[Mesa-dev] [RFC 17/16] glsl: add AoA support for atmoic counters

[Timothy Arceri]

---
 src/glsl/link_atomics.cpp | 73 +++++++++++++++++++++++++++++++++++------------
 1 file changed, 55 insertions(+), 18 deletions(-)

diff --git a/src/glsl/link_atomics.cpp b/src/glsl/link_atomics.cpp
index 100d03c..21f9af7 100644
--- a/src/glsl/link_atomics.cpp
+++ b/src/glsl/link_atomics.cpp
@@ -95,6 +95,56 @@ namespace {
                y->data.atomic.offset < x->data.atomic.offset + x->type->atomic_size()));
    }
 
+   void
+   process_atomic_variable(const glsl_type *t, struct gl_shader_program *prog,
+                           char **name, size_t name_length, ir_variable *var,
+                           active_atomic_buffer *const buffers,
+                           unsigned *num_buffers, int *offset,
+                           const unsigned shader_stage)
+   {
+      /* FIXME: Arrays of arrays get counted separately. For example:
+       * x1[3][3][2] = 9 counters
+       * x2[3][2]    = 3 counters
+       * x3[2]       = 1 counter
+       *
+       * However this code marks all the counters as active even when they
+       * might not be used.
+       */
+      if (t->is_array() && t->fields.array->is_array()) {
+         for (unsigned i = 0; i < t->length; i++) {
+	    size_t new_length = name_length;
+
+	    /* Append the subscript to the current variable name */
+	    ralloc_asprintf_rewrite_tail(name, &new_length, "[%u]", i);
+
+            process_atomic_variable(t->fields.array, prog, name, new_length,
+                                    var, buffers, num_buffers, offset,
+                                    shader_stage);
+         }
+      } else {
+         unsigned id = 0;
+         bool found = prog->UniformHash->get(id, *name);
+         assert(found);
+         (void) found;
+         active_atomic_buffer *buf = &buffers[var->data.binding];
+         gl_uniform_storage *const storage = &prog->UniformStorage[id];
+
+         /* If this is the first time the buffer is used, increment
+          * the counter of buffers used.
+          */
+         if (buf->size == 0)
+            (*num_buffers)++;
+
+         buf->push_back(id, var);
+
+         buf->stage_references[shader_stage]++;
+         buf->size = MAX2(buf->size, *offset + t->atomic_size());
+
+         storage->offset = *offset;
+         *offset += t->atomic_size();
+      }
+   }
+
    active_atomic_buffer *
    find_active_atomic_counters(struct gl_context *ctx,
                                struct gl_shader_program *prog,
@@ -114,23 +164,11 @@ namespace {
             ir_variable *var = node->as_variable();
 
             if (var && var->type->contains_atomic()) {
-               unsigned id = 0;
-               bool found = prog->UniformHash->get(id, var->name);
-               assert(found);
-               (void) found;
-               active_atomic_buffer *buf = &buffers[var->data.binding];
-
-               /* If this is the first time the buffer is used, increment
-                * the counter of buffers used.
-                */
-               if (buf->size == 0)
-                  (*num_buffers)++;
-
-               buf->push_back(id, var);
-
-               buf->stage_references[i]++;
-               buf->size = MAX2(buf->size, var->data.atomic.offset +
-                                var->type->atomic_size());
+               char *name = ralloc_strdup(NULL, var->name);
+               int offset = var->data.atomic.offset;
+               process_atomic_variable(var->type, prog, &name, strlen(name),
+                                       var, buffers, num_buffers, &offset, i);
+               ralloc_free(name);
             }
          }
       }
@@ -205,7 +243,6 @@ link_assign_atomic_counter_resources(struct gl_context *ctx,
             var->data.binding = i;
 
          storage->atomic_buffer_index = i;
-         storage->offset = var->data.atomic.offset;
          storage->array_stride = (var->type->is_array() ?
                                   var->type->without_array()->atomic_size() : 0);
       }
-- 
2.4.3