1 files changed, 152 insertions, 0 deletions
diff --git a/src/compiler/glsl/opt_dead_functions.cpp b/src/compiler/glsl/opt_dead_functions.cpp
new file mode 100644
index 0000000..2e90b65
--- /dev/null
+++ b/src/compiler/glsl/opt_dead_functions.cpp
@@ -0,0 +1,152 @@
+/*
+ * 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 opt_dead_functions.cpp
+ *
+ * Eliminates unused functions from the linked program.
+ */
+
+#include "ir.h"
+#include "ir_visitor.h"
+#include "ir_expression_flattening.h"
+#include "compiler/glsl_types.h"
+
+namespace {
+
+class signature_entry : public exec_node
+{
+public:
+   signature_entry(ir_function_signature *sig)
+   {
+      this->signature = sig;
+      this->used = false;
+   }
+
+   ir_function_signature *signature;
+   bool used;
+};
+
+class ir_dead_functions_visitor : public ir_hierarchical_visitor {
+public:
+   ir_dead_functions_visitor()
+   {
+      this->mem_ctx = ralloc_context(NULL);
+   }
+
+   ~ir_dead_functions_visitor()
+   {
+      ralloc_free(this->mem_ctx);
+   }
+
+   virtual ir_visitor_status visit_enter(ir_function_signature *);
+   virtual ir_visitor_status visit_enter(ir_call *);
+
+   signature_entry *get_signature_entry(ir_function_signature *var);
+
+   /* List of signature_entry */
+   exec_list signature_list;
+   void *mem_ctx;
+};
+
+} /* unnamed namespace */
+
+signature_entry *
+ir_dead_functions_visitor::get_signature_entry(ir_function_signature *sig)
+{
+   foreach_in_list(signature_entry, entry, &this->signature_list) {
+      if (entry->signature == sig)
+	 return entry;
+   }
+
+   signature_entry *entry = new(mem_ctx) signature_entry(sig);
+   this->signature_list.push_tail(entry);
+   return entry;
+}
+
+
+ir_visitor_status
+ir_dead_functions_visitor::visit_enter(ir_function_signature *ir)
+{
+   signature_entry *entry = this->get_signature_entry(ir);
+
+   if (strcmp(ir->function_name(), "main") == 0) {
+      entry->used = true;
+   }
+
+
+
+   return visit_continue;
+}
+
+
+ir_visitor_status
+ir_dead_functions_visitor::visit_enter(ir_call *ir)
+{
+   signature_entry *entry = this->get_signature_entry(ir->callee);
+
+   entry->used = true;
+
+   return visit_continue;
+}
+
+bool
+do_dead_functions(exec_list *instructions)
+{
+   ir_dead_functions_visitor v;
+   bool progress = false;
+
+   visit_list_elements(&v, instructions);
+
+   /* Now that we've figured out which function signatures are used, remove
+    * the unused ones, and remove function definitions that have no more
+    * signatures.
+    */
+    foreach_in_list_safe(signature_entry, entry, &v.signature_list) {
+      if (!entry->used) {
+	 entry->signature->remove();
+	 delete entry->signature;
+	 progress = true;
+      }
+      delete(entry);
+   }
+
+   /* We don't just do this above when we nuked a signature because of
+    * const pointers.
+    */
+   foreach_in_list_safe(ir_instruction, ir, instructions) {
+      ir_function *func = ir->as_function();
+
+      if (func && func->signatures.is_empty()) {
+	 /* At this point (post-linking), the symbol table is no
+	  * longer in use, so not removing the function from the
+	  * symbol table should be OK.
+	  */
+	 func->remove();
+	 delete func;
+	 progress = true;
+      }
+   }
+
+   return progress;
+}