glsl linker: remove interface block instance names

Convert interface blocks with instance names into flat
interface blocks without an instance name.

Signed-off-by: Jordan Justen <[email protected]>
Reviewed-by: Kenneth Graunke <[email protected]>

1 files changed, 199 insertions, 0 deletions

diff --git a/src/glsl/lower_named_interface_blocks.cpp b/src/glsl/lower_named_interface_blocks.cpp
new file mode 100644
index 00000000000..f3a2ad5d7de
--- /dev/null
+++ b/src/glsl/lower_named_interface_blocks.cpp
@@ -0,0 +1,199 @@
+/*
+ * Copyright (c) 2013 Intel Corporation
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+/**
+ * \file lower_named_interface_blocks.cpp
+ *
+ * This lowering pass converts all interface blocks with instance names
+ * into interface blocks without an instance name.
+ *
+ * For example, the following shader:
+ *
+ *   out block {
+ *     float block_var;
+ *   } inst_name;
+ *
+ *   main()
+ *   {
+ *     inst_name.block_var = 0.0;
+ *   }
+ *
+ * Is rewritten to:
+ *
+ *   out block {
+ *     float block_var;
+ *   };
+ *
+ *   main()
+ *   {
+ *     block_var = 0.0;
+ *   }
+ *
+ * This takes place after the shader code has already been verified with
+ * the interface name in place.
+ *
+ * The linking phase will use the interface block name rather than the
+ * interface's instance name when linking interfaces.
+ *
+ * This modification to the ir allows our currently existing dead code
+ * elimination to work with interface blocks without changes.
+ */
+
+#include "glsl_symbol_table.h"
+#include "ir.h"
+#include "ir_optimization.h"
+#include "ir_rvalue_visitor.h"
+#include "program/hash_table.h"
+
+class flatten_named_interface_blocks_declarations : public ir_rvalue_visitor
+{
+public:
+   void * const mem_ctx;
+   hash_table *interface_namespace;
+
+   flatten_named_interface_blocks_declarations(void *mem_ctx)
+      : mem_ctx(mem_ctx)
+   {
+   }
+
+   void run(exec_list *instructions);
+
+   virtual ir_visitor_status visit_leave(ir_assignment *);
+   virtual void handle_rvalue(ir_rvalue **rvalue);
+};
+
+void
+flatten_named_interface_blocks_declarations::run(exec_list *instructions)
+{
+   interface_namespace = hash_table_ctor(0, hash_table_string_hash,
+                                         hash_table_string_compare);
+
+   /* First pass: adjust instance block variables with an instance name
+    * to not have an instance name.
+    *
+    * The interface block variables are stored in the interface_namespace
+    * hash table so they can be used in the second pass.
+    */
+   foreach_list_safe(node, instructions) {
+      ir_variable *var = ((ir_instruction *) node)->as_variable();
+      if (!var || !var->is_interface_instance())
+         continue;
+
+      /* It should be possible to handle uniforms during this pass,
+       * but, this will require changes to the other uniform block
+       * support code.
+       */
+      if (var->mode == ir_var_uniform)
+         continue;
+
+      const glsl_type *const t = var->type;
+      exec_node *insert_pos = var;
+      char *iface_field_name;
+      for (unsigned i = 0; i < t->length; i++) {
+         iface_field_name = ralloc_asprintf(mem_ctx, "%s.%s", t->name,
+                                            t->fields.structure[i].name);
+
+         ir_variable *found_var =
+            (ir_variable *) hash_table_find(interface_namespace,
+                                            iface_field_name);
+         if (!found_var) {
+            ir_variable *new_var =
+               new(mem_ctx) ir_variable(t->fields.structure[i].type,
+                                        ralloc_strdup(mem_ctx, t->fields.structure[i].name),
+                                        (ir_variable_mode) var->mode);
+            new_var->interface_type = t;
+            hash_table_insert(interface_namespace, new_var,
+                              iface_field_name);
+            insert_pos->insert_after(new_var);
+            insert_pos = new_var;
+         }
+      }
+      var->remove();
+   }
+
+   /* Second pass: visit all ir_dereference_record instances, and if they
+    * reference an interface block, then flatten the refererence out.
+    */
+   visit_list_elements(this, instructions);
+   hash_table_dtor(interface_namespace);
+   interface_namespace = NULL;
+}
+
+ir_visitor_status
+flatten_named_interface_blocks_declarations::visit_leave(ir_assignment *ir)
+{
+   ir_dereference_record *lhs_rec = ir->lhs->as_dereference_record();
+   if (lhs_rec) {
+      ir_rvalue *lhs_rec_tmp = lhs_rec;
+      handle_rvalue(&lhs_rec_tmp);
+      if (lhs_rec_tmp != lhs_rec) {
+         ir->set_lhs(lhs_rec_tmp);
+      }
+   }
+   return rvalue_visit(ir);
+}
+
+void
+flatten_named_interface_blocks_declarations::handle_rvalue(ir_rvalue **rvalue)
+{
+   if (*rvalue == NULL)
+      return;
+
+   ir_dereference_record *ir = (*rvalue)->as_dereference_record();
+   if (ir == NULL)
+      return;
+
+   ir_variable *var = ir->variable_referenced();
+
+   if (!var->is_interface_instance())
+      return;
+
+   /* It should be possible to handle uniforms during this pass,
+    * but, this will require changes to the other uniform block
+    * support code.
+    */
+   if (var->mode == ir_var_uniform)
+      return;
+
+   if (var->interface_type != NULL) {
+      char *iface_field_name =
+         ralloc_asprintf(mem_ctx, "%s.%s", var->interface_type->name,
+                         ir->field);
+      /* Find the variable in the set of flattened interface blocks */
+      ir_variable *found_var =
+         (ir_variable *) hash_table_find(interface_namespace,
+                                         iface_field_name);
+      assert(found_var);
+      ir_dereference_variable *deref_var =
+         new(mem_ctx) ir_dereference_variable(found_var);
+      *rvalue = deref_var;
+   }
+}
+
+void
+lower_named_interface_blocks(void *mem_ctx, gl_shader *shader)
+{
+   flatten_named_interface_blocks_declarations v_decl(mem_ctx);
+   v_decl.run(shader->ir);
+}
+