src/glsl/nir/nir_lower_io.c

   1 /*
   2  * Copyright © 2014 Intel Corporation
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
  20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
  21  * IN THE SOFTWARE.
  22  *
  23  * Authors:
  24  *    Connor Abbott (cwabbott0@gmail.com)
  25  *    Jason Ekstrand (jason@jlekstrand.net)
  26  *
  27  */
  28
  29 /*
  30  * This lowering pass converts references to input/output variables with
  31  * loads/stores to actual input/output intrinsics.
  32  */
  33
  34 #include "nir.h"
  35
  36 struct lower_io_state {
  37    void *mem_ctx;
  38    bool is_scalar;
  39 };
  40
  41 static int
  42 type_size_vec4(const struct glsl_type *type)
  43 {
  44    unsigned int i;
  45    int size;
  46
  47    switch (glsl_get_base_type(type)) {
  48    case GLSL_TYPE_UINT:
  49    case GLSL_TYPE_INT:
  50    case GLSL_TYPE_FLOAT:
  51    case GLSL_TYPE_BOOL:
  52       if (glsl_type_is_matrix(type)) {
  53          return glsl_get_matrix_columns(type);
  54       } else {
  55          return 1;
  56       }
  57    case GLSL_TYPE_ARRAY:
  58       return type_size_vec4(glsl_get_array_element(type)) * glsl_get_length(type);
  59    case GLSL_TYPE_STRUCT:
  60       size = 0;
  61       for (i = 0; i <  glsl_get_length(type); i++) {
  62          size += type_size_vec4(glsl_get_struct_field(type, i));
  63       }
  64       return size;
  65    case GLSL_TYPE_SUBROUTINE:
  66       return 1;
  67    case GLSL_TYPE_SAMPLER:
  68       return 0;
  69    case GLSL_TYPE_ATOMIC_UINT:
  70       return 0;
  71    case GLSL_TYPE_IMAGE:
  72    case GLSL_TYPE_VOID:
  73    case GLSL_TYPE_DOUBLE:
  74    case GLSL_TYPE_ERROR:
  75    case GLSL_TYPE_INTERFACE:
  76       unreachable("not reached");
  77    }
  78
  79    return 0;
  80 }
  81
  82 static unsigned
  83 type_size_scalar(const struct glsl_type *type)
  84 {
  85    unsigned int size, i;
  86
  87    switch (glsl_get_base_type(type)) {
  88    case GLSL_TYPE_UINT:
  89    case GLSL_TYPE_INT:
  90    case GLSL_TYPE_FLOAT:
  91    case GLSL_TYPE_BOOL:
  92       return glsl_get_components(type);
  93    case GLSL_TYPE_ARRAY:
  94       return type_size_scalar(glsl_get_array_element(type)) * glsl_get_length(type);
  95    case GLSL_TYPE_STRUCT:
  96       size = 0;
  97       for (i = 0; i < glsl_get_length(type); i++) {
  98          size += type_size_scalar(glsl_get_struct_field(type, i));
  99       }
 100       return size;
 101    case GLSL_TYPE_SUBROUTINE:
 102       return 1;
 103    case GLSL_TYPE_SAMPLER:
 104       return 0;
 105    case GLSL_TYPE_ATOMIC_UINT:
 106       return 0;
 107    case GLSL_TYPE_INTERFACE:
 108       return 0;
 109    case GLSL_TYPE_IMAGE:
 110       return 0;
 111    case GLSL_TYPE_FUNCTION:
 112    case GLSL_TYPE_VOID:
 113    case GLSL_TYPE_ERROR:
 114    case GLSL_TYPE_DOUBLE:
 115       unreachable("not reached");
 116    }
 117
 118    return 0;
 119 }
 120
 121 static unsigned
 122 type_size(const struct glsl_type *type, bool is_scalar)
 123 {
 124    if (is_scalar)
 125       return type_size_scalar(type);
 126    else
 127       return type_size_vec4(type);
 128 }
 129
 130 void
 131 nir_assign_var_locations(struct exec_list *var_list, unsigned *size, bool is_scalar)
 132 {
 133    unsigned location = 0;
 134
 135    foreach_list_typed(nir_variable, var, node, var_list) {
 136       /*
 137        * UBO's have their own address spaces, so don't count them towards the
 138        * number of global uniforms
 139        */
 140       if ((var->data.mode == nir_var_uniform || var->data.mode == nir_var_shader_storage) &&
 141           var->interface_type != NULL)
 142          continue;
 143
 144       var->data.driver_location = location;
 145       location += type_size(var->type, is_scalar);
 146    }
 147
 148    *size = location;
 149 }
 150
 151 static bool
 152 deref_has_indirect(nir_deref_var *deref)
 153 {
 154    for (nir_deref *tail = deref->deref.child; tail; tail = tail->child) {
 155       if (tail->deref_type == nir_deref_type_array) {
 156          nir_deref_array *arr = nir_deref_as_array(tail);
 157          if (arr->deref_array_type == nir_deref_array_type_indirect)
 158             return true;
 159       }
 160    }
 161
 162    return false;
 163 }
 164
 165 static bool
 166 mark_indirect_uses_block(nir_block *block, void *void_state)
 167 {
 168    struct set *indirect_set = void_state;
 169
 170    nir_foreach_instr(block, instr) {
 171       if (instr->type != nir_instr_type_intrinsic)
 172          continue;
 173
 174       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
 175
 176       for (unsigned i = 0;
 177            i < nir_intrinsic_infos[intrin->intrinsic].num_variables; i++) {
 178          if (deref_has_indirect(intrin->variables[i]))
 179             _mesa_set_add(indirect_set, intrin->variables[i]->var);
 180       }
 181    }
 182
 183    return true;
 184 }
 185
 186 /* Identical to nir_assign_var_locations_packed except that it assigns
 187  * locations to the variables that are used 100% directly first and then
 188  * assigns locations to variables that are used indirectly.
 189  */
 190 void
 191 nir_assign_var_locations_direct_first(nir_shader *shader,
 192                                       struct exec_list *var_list,
 193                                       unsigned *direct_size,
 194                                       unsigned *size,
 195                                       bool is_scalar)
 196 {
 197    struct set *indirect_set = _mesa_set_create(NULL, _mesa_hash_pointer,
 198                                                _mesa_key_pointer_equal);
 199
 200    nir_foreach_overload(shader, overload) {
 201       if (overload->impl)
 202          nir_foreach_block(overload->impl, mark_indirect_uses_block,
 203                            indirect_set);
 204    }
 205
 206    unsigned location = 0;
 207
 208    foreach_list_typed(nir_variable, var, node, var_list) {
 209       if ((var->data.mode == nir_var_uniform || var->data.mode == nir_var_shader_storage) &&
 210           var->interface_type != NULL)
 211          continue;
 212
 213       if (_mesa_set_search(indirect_set, var))
 214          continue;
 215
 216       var->data.driver_location = location;
 217       location += type_size(var->type, is_scalar);
 218    }
 219
 220    *direct_size = location;
 221
 222    foreach_list_typed(nir_variable, var, node, var_list) {
 223       if ((var->data.mode == nir_var_uniform || var->data.mode == nir_var_shader_storage) &&
 224           var->interface_type != NULL)
 225          continue;
 226
 227       if (!_mesa_set_search(indirect_set, var))
 228          continue;
 229
 230       var->data.driver_location = location;
 231       location += type_size(var->type, is_scalar);
 232    }
 233
 234    *size = location;
 235
 236    _mesa_set_destroy(indirect_set, NULL);
 237 }
 238
 239 static unsigned
 240 get_io_offset(nir_deref_var *deref, nir_instr *instr, nir_src *indirect,
 241               struct lower_io_state *state)
 242 {
 243    bool found_indirect = false;
 244    unsigned base_offset = 0;
 245
 246    nir_deref *tail = &deref->deref;
 247    while (tail->child != NULL) {
 248       const struct glsl_type *parent_type = tail->type;
 249       tail = tail->child;
 250
 251       if (tail->deref_type == nir_deref_type_array) {
 252          nir_deref_array *deref_array = nir_deref_as_array(tail);
 253          unsigned size = type_size(tail->type, state->is_scalar);
 254
 255          base_offset += size * deref_array->base_offset;
 256
 257          if (deref_array->deref_array_type == nir_deref_array_type_indirect) {
 258             nir_load_const_instr *load_const =
 259                nir_load_const_instr_create(state->mem_ctx, 1);
 260             load_const->value.u[0] = size;
 261             nir_instr_insert_before(instr, &load_const->instr);
 262
 263             nir_alu_instr *mul = nir_alu_instr_create(state->mem_ctx,
 264                                                       nir_op_imul);
 265             mul->src[0].src.is_ssa = true;
 266             mul->src[0].src.ssa = &load_const->def;
 267             nir_src_copy(&mul->src[1].src, &deref_array->indirect,
 268                          state->mem_ctx);
 269             mul->dest.write_mask = 1;
 270             nir_ssa_dest_init(&mul->instr, &mul->dest.dest, 1, NULL);
 271             nir_instr_insert_before(instr, &mul->instr);
 272
 273             if (found_indirect) {
 274                nir_alu_instr *add = nir_alu_instr_create(state->mem_ctx,
 275                                                          nir_op_iadd);
 276                add->src[0].src = *indirect;
 277                add->src[1].src.is_ssa = true;
 278                add->src[1].src.ssa = &mul->dest.dest.ssa;
 279                add->dest.write_mask = 1;
 280                nir_ssa_dest_init(&add->instr, &add->dest.dest, 1, NULL);
 281                nir_instr_insert_before(instr, &add->instr);
 282
 283                indirect->is_ssa = true;
 284                indirect->ssa = &add->dest.dest.ssa;
 285             } else {
 286                indirect->is_ssa = true;
 287                indirect->ssa = &mul->dest.dest.ssa;
 288                found_indirect = true;
 289             }
 290          }
 291       } else if (tail->deref_type == nir_deref_type_struct) {
 292          nir_deref_struct *deref_struct = nir_deref_as_struct(tail);
 293
 294          for (unsigned i = 0; i < deref_struct->index; i++)
 295             base_offset += type_size(glsl_get_struct_field(parent_type, i),
 296                                      state->is_scalar);
 297       }
 298    }
 299
 300    return base_offset;
 301 }
 302
 303 static bool
 304 nir_lower_io_block(nir_block *block, void *void_state)
 305 {
 306    struct lower_io_state *state = void_state;
 307
 308    nir_foreach_instr_safe(block, instr) {
 309       if (instr->type != nir_instr_type_intrinsic)
 310          continue;
 311
 312       nir_intrinsic_instr *intrin = nir_instr_as_intrinsic(instr);
 313
 314       switch (intrin->intrinsic) {
 315       case nir_intrinsic_load_var: {
 316          nir_variable_mode mode = intrin->variables[0]->var->data.mode;
 317          if (mode != nir_var_shader_in && mode != nir_var_uniform)
 318             continue;
 319
 320          bool has_indirect = deref_has_indirect(intrin->variables[0]);
 321
 322          /* Figure out the opcode */
 323          nir_intrinsic_op load_op;
 324          switch (mode) {
 325          case nir_var_shader_in:
 326             load_op = has_indirect ? nir_intrinsic_load_input_indirect :
 327                                      nir_intrinsic_load_input;
 328             break;
 329          case nir_var_uniform:
 330             load_op = has_indirect ? nir_intrinsic_load_uniform_indirect :
 331                                      nir_intrinsic_load_uniform;
 332             break;
 333          default:
 334             unreachable("Unknown variable mode");
 335          }
 336
 337          nir_intrinsic_instr *load = nir_intrinsic_instr_create(state->mem_ctx,
 338                                                                 load_op);
 339          load->num_components = intrin->num_components;
 340
 341          nir_src indirect;
 342          unsigned offset = get_io_offset(intrin->variables[0],
 343                                          &intrin->instr, &indirect, state);
 344          offset += intrin->variables[0]->var->data.driver_location;
 345
 346          load->const_index[0] = offset;
 347
 348          if (has_indirect)
 349             load->src[0] = indirect;
 350
 351          if (intrin->dest.is_ssa) {
 352             nir_ssa_dest_init(&load->instr, &load->dest,
 353                               intrin->num_components, NULL);
 354             nir_ssa_def_rewrite_uses(&intrin->dest.ssa,
 355                                      nir_src_for_ssa(&load->dest.ssa),
 356                                      state->mem_ctx);
 357          } else {
 358             nir_dest_copy(&load->dest, &intrin->dest, state->mem_ctx);
 359          }
 360
 361          nir_instr_insert_before(&intrin->instr, &load->instr);
 362          nir_instr_remove(&intrin->instr);
 363          break;
 364       }
 365
 366       case nir_intrinsic_store_var: {
 367          if (intrin->variables[0]->var->data.mode != nir_var_shader_out)
 368             continue;
 369
 370          bool has_indirect = deref_has_indirect(intrin->variables[0]);
 371
 372          nir_intrinsic_op store_op;
 373          if (has_indirect) {
 374             store_op = nir_intrinsic_store_output_indirect;
 375          } else {
 376             store_op = nir_intrinsic_store_output;
 377          }
 378
 379          nir_intrinsic_instr *store = nir_intrinsic_instr_create(state->mem_ctx,
 380                                                                  store_op);
 381          store->num_components = intrin->num_components;
 382
 383          nir_src indirect;
 384          unsigned offset = get_io_offset(intrin->variables[0],
 385                                          &intrin->instr, &indirect, state);
 386          offset += intrin->variables[0]->var->data.driver_location;
 387
 388          store->const_index[0] = offset;
 389
 390          nir_src_copy(&store->src[0], &intrin->src[0], state->mem_ctx);
 391
 392          if (has_indirect)
 393             store->src[1] = indirect;
 394
 395          nir_instr_insert_before(&intrin->instr, &store->instr);
 396          nir_instr_remove(&intrin->instr);
 397          break;
 398       }
 399
 400       default:
 401          break;
 402       }
 403    }
 404
 405    return true;
 406 }
 407
 408 static void
 409 nir_lower_io_impl(nir_function_impl *impl, bool is_scalar)
 410 {
 411    struct lower_io_state state;
 412
 413    state.mem_ctx = ralloc_parent(impl);
 414    state.is_scalar = is_scalar;
 415
 416    nir_foreach_block(impl, nir_lower_io_block, &state);
 417
 418    nir_metadata_preserve(impl, nir_metadata_block_index |
 419                                nir_metadata_dominance);
 420 }
 421
 422 void
 423 nir_lower_io(nir_shader *shader, bool is_scalar)
 424 {
 425    nir_foreach_overload(shader, overload) {
 426       if (overload->impl)
 427          nir_lower_io_impl(overload->impl, is_scalar);
 428    }
 429 }