Mesa (main): broadcom/compiler: fix end of TMU sequence check

[GitLab Mirror]

Module: Mesa
Branch: main
Commit: 92d819aaa00aaa185b78793ccfc2151d92538a75
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=92d819aaa00aaa185b78793ccfc2151d92538a75

Author: Iago Toral Quiroga <itoral at igalia.com>
Date:   Mon Feb 14 11:42:16 2022 +0100

broadcom/compiler: fix end of TMU sequence check

We may be pipelining TMU writes and reads, in which case we can
see both TMUWT and LDTMU at the end of a TMU sequence, so we should
not assume that a TMUWT always terminates a sequence.

Also, we had a bug where we were using inst instead of scan_inst
to check if we find another TMUWT after the curent instruction.

Reviewed-by: Alejandro Piñeiro <apinheiro at igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/15041>

---

 src/broadcom/compiler/vir_register_allocate.c | 23 +++++++++++------------
 1 file changed, 11 insertions(+), 12 deletions(-)

diff --git a/src/broadcom/compiler/vir_register_allocate.c b/src/broadcom/compiler/vir_register_allocate.c
index 05b71e3369a..6e47ff837f6 100644
--- a/src/broadcom/compiler/vir_register_allocate.c
+++ b/src/broadcom/compiler/vir_register_allocate.c
@@ -44,23 +44,22 @@ static bool
 is_end_of_tmu_sequence(const struct v3d_device_info *devinfo,
                        struct qinst *inst, struct qblock *block)
 {
-        if (inst->qpu.type == V3D_QPU_INSTR_TYPE_ALU &&
-            inst->qpu.alu.add.op == V3D_QPU_A_TMUWT) {
-                return true;
-        }
-
-        if (!inst->qpu.sig.ldtmu)
+        /* Only tmuwt and ldtmu can finish TMU sequences */
+        bool is_tmuwt = inst->qpu.type == V3D_QPU_INSTR_TYPE_ALU &&
+                        inst->qpu.alu.add.op == V3D_QPU_A_TMUWT;
+        bool is_ldtmu = inst->qpu.sig.ldtmu;
+        if (!is_tmuwt && !is_ldtmu)
                 return false;
 
+        /* Check if this is the last tmuwt or ldtmu in the sequence */
         list_for_each_entry_from(struct qinst, scan_inst, inst->link.next,
                                  &block->instructions, link) {
-                if (scan_inst->qpu.sig.ldtmu)
-                        return false;
+                is_tmuwt = scan_inst->qpu.type == V3D_QPU_INSTR_TYPE_ALU &&
+                           scan_inst->qpu.alu.add.op == V3D_QPU_A_TMUWT;
+                is_ldtmu = scan_inst->qpu.sig.ldtmu;
 
-                if (inst->qpu.type == V3D_QPU_INSTR_TYPE_ALU &&
-                    inst->qpu.alu.add.op == V3D_QPU_A_TMUWT) {
-                        return true;
-                }
+                if (is_tmuwt || is_ldtmu)
+                        return false;
 
                 if (qinst_writes_tmu(devinfo, scan_inst))
                         return true;