1 files changed, 361 insertions, 0 deletions

diff --git a/mesalib/src/glsl/ir_structure_splitting.cpp b/mesalib/src/glsl/ir_structure_splitting.cpp
new file mode 100644
index 000000000..ff3ec936e
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+++ b/mesalib/src/glsl/ir_structure_splitting.cpp
@@ -0,0 +1,361 @@
+/*
+ * Copyright © 2010 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 ir_structure_splitting.cpp
+ *
+ * If a structure is only ever referenced by its components, then
+ * split those components out to individual variables so they can be
+ * handled normally by other optimization passes.
+ *
+ * This skips structures like uniforms, which need to be accessible as
+ * structures for their access by the GL.
+ */
+
+#include "ir.h"
+#include "ir_visitor.h"
+#include "ir_print_visitor.h"
+#include "ir_rvalue_visitor.h"
+#include "glsl_types.h"
+
+static bool debug = false;
+
+// XXX using variable_entry2 here to avoid collision (MSVC multiply-defined
+// function) with the variable_entry class seen in ir_variable_refcount.h
+// Perhaps we can use the one in ir_variable_refcount.h and make this class
+// here go away?
+class variable_entry2 : public exec_node
+{
+public:
+   variable_entry2(ir_variable *var)
+   {
+      this->var = var;
+      this->whole_structure_access = 0;
+      this->declaration = false;
+      this->components = NULL;
+      this->mem_ctx = NULL;
+   }
+
+   ir_variable *var; /* The key: the variable's pointer. */
+
+   /** Number of times the variable is referenced, including assignments. */
+   unsigned whole_structure_access;
+
+   bool declaration; /* If the variable had a decl in the instruction stream */
+
+   ir_variable **components;
+
+   /** talloc_parent(this->var) -- the shader's talloc context. */
+   void *mem_ctx;
+};
+
+
+class ir_structure_reference_visitor : public ir_hierarchical_visitor {
+public:
+   ir_structure_reference_visitor(void)
+   {
+      this->mem_ctx = talloc_new(NULL);
+      this->variable_list.make_empty();
+   }
+
+   ~ir_structure_reference_visitor(void)
+   {
+      talloc_free(mem_ctx);
+   }
+
+   virtual ir_visitor_status visit(ir_variable *);
+   virtual ir_visitor_status visit(ir_dereference_variable *);
+   virtual ir_visitor_status visit_enter(ir_dereference_record *);
+   virtual ir_visitor_status visit_enter(ir_assignment *);
+   virtual ir_visitor_status visit_enter(ir_function_signature *);
+
+   variable_entry2 *get_variable_entry2(ir_variable *var);
+
+   /* List of variable_entry */
+   exec_list variable_list;
+
+   void *mem_ctx;
+};
+
+variable_entry2 *
+ir_structure_reference_visitor::get_variable_entry2(ir_variable *var)
+{
+   assert(var);
+
+   if (!var->type->is_record() || var->mode == ir_var_uniform)
+      return NULL;
+
+   foreach_iter(exec_list_iterator, iter, this->variable_list) {
+      variable_entry2 *entry = (variable_entry2 *)iter.get();
+      if (entry->var == var)
+	 return entry;
+   }
+
+   variable_entry2 *entry = new(mem_ctx) variable_entry2(var);
+   this->variable_list.push_tail(entry);
+   return entry;
+}
+
+
+ir_visitor_status
+ir_structure_reference_visitor::visit(ir_variable *ir)
+{
+   variable_entry2 *entry = this->get_variable_entry2(ir);
+
+   if (entry)
+      entry->declaration = true;
+
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_structure_reference_visitor::visit(ir_dereference_variable *ir)
+{
+   ir_variable *const var = ir->variable_referenced();
+   variable_entry2 *entry = this->get_variable_entry2(var);
+
+   if (entry)
+      entry->whole_structure_access++;
+
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_structure_reference_visitor::visit_enter(ir_dereference_record *ir)
+{
+   (void) ir;
+   /* Don't descend into the ir_dereference_variable below. */
+   return visit_continue_with_parent;
+}
+
+ir_visitor_status
+ir_structure_reference_visitor::visit_enter(ir_assignment *ir)
+{
+   if (ir->lhs->as_dereference_variable() &&
+       ir->rhs->as_dereference_variable() &&
+       !ir->condition) {
+      /* We'll split copies of a structure to copies of components, so don't
+       * descend to the ir_dereference_variables.
+       */
+      return visit_continue_with_parent;
+   }
+   return visit_continue;
+}
+
+ir_visitor_status
+ir_structure_reference_visitor::visit_enter(ir_function_signature *ir)
+{
+   /* We don't want to descend into the function parameters and
+    * dead-code eliminate them, so just accept the body here.
+    */
+   visit_list_elements(this, &ir->body);
+   return visit_continue_with_parent;
+}
+
+class ir_structure_splitting_visitor : public ir_rvalue_visitor {
+public:
+   ir_structure_splitting_visitor(exec_list *vars)
+   {
+      this->variable_list = vars;
+   }
+
+   virtual ~ir_structure_splitting_visitor()
+   {
+   }
+
+   virtual ir_visitor_status visit_leave(ir_assignment *);
+
+   void split_deref(ir_dereference **deref);
+   void handle_rvalue(ir_rvalue **rvalue);
+   variable_entry2 *get_splitting_entry(ir_variable *var);
+
+   exec_list *variable_list;
+   void *mem_ctx;
+};
+
+variable_entry2 *
+ir_structure_splitting_visitor::get_splitting_entry(ir_variable *var)
+{
+   assert(var);
+
+   if (!var->type->is_record())
+      return NULL;
+
+   foreach_iter(exec_list_iterator, iter, *this->variable_list) {
+      variable_entry2 *entry = (variable_entry2 *)iter.get();
+      if (entry->var == var) {
+	 return entry;
+      }
+   }
+
+   return NULL;
+}
+
+void
+ir_structure_splitting_visitor::split_deref(ir_dereference **deref)
+{
+   if ((*deref)->ir_type != ir_type_dereference_record)
+      return;
+
+   ir_dereference_record *deref_record = (ir_dereference_record *)*deref;
+   ir_dereference_variable *deref_var = deref_record->record->as_dereference_variable();
+   if (!deref_var)
+      return;
+
+   variable_entry2 *entry = get_splitting_entry(deref_var->var);
+   if (!entry)
+      return;
+
+   unsigned int i;
+   for (i = 0; i < entry->var->type->length; i++) {
+      if (strcmp(deref_record->field,
+		 entry->var->type->fields.structure[i].name) == 0)
+	 break;
+   }
+   assert(i != entry->var->type->length);
+
+   *deref = new(entry->mem_ctx) ir_dereference_variable(entry->components[i]);
+}
+
+void
+ir_structure_splitting_visitor::handle_rvalue(ir_rvalue **rvalue)
+{
+   if (!*rvalue)
+      return;
+
+   ir_dereference *deref = (*rvalue)->as_dereference();
+
+   if (!deref)
+      return;
+
+   split_deref(&deref);
+   *rvalue = deref;
+}
+
+ir_visitor_status
+ir_structure_splitting_visitor::visit_leave(ir_assignment *ir)
+{
+   ir_dereference_variable *lhs_deref = ir->lhs->as_dereference_variable();
+   ir_dereference_variable *rhs_deref = ir->rhs->as_dereference_variable();
+   variable_entry2 *lhs_entry = lhs_deref ? get_splitting_entry(lhs_deref->var) : NULL;
+   variable_entry2 *rhs_entry = rhs_deref ? get_splitting_entry(rhs_deref->var) : NULL;
+   const glsl_type *type = ir->rhs->type;
+
+   if ((lhs_entry || rhs_entry) && !ir->condition) {
+      for (unsigned int i = 0; i < type->length; i++) {
+	 ir_dereference *new_lhs, *new_rhs;
+	 void *mem_ctx = lhs_entry ? lhs_entry->mem_ctx : rhs_entry->mem_ctx;
+
+	 if (lhs_entry) {
+	    new_lhs = new(mem_ctx) ir_dereference_variable(lhs_entry->components[i]);
+	 } else {
+	    new_lhs = new(mem_ctx)
+	       ir_dereference_record(ir->lhs->clone(mem_ctx, NULL),
+				     type->fields.structure[i].name);
+	 }
+
+	 if (rhs_entry) {
+	    new_rhs = new(mem_ctx) ir_dereference_variable(rhs_entry->components[i]);
+	 } else {
+	    new_rhs = new(mem_ctx)
+	       ir_dereference_record(ir->rhs->clone(mem_ctx, NULL),
+				     type->fields.structure[i].name);
+	 }
+
+	 ir->insert_before(new(mem_ctx) ir_assignment(new_lhs,
+						      new_rhs,
+						      NULL));
+      }
+      ir->remove();
+   } else {
+      handle_rvalue(&ir->rhs);
+      split_deref(&ir->lhs);
+   }
+
+   handle_rvalue(&ir->condition);
+
+   return visit_continue;
+}
+
+bool
+do_structure_splitting(exec_list *instructions)
+{
+   ir_structure_reference_visitor refs;
+
+   visit_list_elements(&refs, instructions);
+
+   /* Trim out variables we can't split. */
+   foreach_iter(exec_list_iterator, iter, refs.variable_list) {
+      variable_entry2 *entry = (variable_entry2 *)iter.get();
+
+      if (debug) {
+	 printf("structure %s@%p: decl %d, whole_access %d\n",
+		entry->var->name, (void *) entry->var, entry->declaration,
+		entry->whole_structure_access);
+      }
+
+      if (!entry->declaration || entry->whole_structure_access) {
+	 entry->remove();
+      }
+   }
+
+   if (refs.variable_list.is_empty())
+      return false;
+
+   void *mem_ctx = talloc_new(NULL);
+
+   /* Replace the decls of the structures to be split with their split
+    * components.
+    */
+   foreach_iter(exec_list_iterator, iter, refs.variable_list) {
+      variable_entry2 *entry = (variable_entry2 *)iter.get();
+      const struct glsl_type *type = entry->var->type;
+
+      entry->mem_ctx = talloc_parent(entry->var);
+
+      entry->components = talloc_array(mem_ctx,
+				       ir_variable *,
+				       type->length);
+
+      for (unsigned int i = 0; i < entry->var->type->length; i++) {
+	 const char *name = talloc_asprintf(mem_ctx, "%s_%s",
+					    entry->var->name,
+					    type->fields.structure[i].name);
+
+	 entry->components[i] =
+	    new(entry->mem_ctx) ir_variable(type->fields.structure[i].type,
+					    name,
+					    ir_var_temporary);
+	 entry->var->insert_before(entry->components[i]);
+      }
+
+      entry->var->remove();
+   }
+
+   ir_structure_splitting_visitor split(&refs.variable_list);
+   visit_list_elements(&split, instructions);
+
+   talloc_free(mem_ctx);
+
+   return true;
+}