1 files changed, 103 insertions, 0 deletions
diff --git a/mesalib/src/glsl/nir/nir_opt_global_to_local.c b/mesalib/src/glsl/nir/nir_opt_global_to_local.c
new file mode 100644
index 000000000..00db37ba7
--- /dev/null
+++ b/mesalib/src/glsl/nir/nir_opt_global_to_local.c
@@ -0,0 +1,103 @@
+/*
+ * Copyright © 2014 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.
+ *
+ * Authors:
+ *    Connor Abbott (cwabbott0@gmail.com)
+ *
+ */
+
+#include "nir.h"
+
+static bool
+global_to_local(nir_register *reg)
+{
+   nir_function_impl *impl = NULL;
+
+   assert(reg->is_global);
+
+   struct set_entry *entry;
+   set_foreach(reg->defs, entry) {
+      nir_instr *instr = (nir_instr *) entry->key;
+      nir_function_impl *instr_impl =
+         nir_cf_node_get_function(&instr->block->cf_node);
+      if (impl != NULL) {
+         if (impl != instr_impl)
+            return false;
+      } else {
+         impl = instr_impl;
+      }
+   }
+
+   set_foreach(reg->uses, entry) {
+      nir_instr *instr = (nir_instr *) entry->key;
+      nir_function_impl *instr_impl =
+         nir_cf_node_get_function(&instr->block->cf_node);
+      if (impl != NULL) {
+         if (impl != instr_impl)
+            return false;
+      } else {
+         impl = instr_impl;
+      }
+   }
+
+   set_foreach(reg->if_uses, entry) {
+      nir_if *if_stmt = (nir_if *) entry->key;
+      nir_function_impl *if_impl = nir_cf_node_get_function(&if_stmt->cf_node);
+      if (impl != NULL) {
+         if (impl != if_impl)
+            return false;
+      } else {
+         impl = if_impl;
+      }
+   }
+
+   if (impl == NULL) {
+      /* this instruction is never used/defined, delete it */
+      nir_reg_remove(reg);
+      return true;
+   }
+
+   /*
+    * if we've gotten to this point, the register is always used/defined in
+    * the same implementation so we can move it to be local to that
+    * implementation.
+    */
+
+   exec_node_remove(&reg->node);
+   exec_list_push_tail(&impl->registers, &reg->node);
+   reg->index = impl->reg_alloc++;
+   reg->is_global = false;
+   return true;
+}
+
+bool
+nir_opt_global_to_local(nir_shader *shader)
+{
+   bool progress = false;
+
+   foreach_list_typed_safe(nir_register, reg, node, &shader->registers) {
+      if (global_to_local(reg))
+         progress = true;
+   }
+
+   return progress;
+}