nir: move to compiler/

Signed-off-by: Emil Velikov <[email protected]>
Acked-by: Matt Turner <[email protected]>
Acked-by: Jose Fonseca <[email protected]>

1 files changed, 183 insertions, 0 deletions

diff --git a/src/compiler/nir/nir_opt_dce.c b/src/compiler/nir/nir_opt_dce.c
new file mode 100644
index 00000000000..32436c18b60
--- /dev/null
+++ b/src/compiler/nir/nir_opt_dce.c
@@ -0,0 +1,183 @@
+/*
+ * 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 ([email protected])
+ *
+ */
+
+#include "nir.h"
+
+/* SSA-based mark-and-sweep dead code elimination */
+
+typedef struct {
+   struct exec_node node;
+   nir_instr *instr;
+} worklist_elem;
+
+static void
+worklist_push(struct exec_list *worklist, nir_instr *instr)
+{
+   worklist_elem *elem = ralloc(worklist, worklist_elem);
+   elem->instr = instr;
+   instr->pass_flags = 1;
+   exec_list_push_tail(worklist, &elem->node);
+}
+
+static nir_instr *
+worklist_pop(struct exec_list *worklist)
+{
+   struct exec_node *node = exec_list_pop_head(worklist);
+   worklist_elem *elem = exec_node_data(worklist_elem, node, node);
+   return elem->instr;
+}
+
+static bool
+mark_live_cb(nir_src *src, void *_state)
+{
+   struct exec_list *worklist = (struct exec_list *) _state;
+
+   if (src->is_ssa && !src->ssa->parent_instr->pass_flags) {
+      worklist_push(worklist, src->ssa->parent_instr);
+   }
+
+   return true;
+}
+
+static void
+init_instr(nir_instr *instr, struct exec_list *worklist)
+{
+   nir_alu_instr *alu_instr;
+   nir_intrinsic_instr *intrin_instr;
+   nir_tex_instr *tex_instr;
+
+   /* We use the pass_flags to store the live/dead information.  In DCE, we
+    * just treat it as a zero/non-zerl boolean for whether or not the
+    * instruction is live.
+    */
+   instr->pass_flags = 0;
+
+   switch (instr->type) {
+   case nir_instr_type_call:
+   case nir_instr_type_jump:
+      worklist_push(worklist, instr);
+      break;
+
+   case nir_instr_type_alu:
+      alu_instr = nir_instr_as_alu(instr);
+      if (!alu_instr->dest.dest.is_ssa)
+         worklist_push(worklist, instr);
+      break;
+
+   case nir_instr_type_intrinsic:
+      intrin_instr = nir_instr_as_intrinsic(instr);
+      if (nir_intrinsic_infos[intrin_instr->intrinsic].flags &
+          NIR_INTRINSIC_CAN_ELIMINATE) {
+         if (nir_intrinsic_infos[intrin_instr->intrinsic].has_dest &&
+             !intrin_instr->dest.is_ssa) {
+            worklist_push(worklist, instr);
+         }
+      } else {
+         worklist_push(worklist, instr);
+      }
+      break;
+
+   case nir_instr_type_tex:
+      tex_instr = nir_instr_as_tex(instr);
+      if (!tex_instr->dest.is_ssa)
+         worklist_push(worklist, instr);
+      break;
+
+   default:
+      break;
+   }
+}
+
+static bool
+init_block_cb(nir_block *block, void *_state)
+{
+   struct exec_list *worklist = (struct exec_list *) _state;
+
+   nir_foreach_instr(block, instr)
+      init_instr(instr, worklist);
+
+   nir_if *following_if = nir_block_get_following_if(block);
+   if (following_if) {
+      if (following_if->condition.is_ssa &&
+          !following_if->condition.ssa->parent_instr->pass_flags)
+         worklist_push(worklist, following_if->condition.ssa->parent_instr);
+   }
+
+   return true;
+}
+
+static bool
+delete_block_cb(nir_block *block, void *_state)
+{
+   bool *progress = (bool *) _state;
+
+   nir_foreach_instr_safe(block, instr) {
+      if (!instr->pass_flags) {
+         nir_instr_remove(instr);
+         *progress = true;
+      }
+   }
+
+   return true;
+}
+
+static bool
+nir_opt_dce_impl(nir_function_impl *impl)
+{
+   struct exec_list *worklist = ralloc(NULL, struct exec_list);
+   exec_list_make_empty(worklist);
+
+   nir_foreach_block(impl, init_block_cb, worklist);
+
+   while (!exec_list_is_empty(worklist)) {
+      nir_instr *instr = worklist_pop(worklist);
+      nir_foreach_src(instr, mark_live_cb, worklist);
+   }
+
+   ralloc_free(worklist);
+
+   bool progress = false;
+   nir_foreach_block(impl, delete_block_cb, &progress);
+
+   if (progress)
+      nir_metadata_preserve(impl, nir_metadata_block_index |
+                                  nir_metadata_dominance);
+
+   return progress;
+}
+
+bool
+nir_opt_dce(nir_shader *shader)
+{
+   bool progress = false;
+   nir_foreach_function(shader, function) {
+      if (function->impl && nir_opt_dce_impl(function->impl))
+         progress = true;
+   }
+
+   return progress;
+}