pan/midgard: Move DCE into its own file

Signed-off-by: Alyssa Rosenzweig <[email protected]>

1 files changed, 46 insertions, 0 deletions

diff --git a/src/panfrost/midgard/midgard_opt_dce.c b/src/panfrost/midgard/midgard_opt_dce.c
new file mode 100644
index 00000000000..6621c2fe2dd
--- /dev/null
+++ b/src/panfrost/midgard/midgard_opt_dce.c
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2018 Alyssa Rosenzweig
+ * Copyright (C) 2019 Collabora, Ltd.
+ *
+ * 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.
+ */
+
+#include "compiler.h"
+
+/* Basic dead code elimination on the MIR itself */
+
+bool
+midgard_opt_dead_code_eliminate(compiler_context *ctx, midgard_block *block)
+{
+        bool progress = false;
+
+        mir_foreach_instr_in_block_safe(block, ins) {
+                if (ins->type != TAG_ALU_4) continue;
+                if (ins->compact_branch) continue;
+
+                if (ins->ssa_args.dest >= SSA_FIXED_MINIMUM) continue;
+                if (mir_is_live_after(ctx, block, ins, ins->ssa_args.dest)) continue;
+
+                mir_remove_instruction(ins);
+                progress = true;
+        }
+
+        return progress;
+}