Mesa (master): glsl: add AoA support for atomic counters

[Timothy Arceri]

Module: Mesa
Branch: master
Commit: 2d7a98de18e4cdd69daa63b09b504d01ad4c9f50
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=2d7a98de18e4cdd69daa63b09b504d01ad4c9f50

Author: Timothy Arceri <t_arceri at yahoo.com.au>
Date:   Sun Aug 30 21:08:22 2015 +1000

glsl: add AoA support for atomic counters

This marks all counters in an AoA as active.

For AoA all but the innermost array are treated as separate
counters/uniforms. The Nvidia binary also goes further and
finds inactive counters in the AoA, in future we should do
this too, however this gets things working for the time being.

This change also removes the use of UniformHash for atomic counters,
this avoids having to generate name strings used as hash keys.

Reviewed-by: Ian Romanick <ian.d.romanick at intel.com>

---

 src/glsl/link_atomics.cpp |   77 +++++++++++++++++++++++++++++++--------------
 1 file changed, 54 insertions(+), 23 deletions(-)

diff --git a/src/glsl/link_atomics.cpp b/src/glsl/link_atomics.cpp
index 100d03c..70ef0e1 100644
--- a/src/glsl/link_atomics.cpp
+++ b/src/glsl/link_atomics.cpp
@@ -33,7 +33,7 @@ namespace {
     * Atomic counter as seen by the program.
     */
    struct active_atomic_counter {
-      unsigned id;
+      unsigned uniform_loc;
       ir_variable *var;
    };
 
@@ -52,7 +52,7 @@ namespace {
          free(counters);
       }
 
-      void push_back(unsigned id, ir_variable *var)
+      void push_back(unsigned uniform_loc, ir_variable *var)
       {
          active_atomic_counter *new_counters;
 
@@ -66,7 +66,7 @@ namespace {
          }
 
          counters = new_counters;
-         counters[num_counters].id = id;
+         counters[num_counters].uniform_loc = uniform_loc;
          counters[num_counters].var = var;
          num_counters++;
       }
@@ -95,6 +95,50 @@ 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,
+                           unsigned *uniform_loc, 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++) {
+            process_atomic_variable(t->fields.array, prog, uniform_loc,
+                                    var, buffers, num_buffers, offset,
+                                    shader_stage);
+         }
+      } else {
+         active_atomic_buffer *buf = &buffers[var->data.binding];
+         gl_uniform_storage *const storage =
+            &prog->UniformStorage[*uniform_loc];
+
+         /* 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(*uniform_loc, var);
+
+         buf->stage_references[shader_stage]++;
+         buf->size = MAX2(buf->size, *offset + t->atomic_size());
+
+         storage->offset = *offset;
+         *offset += t->atomic_size();
+
+         (*uniform_loc)++;
+      }
+   }
+
    active_atomic_buffer *
    find_active_atomic_counters(struct gl_context *ctx,
                                struct gl_shader_program *prog,
@@ -114,23 +158,10 @@ 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());
+               int offset = var->data.atomic.offset;
+               unsigned uniform_loc = var->data.location;
+               process_atomic_variable(var->type, prog, &uniform_loc,
+                                       var, buffers, num_buffers, &offset, i);
             }
          }
       }
@@ -197,10 +228,10 @@ link_assign_atomic_counter_resources(struct gl_context *ctx,
       /* Assign counter-specific fields. */
       for (unsigned j = 0; j < ab.num_counters; j++) {
          ir_variable *const var = ab.counters[j].var;
-         const unsigned id = ab.counters[j].id;
-         gl_uniform_storage *const storage = &prog->UniformStorage[id];
+         gl_uniform_storage *const storage =
+            &prog->UniformStorage[ab.counters[j].uniform_loc];
 
-         mab.Uniforms[j] = id;
+         mab.Uniforms[j] = ab.counters[j].uniform_loc;
          if (!var->data.explicit_binding)
             var->data.binding = i;