src/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 "program/hash_table.h"
  29 #include "main/macros.h"
  30
  31 namespace {
  32    /*
  33     * Atomic counter as seen by the program.
  34     */
  35    struct active_atomic_counter {
  36       unsigned id;
  37       ir_variable *var;
  38    };
  39
  40    /*
  41     * Atomic counter buffer referenced by the program.  There is a one
  42     * to one correspondence between these and the objects that can be
  43     * queried using glGetActiveAtomicCounterBufferiv().
  44     */
  45    struct active_atomic_buffer {
  46       active_atomic_buffer()
  47          : counters(0), num_counters(0), stage_references(), size(0)
  48       {}
  49
  50       ~active_atomic_buffer()
  51       {
  52          free(counters);
  53       }
  54
  55       void push_back(unsigned id, ir_variable *var)
  56       {
  57          active_atomic_counter *new_counters;
  58
  59          new_counters = (active_atomic_counter *)
  60             realloc(counters, sizeof(active_atomic_counter) *
  61                     (num_counters + 1));
  62
  63          if (new_counters == NULL) {
  64             _mesa_error_no_memory(__func__);
  65             return;
  66          }
  67
  68          counters = new_counters;
  69          counters[num_counters].id = id;
  70          counters[num_counters].var = var;
  71          num_counters++;
  72       }
  73
  74       active_atomic_counter *counters;
  75       unsigned num_counters;
  76       unsigned stage_references[MESA_SHADER_STAGES];
  77       unsigned size;
  78    };
  79
  80    int
  81    cmp_actives(const void *a, const void *b)
  82    {
  83       const active_atomic_counter *const first = (active_atomic_counter *) a;
  84       const active_atomic_counter *const second = (active_atomic_counter *) b;
  85
  86       return int(first->var->data.atomic.offset) - int(second->var->data.atomic.offset);
  87    }
  88
  89    bool
  90    check_atomic_counters_overlap(const ir_variable *x, const ir_variable *y)
  91    {
  92       return ((x->data.atomic.offset >= y->data.atomic.offset &&
  93                x->data.atomic.offset < y->data.atomic.offset + y->type->atomic_size()) ||
  94               (y->data.atomic.offset >= x->data.atomic.offset &&
  95                y->data.atomic.offset < x->data.atomic.offset + x->type->atomic_size()));
  96    }
  97
  98    active_atomic_buffer *
  99    find_active_atomic_counters(struct gl_context *ctx,
 100                                struct gl_shader_program *prog,
 101                                unsigned *num_buffers)
 102    {
 103       active_atomic_buffer *const buffers =
 104          new active_atomic_buffer[ctx->Const.MaxAtomicBufferBindings];
 105
 106       *num_buffers = 0;
 107
 108       for (unsigned i = 0; i < MESA_SHADER_STAGES; ++i) {
 109          struct gl_shader *sh = prog->_LinkedShaders[i];
 110          if (sh == NULL)
 111             continue;
 112
 113          foreach_in_list(ir_instruction, node, sh->ir) {
 114             ir_variable *var = node->as_variable();
 115
 116             if (var && var->type->contains_atomic()) {
 117                unsigned id = 0;
 118                bool found = prog->UniformHash->get(id, var->name);
 119                assert(found);
 120                (void) found;
 121                active_atomic_buffer *buf = &buffers[var->data.binding];
 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(id, var);
 130
 131                buf->stage_references[i]++;
 132                buf->size = MAX2(buf->size, var->data.atomic.offset +
 133                                 var->type->atomic_size());
 134             }
 135          }
 136       }
 137
 138       for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 139          if (buffers[i].size == 0)
 140             continue;
 141
 142          qsort(buffers[i].counters, buffers[i].num_counters,
 143                sizeof(active_atomic_counter),
 144                cmp_actives);
 145
 146          for (unsigned j = 1; j < buffers[i].num_counters; j++) {
 147             /* If an overlapping counter found, it must be a reference to the
 148              * same counter from a different shader stage.
 149              */
 150             if (check_atomic_counters_overlap(buffers[i].counters[j-1].var,
 151                                               buffers[i].counters[j].var)
 152                 && strcmp(buffers[i].counters[j-1].var->name,
 153                           buffers[i].counters[j].var->name) != 0) {
 154                linker_error(prog, "Atomic counter %s declared at offset %d "
 155                             "which is already in use.",
 156                             buffers[i].counters[j].var->name,
 157                             buffers[i].counters[j].var->data.atomic.offset);
 158             }
 159          }
 160       }
 161       return buffers;
 162    }
 163 }
 164
 165 void
 166 link_assign_atomic_counter_resources(struct gl_context *ctx,
 167                                      struct gl_shader_program *prog)
 168 {
 169    unsigned num_buffers;
 170    active_atomic_buffer *abs =
 171       find_active_atomic_counters(ctx, prog, &num_buffers);
 172
 173    prog->AtomicBuffers = rzalloc_array(prog, gl_active_atomic_buffer,
 174                                        num_buffers);
 175    prog->NumAtomicBuffers = num_buffers;
 176
 177    unsigned i = 0;
 178    for (unsigned binding = 0;
 179         binding < ctx->Const.MaxAtomicBufferBindings;
 180         binding++) {
 181
 182       /* If the binding was not used, skip.
 183        */
 184       if (abs[binding].size == 0)
 185          continue;
 186
 187       active_atomic_buffer &ab = abs[binding];
 188       gl_active_atomic_buffer &mab = prog->AtomicBuffers[i];
 189
 190       /* Assign buffer-specific fields. */
 191       mab.Binding = binding;
 192       mab.MinimumSize = ab.size;
 193       mab.Uniforms = rzalloc_array(prog->AtomicBuffers, GLuint,
 194                                    ab.num_counters);
 195       mab.NumUniforms = ab.num_counters;
 196
 197       /* Assign counter-specific fields. */
 198       for (unsigned j = 0; j < ab.num_counters; j++) {
 199          ir_variable *const var = ab.counters[j].var;
 200          const unsigned id = ab.counters[j].id;
 201          gl_uniform_storage *const storage = &prog->UniformStorage[id];
 202
 203          mab.Uniforms[j] = id;
 204          if (!var->data.explicit_binding)
 205             var->data.binding = i;
 206
 207          storage->atomic_buffer_index = i;
 208          storage->offset = var->data.atomic.offset;
 209          storage->array_stride = (var->type->is_array() ?
 210                                   var->type->without_array()->atomic_size() : 0);
 211       }
 212
 213       /* Assign stage-specific fields. */
 214       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j)
 215          mab.StageReferences[j] =
 216             (ab.stage_references[j] ? GL_TRUE : GL_FALSE);
 217
 218       i++;
 219    }
 220
 221    delete [] abs;
 222    assert(i == num_buffers);
 223 }
 224
 225 void
 226 link_check_atomic_counter_resources(struct gl_context *ctx,
 227                                     struct gl_shader_program *prog)
 228 {
 229    unsigned num_buffers;
 230    active_atomic_buffer *const abs =
 231       find_active_atomic_counters(ctx, prog, &num_buffers);
 232    unsigned atomic_counters[MESA_SHADER_STAGES] = {};
 233    unsigned atomic_buffers[MESA_SHADER_STAGES] = {};
 234    unsigned total_atomic_counters = 0;
 235    unsigned total_atomic_buffers = 0;
 236
 237    /* Sum the required resources.  Note that this counts buffers and
 238     * counters referenced by several shader stages multiple times
 239     * against the combined limit -- That's the behavior the spec
 240     * requires.
 241     */
 242    for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 243       if (abs[i].size == 0)
 244          continue;
 245
 246       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 247          const unsigned n = abs[i].stage_references[j];
 248
 249          if (n) {
 250             atomic_counters[j] += n;
 251             total_atomic_counters += n;
 252             atomic_buffers[j]++;
 253             total_atomic_buffers++;
 254          }
 255       }
 256    }
 257
 258    /* Check that they are within the supported limits. */
 259    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
 260       if (atomic_counters[i] > ctx->Const.Program[i].MaxAtomicCounters)
 261          linker_error(prog, "Too many %s shader atomic counters",
 262                       _mesa_shader_stage_to_string(i));
 263
 264       if (atomic_buffers[i] > ctx->Const.Program[i].MaxAtomicBuffers)
 265          linker_error(prog, "Too many %s shader atomic counter buffers",
 266                       _mesa_shader_stage_to_string(i));
 267    }
 268
 269    if (total_atomic_counters > ctx->Const.MaxCombinedAtomicCounters)
 270       linker_error(prog, "Too many combined atomic counters");
 271
 272    if (total_atomic_buffers > ctx->Const.MaxCombinedAtomicBuffers)
 273       linker_error(prog, "Too many combined atomic buffers");
 274
 275    delete [] abs;
 276 }