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          counters = (active_atomic_counter *)
  58             realloc(counters, sizeof(active_atomic_counter) * (num_counters + 1));
  59
  60          counters[num_counters].id = id;
  61          counters[num_counters].var = var;
  62          num_counters++;
  63       }
  64
  65       active_atomic_counter *counters;
  66       unsigned num_counters;
  67       unsigned stage_references[MESA_SHADER_STAGES];
  68       unsigned size;
  69    };
  70
  71    int
  72    cmp_actives(const void *a, const void *b)
  73    {
  74       const active_atomic_counter *const first = (active_atomic_counter *) a;
  75       const active_atomic_counter *const second = (active_atomic_counter *) b;
  76
  77       return int(first->var->data.atomic.offset) - int(second->var->data.atomic.offset);
  78    }
  79
  80    bool
  81    check_atomic_counters_overlap(const ir_variable *x, const ir_variable *y)
  82    {
  83       return ((x->data.atomic.offset >= y->data.atomic.offset &&
  84                x->data.atomic.offset < y->data.atomic.offset + y->type->atomic_size()) ||
  85               (y->data.atomic.offset >= x->data.atomic.offset &&
  86                y->data.atomic.offset < x->data.atomic.offset + x->type->atomic_size()));
  87    }
  88
  89    active_atomic_buffer *
  90    find_active_atomic_counters(struct gl_context *ctx,
  91                                struct gl_shader_program *prog,
  92                                unsigned *num_buffers)
  93    {
  94       active_atomic_buffer *const buffers =
  95          new active_atomic_buffer[ctx->Const.MaxAtomicBufferBindings];
  96
  97       *num_buffers = 0;
  98
  99       for (unsigned i = 0; i < MESA_SHADER_STAGES; ++i) {
 100          struct gl_shader *sh = prog->_LinkedShaders[i];
 101          if (sh == NULL)
 102             continue;
 103
 104          foreach_list(node, sh->ir) {
 105             ir_variable *var = ((ir_instruction *)node)->as_variable();
 106
 107             if (var && var->type->contains_atomic()) {
 108                unsigned id = 0;
 109                bool found = prog->UniformHash->get(id, var->name);
 110                assert(found);
 111                (void) found;
 112                active_atomic_buffer *buf = &buffers[var->data.binding];
 113
 114                /* If this is the first time the buffer is used, increment
 115                 * the counter of buffers used.
 116                 */
 117                if (buf->size == 0)
 118                   (*num_buffers)++;
 119
 120                buf->push_back(id, var);
 121
 122                buf->stage_references[i]++;
 123                buf->size = MAX2(buf->size, var->data.atomic.offset +
 124                                 var->type->atomic_size());
 125             }
 126          }
 127       }
 128
 129       for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 130          if (buffers[i].size == 0)
 131             continue;
 132
 133          qsort(buffers[i].counters, buffers[i].num_counters,
 134                sizeof(active_atomic_counter),
 135                cmp_actives);
 136
 137          for (unsigned j = 1; j < buffers[i].num_counters; j++) {
 138             /* If an overlapping counter found, it must be a reference to the
 139              * same counter from a different shader stage.
 140              */
 141             if (check_atomic_counters_overlap(buffers[i].counters[j-1].var,
 142                                               buffers[i].counters[j].var)
 143                 && strcmp(buffers[i].counters[j-1].var->name,
 144                           buffers[i].counters[j].var->name) != 0) {
 145                linker_error(prog, "Atomic counter %s declared at offset %d "
 146                             "which is already in use.",
 147                             buffers[i].counters[j].var->name,
 148                             buffers[i].counters[j].var->data.atomic.offset);
 149             }
 150          }
 151       }
 152       return buffers;
 153    }
 154 }
 155
 156 void
 157 link_assign_atomic_counter_resources(struct gl_context *ctx,
 158                                      struct gl_shader_program *prog)
 159 {
 160    unsigned num_buffers;
 161    active_atomic_buffer *abs =
 162       find_active_atomic_counters(ctx, prog, &num_buffers);
 163
 164    prog->AtomicBuffers = rzalloc_array(prog, gl_active_atomic_buffer,
 165                                        num_buffers);
 166    prog->NumAtomicBuffers = num_buffers;
 167
 168    unsigned i = 0;
 169    for (unsigned binding = 0;
 170         binding < ctx->Const.MaxAtomicBufferBindings;
 171         binding++) {
 172
 173       /* If the binding was not used, skip.
 174        */
 175       if (abs[binding].size == 0)
 176          continue;
 177
 178       active_atomic_buffer &ab = abs[binding];
 179       gl_active_atomic_buffer &mab = prog->AtomicBuffers[i];
 180
 181       /* Assign buffer-specific fields. */
 182       mab.Binding = binding;
 183       mab.MinimumSize = ab.size;
 184       mab.Uniforms = rzalloc_array(prog->AtomicBuffers, GLuint,
 185                                    ab.num_counters);
 186       mab.NumUniforms = ab.num_counters;
 187
 188       /* Assign counter-specific fields. */
 189       for (unsigned j = 0; j < ab.num_counters; j++) {
 190          ir_variable *const var = ab.counters[j].var;
 191          const unsigned id = ab.counters[j].id;
 192          gl_uniform_storage *const storage = &prog->UniformStorage[id];
 193
 194          mab.Uniforms[j] = id;
 195          var->data.atomic.buffer_index = i;
 196          storage->atomic_buffer_index = i;
 197          storage->offset = var->data.atomic.offset;
 198          storage->array_stride = (var->type->is_array() ?
 199                                   var->type->element_type()->atomic_size() : 0);
 200       }
 201
 202       /* Assign stage-specific fields. */
 203       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j)
 204          mab.StageReferences[j] =
 205             (ab.stage_references[j] ? GL_TRUE : GL_FALSE);
 206
 207       i++;
 208    }
 209
 210    delete [] abs;
 211    assert(i == num_buffers);
 212 }
 213
 214 void
 215 link_check_atomic_counter_resources(struct gl_context *ctx,
 216                                     struct gl_shader_program *prog)
 217 {
 218    unsigned num_buffers;
 219    active_atomic_buffer *const abs =
 220       find_active_atomic_counters(ctx, prog, &num_buffers);
 221    unsigned atomic_counters[MESA_SHADER_STAGES] = {};
 222    unsigned atomic_buffers[MESA_SHADER_STAGES] = {};
 223    unsigned total_atomic_counters = 0;
 224    unsigned total_atomic_buffers = 0;
 225
 226    /* Sum the required resources.  Note that this counts buffers and
 227     * counters referenced by several shader stages multiple times
 228     * against the combined limit -- That's the behavior the spec
 229     * requires.
 230     */
 231    for (unsigned i = 0; i < ctx->Const.MaxAtomicBufferBindings; i++) {
 232       if (abs[i].size == 0)
 233          continue;
 234
 235       for (unsigned j = 0; j < MESA_SHADER_STAGES; ++j) {
 236          const unsigned n = abs[i].stage_references[j];
 237
 238          if (n) {
 239             atomic_counters[j] += n;
 240             total_atomic_counters += n;
 241             atomic_buffers[j]++;
 242             total_atomic_buffers++;
 243          }
 244       }
 245    }
 246
 247    /* Check that they are within the supported limits. */
 248    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
 249       if (atomic_counters[i] > ctx->Const.Program[i].MaxAtomicCounters)
 250          linker_error(prog, "Too many %s shader atomic counters",
 251                       _mesa_shader_stage_to_string(i));
 252
 253       if (atomic_buffers[i] > ctx->Const.Program[i].MaxAtomicBuffers)
 254          linker_error(prog, "Too many %s shader atomic counter buffers",
 255                       _mesa_shader_stage_to_string(i));
 256    }
 257
 258    if (total_atomic_counters > ctx->Const.MaxCombinedAtomicCounters)
 259       linker_error(prog, "Too many combined atomic counters");
 260
 261    if (total_atomic_buffers > ctx->Const.MaxCombinedAtomicBuffers)
 262       linker_error(prog, "Too many combined atomic buffers");
 263
 264    delete [] abs;
 265 }