commit a658a4f7a5599141c678794676f4a5cfc16ba7f1
author Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Tue May 05 16:15:16 2020 -0400
committer Marge Bot <eric+marge@anholt.net> Fri May 29 20:34:55 2020 +0000
tree 6781b47cf0c030ed0715d9d282704691914ee717
parent ac64bf9b207f6a4e7f41d57ee123b173f631cb28

pan/bi: Document constant count invariant

   constants + instructions <= 13

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/5260>

src/panfrost/bifrost/compiler.h

diff --git a/src/panfrost/bifrost/compiler.h b/src/panfrost/bifrost/compiler.h
index 43bd8bb..e4d37a8 100644
--- a/src/panfrost/bifrost/compiler.h
+++ b/src/panfrost/bifrost/compiler.h
@@ -373,7 +373,13 @@
         /* Corresponds to the usual bit but shifted by a clause */
         bool data_register_write_barrier;
 
-        /* Constants read by this clause. ISA limit. */
+        /* Constants read by this clause. ISA limit. Must satisfy:
+         *
+         *      constant_count + bundle_count <= 13
+         *
+         * Also implicitly constant_count <= bundle_count since a bundle only
+         * reads a single constant.
+         */
         uint64_t constants[8];
         unsigned constant_count;