commit 8477678cfeb3ab0d80983ec5901742baf786d8cf
author Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Wed Oct 14 21:23:00 2020 -0400
committer Marge Bot <eric+marge@anholt.net> Fri Oct 23 14:48:23 2020 +0000
tree 824c6fe829c91989c978a0b40a868daaf4da0e06
parent 82a62a6f3313a20a090806e3f67536e846ee2d07

pan/bi: Fix handling of small constants in bi_lookup_constant

Streamline the logic and the bug goes away.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/7206>

src/panfrost/bifrost/bi_pack.c

diff --git a/src/panfrost/bifrost/bi_pack.c b/src/panfrost/bifrost/bi_pack.c
index dfff5ec..9f0884b 100644
--- a/src/panfrost/bifrost/bi_pack.c
+++ b/src/panfrost/bifrost/bi_pack.c
@@ -74,24 +74,14 @@
 static unsigned
 bi_lookup_constant(bi_clause *clause, uint32_t cons, bool *hi)
 {
-        uint64_t want = (cons >> 4);
-
         for (unsigned i = 0; i < clause->constant_count; ++i) {
-                /* Only check top 60-bits since that's what's actually embedded
-                 * in the clause, the bottom 4-bits are bundle-inline */
+                /* Try to apply to top or to bottom */
+                uint64_t top = clause->constants[i];
 
-                uint64_t candidates[2] = {
-                        clause->constants[i] >> 4,
-                        clause->constants[i] >> 36
-                };
-
-                /* Treat lo/hi separately */
-                candidates[0] &= (0xFFFFFFFF >> 4);
-
-                if (candidates[0] == want)
+                if (cons == ((uint32_t) top | (cons & 0xF)))
                         return i;
 
-                if (candidates[1] == want) {
+                if (cons == (top >> 32ul)) {
                         *hi = true;
                         return i;
                 }