index dc4f1d4879c..bdc883e5364 100644
--- a/src/intel/compiler/brw_fs_nir.cpp
+++ b/src/intel/compiler/brw_fs_nir.cpp
@@ -2895,10 +2895,6 @@ fs_visitor::emit_non_coherent_fb_read(const fs_builder &bld, const fs_reg &dst,
       wm_prog_data->binding_table.render_target_read_start -
       wm_prog_data->base.binding_table.texture_start;
 
-   brw_mark_surface_used(
-      bld.shader->stage_prog_data,
-      wm_prog_data->binding_table.render_target_read_start + target);
-
    /* Calculate the fragment coordinates. */
    const fs_reg coords = bld.vgrf(BRW_REGISTER_TYPE_UD, 3);
    bld.MOV(offset(coords, bld, 0), pixel_x);
@@ -3380,7 +3376,6 @@ fs_visitor::nir_emit_cs_intrinsic(const fs_builder &bld,
       cs_prog_data->uses_num_work_groups = true;
 
       fs_reg surf_index = brw_imm_ud(surface);
-      brw_mark_surface_used(prog_data, surface);
 
       /* Read the 3 GLuint components of gl_NumWorkGroups */
       for (unsigned i = 0; i < 3; i++) {
@@ -3600,18 +3595,10 @@ fs_visitor::get_nir_ssbo_intrinsic_index(const brw::fs_builder &bld,
       unsigned index = stage_prog_data->binding_table.ssbo_start +
                        nir_src_as_uint(instr->src[src]);
       surf_index = brw_imm_ud(index);
-      brw_mark_surface_used(prog_data, index);
    } else {
       surf_index = vgrf(glsl_type::uint_type);
       bld.ADD(surf_index, get_nir_src(instr->src[src]),
               brw_imm_ud(stage_prog_data->binding_table.ssbo_start));
-
-      /* 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,
-                            stage_prog_data->binding_table.ssbo_start +
-                            nir->info.num_ssbos - 1);
    }
 
    return surf_index;
@@ -3897,7 +3884,6 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
          const unsigned index = stage_prog_data->binding_table.ubo_start +
                                 nir_src_as_uint(instr->src[0]);
          surf_index = brw_imm_ud(index);
-         brw_mark_surface_used(prog_data, 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
@@ -3907,13 +3893,6 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
          bld.ADD(surf_index, get_nir_src(instr->src[0]),
                  brw_imm_ud(stage_prog_data->binding_table.ubo_start));
          surf_index = bld.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,
-                               stage_prog_data->binding_table.ubo_start +
-                               nir->info.num_ubos - 1);
       }
 
       if (!nir_src_is_const(instr->src[1])) {
@@ -4170,8 +4149,6 @@ fs_visitor::nir_emit_intrinsic(const fs_builder &bld, nir_intrinsic_instr *instr
       ubld.ADD(buffer_size, size_aligned4, negate(size_padding));
 
       bld.MOV(retype(dest, ret_payload.type), component(buffer_size, 0));
-
-      brw_mark_surface_used(prog_data, index);
       break;
    }
 
@@ -4757,15 +4734,6 @@ fs_visitor::nir_emit_texture(const fs_builder &bld, nir_tex_instr *instr)
          unreachable("should be lowered");
 
       case nir_tex_src_texture_offset: {
-         /* Figure out the highest possible texture index and mark it as used */
-         uint32_t max_used = texture + instr->texture_array_size - 1;
-         if (instr->op == nir_texop_tg4 && devinfo->gen < 8) {
-            max_used += stage_prog_data->binding_table.gather_texture_start;
-         } else {
-            max_used += stage_prog_data->binding_table.texture_start;
-         }
-         brw_mark_surface_used(prog_data, max_used);
-
          /* Emit code to evaluate the actual indexing expression */
          fs_reg tmp = vgrf(glsl_type::uint_type);
          bld.ADD(tmp, src, brw_imm_ud(texture));