[Mesa-dev] [PATCH] glsl: move uniform calculation to link_uniforms

Tapani Pälli tapani.palli at intel.com
Fri Jan 15 21:40:22 PST 2016


Patch moves uniform calculation to happen during link_uniforms, this
is possible with help of UniformRemapTable that has all the reserved
locations.

Location assignment for implicit locations is changed so that we
utilize also the 'holes' that explicit uniform location assignment
might have left in UniformRemapTable, this makes it possible to fit
more uniforms as previously we were lazy here and wasting space.

Fixes following CTS tests:
   ES31-CTS.explicit_uniform_location.uniform-loc-mix-with-implicit-max
   ES31-CTS.explicit_uniform_location.uniform-loc-mix-with-implicit-max-array

Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
---
 src/glsl/link_uniforms.cpp | 78 ++++++++++++++++++++++++++++++++++++++++------
 src/glsl/linker.cpp        | 19 ++++-------
 src/glsl/linker.h          |  3 +-
 3 files changed, 77 insertions(+), 23 deletions(-)

diff --git a/src/glsl/link_uniforms.cpp b/src/glsl/link_uniforms.cpp
index 33b2d4c..91e973a 100644
--- a/src/glsl/link_uniforms.cpp
+++ b/src/glsl/link_uniforms.cpp
@@ -1057,9 +1057,31 @@ assign_hidden_uniform_slot_id(const char *name, unsigned hidden_id,
    uniform_size->map->put(hidden_uniform_start + hidden_id, name);
 }
 
+/**
+ * Search UniformRemapTable for empty block big enough to hold given uniform.
+ * TODO Optimize this algorithm later if it turns out to be a major bottleneck.
+ */
+static int
+seek_empty_block(struct gl_shader_program *prog,
+                 struct gl_uniform_storage *uniform)
+{
+   const unsigned entries = MAX2(1, uniform->array_elements);
+   for (unsigned i = 0, j; i < prog->NumUniformRemapTable; i++)
+      if (prog->UniformRemapTable[i] == NULL) {
+         for (j = i; j < entries && j < prog->NumUniformRemapTable; j++)
+            if (prog->UniformRemapTable[j] != NULL) {
+               i = j;
+               break;
+            }
+         return i;
+      }
+   return -1;
+}
+
 void
 link_assign_uniform_locations(struct gl_shader_program *prog,
-                              unsigned int boolean_true)
+                              unsigned int boolean_true,
+                              unsigned int max_locations)
 {
    ralloc_free(prog->UniformStorage);
    prog->UniformStorage = NULL;
@@ -1150,6 +1172,20 @@ link_assign_uniform_locations(struct gl_shader_program *prog,
 
    parcel_out_uniform_storage parcel(prog->UniformHash, uniforms, data);
 
+   unsigned total_entries = 0;
+
+   /* Calculate amount of 'holes' left after explicit locations were
+    * reserved from UniformRemapTable.
+    */
+   unsigned empty_locs = 0;
+   for (unsigned i = 0; i < prog->NumUniformRemapTable; i++)
+      if (prog->UniformRemapTable[i] == NULL)
+         empty_locs++;
+
+   /* Add all the reserved explicit locations - empty locations in remap table. */
+   if (prog->NumUniformRemapTable)
+      total_entries += (prog->NumUniformRemapTable - 1) - empty_locs;
+
    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
       if (prog->_LinkedShaders[i] == NULL)
 	 continue;
@@ -1213,23 +1249,47 @@ link_assign_uniform_locations(struct gl_shader_program *prog,
       /* how many new entries for this uniform? */
       const unsigned entries = MAX2(1, uniforms[i].array_elements);
 
-      /* resize remap table to fit new entries */
-      prog->UniformRemapTable =
-         reralloc(prog,
-                  prog->UniformRemapTable,
-                  gl_uniform_storage *,
-                  prog->NumUniformRemapTable + entries);
+      /* Find UniformRemapTable for empty blocks where we can fit this uniform. */
+      int chosen_location = -1;
+
+      if (empty_locs)
+         chosen_location = seek_empty_block(prog, &uniforms[i]);
+
+      if (chosen_location != -1) {
+         empty_locs -= entries;
+      } else {
+         chosen_location = prog->NumUniformRemapTable;
+
+         /* Add new entries to the total amount of entries. */
+         total_entries += entries;
+
+         /* resize remap table to fit new entries */
+         prog->UniformRemapTable =
+            reralloc(prog,
+                     prog->UniformRemapTable,
+                     gl_uniform_storage *,
+                     prog->NumUniformRemapTable + entries);
+      }
 
       /* set pointers for this uniform */
       for (unsigned j = 0; j < entries; j++)
-         prog->UniformRemapTable[prog->NumUniformRemapTable+j] = &uniforms[i];
+         prog->UniformRemapTable[chosen_location + j] = &uniforms[i];
 
       /* set the base location in remap table for the uniform */
-      uniforms[i].remap_location = prog->NumUniformRemapTable;
+      uniforms[i].remap_location = chosen_location;
 
       prog->NumUniformRemapTable += entries;
    }
 
+    /* Verify that total amount of entries for explicit and implicit locations
+     * is less than MAX_UNIFORM_LOCATIONS.
+     */
+   if (total_entries >= max_locations) {
+      linker_error(prog, "count of uniform locations >= MAX_UNIFORM_LOCATIONS"
+                   "(%u >= %u)", total_entries, max_locations);
+   }
+
+
    /* Reserve all the explicit locations of the active subroutine uniforms. */
    for (unsigned i = 0; i < num_uniforms; i++) {
       if (!uniforms[i].type->is_subroutine())
diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
index 3f40c0b..ff33fa1 100644
--- a/src/glsl/linker.cpp
+++ b/src/glsl/linker.cpp
@@ -3146,7 +3146,6 @@ check_explicit_uniform_locations(struct gl_context *ctx,
       return;
    }
 
-   unsigned entries_total = 0;
    for (unsigned i = 0; i < MESA_SHADER_STAGES; i++) {
       struct gl_shader *sh = prog->_LinkedShaders[i];
 
@@ -3158,8 +3157,6 @@ check_explicit_uniform_locations(struct gl_context *ctx,
          if (!var || var->data.mode != ir_var_uniform)
             continue;
 
-         entries_total += var->type->uniform_locations();
-
          if (var->data.explicit_location) {
             bool ret;
             if (var->type->is_subroutine())
@@ -3173,15 +3170,6 @@ check_explicit_uniform_locations(struct gl_context *ctx,
          }
       }
    }
-
-   /* Verify that total amount of entries for explicit and implicit locations
-    * is less than MAX_UNIFORM_LOCATIONS.
-    */
-   if (entries_total >= ctx->Const.MaxUserAssignableUniformLocations) {
-      linker_error(prog, "count of uniform locations >= MAX_UNIFORM_LOCATIONS"
-                   "(%u >= %u)", entries_total,
-                   ctx->Const.MaxUserAssignableUniformLocations);
-   }
    delete uniform_map;
 }
 
@@ -4556,7 +4544,12 @@ link_shaders(struct gl_context *ctx, struct gl_shader_program *prog)
       goto done;
 
    update_array_sizes(prog);
-   link_assign_uniform_locations(prog, ctx->Const.UniformBooleanTrue);
+   link_assign_uniform_locations(prog, ctx->Const.UniformBooleanTrue,
+                                 ctx->Const.MaxUserAssignableUniformLocations);
+
+   if (!prog->LinkStatus)
+      goto done;
+
    link_assign_atomic_counter_resources(ctx, prog);
    store_fragdepth_layout(prog);
 
diff --git a/src/glsl/linker.h b/src/glsl/linker.h
index c80be1c..76f95c0 100644
--- a/src/glsl/linker.h
+++ b/src/glsl/linker.h
@@ -35,7 +35,8 @@ link_invalidate_variable_locations(exec_list *ir);
 
 extern void
 link_assign_uniform_locations(struct gl_shader_program *prog,
-                              unsigned int boolean_true);
+                              unsigned int boolean_true,
+                              unsigned int max_locations);
 
 extern void
 link_set_uniform_initializers(struct gl_shader_program *prog,
-- 
2.5.0



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