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/errors.h"
  29 #include "main/macros.h"
  30 #include "main/mtypes.h"
  31
  32 namespace {
  33    /*
  34     * Atomic counter uniform as seen by the program.
  35     */
  36    struct active_atomic_counter_uniform {
  37       unsigned uniform_loc;
  38       ir_variable *var;
  39    };
  40
  41    /*
  42     * Atomic counter buffer referenced by the program.  There is a one
  43     * to one correspondence between these and the objects that can be
  44     * queried using glGetActiveAtomicCounterBufferiv().
  45     */
  46    struct active_atomic_buffer {
  47       active_atomic_buffer()
  48          : uniforms(0), num_uniforms(0), stage_counter_references(), size(0)
  49       {}
  50
  51       ~active_atomic_buffer()
  52       {
  53          free(uniforms);
  54       }
  55
  56       void push_back(unsigned uniform_loc, ir_variable *var)
  57       {
  58          active_atomic_counter_uniform *new_uniforms;
  59
  60          new_uniforms = (active_atomic_counter_uniform *)
  61             realloc(uniforms, sizeof(active_atomic_counter_uniform) *
  62                     (num_uniforms + 1));
  63
  64          if (new_uniforms == NULL) {
  65             _mesa_error_no_memory(__func__);
  66             return;
  67          }
  68
  69          uniforms = new_uniforms;
  70          uniforms[num_uniforms].uniform_loc = uniform_loc;
  71          uniforms[num_uniforms].var = var;
  72          num_uniforms++;
  73       }
  74
  75       active_atomic_counter_uniform *uniforms;
  76       unsigned num_uniforms;
  77       unsigned stage_counter_references[MESA_SHADER_STAGES];
  78       unsigned size;
  79    };
  80
  81    int
  82    cmp_actives(const void *a, const void *b)
  83    {
  84       const active_atomic_counter_uniform *const first = (active_atomic_counter_uniform *) a;
  85       const active_atomic_counter_uniform *const second = (active_atomic_counter_uniform *) b;
  86
  87       return int(first->var->data.offset) - int(second->var->data.offset);
  88    }
  89
  90    bool
  91    check_atomic_counters_overlap(const ir_variable *x, const ir_variable *y)
  92    {
  93       return ((x->data.offset >= y->data.offset &&
  94                x->data.offset < y->data.offset + y->type->atomic_size()) ||
  95               (y->data.offset >= x->data.offset &&
  96                y->data.offset < x->data.offset + x->type->atomic_size()));
  97    }
  98
  99    void
 100    process_atomic_variable(const glsl_type *t, struct gl_shader_program *prog,
 101                            unsigned *uniform_loc, ir_variable *var,
 102                            active_atomic_buffer *const buffers,
 103                            unsigned *num_buffers, int *offset,
 104                            const unsigned shader_stage)
 105    {
 106       /* FIXME: Arrays of arrays get counted separately. For example:
 107        * x1[3][3][2] = 9 uniforms, 18 atomic counters
 108        * x2[3][2]    = 3 uniforms, 6 atomic counters
 109        * x3[2]       = 1 uniform, 2 atomic counters
 110        *
 111        * However this code marks all the counters as active even when they
 112        * might not be used.
 113        */
 114       if (t->is_array() && t->fields.array->is_array()) {
 115          for (unsigned i = 0; i < t->length; i++) {
 116             process_atomic_variable(t->fields.array, prog, uniform_loc,
 117                                     var, buffers, num_buffers, offset,
 118                                     shader_stage);
 119          }
 120       } else {
 121          active_atomic_buffer *buf = &buffers[var->data.binding];
 122          gl_uniform_storage *const storage =
 123             &prog->data->UniformStorage[*uniform_loc];
 124
 125          /* If this is the first time the buffer is used, increment
 126           * the counter of buffers used.
 127           */
 128          if (buf->size == 0)
 129             (*num_buffers)++;
 130
 131          buf->push_back(*uniform_loc, var);
 132
 133          /* When checking for atomic counters we should count every member in
 134           * an array as an atomic counter reference.
 135           */
 136          if (t->is_array())
 137             buf->stage_counter_references[shader_stage] += t->length;
 138          else
 139             buf->stage_counter_references[shader_stage]++;
 140          buf->size = MAX2(buf->size, *offset + t->atomic_size());
 141
 142          storage->offset = *offset;
 143          *offset += t->atomic_size();
 144
 145          (*uniform_loc)++;
 146       }
 147    }
 148
 149    active_atomic_buffer *
 150    find_active_atomic_counters(struct gl_context *ctx,
 151                                struct gl_shader_program *prog,
 152                                unsigned *num_buffers)
 153    {
 154       active_atomic_buffer *const buffers =
 155          new active_atomic_buffer[ctx->Const.MaxAtomicBufferBindings];
 156
 157       *num_buffers = 0;
 158
 159       for (unsigned i = 0; i < MESA_SHADER_STAGES; ++i) {
 160          struct gl_linked_shader *sh = prog->_LinkedShaders[i];
 161          if (sh == NULL)
 162             continue;
 163
 164          foreach_in_list(ir_instruction, node, sh->ir) {
 165             ir_variable *var = node->as_variable();
 166
 167             if (var && var->type->contains_atomic()) {
 168                int offset = var->data.offset;
 169                unsigned uniform_loc = var->data.location;
 170                process_atomic_variable(var->type, prog, &uniform_loc,
 171                                        var, buffers, num_buffers, &offset, i);
 172             }
 173          }
 174       }
 175
 176       for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 177          if (buffers[i].size == 0)
 178             continue;
 179
 180          qsort(buffers[i].uniforms, buffers[i].num_uniforms,
 181                sizeof(active_atomic_counter_uniform),
 182                cmp_actives);
 183
 184          for (unsigned j = 1; j < buffers[i].num_uniforms; j++) {
 185             /* If an overlapping counter found, it must be a reference to the
 186              * same counter from a different shader stage.
 187              */
 188             if (check_atomic_counters_overlap(buffers[i].uniforms[j-1].var,
 189                                               buffers[i].uniforms[j].var)
 190                 && strcmp(buffers[i].uniforms[j-1].var->name,
 191                           buffers[i].uniforms[j].var->name) != 0) {
 192                linker_error(prog, "Atomic counter %s declared at offset %d "
 193                             "which is already in use.",
 194                             buffers[i].uniforms[j].var->name,
 195                             buffers[i].uniforms[j].var->data.offset);
 196             }
 197          }
 198       }
 199       return buffers;
 200    }
 201 }
 202
 203 void
 204 link_assign_atomic_counter_resources(struct gl_context *ctx,
 205                                      struct gl_shader_program *prog)
 206 {
 207    unsigned num_buffers;
 208    unsigned num_atomic_buffers[MESA_SHADER_STAGES] = {};
 209    active_atomic_buffer *abs =
 210       find_active_atomic_counters(ctx, prog, &num_buffers);
 211
 212    prog->data->AtomicBuffers = rzalloc_array(prog->data, gl_active_atomic_buffer,
 213                                              num_buffers);
 214    prog->data->NumAtomicBuffers = num_buffers;
 215
 216    unsigned i = 0;
 217    for (unsigned binding = 0;
 218         binding < ctx->Const.MaxAtomicBufferBindings;
 219         binding++) {
 220
 221       /* If the binding was not used, skip.
 222        */
 223       if (abs[binding].size == 0)
 224          continue;
 225
 226       active_atomic_buffer &ab = abs[binding];
 227       gl_active_atomic_buffer &mab = prog->data->AtomicBuffers[i];
 228
 229       /* Assign buffer-specific fields. */
 230       mab.Binding = binding;
 231       mab.MinimumSize = ab.size;
 232       mab.Uniforms = rzalloc_array(prog->data->AtomicBuffers, GLuint,
 233                                    ab.num_uniforms);
 234       mab.NumUniforms = ab.num_uniforms;
 235
 236       /* Assign counter-specific fields. */
 237       for (unsigned j = 0; j < ab.num_uniforms; j++) {
 238          ir_variable *const var = ab.uniforms[j].var;
 239          gl_uniform_storage *const storage =
 240             &prog->data->UniformStorage[ab.uniforms[j].uniform_loc];
 241
 242          mab.Uniforms[j] = ab.uniforms[j].uniform_loc;
 243          if (!var->data.explicit_binding)
 244             var->data.binding = i;
 245
 246          storage->atomic_buffer_index = i;
 247          storage->offset = var->data.offset;
 248          storage->array_stride = (var->type->is_array() ?
 249                                   var->type->without_array()->atomic_size() : 0);
 250          if (!var->type->is_matrix())
 251             storage->matrix_stride = 0;
 252       }
 253
 254       /* Assign stage-specific fields. */
 255       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 256          if (ab.stage_counter_references[j]) {
 257             mab.StageReferences[j] = GL_TRUE;
 258             num_atomic_buffers[j]++;
 259          } else {
 260             mab.StageReferences[j] = GL_FALSE;
 261          }
 262       }
 263
 264       i++;
 265    }
 266
 267    /* Store a list pointers to atomic buffers per stage and store the index
 268     * to the intra-stage buffer list in uniform storage.
 269     */
 270    for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 271       if (prog->_LinkedShaders[j] && num_atomic_buffers[j] > 0) {
 272          struct gl_program *gl_prog = prog->_LinkedShaders[j]->Program;
 273          gl_prog->info.num_abos = num_atomic_buffers[j];
 274          gl_prog->sh.AtomicBuffers =
 275             rzalloc_array(gl_prog, gl_active_atomic_buffer *,
 276                           num_atomic_buffers[j]);
 277
 278          unsigned intra_stage_idx = 0;
 279          for (unsigned i = 0; i < num_buffers; i++) {
 280             struct gl_active_atomic_buffer *atomic_buffer =
 281                &prog->data->AtomicBuffers[i];
 282             if (atomic_buffer->StageReferences[j]) {
 283                gl_prog->sh.AtomicBuffers[intra_stage_idx] = atomic_buffer;
 284
 285                for (unsigned u = 0; u < atomic_buffer->NumUniforms; u++) {
 286                   prog->data->UniformStorage[atomic_buffer->Uniforms[u]].opaque[j].index =
 287                      intra_stage_idx;
 288                   prog->data->UniformStorage[atomic_buffer->Uniforms[u]].opaque[j].active =
 289                      true;
 290                }
 291
 292                intra_stage_idx++;
 293             }
 294          }
 295       }
 296    }
 297
 298    delete [] abs;
 299    assert(i == num_buffers);
 300 }
 301
 302 void
 303 link_check_atomic_counter_resources(struct gl_context *ctx,
 304                                     struct gl_shader_program *prog)
 305 {
 306    unsigned num_buffers;
 307    active_atomic_buffer *const abs =
 308       find_active_atomic_counters(ctx, prog, &num_buffers);
 309    unsigned atomic_counters[MESA_SHADER_STAGES] = {};
 310    unsigned atomic_buffers[MESA_SHADER_STAGES] = {};
 311    unsigned total_atomic_counters = 0;
 312    unsigned total_atomic_buffers = 0;
 313
 314    /* Sum the required resources.  Note that this counts buffers and
 315     * counters referenced by several shader stages multiple times
 316     * against the combined limit -- That's the behavior the spec
 317     * requires.
 318     */
 319    for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 320       if (abs[i].size == 0)
 321          continue;
 322
 323       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 324          const unsigned n = abs[i].stage_counter_references[j];
 325
 326          if (n) {
 327             atomic_counters[j] += n;
 328             total_atomic_counters += n;
 329             atomic_buffers[j]++;
 330             total_atomic_buffers++;
 331          }
 332       }
 333    }
 334
 335    /* Check that they are within the supported limits. */
 336    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
 337       if (atomic_counters[i] > ctx->Const.Program[i].MaxAtomicCounters)
 338          linker_error(prog, "Too many %s shader atomic counters",
 339                       _mesa_shader_stage_to_string(i));
 340
 341       if (atomic_buffers[i] > ctx->Const.Program[i].MaxAtomicBuffers)
 342          linker_error(prog, "Too many %s shader atomic counter buffers",
 343                       _mesa_shader_stage_to_string(i));
 344    }
 345
 346    if (total_atomic_counters > ctx->Const.MaxCombinedAtomicCounters)
 347       linker_error(prog, "Too many combined atomic counters");
 348
 349    if (total_atomic_buffers > ctx->Const.MaxCombinedAtomicBuffers)
 350       linker_error(prog, "Too many combined atomic buffers");
 351
 352    delete [] abs;
 353 }