src/compiler/glsl/link_atomics.cpp

   1 /*
   2  * Copyright © 2013 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
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23
  24 #include "glsl_parser_extras.h"
  25 #include "ir.h"
  26 #include "ir_uniform.h"
  27 #include "linker.h"
  28 #include "main/macros.h"
  29
  30 namespace {
  31    /*
  32     * Atomic counter uniform as seen by the program.
  33     */
  34    struct active_atomic_counter_uniform {
  35       unsigned uniform_loc;
  36       ir_variable *var;
  37    };
  38
  39    /*
  40     * Atomic counter buffer referenced by the program.  There is a one
  41     * to one correspondence between these and the objects that can be
  42     * queried using glGetActiveAtomicCounterBufferiv().
  43     */
  44    struct active_atomic_buffer {
  45       active_atomic_buffer()
  46          : uniforms(0), num_uniforms(0), stage_counter_references(), size(0)
  47       {}
  48
  49       ~active_atomic_buffer()
  50       {
  51          free(uniforms);
  52       }
  53
  54       void push_back(unsigned uniform_loc, ir_variable *var)
  55       {
  56          active_atomic_counter_uniform *new_uniforms;
  57
  58          new_uniforms = (active_atomic_counter_uniform *)
  59             realloc(uniforms, sizeof(active_atomic_counter_uniform) *
  60                     (num_uniforms + 1));
  61
  62          if (new_uniforms == NULL) {
  63             _mesa_error_no_memory(__func__);
  64             return;
  65          }
  66
  67          uniforms = new_uniforms;
  68          uniforms[num_uniforms].uniform_loc = uniform_loc;
  69          uniforms[num_uniforms].var = var;
  70          num_uniforms++;
  71       }
  72
  73       active_atomic_counter_uniform *uniforms;
  74       unsigned num_uniforms;
  75       unsigned stage_counter_references[MESA_SHADER_STAGES];
  76       unsigned size;
  77    };
  78
  79    int
  80    cmp_actives(const void *a, const void *b)
  81    {
  82       const active_atomic_counter_uniform *const first = (active_atomic_counter_uniform *) a;
  83       const active_atomic_counter_uniform *const second = (active_atomic_counter_uniform *) b;
  84
  85       return int(first->var->data.offset) - int(second->var->data.offset);
  86    }
  87
  88    bool
  89    check_atomic_counters_overlap(const ir_variable *x, const ir_variable *y)
  90    {
  91       return ((x->data.offset >= y->data.offset &&
  92                x->data.offset < y->data.offset + y->type->atomic_size()) ||
  93               (y->data.offset >= x->data.offset &&
  94                y->data.offset < x->data.offset + x->type->atomic_size()));
  95    }
  96
  97    void
  98    process_atomic_variable(const glsl_type *t, struct gl_shader_program *prog,
  99                            unsigned *uniform_loc, ir_variable *var,
 100                            active_atomic_buffer *const buffers,
 101                            unsigned *num_buffers, int *offset,
 102                            const unsigned shader_stage)
 103    {
 104       /* FIXME: Arrays of arrays get counted separately. For example:
 105        * x1[3][3][2] = 9 uniforms, 18 atomic counters
 106        * x2[3][2]    = 3 uniforms, 6 atomic counters
 107        * x3[2]       = 1 uniform, 2 atomic counters
 108        *
 109        * However this code marks all the counters as active even when they
 110        * might not be used.
 111        */
 112       if (t->is_array() && t->fields.array->is_array()) {
 113          for (unsigned i = 0; i < t->length; i++) {
 114             process_atomic_variable(t->fields.array, prog, uniform_loc,
 115                                     var, buffers, num_buffers, offset,
 116                                     shader_stage);
 117          }
 118       } else {
 119          active_atomic_buffer *buf = &buffers[var->data.binding];
 120          gl_uniform_storage *const storage =
 121             &prog->data->UniformStorage[*uniform_loc];
 122
 123          /* If this is the first time the buffer is used, increment
 124           * the counter of buffers used.
 125           */
 126          if (buf->size == 0)
 127             (*num_buffers)++;
 128
 129          buf->push_back(*uniform_loc, var);
 130
 131          /* When checking for atomic counters we should count every member in
 132           * an array as an atomic counter reference.
 133           */
 134          if (t->is_array())
 135             buf->stage_counter_references[shader_stage] += t->length;
 136          else
 137             buf->stage_counter_references[shader_stage]++;
 138          buf->size = MAX2(buf->size, *offset + t->atomic_size());
 139
 140          storage->offset = *offset;
 141          *offset += t->atomic_size();
 142
 143          (*uniform_loc)++;
 144       }
 145    }
 146
 147    active_atomic_buffer *
 148    find_active_atomic_counters(struct gl_context *ctx,
 149                                struct gl_shader_program *prog,
 150                                unsigned *num_buffers)
 151    {
 152       active_atomic_buffer *const buffers =
 153          new active_atomic_buffer[ctx->Const.MaxAtomicBufferBindings];
 154
 155       *num_buffers = 0;
 156
 157       for (unsigned i = 0; i < MESA_SHADER_STAGES; ++i) {
 158          struct gl_linked_shader *sh = prog->_LinkedShaders[i];
 159          if (sh == NULL)
 160             continue;
 161
 162          foreach_in_list(ir_instruction, node, sh->ir) {
 163             ir_variable *var = node->as_variable();
 164
 165             if (var && var->type->contains_atomic()) {
 166                int offset = var->data.offset;
 167                unsigned uniform_loc = var->data.location;
 168                process_atomic_variable(var->type, prog, &uniform_loc,
 169                                        var, buffers, num_buffers, &offset, i);
 170             }
 171          }
 172       }
 173
 174       for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 175          if (buffers[i].size == 0)
 176             continue;
 177
 178          qsort(buffers[i].uniforms, buffers[i].num_uniforms,
 179                sizeof(active_atomic_counter_uniform),
 180                cmp_actives);
 181
 182          for (unsigned j = 1; j < buffers[i].num_uniforms; j++) {
 183             /* If an overlapping counter found, it must be a reference to the
 184              * same counter from a different shader stage.
 185              */
 186             if (check_atomic_counters_overlap(buffers[i].uniforms[j-1].var,
 187                                               buffers[i].uniforms[j].var)
 188                 && strcmp(buffers[i].uniforms[j-1].var->name,
 189                           buffers[i].uniforms[j].var->name) != 0) {
 190                linker_error(prog, "Atomic counter %s declared at offset %d "
 191                             "which is already in use.",
 192                             buffers[i].uniforms[j].var->name,
 193                             buffers[i].uniforms[j].var->data.offset);
 194             }
 195          }
 196       }
 197       return buffers;
 198    }
 199 }
 200
 201 void
 202 link_assign_atomic_counter_resources(struct gl_context *ctx,
 203                                      struct gl_shader_program *prog)
 204 {
 205    unsigned num_buffers;
 206    unsigned num_atomic_buffers[MESA_SHADER_STAGES] = {};
 207    active_atomic_buffer *abs =
 208       find_active_atomic_counters(ctx, prog, &num_buffers);
 209
 210    prog->data->AtomicBuffers = rzalloc_array(prog->data, gl_active_atomic_buffer,
 211                                              num_buffers);
 212    prog->data->NumAtomicBuffers = num_buffers;
 213
 214    unsigned i = 0;
 215    for (unsigned binding = 0;
 216         binding < ctx->Const.MaxAtomicBufferBindings;
 217         binding++) {
 218
 219       /* If the binding was not used, skip.
 220        */
 221       if (abs[binding].size == 0)
 222          continue;
 223
 224       active_atomic_buffer &ab = abs[binding];
 225       gl_active_atomic_buffer &mab = prog->data->AtomicBuffers[i];
 226
 227       /* Assign buffer-specific fields. */
 228       mab.Binding = binding;
 229       mab.MinimumSize = ab.size;
 230       mab.Uniforms = rzalloc_array(prog->data->AtomicBuffers, GLuint,
 231                                    ab.num_uniforms);
 232       mab.NumUniforms = ab.num_uniforms;
 233
 234       /* Assign counter-specific fields. */
 235       for (unsigned j = 0; j < ab.num_uniforms; j++) {
 236          ir_variable *const var = ab.uniforms[j].var;
 237          gl_uniform_storage *const storage =
 238             &prog->data->UniformStorage[ab.uniforms[j].uniform_loc];
 239
 240          mab.Uniforms[j] = ab.uniforms[j].uniform_loc;
 241          if (!var->data.explicit_binding)
 242             var->data.binding = i;
 243
 244          storage->atomic_buffer_index = i;
 245          storage->offset = var->data.offset;
 246          storage->array_stride = (var->type->is_array() ?
 247                                   var->type->without_array()->atomic_size() : 0);
 248          if (!var->type->is_matrix())
 249             storage->matrix_stride = 0;
 250       }
 251
 252       /* Assign stage-specific fields. */
 253       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 254          if (ab.stage_counter_references[j]) {
 255             mab.StageReferences[j] = GL_TRUE;
 256             num_atomic_buffers[j]++;
 257          } else {
 258             mab.StageReferences[j] = GL_FALSE;
 259          }
 260       }
 261
 262       i++;
 263    }
 264
 265    /* Store a list pointers to atomic buffers per stage and store the index
 266     * to the intra-stage buffer list in uniform storage.
 267     */
 268    for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 269       if (prog->_LinkedShaders[j] && num_atomic_buffers[j] > 0) {
 270          struct gl_program *gl_prog = prog->_LinkedShaders[j]->Program;
 271          gl_prog->info.num_abos = num_atomic_buffers[j];
 272          gl_prog->sh.AtomicBuffers =
 273             rzalloc_array(gl_prog, gl_active_atomic_buffer *,
 274                           num_atomic_buffers[j]);
 275
 276          unsigned intra_stage_idx = 0;
 277          for (unsigned i = 0; i < num_buffers; i++) {
 278             struct gl_active_atomic_buffer *atomic_buffer =
 279                &prog->data->AtomicBuffers[i];
 280             if (atomic_buffer->StageReferences[j]) {
 281                gl_prog->sh.AtomicBuffers[intra_stage_idx] = atomic_buffer;
 282
 283                for (unsigned u = 0; u < atomic_buffer->NumUniforms; u++) {
 284                   prog->data->UniformStorage[atomic_buffer->Uniforms[u]].opaque[j].index =
 285                      intra_stage_idx;
 286                   prog->data->UniformStorage[atomic_buffer->Uniforms[u]].opaque[j].active =
 287                      true;
 288                }
 289
 290                intra_stage_idx++;
 291             }
 292          }
 293       }
 294    }
 295
 296    delete [] abs;
 297    assert(i == num_buffers);
 298 }
 299
 300 void
 301 link_check_atomic_counter_resources(struct gl_context *ctx,
 302                                     struct gl_shader_program *prog)
 303 {
 304    unsigned num_buffers;
 305    active_atomic_buffer *const abs =
 306       find_active_atomic_counters(ctx, prog, &num_buffers);
 307    unsigned atomic_counters[MESA_SHADER_STAGES] = {};
 308    unsigned atomic_buffers[MESA_SHADER_STAGES] = {};
 309    unsigned total_atomic_counters = 0;
 310    unsigned total_atomic_buffers = 0;
 311
 312    /* Sum the required resources.  Note that this counts buffers and
 313     * counters referenced by several shader stages multiple times
 314     * against the combined limit -- That's the behavior the spec
 315     * requires.
 316     */
 317    for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 318       if (abs[i].size == 0)
 319          continue;
 320
 321       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 322          const unsigned n = abs[i].stage_counter_references[j];
 323
 324          if (n) {
 325             atomic_counters[j] += n;
 326             total_atomic_counters += n;
 327             atomic_buffers[j]++;
 328             total_atomic_buffers++;
 329          }
 330       }
 331    }
 332
 333    /* Check that they are within the supported limits. */
 334    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
 335       if (atomic_counters[i] > ctx->Const.Program[i].MaxAtomicCounters)
 336          linker_error(prog, "Too many %s shader atomic counters",
 337                       _mesa_shader_stage_to_string(i));
 338
 339       if (atomic_buffers[i] > ctx->Const.Program[i].MaxAtomicBuffers)
 340          linker_error(prog, "Too many %s shader atomic counter buffers",
 341                       _mesa_shader_stage_to_string(i));
 342    }
 343
 344    if (total_atomic_counters > ctx->Const.MaxCombinedAtomicCounters)
 345       linker_error(prog, "Too many combined atomic counters");
 346
 347    if (total_atomic_buffers > ctx->Const.MaxCombinedAtomicBuffers)
 348       linker_error(prog, "Too many combined atomic buffers");
 349
 350    delete [] abs;
 351 }