pan/bi: Add bi_layout.c for clause layout helpers

[mesa.git] / src / panfrost / bifrost / bi_layout.c

diff --git a/src/panfrost/bifrost/bi_layout.c b/src/panfrost/bifrost/bi_layout.c
new file mode 100644 (file)
index 0000000..cc40d03
--- /dev/null
+++ b/src/panfrost/bifrost/bi_layout.c
@@ -0,0 +1,51 @@
+/*
+ * Copyright (C) 2020 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"
+
+/* The scheduler packs multiple instructions into a clause (grouped as bundle),
+ * and the packing code takes in a clause and emits it to the wire. During
+ * scheduling, we need to lay out the instructions (bundles) and constants
+ * within the clause so constraints can be resolved during scheduling instead
+ * of failing packing. These routines will help building clauses from
+ * instructions so the scheduler can focus on the high-level algorithm, and
+ * manipulating clause layouts.
+ */
+
+/* Helper to see if a bundle can be inserted. We must satisfy the invariant:
+ *
+ *      constant_count + bundle_count <= 13
+ *
+ * ...which is equivalent to the clause ending up with 8 or fewer quardwords.
+ * Inserting a bundle increases bundle_count by one, and if it reads a unique
+ * constant, it increases constant_count by one.
+ */
+
+bool
+bi_can_insert_bundle(bi_clause *clause, bool constant)
+{
+        unsigned constant_count = clause->constant_count + (constant ? 1 : 0);
+        unsigned bundle_count = clause->bundle_count + 1;
+
+        return (constant_count + bundle_count) <= 13;
+}