path: root/src/mesa/drivers/dri/i965/brw_tcs.c

/*
 * Copyright © 2014 Intel Corporation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

/**
 * \file brw_tcs.c
 *
 * Tessellation control shader state upload code.
 */

#include "brw_context.h"
#include "compiler/brw_nir.h"
#include "brw_program.h"
#include "brw_state.h"
#include "program/prog_parameter.h"
#include "nir_builder.h"

static nir_shader *
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;
}

static void
brw_tcs_debug_recompile(struct brw_context *brw, struct gl_program *prog,
                       const struct brw_tcs_prog_key *key)
{
   perf_debug("Recompiling tessellation control shader for program %d\n",
              prog->Id);

   bool found = false;
   const struct brw_tcs_prog_key *old_key =
      brw_find_previous_compile(&brw->cache, BRW_CACHE_TCS_PROG,
                                key->program_string_id);

   if (!old_key) {
      perf_debug("  Didn't find previous compile in the shader cache for "
                 "debug\n");
      return;
   }

   found |= key_debug(brw, "input vertices", old_key->input_vertices,
                      key->input_vertices);
   found |= key_debug(brw, "outputs written", old_key->outputs_written,
                      key->outputs_written);
   found |= key_debug(brw, "patch outputs written", old_key->patch_outputs_written,
                      key->patch_outputs_written);
   found |= key_debug(brw, "TES primitive mode", old_key->tes_primitive_mode,
                      key->tes_primitive_mode);
   found |= key_debug(brw, "quads and equal_spacing workaround",
                      old_key->quads_workaround, key->quads_workaround);
   found |= brw_debug_recompile_sampler_key(brw, &old_key->tex, &key->tex);

   if (!found) {
      perf_debug("  Something else\n");
   }
}

static bool
brw_codegen_tcs_prog(struct brw_context *brw, struct brw_program *tcp,
                     struct brw_program *tep, struct brw_tcs_prog_key *key)
{
   struct gl_context *ctx = &brw->ctx;
   const struct brw_compiler *compiler = brw->screen->compiler;
   const struct gen_device_info *devinfo = compiler->devinfo;
   struct brw_stage_state *stage_state = &brw->tcs.base;
   nir_shader *nir;
   struct brw_tcs_prog_data prog_data;
   bool start_busy = false;
   double start_time = 0;

   void *mem_ctx = ralloc_context(NULL);
   if (tcp) {
      nir = tcp->program.nir;
   } else {
      /* Create a dummy nir_shader.  We won't actually use NIR code to
       * generate assembly (it's easier to generate assembly directly),
       * but the whole compiler assumes one of these exists.
       */
      const nir_shader_compiler_options *options =
         ctx->Const.ShaderCompilerOptions[MESA_SHADER_TESS_CTRL].NirOptions;
      nir = create_passthrough_tcs(mem_ctx, compiler, options, key);
   }

   memset(&prog_data, 0, sizeof(prog_data));

   /* Allocate the references to the uniforms that will end up in the
    * prog_data associated with the compiled program, and which will be freed
    * by the state cache.
    *
    * Note: param_count needs to be num_uniform_components * 4, since we add
    * padding around uniform values below vec4 size, so the worst case is that
    * every uniform is a float which gets padded to the size of a vec4.
    */
   int param_count = nir->num_uniforms / 4;

   prog_data.base.base.param =
      rzalloc_array(NULL, const gl_constant_value *, param_count);
   prog_data.base.base.pull_param =
      rzalloc_array(NULL, const gl_constant_value *, param_count);
   prog_data.base.base.nr_params = param_count;

   if (tcp) {
      brw_assign_common_binding_table_offsets(devinfo, &tcp->program,
                                              &prog_data.base.base, 0);

      prog_data.base.base.image_param =
         rzalloc_array(NULL, struct brw_image_param,
                       tcp->program.info.num_images);
      prog_data.base.base.nr_image_params = tcp->program.info.num_images;

      brw_nir_setup_glsl_uniforms(nir, &tcp->program, &prog_data.base.base,
                                  compiler->scalar_stage[MESA_SHADER_TESS_CTRL]);
   } else {
      /* Upload the Patch URB Header as the first two uniforms.
       * Do the annoying scrambling so the shader doesn't have to.
       */
      const float **param = (const float **) prog_data.base.base.param;
      static float zero = 0.0f;
      for (int i = 0; i < 8; i++)
         param[i] = &zero;

      if (key->tes_primitive_mode == GL_QUADS) {
         for (int i = 0; i < 4; i++)
            param[7 - i] = &ctx->TessCtrlProgram.patch_default_outer_level[i];

         param[3] = &ctx->TessCtrlProgram.patch_default_inner_level[0];
         param[2] = &ctx->TessCtrlProgram.patch_default_inner_level[1];
      } else if (key->tes_primitive_mode == GL_TRIANGLES) {
         for (int i = 0; i < 3; i++)
            param[7 - i] = &ctx->TessCtrlProgram.patch_default_outer_level[i];

         param[4] = &ctx->TessCtrlProgram.patch_default_inner_level[0];
      } else {
         assert(key->tes_primitive_mode == GL_ISOLINES);
         param[7] = &ctx->TessCtrlProgram.patch_default_outer_level[1];
         param[6] = &ctx->TessCtrlProgram.patch_default_outer_level[0];
      }
   }

   int st_index = -1;
   if (unlikely((INTEL_DEBUG & DEBUG_SHADER_TIME) && tep))
      st_index = brw_get_shader_time_index(brw, &tep->program, ST_TCS, true);

   if (unlikely(brw->perf_debug)) {
      start_busy = brw->batch.last_bo && brw_bo_busy(brw->batch.last_bo);
      start_time = get_time();
   }

   unsigned program_size;
   char *error_str;
   const unsigned *program =
      brw_compile_tcs(compiler, brw, mem_ctx, key, &prog_data, nir, st_index,
                      &program_size, &error_str);
   if (program == NULL) {
      if (tep) {
         tep->program.sh.data->LinkStatus = linking_failure;
         ralloc_strcat(&tep->program.sh.data->InfoLog, error_str);
      }

      _mesa_problem(NULL, "Failed to compile tessellation control shader: "
                    "%s\n", error_str);

      ralloc_free(mem_ctx);
      return false;
   }

   if (unlikely(brw->perf_debug)) {
      if (tcp) {
         if (tcp->compiled_once) {
            brw_tcs_debug_recompile(brw, &tcp->program, key);
         }
         tcp->compiled_once = true;
      }

      if (start_busy && !brw_bo_busy(brw->batch.last_bo)) {
         perf_debug("TCS compile took %.03f ms and stalled the GPU\n",
                    (get_time() - start_time) * 1000);
      }
   }

   /* Scratch space is used for register spilling */
   brw_alloc_stage_scratch(brw, stage_state,
                           prog_data.base.base.total_scratch,
                           devinfo->max_tcs_threads);

   brw_upload_cache(&brw->cache, BRW_CACHE_TCS_PROG,
                    key, sizeof(*key),
                    program, program_size,
                    &prog_data, sizeof(prog_data),
                    &stage_state->prog_offset, &brw->tcs.base.prog_data);
   ralloc_free(mem_ctx);

   return true;
}

void
brw_tcs_populate_key(struct brw_context *brw,
                     struct brw_tcs_prog_key *key)
{
   struct brw_program *tcp = (struct brw_program *) brw->tess_ctrl_program;
   struct brw_program *tep = (struct brw_program *) brw->tess_eval_program;
   struct gl_program *tes_prog = &tep->program;

   uint64_t per_vertex_slots = tes_prog->info.inputs_read;
   uint32_t per_patch_slots = tes_prog->info.patch_inputs_read;

   memset(key, 0, sizeof(*key));

   if (tcp) {
      struct gl_program *prog = &tcp->program;
      per_vertex_slots |= prog->info.outputs_written;
      per_patch_slots |= prog->info.patch_outputs_written;
   }

   if (brw->gen < 8 || !tcp)
      key->input_vertices = brw->ctx.TessCtrlProgram.patch_vertices;
   key->outputs_written = per_vertex_slots;
   key->patch_outputs_written = per_patch_slots;

   /* We need to specialize our code generation for tessellation levels
    * based on the domain the DS is expecting to tessellate.
    */
   key->tes_primitive_mode = tep->program.info.tess.primitive_mode;
   key->quads_workaround = brw->gen < 9 &&
                           tep->program.info.tess.primitive_mode == GL_QUADS &&
                           tep->program.info.tess.spacing == TESS_SPACING_EQUAL;

   if (tcp) {
      key->program_string_id = tcp->id;

      /* _NEW_TEXTURE */
      brw_populate_sampler_prog_key_data(&brw->ctx, &tcp->program, &key->tex);
   }
}

void
brw_upload_tcs_prog(struct brw_context *brw)
{
   struct brw_stage_state *stage_state = &brw->tcs.base;
   struct brw_tcs_prog_key key;
   /* BRW_NEW_TESS_PROGRAMS */
   struct brw_program *tcp = (struct brw_program *) brw->tess_ctrl_program;
   MAYBE_UNUSED struct brw_program *tep =
      (struct brw_program *) brw->tess_eval_program;
   assert(tep);

   if (!brw_state_dirty(brw,
                        _NEW_TEXTURE,
                        BRW_NEW_PATCH_PRIMITIVE |
                        BRW_NEW_TESS_PROGRAMS))
      return;

   brw_tcs_populate_key(brw, &key);

   if (!brw_search_cache(&brw->cache, BRW_CACHE_TCS_PROG,
                         &key, sizeof(key),
                         &stage_state->prog_offset,
                         &brw->tcs.base.prog_data)) {
      bool success = brw_codegen_tcs_prog(brw, tcp, tep, &key);
      assert(success);
      (void)success;
   }
}


bool
brw_tcs_precompile(struct gl_context *ctx,
                   struct gl_shader_program *shader_prog,
                   struct gl_program *prog)
{
   struct brw_context *brw = brw_context(ctx);
   struct brw_tcs_prog_key key;
   uint32_t old_prog_offset = brw->tcs.base.prog_offset;
   struct brw_stage_prog_data *old_prog_data = brw->tcs.base.prog_data;
   bool success;

   struct brw_program *btcp = brw_program(prog);
   const struct gl_linked_shader *tes =
      shader_prog->_LinkedShaders[MESA_SHADER_TESS_EVAL];

   memset(&key, 0, sizeof(key));

   key.program_string_id = btcp->id;
   brw_setup_tex_for_precompile(brw, &key.tex, prog);

   /* Guess that the input and output patches have the same dimensionality. */
   if (brw->gen < 8)
      key.input_vertices = prog->info.tess.tcs_vertices_out;

   struct brw_program *btep;
   if (tes) {
      btep = brw_program(tes->Program);
      key.tes_primitive_mode = tes->Program->info.tess.primitive_mode;
      key.quads_workaround = brw->gen < 9 &&
                             tes->Program->info.tess.primitive_mode == GL_QUADS &&
                             tes->Program->info.tess.spacing == TESS_SPACING_EQUAL;
   } else {
      btep = NULL;
      key.tes_primitive_mode = GL_TRIANGLES;
   }

   key.outputs_written = prog->nir->info.outputs_written;
   key.patch_outputs_written = prog->nir->info.patch_outputs_written;

   success = brw_codegen_tcs_prog(brw, btcp, btep, &key);

   brw->tcs.base.prog_offset = old_prog_offset;
   brw->tcs.base.prog_data = old_prog_data;

   return success;
}